Sample records for prolactin prl secretion

  1. Unmodified prolactin (PRL) promotes PRL secretion and acidophil hypertrophy and is associated with pituitary hyperplasia in female rats.

    Johnson, Terence E; Vue, Mayza; Brekhus, Sharyn; Khong, Amy; Ho, Timothy W C; Walker, Ameae M


    In this study, we have tested the hypothesis that unmodified prolactin (U-PRL) and phosphorylated prolactin (P-PRL) have differential roles in the autoregulation of PRL secretion in vivo. Recombinant human U-PRL and a molecular mimic of P-PRL (S179D PRL) were administered to male rats and to female rats in different physiological states and the effect on rat PRL release was measured. Administration of U-PRL elevated rat PRL in all female animals, but was without effect in males. By contrast, S179D PRL was inactive in females, but inhibited PRL release in males. Morphometric and immunohistochemical analyses demonstrated acidophil hypertrophy and evidence of increased PRL secretion in the pituitaries of U-PRL-treated females. Analysis of the two forms of PRL during prolactinoma induction in two differentially susceptible strains of rats found a strong temporal correlation among increased ratios of U-PRL: P-PRL, increased circulating PRL, and increased cell proliferation. We conclude (1). that the autoregulatory mechanism(s) can distinguish between the two major forms of PRL and that higher proportions of U-PRL not only allow for higher circulating levels of PRL, but are also autostimulatory, (2). that the autoregulatory mechanism( s) are set differently in males and females such that females are more sensitive to autostimulation by U-PRL and less sensitive to inhibition by P-PRL, and (3). that U-PRL and P-PRL may also have differential roles in the regulation of pituitary cell proliferation.

  2. Effects of hypothalamic dopamine (DA) on salsolinol (SAL)-induced prolactin (PRL) secretion in male goats.

    Jin, Jin; Hara, Sayaka; Sawai, Ken; Fülöp, Ferenc; Nagy, György Miklos; Hashizume, Tsutomu


    The aim of the present study was to clarify the effects of hypothalamic dopamine (DA) on salsolinol (SAL)-induced prolactin (PRL) release in goats. The PRL-releasing response to an intravenous (i.v.) injection of SAL was examined after treatment with augmentation of central DA using carbidopa (carbi) and L-dopa in male goats under 8-h (8 h light, 16 h dark) or 16-h (16 h light, 8 h dark) photoperiod conditions. The carbi and L-dopa treatments reduced basal PRL concentrations in the 16-h photoperiod group (P PRL concentration in the control group for the 8-h photoperiod was lower than that for the 16-h photoperiod (P PRL promptly after the injection in both the 8- and 16-h photoperiod groups (P PRL-releasing responses for the 16-h photoperiod were greater than those for the 8-h photoperiod (P PRL release in both the 8- and 16-h photoperiods (P PRL in male goats, regardless of the photoperiod, which suggests that both SAL and DA are involved in regulating the secretion of PRL in goats.

  3. Effects of extracerebral dopamine on salsolinol- or thyrotropin-releasing hormone-induced prolactin (PRL) secretion in goats.

    Inaba, Yuki; Kato, Yuki; Itou, Azumi; Chiba, Aoi; Sawai, Ken; Fülöp, Ferenc; Nagy, György Miklos; Hashizume, Tsutomu


    The aim of the present study was to clarify the effect of extracerebral dopamine (DA) on salsolinol (SAL)-induced prolactin (PRL) secretion in goats. An intravenous injection of SAL or thyrotropin-releasing hormone (TRH) was given to female goats before and after treatment with an extracerebral DA receptor antagonist, domperidone (DOM), and the PRL-releasing response to SAL was compared with that to TRH. DOM alone increased plasma PRL concentrations and the PRL-releasing response to DOM alone was greater than that to either SAL alone or TRH alone. The PRL-releasing response to DOM plus SAL was similar to that to DOM alone, and no additive effect of DOM and SAL on the secretion of PRL was observed. In contrast, the PRL-releasing response to DOM plus TRH was greater than that to either TRH alone or DOM alone and DOM synergistically increased TRH-induced PRL secretion. The present results demonstrate that the mechanism involved in PRL secretion by SAL differs from that by TRH, and suggest that the extracerebral DA might be associated in part with the modulation of SAL-induced PRL secretion in goats.

  4. Hyperprolactinemia after neonatal prolactin (PRL) deficiency in rats: evidence for altered anterior pituitary regulation of PRL secretion.

    Shah, G V; Shyr, S W; Grosvenor, C E; Crowley, W R


    Previous findings from this laboratory suggest a role for milk-borne PRL in the development of the inhibitory neuroendocrine controls over PRL secretion. Thus, rats that consumed milk deficient in PRL on days 2-5 postpartum show reduced concentrations and turnover of DA in the median eminence and elevated serum levels of PRL at 30-35 days of age. The present experiments were undertaken to investigate whether these consequences of neonatal PRL deficiency persist beyond puberty, and whether alterations in pituitary responsiveness to hypothalamic hormones may be involved. Lactating rats received sc injections of either saline or the dopamine (DA) agonist bromocriptine (125 micrograms/ on each of days 2-5 postpartum, a treatment that reduces the amount of PRL in milk without abolishing lactation. Blood samples were obtained from male and female offspring at various postnatal ages, and PRL concentrations were determined by RIA. Serum PRL concentrations in offspring from both groups were low until after weaning, but the female offspring of bromocriptine-treated mothers showed significantly elevated serum PRL between days 30 and 90 postpartum. Male offspring of bromocriptine-treated mothers also had transiently increased serum PRL levels, which returned to control levels by day 40. The turnover rate of DA in the median eminence, calculated from the rate of decline after synthesis inhibition, was reduced on day 35 in neonatally PRL-deficient offspring, as shown previously. However, no differences in DA turnover between the two groups were apparent on day 60, indicating a recovery of normal dopaminergic activity. Anterior pituitary cells of 100-day-old control and neonatally PRL-deficient animals were dispersed, cultured for 3 days, and then exposed to either TRH, to stimulate PRL release, or to the DA agonist bromocriptine, which inhibits PRL release. Pituitary cells of neonatally PRL-deficient offspring were almost completely unresponsive to bromocriptine with

  5. Dynamic evaluation of growth hormone (GH) and prolactin (hPRL) secretion in active acromegaly with high and low GH output.

    Tolis, G; Kovacs, L; Friesen, H; Martin, J B


    Ten patients with active acromegaly were studied. In 9 plasma GH levels failed to suppress after glucose (OGTT), in 8 an increase in serum GH occurred after thyrotropin releasing hormone (TRH). After L-Dopa, 4 patients showed no change in serum GH, 3 exhibited a decrease and in 3 an increase in serum hGH occurred. With a combined insulin (ITT) and arginine (ATT) test, 2 patients exhibited an increase in hGH, and in 6 no change occurred. Fasting serum GH concentration was less than 11 ng/ml in 5 patients. Basal prolactin (hPRL) levels were normal in all patients including two with galactorrhea. L-Dopa suppressed and TRH stimulated hPRL secretion in all, but the responses which were seen were subnormal. Hydrocortisone infusion in two acromegalics did not affect the prolactin induced increase after TRH but blunted the GH increase after TRH.

  6. A point mutation of PRL gene in pituitary prolactin-secreting adenoma induced by 17-b-estradiol in SD rats


    Animal model bearing pituitary prolactin-secreting adenomas (prolactinoma) induced by 17-b -estradiol (E2) in both eutopic pituitary and ectopic pituitary grafted under the renal capsule was generated.Northern blotting assay indicated that PRL mRNA level in eutopic prolactinomas was higher than that in normal pituitaries and ectopic prolactinomas (P<0.05-0.01).By polymerase chain reaction (PCR)-single-strand conformation polymorphism (SSCP) analysis and DNA sequencing,a point mutation from C to A occurring at -36 nt in proximal promoter of rat PRL (rPRL) gene was found only in eutopic prolactinomas.No base change was detected in ectopic prolactinomas.Fusion gene transfection assay in vitro exhibited increased activity of the mutant promoter derived from eutopic prolactinoma (P<0.01).These data suggested that the base change in the proximal promoter of rPRL gene may be associated with hyperexpression of rPRL gene in eutopic prolactinomas.The pathogenesis of eutopic and ectopic prolactinomas induced by E2 in SD rats may be separate.

  7. Prolactin (PRL) and prolactin receptor (PRLR) genes and their role in poultry production traits.

    Wilkanowska, Anna; Mazurowski, Artur; Mroczkowski, Sławomir; Kokoszyński, Dariusz


    Prolactin (PRL), secreted from the anterior pituitary, plays extensive roles in osmoregulation, corpus luteum formation, mammogenesis, lactogenesis, lactopoiesis, and production of crop milk. In birds, prolactin (PRL) is generally accepted as crucial to the onset and maintenance of broodiness. All the actions of prolactin (PRL) hormone are mediated by its receptor (PRLR), which plays an important role in the PRL signal transduction cascade. It has been well established that the PRL gene is closely associated to the onset and maintenance of broody behavior, and could be a genetic marker in breeding against broodiness in chickens. Meanwhile, the prolactin receptor (PRLR) gene is regarded as a candidate genetic marker for reproductive traits. PRLR is also an important regulator gene for cell growth and differentiation. The identified polymorphism of this gene is mainly viewed in terms of egg production traits. Due to different biological activities attributed to PRL and PRLR, they can be used as major candidate genes in molecular animal breeding programs. Characterization of PRL and PRLR genes helps to elucidate their roles in birds and provides insights into the regulatory mechanisms of PRL and PRLR expression conserved in birds and mammals.

  8. Plasticity of the prolactin (PRL) axis: mechanisms underlying regulation of output in female mice.

    Le Tissier, P R; Hodson, D J; Martin, A O; Romanò, N; Mollard, P


    The output of prolactin (PRL) is highly dynamic with dramatic changes in its secretion from the anterior pituitary gland depending on prevailing physiological status. In adult female mice, there are three distinct phases of output and each of these is related to the functions of PRL at specific stages of reproduction. Recent studies of the changes in the regulation of PRL during its period of maximum output, lactation, have shown alterations at both the level of the anterior pituitary and hypothalamus. The PRL-secreting cells of the anterior pituitary are organised into a homotypic network in virgin animals, facilitating coordinated bouts of activity between interconnected PRL cells. During lactation, coordinated activity increases due to the changes in structural connectivity, and this drives large elevations in PRL secretion. Surprisingly, these changes in connectivity are maintained after weaning, despite reversion of PRL output to that of virgin animals, and result in an augmented output of hormone during a second lactation. At the level of the hypothalamus, tuberoinfundibular dopamine (TIDA) neurons, the major inhibitors of PRL secretion, have unexpectedly been shown to remain responsive to PRL during lactation. However, there is an uncoupling between TIDA neuron firing and dopamine secretion, with a potential switch to enkephalin release. Such a process may reinforce hormone secretion through dual disinhibition and stimulation of PRL cell activity. Thus, integration of signalling along the hypothalamo-pituitary axis is responsible for increased secretory output of PRL cells during lactation, as well as allowing the system to anticipate future demands.




    The stimulatory effect of TRH on prolactin (Prl) secretion by the anterior pituitary gland (APG) of the pseudopregnant (PSP) rat was studied in vivo and in vitro. TRH, 500 mug, did not increase Prl release during the Prl peaks which are generated daily between 01.00 and 12.00 for about 10 days (mean

  10. Prolactin (PRL) in adipose tissue: regulation and functions.

    Ben-Jonathan, Nira; Hugo, Eric


    New information concerning the effects of prolactin (PRL) on metabolic processes warrants reevaluation of its overall metabolic actions. PRL affects metabolic homeostasis by regulating key enzymes and transporters associated with glucose and lipid metabolism in several target organs. In the lactating mammary gland, PRL increases the production of milk proteins, lactose, and lipids. In adipose tissue, PRL generally suppresses lipid storage and adipokine release and affect adipogenesis. A specific case is made for PRL in the human breast and adipose tissues, where it acts as a circulating hormone and an autocrine/paracrine factor. Although its overall effects on body composition are both modest and species-specific, PRL may be involved in the manifestation of insulin resistance.

  11. Extra-pituitary prolactin (PRL) and prolactin-like protein (PRL-L) in chickens and zebrafish.

    Bu, Guixian; Liang, Xiaomeng; Li, Juan; Wang, Yajun


    It is generally believed that in vertebrates, prolactin (PRL) is predominantly synthesized and released by pituitary lactotrophs and plays important roles in many physiological processes via activation of PRL receptor (PRLR), including water and electrolyte balance, reproduction, growth and development, metabolism, immuno-modulation, and behavior. However, there is increasing evidence showing that PRL and the newly identified 'prolactin-like protein (PRL-L)', a novel ligand of PRL receptor, are also expressed in a variety of extra-pituitary tissues, such as the brain, skin, ovary, and testes in non-mammalian vertebrates. In this brief review, we summarize the recent research progress on the structure, biological activities, and extra-pituitary expression of PRL and PRL-L in chickens (Gallus gallus) and zebrafish (Danio rerio) from our and other laboratories and briefly discuss their potential paracrine/autocrine roles in non-mammalian vertebrates, which may promote us to rethink the broad spectrum of PRL actions previously attributed to pituitary PRL only.

  12. Histaminergic regulation of prolactin secretion

    Knigge, U P


    of DA synthesis and of DA or serotonin (5-HT) receptors inhibit or prevent the PRL stimulatory action of HA infused centrally or systemically. However, other factors regulating PRL secretion (e.g. beta-endorphin, vasoactive intestinal peptide, vasopressin or TRH) may be involved in the mediation...

  13. Neural regulation and dynamics of prolactin secretion in the rat.

    Wiersma, J.


    The subject of this thesis was an investigation of the neural regulation and dynamics of prolactin (Prl) secretion. Experimentation was performed with freely behaving undisturbed male and female rats, chronically fitted with an atrial blood sampling catheter. In some studies rats were also equip




    The effect of the TRH analogue, CG 703 (AG), on secretion of prolactin (Prl) was studied in pseudopregnant rats. AG stimulated Prl secretion of incubated pituitary glands in the presence of 5. 10(-8) M dopamine (DA) but not in the presence of 0 or 10(-6) M DA. AG did not inhibit the in vitro secreti

  15. Assessment of lactotroph axis functionality in mice: longitudinal monitoring of PRL secretion by ultrasensitive-ELISA.

    Guillou, Anne; Romanò, Nicola; Steyn, Frederik; Abitbol, Karine; Le Tissier, Paul; Bonnefont, Xavier; Chen, Chen; Mollard, Patrice; Martin, Agnès O


    The pattern of prolactin (PRL) secretion depends on the physiological state. Due to insufficient detection sensitivity of existing assays, the precise description of these patterns in mice is lacking. We described an ultrasensitive ELISA assay that can detect mouse PRL in small fractions of whole blood, allowing longitudinal studies of PRL secretion profiles in freely moving mice. Over a 24-hour period, males displayed no oscillation in PRL levels, whereas virgin and lactating females showed large pulses. Peaks of PRL secretion reached 30-40 ng/mL in lactating female mice and rarely exceeded 10 ng/mL in virgin females. These pulses of PRL in lactating females were associated with suckling. The return of pups after an experimental 12-hour weaning induced a pulse of PRL release, reaching 100 ng/mL. This approach also enabled us to assess the inhibitory tone from hypothalamic dopamine neurons on PRL secretion. We used a dopamine D2 receptor antagonist to relieve pituitary lactotrophs from the tuberoinfundibular dopaminergic inhibitory tone and demonstrate a D2-induced PRL rise that can be used to evaluate both the secretory capacity of lactotrophs and the magnitude of the inhibitory tone on pituitary PRL release. We demonstrate that, although lactotroph function is altered to enhance chronic PRL output, their secretory response to acute stimulus is not modified during lactation and that chronic hyperprolactinemia is linked to a lower inhibitory tone. The combination of a sensitive PRL ELISA and administration of D2 receptor antagonist provide a unique opportunity to investigate the function and plasticity of the lactotroph axis in freely moving mice.

  16. Gender-related differences in prolactin secretion in pituitary prolactinomas

    Nishioka, H.; Haraoka, J.; Akada, K.; Azuma, S. [Department of Neurosurgery, Tokyo Medical University (Japan)


    In pituitary prolactinomas, serum prolactin (PRL) levels usually parallel the tumor size. We conducted a retrospective study to determine differences in PRL production between men and women with prolactinomas. A total of 51 patients, 16 men and 35 women, was studied. We investigated clinical, endocrinological, radiological and histological findings, and estimated the tumor volume (TV) by high-resolution magnetic resonance imaging (MRI). Correlation between PRL level and TV was low in men (R=0.458), in contrast to women (R=0.953), c. Men with prolactinomas showed predominance of large tumors (P=0.0009) with high PRL levels (P=0.0009) and had greater tendencies for cyst formation (P=0.0047). Large prolactinomas tended to be accompanied by cyst(s) (P=0.0051) and hemorrhage (P=0.0015), both of which were associated with reduced PRL secretion (P=0.0004 and P<0.0001, respectively). When the volume of the cysts and hemorrhage was subtracted from the total TV, correlation between PRL level and TV became greater (R=0.905) with no gender difference. Histological examination demonstrated a sparsely granulated type of lactotroph adenoma with occasional fibrosis, particularly in tumors with hemorrhage and cysts. Although a significant discrepancy between PRL level and TV may exist in prolactinomas when intratumoral hemorrhage and/or cysts are present, there is no essential difference in PRL secretion between the sexes. (orig.)

  17. Both prolactin (PRL) and a molecular mimic of phosphorylated PRL, S179D-PRL, protect the hippocampus of female rats against excitotoxicity.

    Morales, T; Lorenson, M; Walker, A M; Ramos, E


    Prolactin (PRL) has many functions in the CNS, including neuroprotection. During lactation, the dorsal hippocampus is protected from excitotoxic kainic acid (KA)-induced cellular damage. We have previously reported that systemic pre-treatment with ovine PRL had similar protective effects in female rats. Here, we asked (1) whether intracerebral human PRL (hPRL) would have the same action, (2) because phosphorylated PRL is high in lactation, whether a mimic of phosphorylated hPRL, human prolactin in which the normally phosphorylated serine at position 179 is replaced with an aspartate (S179D-PRL), had similar activity, and (3) what signaling pathways mediated the protective effect. Female ovariectomized (OVX, 1 month) rats were implanted with micro-osmotic pumps connected to unilateral icv cannulae directed at the right lateral ventricle. The pumps delivered 0.10 ng/h of hPRL, S179D-PRL, a combination of hPRL+S179D-PRL, or saline vehicle for 7 days prior to a systemic dose of 7.5mg/kg of KA. Rats were sacrificed 48 h after KA injection. Immunostaining for neuronal nuclei (Neu-N) revealed a significant KA-induced decrease in cell number in the CA1, CA3, and CA4 hippocampal areas of rats (∼55% of control). Treatment with either hPRL or S179D-PRL or the combination prevented the damaging effect of KA in these hippocampal regions (∼95% of corresponding control), but was not completely effective at preventing early seizure-related behaviors such as staring and wet dog shakes. Analysis of signals generated by hPRL and S179D-PRL showed no activation of signal transducer and activation of transcription 5 (Stat5) or other signaling molecules in the hippocampus, but activation of extracellular-regulated kinase (ERK)1/2 in the amygdala. These results support a central protective effect of both PRL forms and suggest that PRL could be exerting its protective action by indirectly modulating input signals to the hippocampus and thus regulating excitability.

  18. Modeling prolactin actions in breast cancer in vivo: insights from the NRL-PRL mouse.

    O'Leary, Kathleen A; Shea, Michael P; Schuler, Linda A


    Elevated exposure to prolactin (PRL) is epidemiologically associated with an increased risk of aggressive ER+ breast cancer. To understand the underlying mechanisms and crosstalk with other oncogenic factors, we developed the NRL-PRL mouse. In this model, mammary expression of a rat prolactin transgene raises local exposure to PRL without altering estrous cycling. Nulliparous females develop metastatic, histotypically diverse mammary carcinomas independent from ovarian steroids, and most are ER+. These characteristics resemble the human clinical disease, facilitating study of tumorigenesis, and identification of novel preventive and therapeutic approaches.

  19. Failure of serotonin inhibitor to effect nocturnal GH and prolactin secretion in patients with Duchenne muscular dystrophy.

    Marlarkey, W B; Mendall, J R


    Growth hormone (GH) and prolactin (PRL) secretion was evaluated in seven patients with Duchenne muscular dystrophy. GH and PRL levels following sleep and 24 h mean serum GH and PRL concentrations were normal in these subjects. Overnight GH and PRL concentrations were evaluated in four of these patients before and following administration of the serotonin inhibitor, parachlorophenylalanine (PCPA). Although PCPA produced a significant decrease in urinary 5HIAA concentrations, the treatment had no significant effect on GH and PRL levels. These findings raise the possibility that serotonin may not be involved in nocturnal GH and PRL secretion in these patients.

  20. A comprehensive analysis of common genetic variation in prolactin (PRL and PRL receptor (PRLR genes in relation to plasma prolactin levels and breast cancer risk: the Multiethnic Cohort

    Altshuler David


    Full Text Available Abstract Background Studies in animals and humans clearly indicate a role for prolactin (PRL in breast epithelial proliferation, differentiation, and tumorigenesis. Prospective epidemiological studies have also shown that women with higher circulating PRL levels have an increase in risk of breast cancer, suggesting that variability in PRL may also be important in determining a woman's risk. Methods We evaluated genetic variation in the PRL and PRL receptor (PRLR genes as predictors of plasma PRL levels and breast cancer risk among African-American, Native Hawaiian, Japanese-American, Latina, and White women in the Multiethnic Cohort Study (MEC. We selected single nucleotide polymorphisms (SNPs from both the public (dbSNP and private (Celera databases to construct high density SNP maps that included up to 20 kilobases (kb upstream of the transcription initiation site and 10 kb downstream of the last exon of each gene, for a total coverage of 59 kb in PRL and 210 kb in PRLR. We genotyped 80 SNPs in PRL and 173 SNPs in PRLR in a multiethnic panel of 349 unaffected subjects to characterize linkage disequilibrium (LD and haplotype patterns. We sequenced the coding regions of PRL and PRLR in 95 advanced breast cancer cases (19 of each racial/ethnic group to uncover putative functional variation. A total of 33 and 60 haplotype "tag" SNPs (tagSNPs that allowed for high predictability (Rh2 ≥ 0.70 of the common haplotypes in PRL and PRLR, respectively, were then genotyped in a multiethnic breast cancer case-control study of 1,615 invasive breast cancer cases and 1,962 controls in the MEC. We also assessed the association of common genetic variation with circulating PRL levels in 362 postmenopausal controls without a history of hormone therapy use at blood draw. Because of the large number of comparisons being performed we used a relatively stringent type I error criteria (p Results We observed no significant associations between PRL and PRLR haplotypes

  1. Characterization of the oligosaccharide structure of human glycosylated prolactin (G-hPRL) native and recombinant; Caracterizacao da estrutura oligossacaridica de prolactina glicosilada humana (G-hPRL) nativa e recombinante

    Marcos Vinicius Nucci Capone


    Human prolactin (hPRL) is a polypeptide hormone secreted by the anterior pituitary under the regulation of the hypothalamus, involved in a variety of biological processes such as mammary gland development and lactation. The recombinant product is important in medical diagnosis and treatment of failure of lactation. This hormone may occur in the form of non-glycosylated protein (NGhPRL) and glycosylated (G-hPRL) with molecular weights of approximately 23 and 25 kilodalton (kDa), respectively; has a single N-glycosylation site located at asparagine (Asn) position 31, which is partially occupied, thus being a particularly interesting model of glycosylation. The biological activity of G-hPRL is lower compared to NG-hPRL (~4 times) and its physiological function is not well defined: the portion of carbohydrate appears to have an important role in the hormone biosynthesis, secretion, biological activity, and plasma survival of the hormone. The main objective of this study was to compare the structures of N-glycans present in glycosylated pituitary prolactin (G-hPRL-NHPP) with those present in the recombinant. To obtain the recombinant G-hPRL the production was performed in laboratory scale from Chinese hamster ovary cells (CHO), genetically modified and adapted to growth in suspension. Cycloheximide (CHX), whose main effect was to increase the ratio G-hPRL/NG-hPRL from 5% to 38% was added to the culture medium, thereby facilitating the purification of G-hPRL. The G-hPRL was purified in two steps, a cation exchanger followed by a purification by reversed-phase high performance liquid chromatography (RP-HPLC) which demonstrated the efficient separation of the two isoforms of hPRL. Recombinant G-hPRL-IPEN was well characterized by several techniques confirming its purity and biological activity, including comparisons with other reference preparation of pituitary origin purchased from the {sup N}ational Hormone & Peptide Program (NHPPU. S.){sup .} The composition of N

  2. Sodium oxybate increases prolactin secretion in narcolepsy patients and healthy controls

    Donjacour, C.E.; Aziz, N.A.; Frolich, M.; Roelfsema, F.; Overeem, S.; Lammers, G.J.; Pijl, H.


    OBJECTIVE: Hypocretin deficiency causes narcolepsy and may affect neuroendocrine systems, including TSH, ACTH and LH secretion. Symptoms can be treated effectively with sodium oxybate (SXB) in many patients. This study was performed to compare prolactin (PRL) secretion in patients and matched contro

  3. Transformation of a microprolactinoma into a mixed growth hormone and prolactin-secreting pituitary adenoma



    Full Text Available Combined prolactin (PRL and growth hormone (GH secretion by a single pituitary tumor can occur in approximately 5% of cases. However, in all previously reported patients, combined secretion of both hormones was present at the time of diagnosis. Here we describe a patient initially diagnosed with a pure prolactin-secreting microadenoma, who experienced the progressive apparition of symptomatic autonomous GH secretion while on intermittent long term dopamine agonist therapy. She was operated on, and immunohistochemical analysis of tumour tissue confirmed the diagnosis of pituitary adenoma with uniform co-staining of all cells for both GH and PRL. This patient represents the first documented occurrence of asynchronous development of combined GH and PRL secretion in a pituitary adenoma. Although pathogenic mechanisms implicated remain largely speculative, it emphasizes the need for long term hormonal follow up of patients harboring prolactinomas.

  4. Molecular characterization of prolactin receptor (cPRLR) gene in chickens: gene structure, tissue expression, promoter analysis, and its interaction with chicken prolactin (cPRL) and prolactin-like protein (cPRL-L).

    Bu, Guixian; Ying Wang, Crystal; Cai, Guoqing; Leung, Frederick C; Xu, Min; Wang, Hongning; Huang, Guian; Li, Juan; Wang, Yajun


    In this study, gene structure, tissue expression, and promoter usage of prolactin receptor (PRLR) and its interaction with prolactin (PRL) and the newly identified prolactin-like protein (PRL-L) were investigated in chickens. The results showed that (1) PRLR gene was found to consist of at least 25 exons by 5'-RACE and RT-PCR assays; (2) multiple PRLR 5'-UTR sequences different in exon composition were isolated from chicken liver or intestine by 5'-RACE and could be subdivided into type I and type II transcripts according to the first exon used (exon 1G or exon 1A); (3) PRLR Type I transcripts with exon 1G were detected to be predominantly expressed in adult kidney and small intestine by RT-PCR, implying their expression is likely controlled by a tissue-specific promoter (P1). By contrast, PRLR type II transcripts containing exon 1A are widely expressed in adult and embryonic tissues examined and their expression is controlled by a generic promoter (P2) near exon 1A, which was demonstrated to display promoter activities in cultured DF-1, HEK293 and LoVo cells by the dual-luciferase reporter assay; (4) Using a 5×STAT5-luciferase reporter system, cPRLR expressed in HepG2 cells was shown to be activated by recombinant cPRL and cPRL-L via interaction with PRLR membrane-proximal ligand-binding domain, suggesting that like cPRL, cPRL-L is also a functional ligand of cPRLR. Collectively, characterization of cPRLR gene helps to elucidate the roles of PRLR and its ligands in birds and provides insights into the regulatory mechanisms of PRLR expression conserved in birds and mammals. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  5. Paradoxical effects of oxytocin and vasopressin on basal prolactin secretion and the estrogen-induced prolactin surge

    Mai, Leemin (National Yang-Ming Medical College, Taipei (Taiwan)); Pan, Jenntser (Michigan State Univ., East Lansing (USA))


    The roles of oxytocin (OT) and vasopressin (AVP) on both basal and estrogen-induced prolactin (PRL) secretion were examined. Adult female Sprague-Dawley rats that were ovariectomized for 3 weeks and received estrogen treatment for 1 week were used. Intravenous administration of hormones and serial blood sampling were accomplished through indwelling intraatrial catheters which were implanted two days before. Plasma PRL levels were measured by radioimmunoassay. Oxytocin at a dose of 20 {mu}g/rat stimulated a moderate PRL release in the morning and lower doses were without effect. Vasopressin was most effective at a dose of 5 {mu}g/rat in stimulating PRL release, while consecutive injections of higher doses were less effective. In contrast, TRH, ranging from 1 to 8 {mu}g/rat, induced a dose-dependent increases in PRL secretion. Using the effective dosages determined from the morning studies, repeated injections of either OT, AVP or their specific antagonists MPOMeOVT were given hourly between 1300 to 1800h and blood samples were obtained hourly from 1100 to 1900h. It was found that either OT or AVP significantly reduced the afternoon PRL surge, while their antagonists were not as effective.

  6. Activation of GABA B receptors in the anterior pituitary inhibits prolactin and luteinizing hormone secretion.

    Lux-Lantos, V; Rey, E; Libertun, C


    Previous work from our laboratory showed that baclofen could lower serum prolactin (PRL) levels acting at the central nervous system. The present experiments were designed to evaluate whether the gamma-aminobutyric acid B agonist was also effective in inhibiting hormone release at the pituitary level. In monolayer cultures of adenohypophyseal dispersed cells, baclofen inhibited basal PRL secretion after 1 or 2 h of incubation. This inhibition was significantly abolished by three antagonists: phaclofen, 3-aminopropyl-phosphonic acid and 4-aminobutylphosphonic acid. Furthermore, baclofen inhibited the thyrotropin-releasing hormone-induced PRL release in a concentration-dependent manner. With regard to gonadotropin secretion, baclofen was unable to modify basal luteinizing hormone (LH) secretion, but significantly inhibited the LH-releasing hormone-induced LH release. These results show that baclofen, in addition to its central neuroendocrine effects, inhibits pituitary hormone secretion, under basal and/or stimulated conditions, by direct action at the pituitary level.

  7. Somatomammotrophic cells in GH-secreting and PRL-secreting human pituitary adenomas.

    Bassetti, M; Brina, M; Spada, A; Giannattasio, G


    A morphological study has been carried out on 20 GH-secreting adenomas removed from acromegalic normoprolactinemic patients, on 29 PRL-secreting adenomas removed from hyperprolactinemic patients without signs of acromegaly and on one normal human anterior pituitary gland collected at autopsy. The protein A-gold immunoelectron microscopic technique has been utilized in order to verify the presence of mixed cells producing both GH and PRL (somatomammotrophs) in these pituitary tissues. In the normal pituitary a considerable number of somatomammotrophs (15-20%) was found, thus supporting the idea that these cells are normal components of the human anterior pituitary gland. In 10 GH-secreting adenomas and in 10 PRL-secreting adenomas somatomammotrophs were present in a variable number (from 4 to 20% of the whole cell population in GH adenomas and from 1 to 47% in PRL tumors). It can be concluded therefore that these cells, largely present in all GH/PRL-secreting adenomas, can also be found in GH-secreting and PRL-secreting tumors without clinical evidence of a mixed secretion. Adenomatous somatomammotrophs displayed ultrastructural features of adenomatous somatotrophs and mammotrophs (prominent Golgi complexes, abundant rough endoplasmic reticulum, irregular nuclei). The size and the number of granules were variable. In some cells GH and PRL were stored in distinct secretory granules, in others in mixed granules or both in mixed and distinct granules, thus suggesting that in adenomatous somatomammotrophs the efficiency of the mechanisms of sorting of the two hormones varies from one cell to another.(ABSTRACT TRUNCATED AT 250 WORDS)

  8. Temporal relationships of a pulse of prolactin (PRL) to a pulse of a metabolite of PGF2α in mares.

    Ginther, O J; Pinaffi, F L V; Silva, L A; Beg, M A


    Hourly blood samples were collected from 10 mares during 24 h of each of the preluteolytic, luteolytic, and postluteolytic periods. The autocorrelation function of the R program was used to detect pulse rhythmicity, and the intra-assay CV was used to locate and characterize pulses of prolactin (PRL) and a metabolite of prostaglandin F2α (PGFM). Rhythmicity of PRL and PGFM concentrations was detected in 67% and 89% of mares, respectively. Combined for the three periods (no difference among periods), the PRL pulses were 5.2±0.4 h (mean±SEM) at the base, 7.5±1.5 h between nadirs of adjacent pulses, and 12.3±1.5 h from peak to peak. The peaks of PRL pulses were greater (PPRL during hours of a PGFM pulse were different (PPRL concentrations during a PGFM pulse were not different during the preluteolytic period. The frequency of the peak of PRL and PGFM pulses occurring at the same hour (synchrony) was greater for the luteolytic period (65%, PPRL pulses, synchrony between PRL and PGFM pulses, and greater PRL activity during the luteolytic and postluteolytic periods than during the preluteolytic period.

  9. Prolactin (PRL) induction of cyclooxygenase 2 (COX2) expression and prostaglandin (PG) production in hamster Leydig cells.

    Matzkin, María Eugenia; Ambao, Verónica; Carino, Mónica Herminia; Rossi, Soledad Paola; González, Lorena; Turyn, Daniel; Campo, Stella; Calandra, Ricardo Saúl; Frungieri, Mónica Beatriz


    Serum prolactin (PRL) variations play a crucial role in the photoperiodic-induced testicular regression-recrudescence transition in hamsters. We have previously shown that cyclooxygenase 2 (COX2), a key enzyme in the biosynthesis of prostaglandins (PGs), is expressed mostly in Leydig cells of reproductively active hamsters with considerable circulating and pituitary levels of PRL. In this study, we describe a stimulatory effect of PRL on COX2/PGs in hamster Leydig cells, which is mediated by IL-1β and prevented by P38-MAPK and JAK2 inhibitors. Furthermore, by preparative isoelectric focusing (IEF), we isolated PRL charge analogues from pituitaries of active [isoelectric points (pI): 5.16, 4.61, and 4.34] and regressed (pI: 5.44) hamsters. More acidic PRL charge analogues strongly induced COX2 expression, while less acidic ones had no effect. Our studies suggest that PRL induces COX2/PGs in hamster Leydig cells through IL-1β and activation of P38-MAPK and JAK2. PRL microheterogeneity detected in active/inactive hamsters may be responsible for the photoperiodic variations of COX2 expression in Leydig cells.

  10. Prolactin secretion in healthy adults is determined by gender, age and body mass index.

    Ferdinand Roelfsema

    Full Text Available BACKGROUND: Prolactin (PRL secretion is quantifiable as mean, peak and nadir PRL concentrations, degree of irregularity (ApEn, approximate entropy and spikiness (brief staccato-like fluctuations. HYPOTHESIS: Distinct PRL dynamics reflect relatively distinct (combinations of subject variables, such as gender, age, and BMI. LOCATION: Clinical Research Unit. SUBJECTS: Seventy-four healthy adults aged 22-77 yr (41 women and 33 men, with BMI 18.3-39.4 kg/m(2. MEASURES: Immunofluorometric PRL assay of 10-min samples collected for 24 hours. RESULTS: Mean 24-h PRL concentration correlated jointly with gender (P<0.0001 and BMI (P = 0.01, but not with age (overall R(2 = 0.308, P<0.0001. Nadir PRL concentration correlated with gender only (P = 0.017 and peak PRL with gender (P<0.001 and negatively with age (P<0.003, overall R(2 = 0.325, P<0.0001. Forward-selection multivariate regression of PRL deconvolution results demonstrated that basal (nonpulsatile PRL secretion tended to be associated with BMI (R(2 = 0.058, P = 0.03, pulsatile secretion with gender (R(2 = 0.152, P = 0.003, and total secretion with gender and BMI (R(2 = 0.204, P<0.0001. Pulse mass was associated with gender (P = 0.001 and with a negative tendency to age (P = 0.038. In male subjects older than 50 yr (but not in women approximate entropy was increased (0.942±0.301 vs. 1.258±0.267, P = 0.007 compared with younger men, as well as spikiness (0.363±0.122 vs. 0463±2.12, P = 0.031. Cosinor analysis disclosed higher mesor and amplitude in females than in men, but the acrophase was gender-independent. The acrophase was determined by age and BMI (R(2 = 0.186, P = 0.001. CONCLUSION: In healthy adults, selective combinations of gender, age, and BMI specify distinct PRL dynamics, thus requiring balanced representation of these variables in comparative PRL studies.




    The release of dopamine (DA) from tuberoinfundibular (TIDA) neurons during prolactin (PRL) surge and nonsurge periods and the effects of the thyrotropin-releasing hormone (TRH) analogue CG 3703 on DA and PRL secretion were studied in awake pseudopregnant (PSP) rats by simultaneous measurement of ext

  12. Antibody Array Revealed PRL-3 Affects Protein Phosphorylation and Cytokine Secretion.

    Yang, Yongyong; Lian, Shenyi; Meng, Lin; Qu, Like; Shou, Chengchao


    Phosphatase of regenerating liver 3 (PRL-3) promotes cancer metastasis and progression via increasing cell motility and invasiveness, however the mechanism is still not fully understood. Previous reports showed that PRL-3 increases the phosphorylation of many important proteins and suspected that PRL-3-enhanced protein phosphorylation may be due to its regulation on cytokines. To investigate PRL-3's impact on protein phosphorylation and cytokine secretion, we performed antibody arrays against protein phosphorylation and cytokines separately. The data showed that PRL-3 could enhance tyrosine phosphorylation and serine/threonine phosphorylation of diverse signaling proteins. Meanwhile, PRL-3 could affect the secretion of a subset of cytokines. Furthermore, we discovered the PRL-3-increased IL-1α secretion was regulated by NF-κB and Jak2-Stat3 pathways and inhibiting IL-1α could reduce PRL-3-enhanced cell migration. Therefore, our result indicated that PRL-3 promotes protein phosphorylation by acting as an 'activator kinase' and consequently regulates cytokine secretion.

  13. Role of Estradiol in the Regulation of Prolactin Secretion During Late Pregnancy.

    Villegas-Gabutti, Carlos; Pennacchio, Gisela E; Jahn, Graciela A; Soaje, Marta


    Estrogen action is necessary for evidencing the stimulatory action of mifepristone and naloxone on prolactin (PRL) secretion during late pregnancy. Our aim is to determine the mechanism mediating this facilitator action of estrogens. To investigate the hypothalamic mechanisms involved in estrogen actions in PRL secretion at the end of pregnancy, we measured the effect of pretreatment with the estrogen antagonist tamoxifen on the expression of tyrosine hydroxylase (TH), hormone receptors (ERα and β, PRs, PRLR(long)), and μ- and κ- opioid receptors (ORs) at mRNA (by semiquantitative RT-PCR) and protein (by western blot for TH, PRLR(long), ERα, PRs, μ- and ORs) levels in extracts of medial basal hypothalamus (MBH) and serum PRL, E2 and P4 levels (by RIA) in mifepristone- and naloxone-treated rats. Tamoxifen administration partially prevented PRL release induced by the combined treatment. TH expression diminished and ERα expression increased in mifepristone-treated rats at mRNA and protein levels and tamoxifen partially prevented these changes with no effect on PRs expression. Mifepristone increased PRLR(long) mRNA levels; this increase was blocked by tamoxifen. Combined tamoxifen and mifepristone treatment decreased μ- and k-ORs mRNA but not protein levels. In conclusion, E2 induces neuroadaptive mechanisms necessary to facilitate PRL release preceding delivery. Acting through ERα, E2 modulates hypothalamic dopaminergic neurons activity, regulating TH, μ- and κ-ORs and PRLR(long) expression, and is necessary for evidencing the effects of P4 withdrawal. Its presence on days 14 and 15 of pregnancy is crucial to facilitate the opioid system modulation of PRL secretion at the end of pregnancy in the rat.

  14. [Irregular secretion of prolactin in infertile women with normoprolactinemic galactorrhea].

    Villanueva Díaz, Carlos A; Echavarria Sánchez, Mirna; Juárez Bengoa, Armando


    Abnormal frequency and pulse amplitud of prolactin secretion in micro and macroprolactinomas has been atributed to a dysfunctional tumoral lactotrope. Previous evidence suggests that non tumoral hyperprolactinemia is caused by a hypothalamic dysfunction. The regularity of prolactin secretion has not been studied with cuantitative methods in patients with normoprolactinemic galactorrhea (NPG) which could be considered an entity that precedes non tumoral and tumoral hyperprolactinemia. To analyze the 24-hour prolactin secretion pattern and its secretion regularity in a group of infertile women with normoprolactinemic galatorea. A transversal-comparative study was carried out in 6 infertile women with normoprolactinemic galactorrhea and 4 healthy women as controls. The 24 hour prolactin profile, the ratio night time mean concentration/daytime mean concentrattion (NM/DM ratio) and apparent entropy (Ap En, Ap En ratio) were compared in the two groups. Blunting of the nyctohemeral rythm and nocturn hyperprolactinaemia occurred in patients with normoprolactinemic galactorrhea (NPG). NM/DM ratio was lower in patients with NPG than in controls (1.28 +/- 0.25 vs. 1.75 +/- 0.05; p= 0.01). Higher irregularity of prolactin secretion was found in patients with NPG (ApEn: 0.853 +/- 0.158 vs 0.608 +/- 0.171, p=0.04; Ap En ratio: 0.839 +/- 0.11 vs 0.661 +/- 0.14; p=0.04). The irregularity of prolactin secretion in patients with NPG is not dependant on the presence of a pituitary tumour which suggests that a hypothalamic dysfunction underlies this condition. An irregular secretion and a higher daily mass production of prolactin in patients with NPG could explain both galactorrhea and infertility.

  15. Heterogeneity of pituitary and plasma prolactin in man: decreased affinity of big prolactin in a radioreceptor assay and evidence for its secretion

    Garnier, P.E.; Aubert, M.L.; Kaplan, S.L.; Grumbach, M.M.


    Molecular heterogeneity of immunoreactive human PRL (IR-hPRL) plasma was assessed by exclusion chromatography in blood from 4 normal adults, 3 newborn infants, 2 late gestational women, 3 patients with primary hypothyroidism and high PRL levels, 2 with functional hyperprolactinemia, 3 with acromegaly, and 10 with PRL-secreting tumors. Three forms of PRL were detected: big-big hPRL, big hPRL, and little hPRL. In normal subjects, the proportion of big-big, big, and little hPRL components was 5.1%, 9.1%, and 85.8%, respectively, without change in the distribution after TRF stimulation. In 8 of 10 patients with PRL-secreting tumors, we detected a significantly higher proportion of big PRL. In 2 additional patients with prolactinomas, the proportion of big PRL was much higher. In 3 of 10 patients, the molecular heterogeneity of the tumor PRL was similar to that in plasma. In 1 acromegalic, there was a very high proportion of big-big hPRL. The PRL fractions were tested in a radioreceptor assay (RRA) using membranes from rabbit mammary gland. Big PRL was much less active than little PRL in the RRA. The fractions were rechromatographed after storage. Big PRL partially distributed as little or big-big PRL, while little PRL remained unchanged. Big-big PRL from tumor extract partially converted into big and little PRL. The big PRL obtained by rechromatography had low activity in the RRA. These observations suggest at least part of the receptor activity of big PRL may arise from generation of or contamination by little PRL. The decreased binding affinity of big PRL in the RRA also indicates that big PRL has little, if any, biological activity. The evidence suggests big PRL is a native PRL dimer linked by intermolecular disulfide bonds which arises in the lactotrope as a postsynthetic product or derivative and is not a true precursor prohormone.

  16. Estradiol and its membrane-impermeable conjugate estradiol-BSA inhibit tamoxifen-stimulated prolactin secretion in incubated rat pituitaries.

    Aguilar, R; Bellido, C; Garrido-Gracia, J C; Alonso, R; Sánchez-Criado, J E


    In the absence of estrogen (E), the selective E receptor modulator tamoxifen (TX) has two agonist effects in the rat pituitary: induction of progesterone receptor (PR)-dependent GnRH self-priming in the gonadotrope, and stimulation of prolactin (PRL) secretion in the lactotrope. TX-induced gonadotropin (GnRH) self-priming is absent when 10(-8) M estradiol-17beta (E2) is added to the incubation medium of pituitaries from TX-treated rats. The present experiments investigated whether PR-independent PRL release into the incubation medium of pituitaries from TX-treated ovariectomized (OVX) rats was affected by E2, and the effect of different ER ligands (ICI182780, TX, estradiol-17alpha, E2 -BSA) on TX-stimulated PRL secretion. Moreover, the effect of E2 on TRH-stimulated PRL secretion in pituitaries collected from estradiol benzoate- and TX-treated OVX rats was studied. It was found that: i) incubation with E2 supressed the PRL releasing effect of injected TX; ii) whereas coincubation with the pure anti-E type II ICI182780 antagonized the inhibitory effect of E2, coincubation with the anti-E type I TX did not; iii) estradiol-17alpha lacked inhibitory action, whereas a dose-dependent inhibitory effect of both E2 and E2 -BSA was noticed; and iv) TRH stimulatory effect on PRL release in pituitaries from TX-treated rats was blocked by addition of E2 to the medium. Taken together, these data argue in favor of the presence of specific membrane recognition sites for E in the lactotrope involved in steroid-specific E2 inhibition of TX-stimulated PRL secretion.

  17. Modulating effect of the nootropic drug, piracetam on stress- and subsequent morphine-induced prolactin secretion in male rats.

    Matton, A.; Engelborghs, S.; Bollengier, F.; Finné, E.; Vanhaeist, L.


    1. The effect of the nootropic drug, piracetam on stress- and subsequent morphine-induced prolactin (PRL) secretion was investigated in vivo in male rats, by use of a stress-free blood sampling and drug administration method by means of a permanent indwelling catheter in the right jugular vein. 2. Four doses of piracetam were tested (20, 100, 200 and 400 mg kg-1), being given intraperitoneally 1 h before blood sampling; control rats received saline instead. After a first blood sample, rats were subjected to immobilization stress and received morphine, 6 mg kg-1, 90 min later. 3. Piracetam had no effect on basal plasma PRL concentration. 4. While in the non-piracetam-treated rats, stress produced a significant rise in plasma PRL concentration, in the piracetam-pretreated rats PRL peaks were attenuated, especially in the group given 100 mg kg-1 piracetam, where plasma PRL concentration was not significantly different from basal values. The dose-response relationship showed a U-shaped curve; the smallest dose had a minor inhibitory effect and the highest dose had no further effect on the PRL rise. 5. In unrestrained rats, morphine led to a significant elevation of plasma PRL concentration. After the application of immobilization stress it lost its ability to raise plasma PRL concentration in the control rats, but not in the piracetam-treated rats. This tolerance was overcome by piracetam in a significant manner but with a reversed dose-response curve; i.e. the smaller the dose of piracetam, the higher the subsequent morphine-induced PRL peak. 6. There is no simple explanation for the mechanism by which piracetam induces these contradictory effects. Interference with the excitatory amino acid system, which is also involved in opiate action, is proposed speculatively as a possible mediator of the effects of piracetam. PMID:8821540

  18. Effects of Neonatal Exposure to Estradiol on Prolactin Secretion and Activity of the Tubero-lnfundibular Dopamine System in Young Adulthood: Comparison with Neonatal Prolactin Deficiency*.

    Crowley, W R; Shah, G V; Watanobe, H; Grosvenor, C E


    Abstract Previous results from this laboratory indicate that female rats who consume milk deficient in prolactin (PRL) during the neonatal period subsequently display hyperprolactinemia, associated with decreased activity in the tubero-infundibular dopamine (DA) system and decreased lactotrope responsiveness to DA receptor stimulation. The present studies tested whether these neuroendocrine consequences of neonatal PRL deficiency can be mimicked by exposure of neonatal rats to estradiol. Female rats were injected sc with 1 mUg estradiol benzoate or oil vehicle on postpartum Days one to 3, while in other experiments, females were made neonatally deficient in PRL through treatment of their mothers with the DA agonist bromocriptine, a treatment that reduces the levels of PRL in milk. Females treated neonatally with estradiol benzoate, as well as offspring of the bromocriptine-treated mothers, displayed hyperprolactinemia as young adults, as compared to their respective vehicle-matched controls, and in both cases, this was abolished by ovariectomy, indicating dependence upon ovarian secretions. As reported previously in neonatal PRL-deficient females, neonatal estradiol benzoate-treated animals also exhibited reduced steady state levels and decreased turnover rates of DA in the median eminence when 35 days of age. DA levels and turnover rates in this region were still significantly reduced on postpartum Day 60. The DA agonist bromocriptine suppressed PRL release to a similar extent in cultured anterior pituitary cells from neonatal estrogen-treated and control rats, suggesting normal responsiveness of DA receptors on lactotrope cells in both groups. The present results confirm the ability of estradiol treatment or induction of a PRL deficiency during the early neonatal period to induce subsequent hyperprolactinemia in female rats, and further indicate that the hyperprolactinemic conditions resulting from either neonatal manipulation are dependent on the ovary and are

  19. Interactions of histaminergic and serotonergic neurons in the hypothalamic regulation of prolactin and ACTH secretion.

    Jørgensen, H; Knigge, U; Kjaer, A; Warberg, J


    Serotonergic and histaminergic neuronal systems are both involved in mediation of the stress-induced release of the pituitary hormones prolactin (PRL) and ACTH. We investigated the possibility of an interaction between serotonin (5-HT) and histamine (HA) in regulation of PRL and ACTH secretion in conscious male rats. Animals were pretreated systemically with antagonists to 5-HT1, 5-HT2 or 5-HT3 receptors prior to intracerebroventricular (icv) administration of HA. The 5-HT1 + 2 receptor antagonist methysergide prevented and the 5-HT2 receptor antagonist LY 53857 attenuated the HA-induced PRL release while the 5-HT3 receptor antagonist ondansetron had no effect on this response. None of the three 5-HT receptor antagonists affected the ACTH response to HA. Specific blockade of HA synthesis by alpha-fluoromethylhistidine or blockade of postsynaptic HA receptors by icv infusion of the H1 receptor antagonist mepyramine or the H2 receptor antagonist cimetidine inhibited the PRL response to 5-HT or to the 5-HT precursor 5-hydroxytryptophan (5- HTP) given in combination with the 5-HT reuptake inhibitor fluoxetine (Flx). Blockade of the histaminergic system had no effect on the ACTH response to serotonergic stimulation. The H3 receptors are inhibitory HA receptors. Systemic pretreatment with the H3 receptor agonist R(alpha)methylhistamine, or the H3 receptor antagonist thioperamide had no effect on the hormone response to activation of the serotonergic system by 5-HTP plus Flx. We conclude that the serotonergic and histaminergic neuronal systems interact in their stimulation of PRL secretion, but not in their stimulation of ACTH secretion. This interaction involves serotonergic 5-HT1 and 5-HT2 receptors and histaminergic H1 and H2 receptors. Furthermore, the previously observed inhibitory effect of the H3 receptor agonist R(alpha)methylhistamine on stress-induced PRL and ACTH release seems not to be exerted by activation of presynaptic H3 receptors located on serotonergic

  20. Structural and thermodynamic bases for the design of pure prolactin receptor antagonists: X-ray structure of Del1-9-G129R-hPRL

    Jomain, Jean-Baptiste; Tallet, Estelle; Broutin, Isabelle;


    Competitive antagonists of the human prolactin (hPRL) receptor are a novel class of molecules of potential therapeutic interest in the context of cancer. We recently developed the pure antagonist Del1-9-G129R-hPRL by deleting the nine N-terminal residues of G129R-hPRL, a first generation partial...... antagonist. We determined the crystallographic structure of Del1-9-G129R-hPRL, which revealed no major change compared with wild type hPRL, indicating that its pure antagonistic properties are intrinsically due to the mutations. To decipher the molecular bases of pure antagonism, we compared the biological...... agonism can be abolished either by further disrupting hormone site 2-receptor contacts by N-terminal deletion, as in Del1-9-G129R-hPRL, or by stabilizing hPRL and constraining its intrinsic flexibility, as in G129V-hPRL. Udgivelsesdato: 2007-Nov-9...

  1. Prolactin is a major inhibitor of hepatic Leptin A synthesis and secretion: studies utilizing a homologous Leptin A ELISA in the tilapia.

    Douros, Jonathan D; Baltzegar, David A; Breves, Jason P; Lerner, Darren T; Seale, Andre P; Gordon Grau, E; Borski, Russell J


    The present study identifies regulatory interactions between leptin A (LepA) and the pituitary hormone prolactin (PRL). In order to measure tilapia (Oreochromis mossambicus) LepA, an enzyme-linked immunosorbent assay (ELISA) utilizing a rabbit polyclonal antibody specific to tilapia LepA was first developed. The antibody shows strong cross reactivity to recombinant tilapia LepA (rtLepA), and a corresponding 16kDa protein in both tilapia and striped bass plasma, but not to recombinant human leptin (rhLep). The assay has a linear detection range of 0.25-1000nM, with intra- and interassay variability of 9% and 16%, respectively. Plasma LepA levels measured in tilapia ranged from 0.8 to 3.9nM, similar to that found for other vertebrates. Hypophysectomy (Hx) increased circulating LepA and lepa mRNA levels in the liver, the dominant source of hormone production. Adminstration of ovine PRL (oPRL, 5μg/g BW) to Hx fish restored circulating LepA and hepatic lepa mRNA levels to those of control fish. Additionally, oPRL reduced lepa mRNA levels in a dose-dependent fashion in cultured hepatocytes following an 18h incubation. Previous work in our lab indicates that rhLep stimulates PRL release in vitro from tilapia pituitaries. Here, both rtLepA and rhLep (0.5μg/g BW) increased mRNA expression of tilapia prolactin mRNAs (prl1, prl2) in the pituitary in vivo. These results demonstrate that LepA enhances pituitary prolactin synthesis and release, while PRL in turn inhibits hepatic leptin secretion and synthesis in teleosts. We postulate this regulatory interaction may be necessary for mobilizing energy reserves during acute hyperosmotic adaptation.

  2. Correlation of prolactin levels and PRL-receptor expression with Stat and Mapk cell signaling in the prostate of long-term sexually active rats.

    Rojas-Durán, Fausto; Pascual-Mathey, Luz I; Serrano, Karina; Aranda-Abreu, Gonzalo E; Manzo, Jorge; Soto-Cid, Abraham H; Hernandez, Ma Elena


    Prolactin (PRL) is a key hormone for prostate function, with a basal level in serum and associated with two characteristic circadian peaks. In the male rat, the execution of one bout of sexual behavior with consecutive ejaculations produces a significant transient increase in PRL. However, the impact of a constant sexual life on both PRL levels and prostate function is unknown. Thus, by using constantly copulating males we analyzed the levels of serum PRL, the effect on prostate PRL receptors, and activation of pStat3, pStat5 and Mapk signaling pathways. Sexually experienced Wistar male rats were used, which underwent periodic sessions of sexual behavior tests. Males were subjected to a session of sexual behavior to achieve at least one and up to four ejaculations. Of these, a blood sample was collected from randomly selected males and the ventral prostate was removed for analysis. Serum PRL was quantified, the mRNA for PRL receptors was determined, and signaling pathways were analyzed. Data show that a constant sexual life produced a constant elevation of PRL in serum during four consecutive ejaculations. The ventral prostate showed a different mRNA expression profile for the long and short isoform of the PRL receptor, and both mRNA levels increased. Although the gland did not show modification of the activation of the pStat5 signaling pathway, the levels of pStat3 increased, and the Mapk pathway showed one significant elevation after the third ejaculation. Thus, we showed that an active and constant sexual life produces a sustained increase in serum PRL, its receptors, and the pStat3 signaling pathway. These responses seem to underlie the required physiological need to produce the quantity and quality of prostatic semen to ensure the appropriate environment for sperm to reach and fertilize the ovum.

  3. Modulating effect of the nootropic drug, piracetam on stress- and subsequent morphine-induced prolactin secretion in male rats.


    1. The effect of the nootropic drug, piracetam on stress- and subsequent morphine-induced prolactin (PRL) secretion was investigated in vivo in male rats, by use of a stress-free blood sampling and drug administration method by means of a permanent indwelling catheter in the right jugular vein. 2. Four doses of piracetam were tested (20, 100, 200 and 400 mg kg-1), being given intraperitoneally 1 h before blood sampling; control rats received saline instead. After a first blood sample, rats we...

  4. Melatonin inhibits the proliferation of pituitary prolactin-secreting tumor by suppressing the enhancer elements mutation of PRL gene in the rat%褪黑素通过减弱催乳素基因增强子的突变抑制大鼠垂体催乳素瘤的增生

    高列; 杨全会; 许荣焜


    本工作旨在探讨褪黑素(melatonin,MLT)抑制17-β-雌二醇(17-β-estradiol,E2)诱发的Sprague-Dawley大鼠垂体催乳素(prolactin,PRL)瘤增生的分子机制.结果表明,每只大鼠每日定时皮下注射一定剂量的MLT(0.25、0.50 mg)能显著抑制E2诱发的大鼠垂体PRL瘤的增生;偏低(0.05 mg)或过高剂量(1.00、2.00 mg)的MLT也抑制PRL瘤的增生,但无统计学意义.采用PCR和DNA直接测序显示,与正常垂体对照组比较,PRL瘤中PRL基因增强子出现五处突变,-1885 bp位点由C突变为G,-1 857~-1 855由ACA替换为G,-1792~-1791插入G,-1 383~-1 382插入GGTGTGTG片段,-1265~-1250缺失GTGTGTGTGTGTGTGT片段.0.25 mg/d MLT处理组,PRL瘤中的PRL基因增强子上述个别突变部位仍然存在(-1 885由C突变为G),突变消失(-1792~-1791无插入G),大部分表现为突变减弱(-1856~-1 855缺失AC,-1385~-1384缺失TG,-1250~-1253缺失GTGT).采用荧光素酶报告基因检测PRL基因增强子活性显示,正常垂体、PRL瘤和0.25 mg/d MLT处理的PRL瘤三组中,PRL基因增强子的活性分别为(13448.17±3012.74)、(161831.67±60996.01)和(10212.17±2634.71)OD单位.PRL瘤组增强子活性较正常垂体升高11倍(P<0.001),MLT处理组增强子活性较PRL瘤组降低93.69%(P<0.001).上述三组PRL基因增强子空间结构的分析表明,PRL基因增强子DNA的曲折程度为PRL瘤组>MLT处理组>正常垂体.以上结果证实,MLT抑制大鼠垂体PRL瘤增生的重要分子机制之一可能是减弱PRL基因增强子的突变,也提示MLT可减弱PRL基因增强子的突变,从而下调PRL基因的高表达,可能与降低DNA的曲折程度有关.

  5. The orphan nuclear receptor Nur77 regulates decidual prolactin expression in human endometrial stromal cells

    Jiang, Yue; Hu, Yali; Zhao, Jing; Zhen, Xin [Reproductive Medicine Center, The Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing 210008 (China); Yan, Guijun, E-mail: [Reproductive Medicine Center, The Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing 210008 (China); Sun, Haixiang, E-mail: [Reproductive Medicine Center, The Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing 210008 (China)


    Research highlights: {yields} Decidually produced PRL plays a key role during pregnancy. {yields} Overexpression of Nur77 increased PRL mRNA expression and enhanced decidual PRL promoter activity. {yields} Knockdown of Nur77 decreased decidual PRL secretion induced by 8-Br-cAMP and MPA. {yields} Nur77 is a novel transcription factor that plays an active role in decidual prolactin expression. -- Abstract: Prolactin (PRL) is synthesized and released by several extrapituitary tissues, including decidualized stromal cells. Despite the important role of decidual PRL during pregnancy, little is understood about the factors involved in the proper regulation of decidual PRL expression. Here we present evidence that the transcription factor Nur77 plays an active role in decidual prolactin expression in human endometrial stromal cells (hESCs). Nur77 mRNA expression in hESCs was significantly increased after decidualization stimulated by 8-Br-cAMP and medroxyprogesterone acetate (MPA). Adenovirus-mediated overexpression of Nur77 in hESCs markedly increased PRL mRNA expression and enhanced decidual PRL promoter (dPRL/-332Luc) activity in a concentration-dependent manner. Furthermore, knockdown of Nur77 in hESCs significantly decreased decidual PRL promoter activation and substantially attenuated PRL mRNA expression and PRL secretion (P < 0.01) induced by 8-Br-cAMP and MPA. These results demonstrate that Nur77 is a novel transcription factor that contributes significantly to the regulation of prolactin gene expression in human endometrial stromal cells.

  6. Fluoxetine, but not tricyclic antidepressants, potentiates the 5-hydroxytryptophan-mediated increase in plasma cortisol and prolactin secretion in subjects with major depression or with obsessive compulsive disorder.

    Meltzer, H; Bastani, B; Jayathilake, K; Maes, M


    It has been suggested that the clinical efficacy of chronic treatment with selective serotonin reuptake inhibitors (SSRIs) such as fluoxetine and perhaps all antidepressants is due to their ability to enhance serotonergic activity. The effects of chronic treatment with fluoxetine or tricyclic antidepressants on the L-5-hydroxytryptophan (200 mg, L-5-HTP; PO)-induced increases in plasma cortisol and prolactin (PRL) concentrations were studied in patients with major depression or obsessive compulsive disorder (OCD). Administration of L-5-HTP increased plasma cortisol and PRL levels in medicated and unmedicated patients with major depression or OCD. The L-5-HTP-induced cortisol and PRL responses were significantly higher in fluoxetine-treated than in tricyclic-treated or unmedicated major depressed patients. The latter two groups did not differ significantly in their cortisol or PRL responses to L-5-HTP. The L-5-HTP-induced increases in cortisol and PRL in fluoxetine-treated patients with major depression or OCD were not significantly different. The results suggest that fluoxetine, but not tricyclic antidepressants, potentiates 5-HT receptor-mediated stimulation of cortisol and PRL secretion in humans, consistent with available evidence that fluoxetine treatment, but not tricyclic antidepressants, increases central serotonergic activity in patients with MD or OCD by a presynaptic mechanism.

  7. Effects of chronic alternating cadmium exposure on the episodic secretion of prolactin in male rats

    Esquifino, A.I. [Madrid Univ. (Spain). Facultad de Medicina Complutense; Marquez, N.; Alvarez-Demanuel, E.; Lafuente, A. [Vigo Univ., Orense (Spain). Lab. de Toxicologia


    Cadmium increases or decreases prolactin secretion depending on the dose and duration of the exposure to the metal. However, whether there are cadmium effects on the episodic prolactin secretion is less well known. This study was undertaken to address whether chronic alternating exposure to two different doses of cadmium affects the episodic pattern of prolactin and to what extent the effects of cadmium are age-dependent. Male rats were treated s.c. with cadmium chloride (0.5 or 1.0 mg/kg) from day 30 to 60, or from day 60 to 90 of age, with alteration of the doses every 4 days, starting with the smaller dose. Controls received vehicle every 4 days. The last dose of cadmium was given 48 h prior to the pulsatility study. Prolactin secretion in the 4 experimental groups studied was episodic and changed significantly after cadmium exposure. Cadmium administration from day 30 to 60 of life significantly decreased the mean half-life of prolactin. On the other hand, when administered from day 60 to 90 cadmium significantly decreased the mean as well as serum prolactin levels and the absolute amplitude of the prolactin pulses, their duration, the relative amplitude or the mean half-life of the hormone. The frequency of prolactin peaks was not changed by cadmium administration. The results indicate that low intermittent doses of cadmium chronically administered change the episodic secretion pattern of prolactin in rats. The effects of cadmium on prolactin secretion were age dependent. (orig.)

  8. Effects on prolactin secretion and binding to dopaminergic receptors in sleep-deprived lupus-prone mice

    B.D. Palma


    Full Text Available Sleep disturbances have far-reaching effects on the neuroendocrine and immune systems and may be linked to disease manifestation. Sleep deprivation can accelerate the onset of lupus in NZB/NZWF1 mice, an animal model of severe systemic lupus erythematosus. High prolactin (PRL concentrations are involved in the pathogenesis of systemic lupus erythematosus in human beings, as well as in NZB/NZWF1 mice. We hypothesized that PRL could be involved in the earlier onset of the disease in sleep-deprived NZB/NZWF1 mice. We also investigated its binding to dopaminergic receptors, since PRL secretion is mainly controlled by dopamine. Female NZB/NZWF1 mice aged 9 weeks were deprived of sleep using the multiple platform method. Blood samples were taken for the determination of PRL concentrations and quantitative receptor autoradiography was used to map binding of the tritiated dopaminergic receptor ligands [³H]-SCH23390, [³H]-raclopride and [³H]-WIN35,428 to D1 and D2 dopaminergic receptors and dopamine transporter sites throughout the brain, respectively. Sleep deprivation induced a significant decrease in plasma PRL secretion (2.58 ± 0.95 ng/mL compared with the control group (25.25 ± 9.18 ng/mL. The binding to D1 and D2 binding sites was not significantly affected by sleep deprivation; however, dopamine transporter binding was significantly increased in subdivisions of the caudate-putamen - posterior (16.52 ± 0.5 vs 14.44 ± 0.6, dorsolateral (18.84 ± 0.7 vs 15.97 ± 0.7 and ventrolateral (24.99 ± 0.5 vs 22.54 ± 0.7 µCi/g, in the sleep-deprived mice when compared to the control group. These results suggest that PRL is not the main mechanism involved in the earlier onset of the disease observed in sleep-deprived NZB/NZWF1 mice and the reduction of PRL concentrations after sleep deprivation may be mediated by modifications in the dopamine transporter sites of the caudate-putamen.

  9. Immunodetection of Luteinizing Hormone (LH, Follicle-Stimulating Hormone (FSH, Thyroid Stimulating Hormone (TSH and Prolactin (PRL in Brachionus calyciflorus (Rotifera: Monogononta

    Jesús Alvarado-Flores


    Full Text Available The endocrine system controls and coordinates behavioral, biochemical, and physiological processes through signal mechanisms using neuropeptides or products of neurosecretory cells. Among invertebrates, this system is poorly studied in rotifers, in which estrogens and androgens significantly affect sexual reproduction. This is the first report of the presence of the Luteinizing Hormone (LH, Follicle-Stimulating Hormone (FSH, Thyroid Stimulating Hormone (TSH and Prolactin (PRL in rotifers. Analyses included the avidin-biotin-peroxidase complex method with primary antibodies LH (Anti-Rat LH serum for RIA, PRL (Anti-Rat PRL serum for RIA, FSH (Anti-Rat FSH serum for RIA and TSH (Anti-Rat TSH serum for RIA. These hormones were found in females, males and parthenogenetic and sexual eggs of the freshwater Brachionus calyciflorus. The immunoreactivity of FSH, LH, TSH and PRL in females was observed in: ovaries, cerebrum, mastax, stomach, lorica, and the stomach gland. However, in males LH was observed only at the trochal disk and cerebrum. The hormones FSH, TSH and PRL, were observed in testicles, contractil vesicles, and cementary gland of males. Regarding amictic or parthenogenetic eggs, the hormones LH, FSH, TSH, and PRL were located mainly in the micromeres, and the staining in the macromeres was weak. On the other hand, in the mictic or sexual eggs the inner shell is stained for the hormones PRL and LH, opposite to the staining of FSH and TSH, located mainly in the embryo. In general, immuno-reactivity was observed in areas important for the reproductive, excretory, digestive and developmental processes. Rev. Biol. Trop. 57 (4: 1049-1058. Epub 2009 December 01.Se logró detectar la presencia de las hormonas: Hormona Luteinizante (LH, Hormona Folículo Estimulante (FSH, Hormona Estimulante de la Tiroides (TSH y Prolactina (PRL en Brachionus calyciflorus siendo el primer reporte de la presencia de dichas hormonas en rotíferos. Estas hormonas fueron

  10. Adenosine A1 receptor-mediated inhibition of in vitro prolactin secretion from the rat anterior pituitary

    D.L.W. Picanço-Diniz


    Full Text Available In previous studies, we demonstrated biphasic purinergic effects on prolactin (PRL secretion stimulated by an adenosine A2 agonist. In the present study, we investigated the role of the activation of adenosine A1 receptors by (R-N6-(2-phenylisopropyladenosine (R-PIA at the pituitary level in in vitro PRL secretion. Hemipituitaries (one per cuvette in five replicates from adult male rats were incubated. Administration of R-PIA (0.001, 0.01, 0.1, 1, and 10 µM induced a reduction of PRL secretion into the medium in a U-shaped dose-response curve. The maximal reduction was obtained with 0.1 µM R-PIA (mean ± SEM, 36.01 ± 5.53 ng/mg tissue weight (t.w. treatment compared to control (264.56 ± 15.46 ng/mg t.w.. R-PIA inhibition (0.01 µM = 141.97 ± 15.79 vs control = 244.77 ± 13.79 ng/mg t.w. of PRL release was blocked by 1 µM cyclopentyltheophylline, a specific A1 receptor antagonist (1 µM = 212.360 ± 26.560 ng/mg t.w., whereas cyclopentyltheophylline alone (0.01, 0.1, 1 µM had no effect. R-PIA (0.001, 0.01, 0.1, 1 µM produced inhibition of PRL secretion stimulated by both phospholipase C (0.5 IU/mL; 977.44 ± 76.17 ng/mg t.w. and dibutyryl cAMP (1 mM; 415.93 ± 37.66 ng/mg t.w. with nadir established at the dose of 0.1 µM (225.55 ± 71.42 and 201.9 ± 19.08 ng/mg t.w., respectively. Similarly, R-PIA (0.01 µM decreased (242.00 ± 24.00 ng/mg t.w. the PRL secretion stimulated by cholera toxin (0.5 mg/mL; 1050.00 ± 70.00 ng/mg t.w.. In contrast, R-PIA had no effect (468.00 ± 34.00 ng/mg t.w. on PRL secretion stimulation by pertussis toxin (0.5 mg/mL; 430.00 ± 26.00 ng/mg t.w.. These results suggest that inhibition of PRL secretion after A1 receptor activation by R-PIA is mediated by a Gi protein-dependent mechanism.

  11. β-Hydroxybutyric Sodium Salt Inhibition of Growth Hormone and Prolactin Secretion via the cAMP/PKA/CREB and AMPK Signaling Pathways in Dairy Cow Anterior Pituitary Cells

    Shou-Peng Fu


    Full Text Available β-hydroxybutyric acid (BHBA regulates the synthesis and secretion of growth hormone (GH and prolactin (PRL, but its mechanism is unknown. In this study, we detected the effects of BHBA on the activities of G protein signaling pathways, AMPK-α activity, GH, and PRL gene transcription, and GH and PRL secretion in dairy cow anterior pituitary cells (DCAPCs. The results showed that BHBA decreased intracellular cAMP levels and a subsequent reduction in protein kinase A (PKA activity. Inhibition of PKA activity reduced cAMP response element-binding protein (CREB phosphorylation, thereby inhibiting GH and PRL transcription and secretion. The effects of BHBA were attenuated by a specific Gαi inhibitor, pertussis toxin (PTX. In addition, intracellular BHBA uptake mediated by monocarboxylate transporter 1 (MCT1 could trigger AMPK signaling and result in the decrease in GH and PRL mRNA translation in DCAPCs cultured under low-glucose and non-glucose condition when compared with the high-glucose group. This study identifies a biochemical mechanism for the regulatory action of BHBA on GH and PRL gene transcription, translation, and secretion in DCAPCs, which may be one of the factors that regulate pituitary function during the transition period in dairy cows.

  12. PRL — EDRN Public Portal

    There is increasing evidence that prolactin (PRL), a hormone/cytokine, plays a role in breast, prostate, and colorectal cancers via local production or accumulation. Elevated levels of serum PRL in ovarian and endometrial cancers have been reported, indicating a potential role for PRL in endometrial and ovarian carcinogenesis.

  13. Increased secretion of growth hormone, prolactin, antidiuretic hormone, and cortisol induced by the stress of motion sickness.

    Eversmann, T; Gottsmann, M; Uhlich, E; Ulbrecht, G; von Werder, K; Scriba, P C


    The stress of motion sickness was experimentally provoked by Coriolis effect. Significant and reproducible increases from the basal serum level (delta mean +/- S.E.) of antidiuretic hormone delta - ADH: 48.2 +/- 4.6 pg/ml; p less than 0.0005), of growth hormone (delta - hGH: 10.0 +/- 1.2 ng/ml; p less than 0.0005), of prolactin (delta - hPRL: 186.5 +/- 29.9 muU/ml; p less than 0.0005), and of cortisol (delta - F; 12.3 +/- 0.9 microgram%; p less than 0.0005) were observed, whereas the luteinizing hormone levels did not change significantly. The stimulation of hormone secretion induced by different degrees of motion sickness seems to correlate with the severity of motion sickness. The secretion of antidiuretic hormones is the most sensitive indicator for the stress of motion sickness whereas growth hormone, prolactin, and cortisol responses to the stress of motion sickness are more delayed and less pronounced.

  14. Non-opiate [beta]-endorphin fragments and dopamine--V [gamma]-type endorphins and prolactin secretion in rats

    Lamberts, S.W.J.; De Quijada, M.; Ree, J.M. van; Wied, D. de


    The effects on prolactin secretion of three peptide-derivatives of β-endorphin which show neuroleptic-like activities in rats were studied. Intravenous administration of γ-endorphin (β-endorphin (βE) 1–17) enhanced plasma prolactin levels. γ-Endorphin did not affect the prolactin secretion by hemip

  15. Influence of age on the relationship between annual changes in horn growth rate and prolactin secretion in the European mouflon (Ovis gmelini musimon).

    Santiago-Moreno, J; Gómez-Brunet, A; Toledano-Díaz, A; González-Bulnes, A; Picazo, R A; López-Sebastián, A


    Annual variations in the growth of horns, and their correlation with seasonal changes of testicular size, and prolactin (PRL) and melatonin secretion were monitored in six pubertal mouflon rams living in their original latitude (40 degrees N). Mouflons born and maintained under captive conditions were classified in two age classes: sub-adult (2 years; n=3) and adult (> or =3 years; n=3). The rate of horn growth was greater (P mouflon rams. Horn growth was influenced by season in both adult and sub-adult mouflons (P mouflon rams. The rate of horn growth was inversely correlated with testicular size (r=-0.5, P=0.07). Seasonal changes in the amplitude of the daily melatonin rhythm in solstices and equinoxes were observed, which were not correlated with variations in the rate of horn growth. These results provide support for a possible role of PRL in the control of growth of horns in the adult mouflon.


    Prepubertal exposure to compounds that increase prolactin secretion in the male rat: effects on the adult prostate.Stoker TE, Robinette CL, Britt BH, Laws SC, Cooper RL.Endocrinology Branch, Reproductive Toxicology Division, National Health and Environmental Effec...

  17. Endoscopic transsphenoidal excision of a GH-PRL-secreting pituitary macroadenoma in a patient with McCune-Albright syndrome.

    Natarajan, Manikandan S; Prabhu, Krishna; Chacko, Geeta; Rajaratnam, Simon; Chacko, Ari G


    We describe an endoscopic transsphenoidal excision of a GH-PRL-secreting pituitary adenoma and remodeling of frontotemporal fibrous dysplasia in a patient with McCune-Albright syndrome. Sphenoid dysplasia rendered transsphenoidal surgery challenging, but a study of the radiological anatomy and good surgical planning made this feasible. Medical therapy and radiation was required for persistent acromegaly after surgery.

  18. 伊犁马及其杂交马催乳素(PRL)基因多态性的研究%Studies of Polymorphisms in Prolactin (PRL)Gene of Yili Horse and Its Hybrids

    热阳古·阿布拉; 张慧玲; 陈勇; 刘武军; 罗淑萍; 姚新奎


    Through PCR-SSCP technology,this paper tried to analyze SNP of prolactin gene of Yili Horses and the Fl hybrids of new Kirghiz horses and Yili horses and to analyze the relations between different genotypes and average milk production with statistic method. The results showed that no mutation was found in the first four exons of PRL gene of the Yili horse and its hybrids. Two novel mutations and four genotypes were found in the fifth exon of PRL gene. The AA genotype was the predominant in the two populations. DNA sequence analysis revealed that the two mutations occurred in 591T→G and 654C→T, both of which were silent mutations. Through the analysis of genotype and milk yield,the Yili horses with AA genotype produced more milk by 850 g/d than those with AB genotype (P <0. 05). The above results suggested that mutations in the fifth exon of PRL gene may be an important locus affecting milk performance of equine.%采用PCR-SSCP技术对伊犁马及新吉尔吉斯马与伊犁马的杂交F1代(杂交马)催乳素(PRL)基因所有外显子区域的单核苷酸多态性进行了分析,并对不同基因型和产奶量的关系进行统计分析.结果表明,在伊犁马及其杂交马PRL基因外显子1、外显子2、外显子3、外显子4上未发现突变.在外显子5发现了2个碱基突变,共4种基因型,其中AA基因型在两个群体中为优势基因型.DNA序列分析显示,2个突变分别为第591个碱基处的T→G和第654个碱基处的C→T,均为沉默突变.通过对基因型与产奶量的关系进行分析后发现,伊犁马AA基因型的日均产奶量较AB基因型高850 g/d (P <0.05).马PRL基因外显子5上的突变可能是影响马产奶性能的重要位点.

  19. Effect of ghrelin and thyrotropin-releasing hormone on prolactin secretion in normal women.

    Messini, C I; Dafopoulos, K; Chalvatzas, N; Georgoulias, P; Anifandis, G; Messinis, I E


    It is known that ghrelin stimulates the secretion of prolactin in women. The aim of this study was to examine the effect of exogenous thyrotropin-releasing hormone (TRH) on ghrelin-induced prolactin release. Ten healthy normally cycling women were studied in four menstrual cycles. The women were injected intravenously in late follicular phase (follicle size 16-17 mm) with a single dose of normal saline (cycle 1), ghrelin (1 microg/kg) (cycle 2), thyrotropin-releasing hormone (200 microg) (cycle 3), and ghrelin plus thyrotropin-releasing hormone (cycle 4). Blood samples in relation to saline or drugs injection (time 0) were taken at -15, 0, 15, 30, 45, 60, 75, 90, and 120 min. The prolactin and growth hormone responses were assessed. After ghrelin administration (cycles 2 and 4), plasma ghrelin, serum prolactin, and growth hormone levels increased rapidly, peaking at 15-30 min (psecretion markedly (pGhrelin induced a smaller prolactin increase than thyrotropin-releasing hormone (pghrelin and thyrotropin-releasing hormone induced a similar increase in prolactin levels as with thyrotropin-releasing hormone alone. No changes in growth hormone and prolactin levels were seen after saline injection. These results demonstrate that the stimulating effect of ghrelin on prolactin secretion is not additive with that of thyrotropin-releasing hormone.

  20. Increased serum interleukin-22 levels in patients with PRL-secreting and non-functioning pituitary macroadenomas.

    Cannavo, S; Ferrau, F; Cotta, O R; Saitta, S; Barresi, V; Cristani, M T; Saija, A; Ruggeri, R M; Trimarchi, F; Gangemi, S


    Cytokines' involvement in tumorigenesis has been hypothesized. Interleukin-22 (IL-22) is implicated in proliferative and anti-apoptotic pathways via its receptor IL-22R. Its role in pituitary adenomas has never been investigated. Twenty-seven patients with pituitary macroadenomas (PA, 21 males, mean age 53.8 ± 14.4 years) and 30 healthy controls (19 males, mean age 50.4 ± 8.4 years) were enrolled. Out of 27 PA patients, 17 had a non-functioning tumour (NFPA) and 10 a PRL-secreting adenoma (PRL-oma). Serum IL-22 levels were measured in both patients and controls. Immunohistochemical (IHC) tumoral IL-22R expression was evaluated in 10 patients with NFPA and 4 with PRL-oma. IL-22 levels were significantly higher in PA patients than in controls [32.47 (11.29-70.12) vs. 5.58 (0.19-21.46) pg/mL, p PRL-oma patients had significantly higher IL-22 levels than NFPA patients [37.18 (14.82-70.12) vs. 21.29 (11.29-56) pg/mL, p = 0.039]. IHC revealed a strong IL-22R staining in 100 % of PRL-omas and 60 % of NFPAs. We provide the first evidence of increased serum IL-22 levels in patients with pituitary macroadenoma, especially in PRL-omas, regardless of tumor size and/or degree of pituitary function impairment. We also demonstrated the expression of IL22R in all PRL-omas and in 60 % of NFPAs.

  1. Neuroendocrine regulation of prolactin secretion during late pregnancy: easing the transition into lactation.

    Andrews, Z B


    Prolactin is an anterior pituitary hormone critical for maintaining pregnancy and lactation. Under normal conditions, prolactin secretion is tightly regulated by inhibitory dopaminergic neuronal systems within the mediobasal hypothalamus in a process known as short-loop negative feedback. This review focuses on neuroendocrine adaptations to prolactin negative feedback during late pregnancy. It is suggested that, in terms of prolactin regulation, late pregnancy is a transition period into lactation because many of the neuroendocrine adaptations promoting hyperprolactinemia in lactation develop during late pregnancy. As a consequence, the maternal brain is geared to provide unrestrained prolactin release critical for milk production, maternal care and thus survival of the offspring before parturition. The mechanisms responsible for these changes are discussed.

  2. Expression of 17?-hydroxysteroid dehydrogenase and the effects of LH, FSH and prolactin on oestrone and 17?-oestradiol secretion in the endometrium of pigs during early pregnancy and the oestrous cycle.

    Wojciechowicz, B; Kotwica, G; Zglejc, K; Waszkiewicz, E; Franczak, A


    The endometrium of pregnant and cyclic pigs is a source of oestrone (E1) and 17β-oestradiol (E2). However, the roles of LH, FSH and prolactin (PRL) as regulators of endometrial steroidogenesis, and the presence of 17β-hydroxysteroid dehydrogenase (17β-HSD) in the porcine endometrium, remain unknown. Therefore, in the present study we examined 17β-HSD expression and the effects of LH, FSH and PRL on E1 and E2 release in vitro in endometrial explants harvested from gravid pigs on Days 10-11 (embryo migration within the uterus), 12-13 (maternal recognition of pregnancy) and 15-16 (beginning of implantation) and compared them with results obtained in non-gravid pigs. The results show that: (1) endometrial 17β-HSD activity was decreased on Days 15-16 in pregnant and cyclic pigs compared with the preceding days; (2) LH, FSH and PRL increased endometrial E1 secretion on Days 10-11 and 15-16 of pregnancy and on Days 12-13 and 15-16 of the oestrous cycle; and (3) LH, FSH and PRL increased endometrial E2 secretion on Days 15-16 of pregnancy and during the days studied in the oestrous cycle. In conclusion, data suggest that LH, FSH and PRL affect endometrial secretion of estrogens in pigs.


    狄安稞; 单惠敏; 黄曼影; 许荣焜


    实验应用雄性SD大鼠,皮下埋植内置10 mg雌二醇(E2)硅胶管3个月致垂体催乳素(prolactin,PRL)瘤后,取PRL瘤细胞进行体外原代培养,并应用原位杂交方法,研究不同剂量的胃泌素释放肽(gastrin-releasing peptide,GRP)和血管活性肠肽(vasoactive intestinal polypeptide,VIP)以及E2对离体培养的垂体PRL瘤细胞PRL基因转录的影响.结果如下:GRP,VIP分别与PRL瘤细胞孵育24 h后,10-8mol/L,10-7mol/L的GRP均不影响PRL瘤细胞内PRL mRNA水平,但10-6mol/L的GRP可使胞内PRL mRNA水平下降20%(P<0.05).在本实验所采用的浓度范围内,VIP均可升高PRL瘤细胞内PRL mRNA水平,10-8mol/L,10-7mol/L,10-8mol/L的VIP分别使胞内PRLmRNA升高为对照组的1.60,2.10,2.21倍(P<0.05).三种浓度的E2分别与PRL瘤细胞孵育48 h后,10-8 mol/L E2不影响胞内PRL mRNA水平,但10-7mol/L,10-8mol/L的E2则分别可使胞内PRL mRNA升高为对照组的2.80,2.92倍(P<0.05).上述结果表明:GRP和VIP可能分别抑制和增强由E2诱致的垂体PRL瘤细胞PRL基因的转录;一定浓度的E2可能直接涉及E2诱发垂体PRL瘤时伴高PRL血症.

  4. Treatment of Aggressive Prolactin-Secreting Pituitary Adenomas with Adjuvant Temozolomide Chemotherapy: A Review.

    Moisi, Marc; Cruz, Aurora S; Benkers, Tara; Rostad, Steven; Broyles, Frances Broyles; Yuen, Kevin; Mayberg, Marc


    Most prolactin-secreting pituitary adenomas demonstrate slow growth and are effectively managed with medical/surgical therapy. Rarely, these tumors can behave aggressively with rapid growth and invasion of local tissues, and are refractory to medical, surgical, or radio-surgical therapies. We report a case of a prolactin-secreting adenoma in a young woman, which became progressively aggressive and refractory to usual treatment modalities, but responded to treatment with the chemotherapeutic agent temozolomide. In addition, we review the literature for treatment of refractory adenomas with temozolomide. The clinical and pathologic characteristics of aggressive prolactin-secreting adenomas are reviewed, as well as their response to dopamine agonists, surgery, radiotherapy, and chemotherapy.

  5. New insights in prolactin: pathological implications.

    Bernard, Valérie; Young, Jacques; Chanson, Philippe; Binart, Nadine


    Prolactin is a hormone that is mainly secreted by lactotroph cells of the anterior pituitary gland, and is involved in many biological processes including lactation and reproduction. Animal models have provided insights into the biology of prolactin proteins and offer compelling evidence that the different prolactin isoforms each have independent biological functions. The major isoform, 23 kDa prolactin, acts via its membrane receptor, the prolactin receptor (PRL-R), which is a member of the haematopoietic cytokine superfamily and for which the mechanism of activation has been deciphered. The 16 kDa prolactin isoform is a cleavage product derived from native prolactin, which has received particular attention as a result of its newly described inhibitory effects on angiogenesis and tumorigenesis. The discovery of multiple extrapituitary sites of prolactin secretion also increases the range of known functions of this hormone. This Review summarizes current knowledge of the biology of prolactin and its receptor, as well as its physiological and pathological roles. We focus on the role of prolactin in human pathophysiology, particularly the discovery of the mechanism underlying infertility associated with hyperprolactinaemia and the identification of the first mutation in human PRLR.

  6. Prolactin has a pathogenic role in systemic lupus erythematosus.

    Jara, Luis J; Medina, Gabriela; Saavedra, Miguel A; Vera-Lastra, Olga; Torres-Aguilar, Honorio; Navarro, Carmen; Vazquez Del Mercado, Monica; Espinoza, Luis R


    Prolactin, a 23-kDa peptide hormone, is produced by the anterior pituitary gland and extrapituitary sites including the immune cells. Prolactin (PRL) participates in innate and adaptive immune response. PRL stimulates the immune cells by binding to receptor (PRL-R). Binding of PRL to its receptor activates the Janus kinase-signal transducer (JAK-STAT). Activation of these cascades results in endpoints such as immunoestimulator and immunosupressor action. Prolactin belongs to the network of immune-neuroendocrine interaction. Hyperprolactinemia has been found in patients with systemic lupus erythematosus (SLE), and new evidence has confirmed a significant correlation between serum PRL levels and disease activity. PRL participates in activation of SLE during pregnancy and in pathogenesis of lupus nephritis, neuropsychiatric, serosal, hematologic, articular, and cutaneous involvement. Hyperprolactinemia was associated with increase IgG concentrations, anti-DNA antibodies, immune complex, glomerulonephritis, and accelerated mortality in murine lupus. Bromocriptine, a dopamine analog that suppresses PRL secretion, was associated with decreased lupus activity, prolonged lifespan, and restoration of immune competence in experimental model. In clinical trials, bromocriptine and derivative drugs showed beneficial therapeutic effect in treating human lupus, including pregnancy. Taken together, clinical and experimental results leave little doubt that PRL indeed contributes to the pathogenesis and clinical expression of SLE.

  7. Use of prolactin receptor antagonist to better understand prolactin regulation of pituitary homeostasis.

    Ferraris, Jimena; Bernichtein, Sophie; Pisera, Daniel; Goffin, Vincent


    The anterior pituitary is permanently regulated by processes of apoptosis and proliferation in order to maintain tissue homeostasis. Several factors have been implicated in this regulation and lately, prolactin (PRL) has been included into that list. However, since PRL is secreted by anterior pituitary lactotropes, the actual outcome of its autocrine/paracrine actions on pituitary cells has remained difficult to assess. The availability of the pure PRL receptor antagonist Del1-9-G129R-hPRL has been helpful to circumvent this problem. While PRL has been traditionally associated with increased cell proliferation, recent studies revealed that this hormone actually induces apoptosis and decreases proliferation of anterior pituitary cells, by mechanisms involving the PRL receptor. The aim of this short review is to overview our current understanding of the regulation of pituitary homeostasis by PRL. Moreover, studies involving Del1-9-G129R-hPRL have helped anticipate to what extent future treatments involving PRL receptor inhibitors may interfere with processes regulated by PRL at the central level. © 2013 S. Karger AG, Basel.

  8. Direct effect of PGF2α pulses on PRL pulses, based on inhibition of PRL or PGF2α secretion in heifers.

    Pinaffi, F L V; Pugliesi, G; Hannan, M A; Silva, L A; Beg, M A; Ginther, O J


    The relationships between PRL and PGF(2α) and their effect on luteolysis were studied. Heifers were treated with a dopamine-receptor agonist (bromocriptine; Bc) and a Cox-1 and -2 inhibitor (flunixin meglumine [FM]) to inhibit PRL and PGF(2α), respectively. The Bc was given (Hour 0) when ongoing luteolysis was indicated by a 12.5% reduction in CL area (cm(2)) from the area on Day 14 postovulation, and FM was given at Hours 0, 4, and 8. Blood samples were collected every 8-h beginning on Day 14 until Hour 48 and hourly for Hours 0 to 12. Three groups of heifers in ongoing luteolysis were used: control (n = 7), Bc (n = 7), and FM (n = 4). Treatment with Bc decreased (P PRL concentrations averaged over Hours 1 to 12. During the greatest decrease in PRL (Hours 2-6), LH concentrations were increased. Progesterone concentrations averaged over hours were greater (P PRL concentrations were reduced. Concentrations of PGFM were not reduced in the Bc group, despite the reduction in PRL. Results supported the hypothesis that a decrease (12.5%) in CL area (cm(2)) is more efficient in targeting ongoing luteolysis (63%) than using any day from Days 14 to ≥ 19 (efficiency/day, 10-24%). The hypothesis that PRL has a role in luteolysis was supported but was confounded by the known positive effect of LH on progesterone. The hypothesis was supported that the synchrony of PGFM and PRL pulses represents a positive effect of PGF(2α) on PRL, rather than an effect of PRL on PGF(2α).

  9. Prolactin secretion and ovarian function in cycling and non-cycling African female elephants (Loxodonta africana).

    Yamamoto, Yuki; Yamamoto, Tatsuya; Watanabe, Gen; Yuto, Natsuki; Keio, Megumi; Narushima, Etsuo; Katayanagi, Masayuki; Nakao, Risa; Morikubo, Syu; Sakurai, Yuko; Kaneko, Mikako; Kaewmanee, Saroch; Taya, Kazuyoshi


    Reproduction of captive elephants in zoos has shown a low fecundity and requires improvement. One of the reasons for low fecundity is ovarian dysfunction in many female elephants. To investigate whether prolactin has a correlation with ovarian function in female elephants, the serum concentrations of prolactin, progesterone and estradiol-17beta in four African female elephants (one cycling female and three non-cycling female elephants) were measured. Cyclic patterns of prolactin and estradiol-17beta were observed in the cycling female elephant, which tended to be high during the follicular phase and low during the luteal phase. On the other hand, a cyclic pattern of prolactin was not observed in the non-cycling female elephants. One of the three non-cycling females (Mako) had developed breasts and showed significantly higher average levels of prolactin than the other female elephants. These results suggested that high concentrations of circulating estradiol-17beta during the follicular phase stimulated prolactin secretion. They also suggested that hyperprolactinemia in Mako was one of the causes of the developed mammary glands and ovarian dysfunction.

  10. Phosphorylated human prolactin (S179D-hPRL) is a potent anti-angiogenic hormone in vitro and in vivo; Prolactina humana pseudofosforilada (S179D-hPRL) e um potente fator anti-angiogenico in vitro e in vivo

    Ueda, Eric Kinnosuke Martins


    S179D-prolactin (hPRL) is an experimentally useful mimic of naturally phosphorylated human prolactin. S179D-hPRL, but not unmodified PRL, was found to be anti-angiogenic in both the chorioallantoic membrane and corneal assays. Further investigation using human endothelial in vitro models showed reduced cell number, reduced tubule formation in Matrigel, and reduced migration and invasion, as a function of treatment with S179D-hPRL. Analysis of growth factors in human endothelial cells in response to S179D-hPRL showed a decreased expression or release of endogenous PRL, heme-oxygenase-1, basic fibroblast growth factor (bFGF), angio genin, epidermal growth factor and vascular endothelial growth factor and an increased expression of inhibitors of matrix metallo proteases. S179D-hPRL also blocked signaling from bFGF in these cells. We conclude that this molecular mimic of a pituitary hormone is a potent anti-angiogenic protein, partly as a result of its ability to reduce utilization of several well-established endothelial autocrine growth loops, partly by its ability to block signaling from bFGF and partly because of its ability to decrease endothelial migration. We also examined the influence of S179D-hPRL on apoptosis in human endothelial cells, using procaspase-8 as a marker of the extrinsic pathway, and cytochrome C release as a marker of the intrinsic pathway. Both pathways converge at caspase-3, which cleaves DNA fragmentation factor (DFF45). A 3-day incubation with 50 ng/ml S179D-hPRL quadrupled the early apoptotic cells; this effect was doubled at 100 ng/ml and maximal at 500 ng/ml. DFF45 and pro-caspase 8 cleavage were detectable at 100 ng/ml. Cytochrome C, however, was unaffected until 500 ng/ml. p21 increased at 100 ng/ml, whereas a change in p53 activity required both triple the time and 500 ng/ml. p21 promoter activity was maximal at 50 ng/ml, whereas 500 ng/ml were required to see a significant change in the Bax promoter (a measure of p53 activity). As

  11. Pharmacological activation of the GABAergic system does not affect GH and PRL release in acromegaly.

    Orio, F; Iovino, M; Monteleone, P; Agrusta, M; Steardo, L; Lombardi, G


    An extensive hypothalamic neurotransmitter impairment has been proposed in acromegaly. However, at the moment, the hypothalamic GABAergic system has been little investigated in this disorder. Since GABA has been shown to modulate growth hormone (GH) and prolactin (PRL) secretion in human subjects, it seemed reasonable to investigate hypothalamic GABAergic functioning through the assessment of basal GH and PRL responses to pharmacological activation of this system. 800 mg of sodium valproate (SV), a drug with GABA facilitating properties, were administered orally to 7 acromegalic patients and 9 healthy volunteers. Blood samples were collected before and after the drug administration for the measurement of plasma GH and PRL levels. SV induced a clear-cut rise in basal GH and a decrease in basal PRL in healthy subjects, but it did not induce any change in the basal levels of these hormones in acromegalics. These results suggest that the response of GH and PRL to SV in acromegaly is qualitatively different from normal controls.

  12. Potentiation of prolactin secretion following lactotrope escape from dopamine action. II. Phosphorylation of the alpha(1) subunit of L-type, voltage-dependent calcium channels.

    Hernández, M E; del Mar Hernández, M; Díaz-Muñoz, M; Clapp, C; de la Escalera, G M


    Modulation of Ca(2+) channels has been shown to alter cellular functions. It can play an important role in the amplification of signals in the endocrine system, including the pleiotropically regulated pituitary lactotropes. Prolactin (PRL) secretion is tonically inhibited by dopamine (DA), the escape from which triggers acute episodes of hormone secretion. The magnitude of these episodes is explained by a potentiation of the PRL-releasing action of secretagogues such as thyrotropin-releasing hormone (TRH). While the mechanisms of this potentiation are not fully understood, it is known to be mimicked by the dihydropyridine, L-type Ca(2+) channel agonist Bay K 8644 and blocked by nifedipine and methoxyverapamil. The potentiation is also blocked by inhibitors of cyclic AMP-dependent protein kinase and protein kinase C. We recently described that the escape from tonic actions of DA results in increased macroscopic Ca(2+) currents in GH(4)C(1) lactotropic clonal cells transfected with a cDNA encoding the long form of the human D(2)-DA receptor. Here we show that the withdrawal from DA potentiates the PRL-releasing action of TRH in GH(4)C(1)/D(2)-DAR cells to the same extent as in enriched lactotropes in primary culture. In both experimental models a low density of dihydropyridine receptors was shown by (+)-[(3)H]PN200-110 binding. Photoaffinity labelling with the dihydropyridine [(3)H]azidopine revealed a protein consistent with the alpha(1) subunit of L-type Ca(2+) channels of 165-170 kDa. In both experimental models, the facilitation of TRH action triggered by the escape from DA was correlated with an enhanced rate of phosphorylation of this putative alpha(1) subunit, the nature of which was further supported by immunoprecipitation with selective antibodies directed against the alpha(1C) and alpha(1D) subunit of voltage-gated calcium channels. We propose that PKA- and PKC-dependent phosphorylation of the alpha(1) subunit of high voltage activated, L-type Ca(2

  13. The regulation of Rasd1 expression by glucocorticoids and prolactin controls peripartum maternal insulin secretion

    Lellis-Santos, Camilo; Sakamoto, Luciano H; Bromati, Carla R.; Nogueira, Tatiane Cristina; Leite, Adriana R.; Yamanaka, Tatiana S.; Kinote, Andrezza; Anhê, Gabriel F; Bordin, Silvana


    The transition from gestation to lactation is characterized by a robust adaptation of maternal pancreatic β-cells. Consistent with the loss of β-cell mass, glucose-induced insulin secretion is down-regulated in the islets of early lactating dams. Extensive experimental evidence has demonstrated that the surge of prolactin is responsible for the morphofunctional remodeling of the maternal endocrine pancreas during pregnancy, but the precise molecular mechanisms by which this phenotype is rapid...

  14. Prolactin as an autocrine/paracrine factor in breast tissue.

    Clevenger, C V; Plank, T L


    The neuroendocrine hormone prolactin (PRL) stimulates breast growth and differentiation during puberty, pregnancy, and lactation. Despite extensive and convincing data indicating that PRL significantly contributes to the pathogenesis and progression of rodent mammary carcinoma, parallel observations for human breast cancer have not been concordant. In particular, the therapeutic alteration of somatolactogenic hormone levels has not consistently altered the course of human breast cancer. Recent data, however, suggest that extra-pituitary tissues are capable of elaborating PRL; indeed, the observation of sustained serum levels of PRL in post-hypophysectomy patients supports this hypothesis. Proof of an autocrine/paracrine loop for PRL within normal and malignant human breast tissues requires that the following three criteria be met: (1) PRL must be synthesized and secreted within mammary tissues; (2) the receptor for PRL (PRLR) must be present within these tissues; and, (3) proliferative responses to autocrine/paracrine PRL must be demonstrated. These criteria have now been fulfilled in several laboratories. With the demonstration of a PRL autocrine/paracrine loop in mammary glands, the basis for the ineffective treatment of human breast cancer by prior endocrine-based anti-somatolactogenic therapies is evident. These findings provide the precedent for novel therapeutic strategies aimed at interrupting the stimulation of breast cancer growth by PRL at both endocrine and autocrine/paracrine levels.

  15. Prolactin and 16K prolactin stimulate release of vasopressin by a direct effect on hypothalamo-neurohypophyseal system.

    Mejía, Salvador; Torner, Luz M; Jeziorski, Michael C; Gonzalez, Carmen; Morales, Miguel A; de la Escalera, Gonzalo Martín; Clapp, Carmen


    Activity of the magnocellular neurons that synthesize vasopressin and oxytocin in the paraventricular and supraoptic nuclei of the hypothalamus can be modulated by local release of neuromediators within the nuclei. Among the bioactive peptides that may play autocrine or paracrine roles in this system is prolactin (PRL). Paraventricular and supraoptic neurons express PRL mRNA and contain and secrete PRL-like proteins of 23 and 14 kDa. We investigated the localization of PRL receptors in vasopressinergic and oxytocinergic magnocellular neurons using dual-label immunofluorescence. The results demonstrate that both vasopressin- and oxytocin-immunoreactive cells of the paraventricular and supraoptic nuclei contain the PRL receptor. In addition, we investigated the possible regulation of vasopressin secretion by PRL using hypothalamo-neurohypophyseal explants in culture. The results show that PRL and a 16 kDa N-terminal fragment of the hormone that is analogous to the neurohypophyseal 14-kDa PRL fragment stimulate the release of vasopressin. Together, these findings support the hypothesis that vasopressinergic and oxytocinergic neurons of the magnocellular secretory system are regulated directly by various isoforms of PRL via autocrine/paracrine mechanisms.

  16. Initial study on the possible mechanisms involved in the effects of high doses of perfluorooctane sulfonate (PFOS) on prolactin secretion.

    Salgado, R; Pereiro, N; López-Doval, S; Lafuente, A


    Perfluorooctane sulfonate (PFOS) is a fluorinated organic compound. This chemical is neurotoxic and can alter the pituitary secretion. This is an initial study aimed at knowing the toxic effects of high doses of PFOS on prolactin secretion and the possible mechanisms involved in these alterations. For that, adult male rats were orally treated with 3.0 and 6.0 mg of PFOS/kg body weight (b.w.)/day for 28 days. At the end of the treatment, the serum levels of prolactin and estradiol as well as the concentration of dopamine, 3,4-dihydroxyphenylacetic acid (DOPAC), homovanillic acid (HVA) and gamma-aminobutyric acid (GABA) were quantified in the anterior and in the mediobasal hypothalamus. PFOS, at the administered doses, reduced prolactin and estradiol secretion, increased the concentration of dopamine and GABA in the anterior hypothalamus, and decreased the ratios DOPAC/dopamine and HVA/dopamine in this same hypothalamic area. The outcomes reported in this study suggest that (1) high doses of PFOS inhibit prolactin secretion in adult male rats; (2) only the periventricular-hypophysial dopaminergic (PHDA) neurons seem to be involved in this inhibitory effect but not the tuberoinfundibular dopaminergic (TIDA) and the tuberohypophysial dopaminergic (THDA) systems; (3) GABAergic cells from the paraventricular and supraoptic nuclei could be partially responsible for the PFOS action on prolactin secretion; and finally (4) estradiol might take part in the inhibition exerted by elevated concentration of PFOS on prolactin release.

  17. Evidence for hepatic involvement in the regulation of amphibian development by prolactin.

    Delidow, B C; Baldocchi, R A; Nicoll, C S


    Hormonal control of amphibian development involves thyroid hormones (TH), which promote metamorphosis, and prolactin (PRL), which antagonizes the effects of TH and promotes larval growth. Although the liver is not considered to be a regulator of developmental processes such as metamorphosis, it secretes a PRL-synergizing factor (synlactin) in response to PRL. We explored the possibility that the liver may participate in the antimetamorphic actions of PRL in Rana catesbeiana. Bullfrog tadpoles, in which release of endogenous PRL was suppressed by injections of bromocryptine to induce metamorphic changes including tail regression, received hormone-containing implants in various sites. PRL implants in the spleen to deliver hormone directly to the liver via the hepatic portal drainage not only prevented tail regression but actually caused a substantial increase in the height of the tail fin. PRL implanted in other sites or GH implanted in the spleen was much less effective. The liver of animals with intrasplenic PRL implants secreted more synlactin in vitro than that of tadpoles with subcutaneous PRL implants. Young grass frogs were injected with ovine (o) GH or oPRL to determine effects on hepatic synlactin secretion. Although the GH stimulated body growth it did not induce the liver to secrete synlactin. By contrast, PRL treatment did stimulate hepatic secretion of synlactin without stimulating body growth. These results indicate that the liver of pre- and postmetamorphic animals can be stimulated by PRL to secrete synlactin. Furthermore, the antimetamorphic actions of PRL in tadpoles appears to be mediated, at least in part, by an action on the liver. Synlactin may mediate this hepatic effect.




    The TIDA neurons, which constitute part of the arcuate nucleus-ME complex, play an important inhibitory role in the regulation of the PRL secretion from the adenohypophysis. To simultaneously study the release of DA from the TIDA neurons and the PRL secretion from the adenohypophysis in awake rats,

  19. The sensitivity of growth hormone and prolactin secretion to the somatostatin analogue SMS 201-995 in patients with prolactinomas and acromegaly.

    Lamberts, S W; Zweens, M; Klijn, J G; van Vroonhoven, C C; Stefanko, S Z; Del Pozo, E


    The somatostatin analogue SMS 201-995 has recently been shown to be effective in suppressing GH secretion in most acromegalic patients. In the present study it was investigated whether PRL release in prolactinoma and acromegalic patients might also be sensitive to SMS 201-995 and whether co-secretion of PRL in acromegaly plays a role in determining the sensitivity of GH secretion to SMS 201-995. The s.c. administration of 50 micrograms SMS 201-995 did not affect high plasma PRL levels in four microprolactinoma patients. Therapy of one of these patients for 3 d with 50 micrograms three times a day also did not affect PRL levels. The single administration of 50 micrograms SMS 201-995 in 22 acromegalic patients lowered plasma GH levels for 2-6 h to less than 5 micrograms/l in 14 patients and to less than 50% of control values in 16 patients. In 18 of these 22 patients the immunohistochemical picture of the pituitary tumour was known. Eleven patients had pure GH-containing tumours and in seven patients there were mixed GH/PRL-containing tumours. In two of these latter patients there was evidence for GH and PRL being secreted by the same tumour cells. The sensitivity of GH secretion to SMS 201-995 did not differ between the patients with pure GH or mixed GH/PRL-containing adenomas. Plasma PRL levels were not affected by SMS 201-995 in the patients with pure GH-secreting tumours, but were significantly suppressed in four of the seven patients with mixed GH/PRL containing tumours. Chronic treatment for 16 weeks of one patient with a mixed GH/PRL-containing tumour with SMS 201-995 (100 micrograms three times a day) resulted in normalization of both the increased GH and PRL levels. It is concluded that SMS 201-995 does not affect tumorous PRL secretion in patients with pure prolactinomas. In acromegalic patients with mixed GH/PRL-containing tumours PRL secretion in some patients is sensitive to SMS 201-995, making these patients good candidates for chronic treatment with

  20. Pindolol pretreatment blocks stimulation by meta-chlorophenylpiperazine of prolactin but not cortisol secretion in normal men.

    Meltzer, H Y; Maes, M


    Previous reports from this laboratory have shown that pindolol, a partial serotonin1A receptor agonist, inhibited prolactin, but not cortisol secretion induced by administration of the serotonin (5-HT) precursor L-5-hydroxytryptophan or the direct-acting 5-HT2A/5HT2C receptor agonist MK-212. The findings suggest additive or interactive effects of 5-HT1A and 5-HT2A/5-HT2C receptors in modulating 5-HT-related prolactin, but not cortisol, responsivity. To examine further the role of 5-HT1A and 5-HT2A/5-HT2C receptors in prolactin and cortisol secretion in healthy men, the effects of meta-chlorophenylpiperazine (mCPP), a potent 5-HT receptor agonist, on the above hormones were studied in eight healthy men with and without pindolol pretreatment. It has previously been demonstrated that ketanserin, a 5-HT2A antagonist, and ritanserin, a 5-HT2A/5-HT2C antagonist, block the prolactin and attenuate the hypothalamic-pituitary-adrenal axis responses to mCPP in man or rodents. Administration of mCPP induced a significant increase in plasma concentrations of prolactin and cortisol. The mCPP-induced prolactin concentrations were significantly blocked by pretreatment with pindolol, whereas mCPP-stimulated cortisol levels were not diminished by pindolol pretreatment. Thus, mCPP-induced prolactin secretion appears to require the availability of both 5-HT2C and 5-HT1A receptor activation, since blockade of either of these receptors may diminish the mCPP-induced prolactin response. Cortisol secretion stimulated by mCPP may occur following 5-HT2C receptor stimulation in the presence of 5-HT1A receptor blockade.

  1. Bovine lactotroph cultures for the study of prolactin synthesis functions.

    Wang, Jianfa; Yang, Zhanqing; Fu, Shoupeng; Liu, Bingrun; Wu, Dianjun; Wang, Wei; Sun, Dongbo; Wu, Rui; Liu, Juxiong


    The aim of this study was to establish a bovine anterior pituitary-derived lactotroph (BAPDL) line that expresses prolactin (PRL) in vitro to study the mechanisms of bovine PRL synthesis and secretion. Immunohistochemistry assay of PRL in the newborn calves' anterior pituitary glands showed that most lactotrophs were located within the superior border of the lateral wings of the anterior pituitary. Tissues of the superior border of the lateral wings of the anterior pituitary were dispersed and cultured in Dulbecco's modified Eagle's medium (DMEM) supplemented with 10% fetal bovine serum (FBS). The limiting dilution method was used to establish BAPDL from single cell clone. BAPDL cells constantly expressed mRNAs for PRL and pituitary-specific transcription factor 1 (Pit-1) gene and grew steadily and rapidly in the DMEM supplemented with 10% FBS. PRL immunoreactivity was present in BAPDL at passage 20. The concentration of bovine PRL in BAPDL at passage 20 culture supernatant was decreased to below 35% compared with that in BAPDL at passage 1. The effects of human epidermal growth factor (hEGF) and dopamine (DA) on the expression and secretion of PRL in BAPDL at passage 4 were also investigated. The results are consistent with those of previous studies. Thus, it can be used successfully for studying the mechanisms of stimuli regulating PRL synthesis and release.

  2. Cysteamine, zinc, and thiols modify detectability of rat pituitary prolactin: a comparison with effects on bovine prolactin suggests differences in hormone storage

    Jacobs, L.S.; Lorenson, M.Y.


    Little is known about the structure of prolactin (PRL) within secretory granules. Evidence from our previous studies in bovine tissue preparations suggests that control of secretion may reside, in part, in the conversion of storage hormone to releasable PRL. The conversion can be monitored by measuring changes in immunodetectability since the oligomeric, storage form is poorly recognized by antisera raised against monomeric PRL. Since many investigators use rats to study the secretory process and changes in detectability of rat pituitary PRL occur during lactation (depletion-transformation), we undertook the present immunodetectability studies to gain insight into the storage structure of rat (r) PRL. Cysteamine and zinc inhibited tissue PRL immunoassayability in male rat pituitary homogenates and also in partially purified secretory granules as they had inhibited bovine (b) PRL; however, zinc inhibited the rodent hormone less potently than the bovine. In vitro incubation of rat tissue samples without additions resulted in increases in rPRL detectability of up to 84% after 180 minutes; such incubation of bovine samples had no significant effect. A striking additional difference between the species was that exposure to reduced glutathione (GSH), cysteine, homocysteine, mercaptoethanol, and dithiothreitol inhibited rPRL by up to 44%. This compared to thiol stimulation of bPRL by as much as 450%. The inhibitory GSH effect on rPRL was abolished when 0.5% sodium dodecyl sulfate (SDS) was included; in contrast, the stimulatory GSH effect on bPRL did not change with added SDS. SDS alone had no effect on rat homogenate PRL, and only increased rat granule rPRL by 23% compared to its ability to increase bPRL assayability by 44%.

  3. Tumour necrosis factor alpha, interferon gamma and substance P are novel modulators of extrapituitary prolactin expression in human skin.

    Langan, Ewan A; Vidali, Silvia; Pigat, Natascha; Funk, Wolfgang; Lisztes, Erika; Bíró, Tamás; Goffin, Vincent; Griffiths, Christopher E M; Paus, Ralf


    Human scalp skin and hair follicles (HFs) are extra-pituitary sources of prolactin (PRL). However, the intracutaneous regulation of PRL remains poorly understood. Therefore we investigated whether well-recognized regulators of pituitary PRL expression, which also impact on human skin physiology and pathology, regulate expression of PRL and its receptor (PRLR) in situ. This was studied in serum-free organ cultures of microdissected human scalp HFs and skin, i.e. excluding pituitary, neural and vascular inputs. Prolactin expression was confirmed at the gene and protein level in human truncal skin, where its expression significantly increased (p = 0.049) during organ culture. There was, however, no evidence of PRL secretion into the culture medium as measured by ELISA. PRL immunoreactivity (IR) in female human epidermis was decreased by substance P (p = 0.009), while neither the classical pituitary PRL inhibitor, dopamine, nor corticotropin-releasing hormone significantly modulated PRL IR in HFs or skin respectively. Interferon (IFN) γ increased PRL IR in the epithelium of human HFs (p = 0.044) while tumour necrosis factor (TNF) α decreased both PRL and PRLR IR. This study identifies substance P, TNFα and IFNγ as novel modulators of PRL and PRLR expression in human skin, and suggests that intracutaneous PRL expression is not under dopaminergic control. Given the importance of PRL in human hair growth regulation and its possible role in the pathogenesis of several common skin diseases, targeting intracutaneous PRL production via these newly identified regulatory pathways may point towards novel therapeutic options for inflammatory dermatoses.

  4. Diurnal secretion profiles of growth hormone, thyrotrophin and prolactin in Parkinson's disease.

    Aziz, N A; Pijl, H; Frölich, M; Roelfsema, F; Roos, R A C


    Recently, a massive loss of both hypocretin and melanin-concentrating hormone (MCH) neurones was found in the hypothalamus of Parkinson's disease (PD) patients. Because both hypocretin and MCH play a key role in the regulation of sleep, energy homeostasis and autonomic function, partly by modulation of the somatotrophic, thyrotrophic and lactotrophic axes, neuroendocrine dysregulation may contribute to some of the non-motor features of PD. In eight de novo, medication-free PD patients and eight age-, sex- and body mass index-matched controls, we measured serum levels of growth hormone (GH), thyroid-stimulating hormone (TSH) and prolactin every 10 min for 24 h. Auto-deconvolution, cosinor and approximate entropy analysis were applied to quantify GH, TSH and prolactin secretion rates, diurnal rhythmicity, as well as regularity of hormone release. Sleep was polygraphically-recorded throughout the night. Total 24-h secretion of GH (191 ± 31 versus 130 ± 39 mU/l/24 h), TSH (38 ± 9 versus 36 ± 2 mU/l/24 h) and prolactin (102 ± 14 versus 116 ± 17 μg/l/24 h), as well as their diurnal rhythmicity and regularity of release, were not significantly different between PD patients and controls (all P ≥ 0.12). Fasting levels of insulin-like growth factor-1 were also unaltered in PD patients. However, free thyroxine (T(4) ) levels were significantly higher in PD patients compared to controls (16.19 ± 0.80 versus 13.88 ± 0.40 pmol/l; P = 0.031). In PD patients, prolactin levels were related to disease duration (r = 0.76, P = 0.028), whereas both GH (r = -0.91, P = 0.002) and free T(4) (r = -0.71, P = 0.050) levels correlated inversely with body fat content. Apart from a mild increase in free T(4) levels, we found no indications for altered somatotrophic, thyrotrophic and lactotrophic axes activity in early-stage PD patients.

  5. Vasoinhibins, N-terminal mouse prolactin fragments, participate in mammary gland involution.

    Ishida, Michiyo; Maehara, Midori; Watanabe, Tsukasa; Yanagisawa, Yu; Takata, Yukiko; Nakajima, Ryojun; Suzuki, Mika; Harigaya, Toshio


    Vasoinhibins are a family of peptides that act on endothelial cells to suppress angiogenesis and promote apoptosis-mediated vascular regression. Vasoinhibins include the N-terminal fragments from prolactin (PRL), GH, and placental lactogen. One of the vasoinhibins, the N-terminal PRL fragment of 16 kDa, is generated by the lysosomal representative protease cathepsin D (Cath D). Because the normal growth and involution of the mammary gland (MG) are profoundly affected by the expansion and regression of blood vessels and also because PRL stimulates the growth and differentiation of MG, we proposed that intact PRL produced during lactation contributes to MG angiogenesis and increased blood flow, whereas during involution, the N-terminal PRL fragment would have proapoptotic effects on mammary epithelial cells (MECs). Therefore, we investigated the production of the N-terminal PRL fragment and its direct effect on the MG. Mouse PRL (mPRL) was proteolytically cleaved by Cath D between amino acids 148 and 149. N-terminal PRL fragment and Cath D expression increased during MG involution. Furthermore, incubation of MG fragments and MCF7 with recombinant 16 kDa mPRL revealed a proapoptotic effect in MECs. Ectopic mPRL in MECs was cleaved to 16 kDa PRL by Cath D in the MG lysosomal fraction. The majority of PRL derived from pituitary gland was cleaved to 16 kDa PRL in culture medium. Therefore, N-terminal PRL fragment increases during the involution period, has a proapoptotic effect on MECs, and is mainly generated by secreted Cath D in the extracellular space of MG.

  6. Prolactin circadian rhythm persists throughout lactation in women.

    Stern, J M; Reichlin, S


    To determine whether the prolactin (PRL) circadian rhythm, with its characteristic nocturnal rise, persists during the hyperprolactinemia of lactation, PRL levels were analyzed in blood samples collected hourly for 24 h from 20 mothers, 4-46 months postpartum. The circadian rhythm of PRL persisted throughout lactation as manifested by: (1) significantly higher mean nighttime than daytime PRL levels in the whole sample, despite higher daytime nursing durations; (2) the distribution of zenith levels which most frequently occur between 23.00 and 07.00 h, when nursing duration is lowest, and which are almost absent between 07.00 and 23.00 h, when nursing duration is highest, and of nadir levels, which have an opposite pattern; (3) spontaneous PRL surges that are more frequent, longer, and of higher magnitude at night than during the day, and (4) the larger magnitude of suckling-induced PRL release from late afternoon through the night compared to the morning in some women. Our data suggest that the mechanisms responsible for the circadian rhythm in PRL secretion are relatively independent of the mechanisms of suckling-induced release. We propose that the nocturnal rise in PRL during lactation functions to ensure a robust milk supply during an extensive nonsuckling interval.


    郭彦斌; 杨海玲; 王慧


    催乳素(prolactin)参与了很多生理活动,包括乳蛋白的合成、免疫活动的调节、促进生殖器官的发育、维持渗透压的平衡以及一些生理行为.催乳素要行使其生物学功能必须与其受体(prolactin receptor)结合.本文就PRL基因及其受体PRLR基因的结构、功能以及在奶牛上的研究进展作一综述.

  8. N-glycoprofiling analysis in a simple glycoprotein model: a comparison between recombinant and pituitary glycosylated human prolactin.

    Capone, Marcos V N; Suzuki, Miriam F; Oliveira, João E; Damiani, Renata; Soares, Carlos R J; Bartolini, Paolo


    Human prolactin (hPRL) is a polypeptide hormone occurring in the non-glycosylated (NG-hPRL) and glycosylated (G-hPRL) forms, with MM of approximately 23 and 25kDa, respectively. It has a single, partially occupied N-glycosylation site located at Asn-31, which makes it a particularly simple and interesting model for glycosylation studies. The bioactivity of G-hPRL is lower than that of NG-hPRL (by ca. 4-fold) and its physiological function is not clear. However, carbohydrate moieties generally play important roles in the biosynthesis, secretion, biological activity, and plasma survival of glycohormones and can vary depending on the host cell. The main objective of this study was to determine the N-glycan structures present in native, pituitary G-hPRL and compare them with those present in the recombinant hormone. To obtain recombinant G-hPRL, genetically modified Chinese hamster ovary cells (CHO), adapted to growth in suspension, were treated with cycloheximide, thus increasing the glycosylation site occupancy from 5.5% to 38.3%, thereby facilitating G-hPRL purification. CHO cell-derived G-hPRL (CHO-G-hPRL) was compared to pituitary G-hPRL (pit-G-hPRL) especially with regard to N-glycoprofiling. Among the main differences found in the pituitary sample were an extremely low presence of sialylated (1.7%) and a high percentage of sulfated (74.0%) and of fucosylated (90.5%) glycans. A ∼6-fold lower in vitro bioactivity and a higher clearance rate in mice were also found for pit-G-hPRL versus CHO-G-hPRL. N-Glycan profiling proved to be a useful and accurate methodology also for MM and carbohydrate content determination for the two G-hPRL preparations, in good agreement with the values obtained directly via MALDI-TOF-MS.

  9. PRL and GH synthesis and release from the sea bream (Sparus auratus L.) pituitary gland in vitro in response to osmotic challenge.

    Fuentes, Juan; Brinca, Lilia; Guerreiro, Pedro M; Power, Deborah M


    The endocrine factors prolactin (PRL) and growth hormone (GH) are believed to have counteracting effects in the adaption of fish to changes in environmental salinity. In order to further investigate this interaction sea bream were challenged with full seawater (SW) or freshwater (FW) for 7 days and the response of pituitary glands cultured in vitro to an osmotic challenge (230, 275 and 320 mOsm/kg) was assessed. In vitro PRL secretion from pituitaries of SW-adapted fish was unaltered in response to an osmotic challenge, while GH secretion increased in the lowest osmolality (230 mOsm/kg). In contrast, both GH and PRL secretion by pituitaries from FW challenged fish was significantly increased (pPRL content and de novo synthesised and released PRL were significantly increased (pPRL secretion was not different from SW animals. GH pituitary content decreased in FW animals while total secretion and secretion of de novo synthesised protein were significantly increased (pPRL and GH increased 3- and 2-fold, respectively. Despite the increase in PRL expression, no increase in total PRL secretion occurred and although in gills a 2-fold increase in the osmoregulatory marker, Na(+)/K(+)-ATPase activity was detected, profound haemodilution and a cumulative mortality of 40% occurred in sea bream placed in FW. Taken together the results suggest that the sea bream pituitary gland fails to respond appropriately to the osmotic challenge caused by low salinity and the physiological response evoked in vivo is not enough to allow this species to withstand and adapt to FW.

  10. Effects of preoperative bromocriptine treatment on prolactin-secreting pituitary adenoma surgery



    Pituitary adenomas are benign intracranial endocrine tumors, accounting for ~10% of intracranial tumors. The aim of the present study was to analyze the effects of preoperative treatment with bromocriptine on the surgical treatment and postoperative complications of prolactin-secreting pituitary adenomas (prolactinomas). Data from 102 patients whose prolactinomas were surgically treated between March 2006 and March 2010 were retrospectively reviewed in the present study. The study group included 54 patients who had been treated preoperatively with bromocriptine. The patients were examined by magnetic resonance imaging (MRI) of the head and coronal computed tomography (CT) scanning, after which the pathological diagnosis of prolactinoma was confirmed. A total of 64 patients underwent total resection surgery through the nose and sphenoid sinus, and 25 patients underwent subtotal resection surgery or excision of a large portion of the tumor, leaving only a small quantity of residual tumor or tumor capsule. Patients were followed up for 1–9 months using MRI and measurements of serum prolactin levels. Seven patients were lost to follow-up. The results of the present study demonstrated that patients who were treated with large doses of bromocriptine or used bromocriptine chronically suffered from an increased rate of surgical difficulties and postoperative complications, as compared with the patents who had not been pre-treated with bromocriptine. In conclusion, oral administration of bromocriptine is important in the treatment of prolactinoma tumors. However, large doses or long-term use of bromocriptine may increase difficulties in surgery or postoperative complications, and reduce its ability to treat prolactinonas, as it can lead to hardening of the tumor tissue and capsules, and aggravate pituitary stalk adhesions. PMID:27168837

  11. The effects of a special Agnus castus extract (BP1095E1) on prolactin secretion in healthy male subjects.

    Merz, P G; Gorkow, C; Schrödter, A; Rietbrock, S; Sieder, C; Loew, D; Dericks-Tan, J S; Taubert, H D


    The effects of three doses of a special Agnus castus extract (BP1095E1)--extracts from 120 mg, 240 mg and 480 mg of drug per day--were examined within the framework of a placebo-controlled clinical study of tolerance and prolactin secretion in 20 healthy male subjects during a period of 14 days. There was good tolerance during the study as regards the following: adverse effects, the effects on blood pressure and heart rate, blood count, Quick's test, clinical chemistry as well as testosterone, FSH and LH values. During each study phase the 24-hour prolactin secretion profile was measured from the penultimate to the final day, and the amount of prolactin release was monitored an hour after TRH stimulation on the last day. A significant increase in the 24-hour profile was registered with the lowest dose in comparison to placebo, the opposite being the case with the higher doses, i.e. a slight reduction. In contrast to the administration of placebo, the 1-hour AUC after TRH stimulation resulted in a significant increase with the lowest dose and a significant reduction with the highest dose. The results suggest effects of the special Agnus castus extract which are dependent on the dose administered and the initial level of prolactin concentration.

  12. Opioid modulation of prolactin secretion induced by stress during late pregnancy. Role of ovarian steroids.

    Valdez, Susana R; Pennacchio, Gisela E; Gamboa, Dante F; de Di Nasso, Elina G; Bregonzio, Claudia; Soaje, Marta


    The opioid system modulates prolactin release during late pregnancy. Its role and the participation of ovarian hormones in this modulation are explored in ether stress-induced prolactin release. Estrous, 3-day and 19-day pregnant rats were used. We administered the antagonist mifepristone (Mp) and tamoxifen to evaluate progesterone and estradiol action in naloxone (NAL, opioid antagonist) or saline treated rats. Ether stress had no effect on serum prolactin levels in controls but increased prolactin release in NAL-treated rats. Prolactin response to stress in NAL-treated rats was blocked by l-DOPA administration. Mp treatment on day 18 of pregnancy increased prolactin levels after stress without alterations by NAL. Tamoxifen on days 14 and 15 of pregnancy completely blocked Mp and NAL effects on prolactin release at late pregnancy. In contrast, stress significantly increased prolactin levels in estrous rats and pretreatment with NAL prevented this. On day 3 of pregnancy, at 6.00 p.m., stress and NAL treatment inhibited prolactin levels in saline-treated rat. No effect of stress or NAL administration was detected on day 3 of pregnancy at 9.00 a.m. icv administration of specific opioids antagonist, B-Funaltrexamine but not Nor-Binaltorphimine or Naltrindole, caused a significant increase in stress-induced prolactin release. Opioid system suppression of prolactin stress response during late pregnancy was observed only after progesterone withdrawal, involving a different opioid mechanism from its well-established stimulatory role. This mechanism acts through a mu opioid receptor and requires estrogen participation. The opioid system and progesterone may modulate stress-induced prolactin release, probably involving a putative prolactin-releasing factor. Copyright © 2014 Institute of Pharmacology, Polish Academy of Sciences. Published by Elsevier Urban & Partner Sp. z o.o. All rights reserved.

  13. Relative prolactin-to-progesterone concentrations around farrowing influence colostrum yield in primiparous sows.

    Loisel, F; Farmer, C; van Hees, H; Quesnel, H


    In swine, colostrum production is induced by the drop of progesterone (P4) concentrations which leads to the prepartum peak of prolactin (PRL). PRL regulates mammary cell turnover and stimulates lacteal nutrient synthesis. P4 inhibits PRL secretion and downregulates the PRL receptor in the mammary gland. The aim of the present study was to determine if the relative prepartum concentrations of P4 and PRL (PRL/P4 ratio) influence sow colostrum production. The performance of 29 Landrace × Large White primiparous sows was analyzed. Colostrum yield was estimated during 24 h starting at the onset of parturition (T0) using litter weight gains. Colostrum was collected at T0 and 24 h later (T24). Repeated jugular blood samples were collected during the peripartum period, that is, from -72 to +24 h related to farrowing and were assayed for P4 and PRL. Sows were retrospectively categorized in 2 groups according to their PRL/P4 ratio 24 h before farrowing being either 3 (high PRL/P4, n = 13). During the peripartum period, the circulating concentrations of P4 were lower (P Colostrum yield was greater in high PRL/P4 compared with low PRL/P4 sows (4.11 vs 3.48 kg [root mean square error = 0.69], P Colostrum composition (dry matter, energy, protein, lipid, and lactose contents) and IgG and IgA concentrations did not differ between the 2 groups of sows (P > 0.10). The Na/K ratio in colostrum 24 h after the onset of farrowing was lower in high PRL/P4 compared with low PRL/P4 sows (P colostrum yield in primiparous sows.


    The estrogenic and antiandrogenic pesticide methoxychlor alters the reproductive tract and behavior without affecting pituitary size or LH and prolactin secretion in male rats.Gray LE Jr, Ostby J, Cooper RL, Kelce WR.Endocrinology Branch, United States Environment...

  15. Pubertal dependent effects of cadmium on episodic prolactin secretion in male rats

    Lafuente, A.; Alvarez-Demanuel, E.; Marquez, N. [Fac. de Cienicas, Orense (Spain). Lab. de Toxicologia; Esquifino, A.I. [Dept. Bioquimica, Facultad de Medicina, Universidad Complutense, 28040-Madrid (Spain)


    This work was undertaken to assess if exposure to cadmium related to puberty may affect the episodic pattern of prolactin. Male rats were submitted to cadmium exposure, from day 30 to 60 or from day 60 to 90 of life respectively, at a dose of 50 ppm in the drinking water. Control age-matched rats received cadmium-free water. Prepubertal cadmium administration decreased mean serum prolactin levels and the absolute amplitude of the prolactin pulses. Subchronic exposure to cadmium of adult rats decreased mean serum prolactin levels, the absolute amplitude of the prolactin pulses and their duration, and the mean half-life of the hormone. These results suggest that subchronic cadmium exposure changes the secretory pattern of prolactin in adult male rats in a puberty-dependent way. (orig.) With 1 fig., 1 tab., 37 refs.

  16. Effects of vasoactive intestinal peptide on prolactin secretion in three species of passerine birds.

    Vleck, C M; Patrick, D J


    Previous work on domesticated species has indicated that vasoactive intestinal peptide (VIP) is an important prolactin-releasing factor in these birds, but no comparative work in passerine birds has been reported. This study showed that iv injections of VIP (50-100 microg/kg body mass) result in a dramatic, but transitory, rise in plasma prolactin in Mexican jays (Aphelocoma ultramarina). Significant increases in prolactin were also observed following VIP injection in blue jays (Cyanocitta cristata) and zebra finches (Poephilla guttata). At the dosage we used, maximum levels of prolactin attained were slightly lower (Mexican jays) or very similar (blue jay and zebra finch) to the maximum prolactin levels observed in other, breeding birds of the same species. In zebra finches that initially had low prolactin, VIP injection resulted in a greater than 10-fold increase in prolactin within 10 min, but those individuals that already had elevated prolactin showed no further increase in response to VIP. Slow-release pellets of VIP implanted subcutaneously in Mexican jays and releasing 10 or 15 microg VIP/day (two or three pellets) produced a significant increase in plasma prolactin (78 and 92% rise, respectively) compared to birds with placebo pellets or with with one pellet releasing only 5 microg/day.

  17. Secretory patterns of prolactin in dogs: circannual and ultradian rhythms.

    Corrada, Y; Castex, G; Sosa, Y; Gobello, C


    The objectives of the present study were to characterize in dogs circannual and ultradian prolactin (PRL) secretory patterns and also to compare gender differences in the ultradian period of study in the Southern hemisphere. Blood samples were collected at 15-min intervals for 2.5 h from seven male and seven female dogs and a single monthly sampling, over a 1-year time span, from six male dogs for the ultradian and circannual studies, respectively. Plasma PRL was measured by a homologous enzyme immunometric assay. The ultradian study evidenced PRL elevations suggesting pulsatile secretion in both genders. Significantly higher mean smoothed baseline (ng / ml [7.02 +/- 1.2 vs 1.23 +/- 1.0, p < 0.01]) and AUC (ng/ml * 2.5 h [25.2 +/- 3.8 vs 4.4 +/- 3.8, p < 0.01]) were found in females when compared with males. In the circannual study, plasma PRL concentrations did not statistically differ among the months of the year. When grouped together the 3 months with a longer daylight had significantly higher PRL concentrations than the 3 months with the shortest (2.31 +/- 0.37 vs 0.96 +/- 0.37, p < 0.01). The correlation between length of daylight and PRL concentrations was 0.24, p < 0.05. It is concluded that PRL does have a circannual rhythmicity and that there are ultradian gender-related differences in the period under study in these groups of dogs. This study also demonstrates plasma PRL elevations suggesting pulsatile secretion in male dogs.

  18. LS14: a novel human adipocyte cell line that produces prolactin.

    Hugo, Eric R; Brandebourg, Terry D; Comstock, Clay E S; Gersin, Keith S; Sussman, Jeffrey J; Ben-Jonathan, Nira


    Adipose tissue is an integral component within the endocrine system. Adipocytes produce numerous bioactive substances, and their dysregulation has serious pathophysiological consequences. We previously reported that human adipose tissue from several depots produces significant amounts of prolactin (PRL). To study locally produced PRL, we sought an acceptable in vitro model. Consequently, we developed an adipocyte cell line derived from a metastatic liposarcoma. The cell line, designated LS14, has been in continuous culture for 2 yr. These cells exhibit many properties of primary preadipocytes, including the ability to undergo terminal differentiation, as judged by morphological alterations, lipid accumulation, and increase in glycerol-3-phosphate dehydrogenase. LS14 cells express many adipose-associated genes, such as adipocyte fatty acid-binding protein (aP(2)), hormone-sensitive lipase, lipoprotein lipase, preadipocyte factor 1, adiponectin, leptin, and IL-6. Similar to primary adipocytes, LS14 cells also produce and respond to PRL, thus making them an attractive model to study adipose PRL production and function. The expression of PRL was confirmed at the transcriptional level by RT-PCR, and PRL secretion was determined by the Nb2 bioassay. Addition of exogenous PRL to LS14 cells resulted in a dose-dependent inhibition of IL-6 release. In summary, we have established a novel human adipocyte cell line with many characteristics of primary adipocytes. The LS14 cells open up new avenues for research on human adipocyte biology and add to the repertoire of nonpituitary, PRL-producing cell lines.

  19. Regulation of prolactin secretion by hypothalamus in some cold blooded vertebrates.

    Singh, S P; Singh, T P


    Effect of homoplastic hypothalamic extract (HHE) on the release of prolactin from the pituitary gland of three aquatic animals -- the fish, Clarias batrachus, the amphibian, Rana tigrina and the reptile, Natrix piscator was studied. Release of prolactin from the pituitary gland in the above animals was blocked within 4 hours by CG 603 (100 microgram/g body wt.) injection. Administration of HHE and perphenazine (15 microgram/g body wt.) in such animals resulted in significantly increased level of prolactin in the blood serum within one hour of treatment indicating an accelerated release of prolactin from the pituitary gland. Injection of cerebral cortical extract failed to induce such response in any of the specimens. From the findings of the present experimentation it is evident that the hypothalamus in C. batrachus, R. tigrina and N. piscator contained predominantly prolactin-release stimulatory factor (PRF) at the time of assessment. Probably in the aquatic poikilotherms where prolactin is not essential for their survival in hypophysectomized condition, hypothalamus contains PRF at least for some period in a year.

  20. Possible modulation of N-methyl-D,L-aspartic acid induced prolactin release by testicular steroids in the adult male rhesus monkey

    Arslan, M.; Rizvi, S.S.R.; Jahan, S.; Zaidi, P.; Shahab, M. (Quaid-i-Azam Univ., Islamabad (Pakistan))


    N-methyl-D,L-aspartic acid (NMA), an agonist of the neurotransmitter glutamate has been shown to acutely stimulate the release of prolactin (PRL) in intact rats and monkeys. To further investigate the role of neuroexcitatory amino acids in PRL secretion, the effects of NMA administration were examined on PRL release in long term orchidectomized adult rhesus monkeys, in both the absence and presence of testosterone. Intact and long term castrated adult male monkeys weighing between 8-13 kg, were implanted with a catheter via the saphenous vein for blood withdrawal and drug infusion. Blood samples were collected at 10 min intervals for 50 min before and 70 min after administration of the drug or vehicle. Plasma PRL concentrations were estimated using radioimmunoassay. Whereas a single iv injection of NMA induced a prompt discharge of PRL in intact monkeys, an identical dose had surprisingly no effect on PRL secretion in orchidectomized animals. On the other hand, plasma PRL increases in response to a challenge dose of thyrotropin releasing hormone were similar in magnitude in the two groups of monkeys. Testosterone replacement in orchidectomized animals by parenteral administration of testosterone enanthate reinitiated the PRL responsiveness to acute NMA stimulation. These results indicate that N-methyl-D-aspartic acid (NMDA) dependent drive to PRL release in the adult male rhesus monkey may be overtly influenced by the sex steroid milieu.

  1. Antisense mRNA for NPY-Y1 receptor in the medial preoptic area increases prolactin secretion

    N.A. Silveira


    Full Text Available We investigated the participation of neuropeptide Y-Y1 receptors within the medial preoptic area in luteinizing hormone, follicle-stimulating hormone and prolactin release. Four bilateral microinjections of sense (control or antisense 18-base oligonucleotides of messenger ribonucleic acid (mRNA (250 ng corresponding to the NH2-terminus of the neuropeptide Y1 receptor were performed at 12-h intervals for two days into the medial preoptic area of ovariectomized Wistar rats (N = 16, weighing 180 to 200 g, treated with estrogen (50 µg and progesterone (25 mg two days before the experiments between 8.00 and 10:00 a.m. Blockade of Y1 receptor synthesis in the medial preoptic area by the antisense mRNA did not change plasma luteinizing hormone or follicle-stimulating hormone but did increase prolactin from 19.6 ± 5.9 ng/ml in the sense group to 52.9 ± 9.6 ng/ml in the antisense group. The plasma hormones were measured by radioimmunoassay and the values are reported as mean ± SEM. These data suggest that endogenous neuropeptide Y in the medial preoptic area has an inhibitory action on prolactin secretion through Y1 receptors.

  2. Studies on prolactin-secreting cells in aging rats of different strains. I. Alterations in pituitary histology and serum prolactin levels as related to ageing.

    Putten, van L.J.A.; Zwieten, van M.J.; Mattheij, J.A.M.; Kemenade, J.A.M.


    Serum PRL levels and histologically tumor-free pituitary glands of 91 aging rats of the BN/BiRij strain, the WAG/Rij strain and their F1 hybrid were studied. In rats with pituitary glands without signs of hyperplasia, serum PRL levels were, in comparison to rats of 15-24 months, increased 25-29-mont

  3. Short-term prolactin administration causes expressible galactorrhea but does not affect bone turnover: pilot data for a new lactation agent

    Smith Patricia C


    Full Text Available Abstract Background Medications used to augment lactation increase prolactin secretion but can have intolerable side effects. We examined the biological activity of recombinant human prolactin (r-hPRL as preliminary data for its use to augment lactation. Methods Healthy, non-postpartum women (n = 21 with regular menstrual cycles underwent a seven day randomized, double-blind, placebo-controlled trial of r-hPRL. Expressible galactorrhea, markers of bone turnover, calcium homeostasis and gonadal function were measured and side effects recorded. Results Prolactin levels increased during r-hPRL administration (20.0 ± 2.8 to 231.7 ± 48.9 μg/L at 6 hours; p Conclusion In summary, r-hPRL can cause expressible galactorrhea. Seven days of r-hPRL administration does not adversely affect bone turnover or menstrual cyclicity. Thus, r-hPRL may be a viable option for short-term lactation augmentation. Trial registration Clinical NCT00438490

  4. Effect of pindolol on the L-5-HTP-induced increase in plasma prolactin and cortisol concentrations in man.

    Meltzer, H Y; Maes, M


    Previous studies with direct-acting serotonin (5-HT) agonists and antagonists have demonstrated that stimulation of 5-HT1A, 5-HT1C and 5-HT2 receptors may promote cortisol and prolactin (PRL) secretion in man. There is also evidence that 5-HT1C/2 receptor stimulation contributes to the cortisol and PRL responses following administration of the 5-HT precursor, L-5-hydroxytryptophan (L-5-HTP), in man. To clarify the possible contribution of 5-HT1A receptor stimulation to the ability of L-5-HTP to stimulate cortisol and PRL secretion in man, the effect of pindolol, a beta adrenoceptor antagonist that is also a 5-HT1A partial agonist, on the L-5-HTP-induced increases in cortisol and PRL secretion, was examined in 12 normal male volunteers. Pretreatment with pindolol, 30 mg orally, significantly inhibited the PRL but not the cortisol response to L-5-HTP, 200 mg PO. Pindolol alone decreased basal plasma PRL levels and increased basal plasma cortisol levels, possibly due to 5-HT1A antagonist and agonists effects, respectively. These data, coupled with observations from other studies, suggest that the L-5-HTP-induced increase in PRL but not cortisol secretion requires 5-HT1A receptor activation. PRL secretion due to 5-HT formed from exogenous L-5-HTP may require the availability of both intact 5-HT1A and 5-HT2/5-HT1C receptors, since blockade of either receptor type inhibited the PRL response to L-5-HTP. The implication of this synergistic effect for interpretation of neuroendocrine studies involving the serotonergic system in man is discussed.

  5. 17-beta-estradiol-dependent regulation of somatostatin receptor subtype expression in the 7315b prolactin secreting rat pituitary tumor in vitro and in vivo

    H.A. Visser-Wisselaar (Heleen); C.J. van Uffelen; P.M. van Koetsveld (Peter); E.G. Lichtenauer-Kaligis; A.M. Waaijers (Annet); P. Uitterlinden (Piet); D.M. Mooy; S.W.J. Lamberts (Steven); L.J. Hofland (Leo)


    textabstractIn the present study, we have investigated the role of estrogens in the regulation of somatostatin receptor subtype (sst) expression in 7315b PRL-secreting rat pituitary tumor cells in vitro and in vivo. sst were undetectable in freshly dispersed cells of the transplant

  6. The secretory pattern and source of immunoreactive prolactin in pregnant African (Loxodonta africana) and Asian (Elephas maximus) elephants.

    Yamamoto, Yuki; Yamamoto, Tatsuya; Yuto, Natsuki; Hildebrandt, Thomas B; Lueders, Imke; Wibbelt, Gudrun; Shiina, Osamu; Mouri, Yasushi; Sugimura, Keisuke; Sakamoto, Sayuri; Kaewmanee, Saroch; Nagaoka, Kentaro; Watanabe, Gen; Taya, Kazuyoshi


    The objective of the present study was to define the secretion of prolactin (PRL) in pregnant African and Asian elephants. Levels of immunoreactive (ir-) PRL in serum and placental homogenates were measured by a heterologous radioimmunoassay (RIA) based on an ovine and human RIA system, and the localization of ir-PRL in the placenta was detected by immunohistochemistry using anti-human PRL. Circulating ir-PRL clearly showed a biphasic pattern during pregnancy in African and Asian elephants. Serum levels of ir-PRL started to increase from the 4 - 6th month of gestation and reached the first peak level around the 11-14th month. A second peak of circulating ir-PRL levels was observed around the 18-20th month of gestation followed by an abrupt decline after parturition. In contrast, in a case of abortion of an African elephant, the second peak of ir-PRL was not observed, and the levels remained low for about four months until parturition. The weight of the fetus delivered at the 17th month of gestation was 23.5 kg, which was quite small compared with normal fetuses in previous reports. Ir-PRL was detected in placental homogenates, and immunolocalization was observed in trophoblasts in both the African and Asian elephants, indicating that the placenta is the source of ir-PRL during pregnancy in elephants. The present results clearly demonstrated that circulating ir-PRL shows a biphasic pattern during normal pregnancy and that the placenta appears to be an important source of circulating ir-PRL during pregnancy in both African and Asian elephants.

  7. Serum Prolactin in Diagnosis of Epileptic Seizures

    J Gordon Millichap


    Full Text Available The results of studies in databases and references concerning serum prolactin levels (PRL in patients with suspected seizures were rated for quality and analyzed by members of the Therapeutics Subcommittee of the American Academy of Neurology.

  8. Effect of Chinese Herbs Bu-shen on Expression of Pituitary PRL-R and PrRP-R in the Bromocriptine-induced Hypoprolactin Rat Abortion Model

    Hai-yan WANG; Sui-qi GUI; Fang-xian LU; Li-min LU; Lin CAO


    Objective To study the effect of Chinese herbs preparation Bu-shen on pituitary prolactin-releasing peptide receptor(PrRP-R) and prolactin receptor(PRL-R) expression in the bromocriptine-induced rat abortion modelMaterials & Methods Female SD rats were divided into five groups randomly. Group A,B,C and D were injected with bromocriptine [0.3 mg/(kg*d)] during the pregnant day 6~8, respectively. Group B was given powder of Bu-shen herbs [3 g/(kg*d)]. Group C was injected with prolactin (8 IU) twice a day and Group D with progesterone [(8 mg/kg*d) in the pregnant day 1~11. The rats in Group E were normal pregnant rats. All these rats were killed at the pregnant day 12 to observe the expression of PrRP-R, PRL-R from the pituitary using RT-PCR.Results The pregnant rate and total number of litters in Group A were significantly lower than those in Group B, C, D and E (P<0.01) and the expression of PrRP-R and PRL-R in the pituitary of Group A was higher than that of any other group.Conclusion Preparation Bu-shen plays a regulatory role in the secretion of prolactin possibly via modulating rats' hypothalamus and pituitary.

  9. Site-specific regulation of ion transport by prolactin in rat colon epithelium.

    Deachapunya, Chatsri; Poonyachoti, Sutthasinee; Krishnamra, Nateetip


    The effect of prolactin (PRL) on ion transport across the rat colon epithelium was investigated using Ussing chamber technique. PRL (1 μg/ml) induced a sustained decrease in short-circuit current (I(sc)) in the distal colon with an EC(50) value of 100 ng/ml and increased I(sc) in the proximal colon with an EC(50) value of 49 ng/ml. In the distal colon, the PRL-induced decrease in I(sc) was not affected by Na(+) channel blocker amiloride or Cl(-) channel blockers, NPPB, DPC, or DIDS, added mucosally. However, the response was inhibited by mucosal application of K(+) channel blockers glibenclamide, quinidine, and chromanol 293B, whereas other K(+) channel blockers, Ba(2+), tetraethylammonium, clotrimazole, and apamin, failed to have effects. The PRL-induced decrease in I(sc) was also inhibited by Na(+)-K(+)-2Cl(-) transporter inhibitor bumetanide, Ba(2+), and chromanol 293B applied serosally. In the transverse and proximal colon, the PRL-induced increase in I(sc) was suppressed by DPC, glibenclamide, and bumetanide, but not by NPPB, DIDS, or amiloride. The PRL-induced changes in I(sc) in both distal and proximal colon were abolished by JAK2 inhibitor AG490, but not BAPTA-AM, the Ca(2+) chelating agent, or phosphatidylinositol 3-kinase inhibitor wortmannin. These results suggest a segment-specific effect of PRL in rat colon, by activation of K(+) secretion in the distal colon and activation of Cl(-) secretion in the transverse and proximal colon. Both PRL actions are mediated by JAK-STAT-dependent pathway, but not phosphatidylinositol 3-kinase pathway or Ca(2+) mobilization. These findings suggest a role of PRL in the regulation of electrolyte transport in mammalian colon.

  10. Synthesis of human prolactin in Chinese hamster ovary (CHO) cells; Sintese de prolactina humana em celulas de ovario de hamster chines (CHO)

    Soares, Carlos Roberto Jorge


    Three different eukaryotic expression vectors, based on the same selectable gene marker (dhfr), have been used for dhf- CHO cells transfection to rapidly isolate stable cell lines capable of secreting high levels of recombinant human prolactin (rec-hPRL). Two vectors, one codifying a human prolactin (p658-hPRL) and the other a tag-prolactin (p658-tagPRL), contain the complete hepatitis B virus-X (HBV-X) gene coding for a viral transactivator and a sequence derived from the granulocyte-macrophage colony-stimulating factor (GM-CSF) that mediates selective dhfr mRNA degradation. These vectors have the advantage of rapidly obtaining stable cell lines without methotrexate amplification. The highest secretion obtained by these vectors was of approximately 10 {mu}g hPRU10{sup 6} cells/day. The other vector (pEDdc-hPRL) is based on a dicistronic expression system, containing an internal ribosome entry site isolated from the encephalomyocarditis (EMC) virus. This vector before amplification provided secretion levels at least 10 fold lower than that obtained with the other two vectors. However, after three steps of methotrexate amplification, it provided some clones able to secrete up to 30 {mu}g hPRU10{sup 6} cells/day. This is the first report describing the production and purification of rec-hPRL from CHO cells, obtaining secretion levels with both vectors higher than those reported so far for this hormone in other eukaryotic systems. CHO-derived rec-hPRL contained approximately 10 % of the glycosylated form, a value that is consistent with results reported for hPRL purified from the pituitary or from transformed murine C-127 cells. CHO-derived rec-hPRL was purified with good yield, obtaining also a good resolution between non-glycosylated and glycosylated prolactin. The latter, when its potency was determined via an in vitro bioassay, presented a 47 % lower bioactivity. A qualitative and quantitative analysis of these forms was also possible thanks to the setting up of a

  11. Clinical significance of the dynamic serum prolactin(PRL)before and after transsphenoidal surgery on large and huge prolactinomas%血清泌乳素动态监测在大及巨大泌乳素腺瘤经蝶手术前后的临床意义

    张威; 王海军; 徐伟光


    Objective To analyze the clinical significance of the dynamic serum prolactin (PRL) before and after transsphenoidal surgery on large and huge prolactinomas. Methods Thirty patients with prolactinomas larger than 2 cm in diameter were studied before and after transsphenoidal surgery. Results 30 cases all have high serum prolactin varying degrees before operation. 21 cases achieved normal prolactin 1 week after tumor was total removed, but 9 cases had persisted abnormal prolactin when tumor was partial excision. Conclusion The dynamic changes of serum prolactin confer important screening functions including diagnosis, estimation of tumor size, prognosis before operation, evaluation of therapeutic effect and recrudescence after operation. It could be used to instruct assistant treatment and save medical expenses.%目的 分析、总结血清泌乳素(prolactin,PRL)动态监测在大及巨大垂体腺瘤经蝶手术前后的临床意义.方法 追踪、随访30例经蝶手术的最大直径≥2 cm的单纯性泌乳素腺瘤患者,动态监测术前、术后内分泌变化,分析其临床意义.结果 30例患者术前PRL均有不同程度升高,与肿瘤大小有一定相关性,其中肿瘤完全切除21例,术后1周PRL基本恢复正常;肿瘤残留9例,PRL持续异常.结论 在大及巨大泌乳索腺瘤经蝶手术前后,PRL的动态监测在术前肿瘤的诊断、肿瘤大小判断、术后疗效、预后的判断以及复发等方面有重要的筛查作用,可以指导临床辅助治疗的选择,节约患者医疗费用.

  12. O papel da prolactina no lúpus eritematoso sistêmico: onde estamos The prolactin role in systemic lupus erythematosus: where we are

    Andrea Glezer


    Full Text Available A prolactina (PRL é um hormônio fundamental para a galactopoiese, porém, desempenha também outras diversas funções no papel de citocina, como a imunomodulação. A PRL é secretada pela maioria das células do sistema imunológico, estimulando a proliferação, diferenciação e maturação de linfócitos T e B, amplificando a ação de IL-2 e promovendo a inibição da apoptose dessas células. Há diversas evidências da participação da PRL na fisiopatologia das doenças autoimunes, especialmente do lúpus eritematoso sistêmico (LES, epidemiológicas e provenientes de estudos em modelos animais, in vitro e in vivo. A presença da PRL monomérica, biologicamente ativa, correlaciona-se com a atividade lúpica, enquanto que a macroprolactinemia, caraterizada pela presença de um anticorpo anti-PRL, se correlaciona negativamente. Há ainda pontos que merecem melhor esclarecimento: Qual a origem da PRL nos pacientes com hiperprolactinemia (hipofisária versus extra-hipofisária? Há aumento da bioatividade da PRL? Há mutações ou polimorfismos no gene da PRL ou de seu receptor? O tratamento da hiperprolactinemia ou o uso de agonistas da PRL podem mudar a história natural do LES?Prolactin (PRL is a fundamental hormone to galactopoiesis. Nevertheless, it has many other actions, including a cytokine that modulates immune system. Most of immune cells secretes PRL, which stimulates proliferation, differentiation and maturation of T and B lymphocytes, amplifies IL-2 action and inhibits lymphocytes apoptosis. There are many evidences of the role of PRL in physiopathology of autoimmune diseases, especially systemic lupus erythematosus (SLE, as shown by data from epidemiologic and animal models studies, in vitro and in vivo. Monomeric PRL, the biologic active isoform, correlates positively to lupus activity, while macroprolactinemia, characterized by an autoantibody anti-PRL, correlates negatively. There are still some issues that deserve more

  13. Prolactin as an Adjunct for Type 1 Diabetes Immunotherapy.

    Hyslop, Colin M; Tsai, Sue; Shrivastava, Vipul; Santamaria, Pere; Huang, Carol


    Type 1 diabetes is caused by autoimmune destruction of β-cells. Although immunotherapy can restore self-tolerance thereby halting continued immune-mediated β-cell loss, residual β-cell mass and function is often insufficient for normoglycemia. Using a growth factor to boost β-cell mass can potentially overcome this barrier and prolactin (PRL) may fill this role. Previous studies have shown that PRL can stimulate β-cell proliferation and up-regulate insulin synthesis and secretion while reducing lymphocytic infiltration of islets, suggesting that it may restore normoglycemia through complementary mechanisms. Here, we test the hypothesis that PRL can improve the efficacy of an immune modulator, the anticluster of differentiation 3 monoclonal antibody (aCD3), in inducing diabetes remission by up-regulating β-cell mass and function. Diabetic nonobese diabetic (NOD) mice were treated with a 5-day course of aCD3 with or without a concurrent 3-week course of PRL. We found that a higher proportion of diabetic mice treated with the aCD3 and PRL combined therapy achieved diabetes reversal than those treated with aCD3 alone. The aCD3 and PRL combined group had a higher β-cell proliferation rate, an increased β-cell fraction, larger islets, higher pancreatic insulin content, and greater glucose-stimulated insulin release. Lineage-tracing analysis found minimal contribution of β-cell neogenesis to the formation of new β-cells. Although we did not detect a significant difference in the number or proliferative capacity of T cells, we observed a higher proportion of insulitis-free islets in the aCD3 and PRL group. These results suggest that combining a growth factor with an immunotherapy may be an effective treatment paradigm for autoimmune diabetes.

  14. Relationship between prolactin and thyroid diseases%催乳素与甲状腺疾病

    郑海兰; 任安


    催乳素(PRL)在哺乳动物的生长、繁殖及免疫调节中起重要作用.甲状腺疾病与高PRL血症关系密切,PRL可能参与了这些疾病的发生、发展.自身免疫性甲状腺疾病时,PRL可通过刺激辅助性T细胞分泌多种细胞因子而促进甲状腺自身抗体的产生.甲状腺功能减退时,雌激素、促甲状腺激素释放激素(TRH)及垂体血管活性肠肽(VIP)水平可能影响了PRL的分泌.甲状腺癌时PRL可能作为抗细胞凋亡因子或有丝分裂原而发挥作用.%Prolactin (PRL) plays an important role in growth, reproduction and immune regulation in mammal. PRL may be involved in the development of thyroid diseases, since that thyroid diseases are related with hyperprolactinemia. In autoimmune thyroid diseases, hyperprolactinemia can stimulate helper T cells secreting a variety of cytokines to produce lots of thyroid autoantibodies. In hypothyroidism, estrogen, thyrotropin releasing hormone(TRH) and vasoactive intestinal peptide (VIP) may affect the secretion of PRL. In thyroid cancer, prolactin may act as an anti-apoptotic factor or mitogen.

  15. Lysergic acid diethylamide (LSD) is a partial agonist of D2 dopaminergic receptors and it potentiates dopamine-mediated prolactin secretion in lactotrophs in vitro.

    Giacomelli, S; Palmery, M; Romanelli, L; Cheng, C Y; Silvestrini, B


    The hallucinogenic effects of lysergic acid diethylamide (LSD) have mainly been attributed to the interaction of this drug with the serotoninergic system, but it seems more likely that they are the result of the complex interactions of the drug with both the serotoninergic and dopaminergic systems. The aim of the present study was to investigate the functional actions of LSD at dopaminergic receptors using prolactin secretion by primary cultures of rat pituitary cells as a model. LSD produced a dose-dependent inhibition of prolactin secretion in vitro with an IC50 at 1.7x10(-9) M. This action was antagonized by spiperone but not by SKF83566 or cyproheptadine, which indicates that LSD has a specific effect on D2 dopaminergic receptors. The maximum inhibition of prolactin secretion achieved by LSD was lower than that by dopamine (60% versus 80%). Moreover, the fact that LSD at 10(-8)-10(-6) M antagonized the inhibitory effect of dopamine (10(-7) M) and bromocriptine (10(-11) M) suggests that LSD acts as a partial agonist at D2 receptors on lactotrophs in vitro. Interestingly, LSD at 10(-13)-10(-10) M, the concentrations which are 10-1000-fold lower than those required to induce direct inhibition on pituitary prolactin secretion, potentiated the dopamine (10(-10)-2.5x10(-9) M)-mediated prolactin secretion by pituitary cells in vitro. These results suggest that LSD not only interacts with dopaminergic receptors but also has a unique capacity for modulating dopaminergic transmission. These findings may offer new insights into the hallucinogenic effect of LSD.

  16. New concepts in prolactin biology.

    Bernichtein, Sophie; Touraine, Philippe; Goffin, Vincent


    Human prolactin (PRL) is currently viewed as a hormone of pituitary origin, whose production (i.e. serum levels) is controlled by dopamine, whose biological actions relate exclusively to lactation and reproductive functions, for which any genetic disorder is yet to be identified, and whose unique associated pathology is hyperprolactinemia. Both experimental studies and human sample/cohort-based investigations performed during the past decade have considerably widened our perception of PRL biology: i) there are now strong epidemiological arguments supporting the fact that circulating PRL is a risk factor for breast cancer, ii) in addition to the endocrine hormone, locally produced PRL has been documented in several human tissues; there is increasing evidence supporting the tumor growth potency of local PRL, acting via autocrine/paracrine mechanisms, in both rodent models, and human breast and prostate tumors, iii) the first functional germinal polymorphisms of the PRL receptor were recently identified in patients presenting with breast tumors, which involve single amino acid substitution variants exhibiting constitutive activity, iv) human PRL analogs have been engineered, which were shown in experimental models to down-regulate the effects triggered by local PRL (competitive antagonism) or by the constitutively active receptor variants (inverse agonism). The aim of this review is to discuss these novel concepts in PRL biology, including their potential pathophysiological outcomes.

  17. Effects of Hypergravity Exposure on Prolactin Levels in Pre-parturient , Parturient and Lactating Rat Dams

    Baer. Lisa A.; Wade, Charles E.; Ronca, April E.; Sun, Sid (Technical Monitor)


    We analyzed the effects of 2.0-g, 1.75-g and 1.5-g hypergravity exposure on plasma concentrations of the lactotrophic hormone, prolactin (PRL), in female rats on pre-parturient (Gestation Day 20), parturient (Post-natal day 0) and lactating (P10) days. PRL levels have been found to be reduced in rat dams around the time of birth following exposure to gravitational loads varying from 2.16 to 3.14-g (Megory et. al., Aviation, Space and Environs 1129-1135, 1984). It has also been reported that at these high gravitational loads, neonatal mortality has been extremely high, suggesting a possible interaction between dam PRL concentration and neonatal outcome. We have previously reported no significant differences in PRL levels of parturient (PO) and lactating (P6 & P 15) dams when exposed to 1.5-g hypergravity, but did observe a slight elevation of PRL on PO and P 15, with a decrease on P6. In the present study, time-bred pregnant dams were exposed to either continuous 2.0-g, 1.75-g or 1.5-g centrifugation, beginning on Gestational day (G) 11 of the rats' 22-day pregnancy. We observed no significant differences in PRL concentrations between SC and any of the HG conditions. On G20 and PO, PRL concentrations of the 2.0-g and 1.5-g groups were slightly elevated as compared to SC. Similar to what we previously reported. PRL secretion was elevated in both HG and SC conditions on the day of birth relative to later during lactation, but on P10 it appeared to be reduced in HG relative to SC dams. These findings suggests that hypergravity slightly elevates plasma concentration of PRL in pre-parturient and lactating rat dams, with effects most pronounced during the periparturitional period and in a direction opposite to that observed following microgravity exposure.

  18. Serum prolactin and dehydroepiandrosterone concentrations during the summer and winter hair growth cycles of mink (Mustela vison).

    Rose, J; Kennedy, M; Johnston, B; Foster, W


    We investigated the relationship between serum concentrations of prolactin (PRL) and dehydroepiandrosterone (DHEA) during initiation and development of summer and winter hair growth (anagen) cycles in mink. In the spring, haloperidol (HAL) increased PRL concentrations and induced summer anagen earlier than controls, whereas melatonin (MEL) inhibited PRL secretion and completely blocked summer anagen. In the fall, HAL increased PRL concentrations, inducing anagen at an earlier time than controls, although the resulting fur was abnormal being almost devoid of underhair fibers. Exogenous MEL during the fall reduced PRL concentrations, initiating winter anagen 4 weeks earlier than controls. Adrenalectomy (ADX) induced earlier onset of summer and winter anagen and neutralized the inhibitory effects of HAL in the fall and MEL in the spring. No change in serum DHEA concentrations was observed during the onset of summer or winter anagen in any group although MEL increased DHEA levels from 27 March through 5 June relative to HAL-treated mink. We conclude that changes in serum levels of DHEA and PRL are not requisite to onset of summer or winter anagen in mink. It is possible that metabolites of DHEA and/or PRL may still affect other aspects of the hair growth cycle.

  19. Protective Effect of Prolactin against Methylmercury-Induced Mutagenicity and Cytotoxicity on Human Lymphocytes

    Liz Carmem Silva-Pereira


    Full Text Available Mercury exhibits cytotoxic and mutagenic properties as a result of its effect on tubulin. This toxicity mechanism is related to the production of free radicals that can cause DNA damage. Methylmercury (MeHg is one of the most toxic of the mercury compounds. It accumulates in the aquatic food chain, eventually reaching the human diet. Several studies have demonstrated that prolactin (PRL may be differently affected by inorganic and organic mercury based on interference with various neurotransmitters involved in the regulation of PRL secretion. This study evaluated the cytoprotective effect of PRL on human lymphocytes exposed to MeHg in vitro, including observation of the kinetics of HL-60 cells (an acute myeloid leukemia lineage treated with MeHg and PRL at different concentrations, with both treatments with the individual compounds and combined treatments. All treatments with MeHg produced a significant increase in the frequency of chromatid gaps, however, no significant difference was observed in the chromosomal breaks with any treatment. A dose-dependent increase in the mitotic index was observed for treatments with PRL, which also acts as a co-mitogenic factor, regulating proliferation by modulating the expression of genes that are essential for cell cycle progression and cytoskeleton organization. These properties contribute to the protective action of PRL against the cytotoxic and mutagenic effects of MeHg.

  20. Salsolinol is present in the bovine posterior pituitary gland and stimulates the release of prolactin both in vivo and in vitro in ruminants.

    Hashizume, T; Shida, R; Suzuki, S; Nonaka, S; Yonezawa, C; Yamashita, T; Kasuya, E; Sutoh, M; Oláh, M; Székács, D; Nagy, G M


    The aims of the present study were to determine whether salsolinol (SAL), a dopamine-related compound, is present in the bovine posterior pituitary (PP) gland, and to clarify the effect of SAL on the secretion of prolactin (PRL) in ruminants. SAL was detected in extract of bovine PP gland using high-pressure liquid chromatography with electrochemical detection (HPLC-EC). A single intravenous (i.v.) injection of SAL (5 and 10mg/kg body weight) significantly and dose-dependently stimulated the release of PRL in goats (Pruminants, and has PRL-releasing activity both in vivo and in vitro. Therefore, this endogenous compound is a strong candidate for the factor having PRL-releasing activity that has been previously detected in extract of the bovine PP gland.

  1. Tissue-specific Regulation of Porcine Prolactin Receptor Expression by Estrogen, Progesterone and Prolactin

    Prolactin (PRL) acts through its receptor (PRLR) via both endocrine and local paracrine/autocrine pathways to regulate biological processes including reproduction and lactation. We analyzed the tissue and stage of gestation-specific regulation of PRL and PRLR expression in various tissues of pigs. ...

  2. Role of Prolactin Receptors in Lymphangioleiomyomatosis.

    Amira Alkharusi

    Full Text Available Pulmonary lymphangioleiomyomatosis (LAM is a rare lung disease caused by mutations in the tumor suppressor genes encoding Tuberous Sclerosis Complex (TSC 1 and TSC2. The protein product of the TSC2 gene is a well-known suppressor of the mTOR pathway. Emerging evidence suggests that the pituitary hormone prolactin (Prl has both endocrine and paracrine modes of action. Here, we have investigated components of the Prl system in models for LAM. In a TSC2 (+/- mouse sarcoma cell line, down-regulation of TSC2 using siRNA resulted in increased levels of the Prl receptor. In human LAM cells, the Prl receptor is detectable by immunohistochemistry, and the expression of Prl in these cells stimulates STAT3 and Erk phosphorylation, as well as proliferation. A high affinity Prl receptor antagonist consisting of Prl with four amino acid substitutions reduced phosphorylation of STAT3 and Erk. Antagonist treatment further reduced the proliferative and invasive properties of LAM cells. In histological sections from LAM patients, Prl receptor immuno reactivity was observed. We conclude that the Prl receptor is expressed in LAM, and that loss of TSC2 increases Prl receptor levels. It is proposed that Prl exerts growth-stimulatory effects on LAM cells, and that antagonizing the Prl receptor can block such effects.

  3. Role of alpha 1- and alpha 2-adrenergic receptors in the growth hormone and prolactin response to insulin-induced hypoglycemia in man.

    Tatár, P; Vigas, M


    The effects of intravenous infusion of the nonselective alpha-adrenergic antagonist phentolamine or of the selective alpha 2-adrenergic antagonist yohimbine on growth hormone (GH), prolactin (PRL) and cortisol secretion during insulin-induced hypoglycemia were studied in 11 healthy young men. The GH response was blunted following each antagonist used, PRL secretion was higher after yohimbine and diminished after phentolamine when compared to controls. The plasma cortisol response was not influenced by either compound. In another series of experiments no effect of an oral administration of prazosin, a selective alpha 1-adrenergic antagonist, on the secretion of GH, PRL and cortisol was found in any of 7 subjects. Prazosin inhibited blood pressure increase during hypoglycemia and induced slight drowsiness and fatigue in the subjects. It is concluded that in man alpha-adrenergic stimulation of GH secretion during hypoglycemia is transmitted via alpha 2-receptors, PRL secretion is mediated via alpha 1-receptors, whereas inhibition of PRL release is mediated via alpha 2-receptors. In this experiment no effect of alpha 1- or alpha 2-blockade on cortisol response to hypoglycemia was seen.

  4. The dopamine antagonist domperidone increases prolactin concentration and enhances milk production in dairy cows.

    Lacasse, P; Ollier, S


    In previous studies, our team showed that the inhibition of prolactin (PRL) secretion by the dopamine agonist quinagolide reduces milk production in dairy cows. The objective of this study was to determine the effects of administration of a dopamine antagonist on basal and milking-induced PRL concentrations in blood and on milk production during positive energy balance and feed restriction in dairy cows. Eighteen mid-lactation Holstein cows received daily s.c. injections of either domperidone (300 mg, DOMP, n=9) or the vehicle, canola oil (CTL, n=9), for 5 wk. During wk 5, all cows were fed at 65% of their dry matter intake in the previous week. Blood and milk samples were collected before (for blood) and during (for milk) the a.m. milking thrice weekly from d -9 to 41 (8d after the last injection). In addition, blood samples were collected during the a.m. milking on d -1 (before the first injection), and on d 1, 28, and 34. Basal PRL concentration was similar in both groups before the start of the treatments. Domperidone injections caused a gradual increase in basal PRL concentration. Feed restriction reduced basal PRL concentration in both the CTL and DOMP cows, but PRL concentration remained higher in the DOMP cows. Prolactin concentration remained elevated in the DOMP cows 7d after the last injection. The milk concentration of PRL increased during the DOMP treatment, but the increase was smaller than that observed in serum. In the CTL cows, the milking-induced PRL release above the premilking concentration was similar on d -1, 1, and 28 but was reduced during feed restriction. In the DOMP cows, the milking-induced PRL release was similar on d -1 and 1 but was reduced on d 28 and 34. Milk production was similar for both groups before the treatments started but was greater in the DOMP cows during the treatment period, at 2.9 ± 0.6 and 2.4 ± 0.6 kg/d greater during wk 3 and 4 of treatment, respectively. Milk production declined in both groups during feed

  5. Cirugía transeptoesfenoidal en adenomas hipofisarios productores de prolactina Transeptosphenoidal surgery in prolactin-secreting hypophyseal adenomas


    paper was to evaluate the results of the microsurgical transeptosphenoidal treatment of the prolactin-secreting adenomas at the service of Neurosurgery of “Hermanos Ameijeiras” Hospital. To this end, we conducted a retrospective descriptive study of 63 patients carriers of this type of adenomas that underwent sublabial transeptosphenoidal microsurgery and were treated in our service from 1996 to 2003. Age, sex, the clinical picture, the size of the lesions, the hormonal levels, as well as the complications and the postoperative evolution were analyzed. As a result, it was found a predominance of females: 86 % (54 patients. 31 patients with macroadenomas and 32 with microadenomas were operated on. The most frequent symptoms improved, mainly headaches, in 82 % (36 cases. The most common complication in the postoperative was temporary diabetes insipidus (11 patients. It was possible to reduce the initial figures of prolactin to non-tumoral values in 90.6 % of the microadenomas (29 cases and in 67.7 % of the macroadenomas (21 cases. It is concluded that transeptosphenoidal adenomectomy is a safe and efficient procedure as an option treatment for patients with prolactin-secreting adenomas with surgical indication.

  6. Prolactin modulates cytokine production induced by culture filtrate proteins of M. bovis through different signaling mechanisms in THP1 cells.

    Martínez-Neri, Priscila A; López-Rincón, Gonzalo; Mancilla-Jiménez, Raúl; del Toro-Arreola, Susana; Muñoz-Valle, José Francisco; Fafutis-Morris, Mary; Bueno-Topete, Miriam Ruth; Estrada-Chávez, Ciro; Pereira-Suárez, Ana Laura


    The immunomodulatory functions of prolactin (PRL) are well recognized. Augmented PRL plasma levels were observed in patients with advanced tuberculosis (TB). Recently, we have reported that LPS and Mycobacterium bovis (M. bovis) induced differential expression of PRL receptor (PRLR) isoforms in THP-1 cells and bovine macrophages, respectively. The aim of this work was to determine whether PRL should be considered as a potential modulator of the signaling pathways and cytokine synthesis, induced by culture filtrate protein (CFP) from M. bovis in THP-1 monocytes. The THP-1 cells were stimulated with PRL (20ng/mL), M. bovis CFP (50μg/mL). PRLR as well as phosphorylated STAT3, STAT5, Akt1/2/3, ERK1/2 and p38 expression were evaluated by Western blot. IL1-β, TNF-α, IL-6, IL-12, IL-8, and IL-10 concentrations were measured by ELISA. Our results demonstrated that the expression pattern of PRLR short isoforms is induced by M. bovis CFP. M bovis CFP induced phosphorylation of Akt2, ERK1/2, p38, STAT3, and STAT5 pathways. In turn, PRL only activated the JAK2/STAT3-5 signaling pathway. However, when combined both stimuli, PRL significantly increased STAT3-5 phosphorylation and downregulated Akt2, ERK1/2, and p38 phosphorylation. As expected, M. bovis CFP induced substantial amounts of IL1-β, IL-6, TNF-α, IL-8, IL-12, and IL-10. However, the PRL costimulation considerably decreased IL1-β, TNF-α, and IL-12 secretion, and increased IL-10 production. This results suggest that up-regulation of IL-10 by PRL might be modulating the pro-inflammatory response against mycobacterial antigens through the MAPK pathway.

  7. 18β-Glycyrrhetinic Acid, a Novel Naturally Derived Agent, Suppresses Prolactin Hyperactivity and Reduces Antipsychotic-Induced Hyperprolactinemia in In Vitro and In Vivo Models.

    Wang, Di; Zhang, Yongfeng; Wang, Chunyue; Jia, Dongxu; Cai, Guangsheng; Lu, Jiahui; Wang, Di; Zhang, Zhang-Jin


    The purpose of this study was to examine the effects of 18β-glycyrrhetinic acid (GA), a novel naturally derived agent, in suppressing prolactin (PRL) hyperactivity and reducing antipsychotic-induced hyperprolactinemia (hyperPRL) and the underlying mechanisms in in vitro and in vivo models. GA treatment for 24 h inhibited PRL synthesis and secretion in MMQ cells and cultured pituitary cells in a dose-dependent fashion; but this effect was not reproduced in GH3 cells that lack the expression of functional dopamine D2 receptors. GA suppressed elevated PRL level and growth hormone, and normalized several sex hormones in a rat model of hyperPRL, produced by repeated injection of the dopamine blocker metoclopramide. GA also modulated the expression 5-HT1A and 5-HT2A receptors in both in vivo and in vitro models. These results indicate that GA is effective in suppressing PRL hyperactivity caused by the blockade of dopamine D2 receptors. This suppressive effect of GA may be related to its modulation of the serotonergic system. This study provides additional evidence in support of GA as an adjunct for the treatment of hyperPRL.

  8. The Role of Protein Kinase C and Its Effect on GHRH in the Regulation of Hormone Secretion by Somatotrophinomas

    LIU Kui; BAI Xiangjun; LEI Ting; XUE Delin; LIU Qin


    Phorbol ester-induced release of growth hormone (GH) and prolactin (PRL) from human somatotrophic tumors was examined in vitro. 12-O-tetradecanoyl-phorbol-13- acetate (TPA)strongly stimulated GH and PRL secretion and showed an additive effect on GH secretion if used in combination with GH releasing hormone (GHRH). In contrast, staurosporine exerted a variable inhibitory effect on GH release. There was no correlation between such effects and gsp mutations.The findings suggested that TPA doesn't act directly through cAMP signal transduction system.

  9. Endogenous prolactin generated during peripheral inflammation contributes to thermal hyperalgesia.

    Scotland, Phoebe E; Patil, Mayur; Belugin, Sergei; Henry, Michael A; Goffin, Vincent; Hargreaves, Kenneth M; Akopian, Armen N


    Prolactin (PRL) is a hormone and a neuromodulator. It sensitizes TRPV1 (transient receptor potential cation channel subfamily V member 1) responses in sensory neurons, but it is not clear whether peripheral inflammation results in the release of endogenous PRL, or whether endogenous PRL is capable of acting as an inflammatory mediator in a sex-dependent manner. To address these questions, we examined inflammation-induced release of endogenous PRL, and its regulation of thermal hyperalgesia in female and male rats. PRL is expressed in several types of peripheral neuronal and non-neuronal cells, including TRPV1-positive nerve fibers, preadipocytes and activated macrophages/monocytes localized in the vicinity of nerves. Evaluation of PRL levels in hindpaws and plasma indicated that complete Freund's adjuvant (CFA) stimulates release of peripheral, but not systemic, PRL within 6-48 h in both ovariectomized females with estradiol replacement (OVX-E) and intact male rats. The time course of release varies in OVX-E and intact male rats. We next employed the prolactin receptor (PRL-R) antagonist Δ1-9-G129R-hPRL to assess the role of locally produced PRL in nociception. Applied at a ratio of 1 : 1 (PRL:Δ1-9-G129R-hPRL; 40 nm each), this antagonist was able to nearly (≈ 80%) reverse PRL-induced sensitization of capsaicin responses in rat sensory neurons. CFA-induced inflammatory thermal hyperalgesia in OVX-E rat hindpaws was significantly reduced in a dose-dependent manner by the PRL-R antagonist at 6 h but not at 24 h. In contrast, PRL contributed to inflammatory thermal hyperalgesia in intact male rats at 24, but not at 6 h. These findings indicate that inflammation leads to accumulation of endogenous PRL in female and male rats. Furthermore, PRL acts as an inflammatory mediator at different time points for female and intact male rats.

  10. Effect of THIP and SL 76002, two clinically experimented GABA-mimetic compounds, on anterior pituitary GABA receptors and prolactin secretion in the rat

    Apud, J.A.; Masotto, C.; Racagni, G.


    In the present study, the ability of three direct GABA agonists, muscimol, THIP and SL 76002 to displace /sup 3/H-GABA binding from anterior pituitary and medio-basal hypothalamus membranes was evaluated. Further, the effect of both THIP and SL 76002 on baseline prolactin levels or after stimulation of hormone release with haloperidol has been also studied. Either muscimol, THIP or SL 76002 have shown to posses 7-, 7- and 3-fold higher affinity, respectively, for the central nervous system than for the anterior pituitary /sup 3/H-GABA binding sites. Moreover, THIP and SL 76002 have demonstrated to be respectively, 25- and 1000- fold less potent than muscimol in inhibiting /sup 3/H- GABA binding at the level of the anterior pituitary and about 25- and 2700-fold less potent at the level of the medio-basal hypothalamus. Under basal conditions, either THIP or SL 76002 were ineffective to reduce prolactin release. However, after stimulation of prolactin secretion through blockade of the dopaminergic neurotransmission with haloperidol (0.1 mg/kg), both THIP (10 mg/kg) and SL 76002 (200 mg/kg) significantly counteracted the neuroleptic-induced prolactin rise with a potency which is in line with their ability to inhibit /sup 3/H-GABA binding in the anterior pituitary. The present results indicate that both compounds inhibit prolactin release under specific experimental situations probably through a GABAergic mechanism. In view of the endocrine effects of these GABA-mimetic compounds, the possibility arises for an application of these type of drugs in clinical neuroendocrinology. 35 references, 3 figures, 2 tables.

  11. Serum prolactin concentrations are elevated after syncope.

    Oribe, E; Amini, R; Nissenbaum, E; Boal, B


    The distinction between syncope and epileptic seizures is a common clinical diagnostic problem. Elevated serum prolactin (PRL) concentrations are used to help differentiate epileptic from nonepileptic attacks such as pseudoseizures. Reports of PRL concentrations following syncope have been variable. To determine whether PRL rises after syncope, we measured serum PRL concentrations during a 45-minute passive 60-degree head-up tilt in 21 patients with a history of near-fainting or syncope. Head-up tilt triggered hypotension (mean arterial pressure 51 mm Hg, 95% CI = 45-57) with syncope in 11 patients. PRL concentrations were elevated ( > 19 ng/mL) and reached a maximum within the first 30 minutes after tilt-induced syncope in nine patients (PRL supine: 11 ng/mL, 95% CI = 7-15, vs. PRL after syncope: 52 ng/mL, 95% CI = 36-67; a greater than fourfold rise), while they remained unchanged in 10 patients who had a normal response to head-up tilt (PRL supine: 6 ng/mL, 95% CI = 5-8, vs. maximum PRL while upright: 8 ng/mL, 95% CI = 6-10). The findings indicate that elevated PRL concentrations are present after hypotensive syncope and are of little use in differentiating such syncope from epileptic seizures.

  12. 体外取精对血清催乳素水平的影响%Effects of ejaculation by masturbation in vitro on serum prolactin secretion

    史轶超; 庄建平; 卢建林; 杨辰; 杨慎敏; 程洪波; 沈丽燕; 王挺; 孙健


    Objective To investigate the effects of ejaculation by masturbation in vitro on serum reproductive hormone release and to evaluate the relationship between prolactin raising and orgasm satisfaction.Methods One hundred and seventy-two men were divided into two groups according to the time of collecting the blood before or after ejaculation.The after ejaculation group was further divided into two subgroups according to the orgasm satisfaction.Serum reproductive hormone levels were then assessed in different groups.Results Serum prolactin level was significant higher in the after ejaculation group (0.55 ± 0.18)nmol/L than in the before ejaculation group [(0.35 ± 0.17) nmol/L,P < 0.05].Prolactin level was significant lower in insufficient orgasm men (0.43 ± 0.13) nmol/L than in orgasm satisfied men [(0.57 ±0.18) nmol/L,P < 0.05].The other reproductive hormone (testosterone,estradiol,follicle stimulating hormone and luteinizing hormone) showed no significant difference in different groups.Conclusions Serum prolactin level is increased after ejaculation and maybe related to the orgasm satisfaction status.Elevated serum prolactin level perhaps could be used as a marker in assessing the semen collection by masturbation.%目的 探讨体外取精对生殖激素水平的影响及催乳素(prolactin,PRL)水平升高与取精充分度之间的关系. 方法 按体外取精时间将172例受检者分为排精前组和排精后组,比较两组间生殖激素的差异;将排精后82例按排精性高潮程度分为性满意组和不充分组,观察两组血清生殖激素水平的差异. 结果 取精前后血清催乳素水平[(0.35±0.17)与(0.55-0.18) nmol/L]差异有统计学意义(P<0.05).性高潮不充分组与满意组血清催乳素水平[(0.43±0.13)与(0.57±0.18)nmol/L]差异有统计学意义(P<0.05).不同组间睾酮、雌二醇、促卵泡激素和促黄体生成素水平差异无统计学意义(P>0.05). 结论 体外排精可引起催乳素分泌

  13. Comparative genomics reveals tissue-specific regulation of prolactin receptor gene expression

    Prolactin (PRL), acting via the prolactin receptor, fulfills a diversity of biological functions including the maintenance of solute balance and mineral homeostasis via tissues such as the heart, kidneys and intestine. Expression and activity of the prolactin receptor (PRLR) is regulated by various ...

  14. Prolactin family of the guinea pig, Cavia porcellus.

    Alam, S M Khorshed; Konno, Toshihiro; Rumi, M A Karim; Dong, Yafeng; Weiner, Carl P; Soares, Michael J


    Prolactin (PRL) is a multifunctional hormone with prominent roles in regulating growth and reproduction. The guinea pig (Cavia porcellus) has been extensively used in endocrine and reproduction research. Thus far, the PRL cDNA and protein have not been isolated from the guinea pig. In the present study, we used information derived from the public guinea pig genome database as a tool for identifying guinea pig PRL and PRL-related proteins. Guinea pig PRL exhibits prominent nucleotide and amino acid sequence differences when compared with PRLs of other eutherian mammals. In contrast, guinea pig GH is highly conserved. Expression of PRL and GH in the guinea pig is prominent in the anterior pituitary, similar to known expression patterns of PRL and GH for other species. Two additional guinea pig cDNAs were identified and termed PRL-related proteins (PRLRP1, PRLRP2). They exhibited a more distant relationship to PRL and their expression was restricted to the placenta. Recombinant guinea pig PRL protein was generated and shown to be biologically active in the PRL-responsive Nb2 lymphoma cell bioassay. In contrast, recombinant guinea pig PRLRP1 protein did not exhibit PRL-like bioactivity. In summary, we have developed a new set of research tools for investigating the biology of the PRL family in an important animal model, the guinea pig.

  15. Immunoradiometric assay for prolactin in serum and tissue; Comparison with radioimmunoassay

    Ohnami, Shumpei; Nakata, Hajime; Eto, Sumiya (University of Occupational and Environmental Health Hospital, Kitakyushu, Fukuoka (Japan))


    Prolactin (PRL) concentrations in sera and tumors of patients with various pituitary tumors were measured by both immunoradiometric assay (IRMA) and radioimmunoassay (RIA). PRL concentrations in sera and tumor tissues measured by IRMA were well correlated with those measured by RIA. PRL concentrations in sera reflected those of tumors removed. This IRMA is a simple and useful method for PRL determination in serum and tissue. (author).

  16. Suppression of Serum Prolactin Levels after Sports Concussion with Prompt Resolution Upon Independent Clinical Assessment To Permit Return-to-Play.

    La Fountaine, Michael F; Toda, Michita; Testa, Anthony; Bauman, William A


    A significant outflow of neurotransmitters and metabolites with associated enhanced cortical excitation occurs after concussive head trauma. Cellular changes in the acute post-injury period cannot be observed directly in humans, and as such, require indirect evidence from systems sufficiently sensitive to central neuronal cellular excitation. Dopamine is a neurotransmitter with numerous targets in the central and peripheral nervous system. Changes to central dopaminergic tone result in reciprocal responses to the level of serum prolactin (PRL). Thus, a concussion may lead to abnormal dopaminergic tone, resulting in dynamic perturbations in the serum PRL concentration. To determine the effect of concussion on serum PRL concentrations, venipuncture was performed in the morning in four male intercollegiate athletes (age, 20 ± 1 years; height, 71 ± 5 inches; weight, 174 ± 21 pounds) within 48 h of concussion and again at 7 and 14 days post-injury. Serum PRL concentrations for each visit were categorized by quartile within the normal range. In all athletes, serum PRL concentrations increased from the lower quartiles in samples obtained closer to the time of injury to the higher quartiles at 14 days post-injury. These serum PRL changes accompanied the resolution of symptoms and the clinical decision to permit return-to-play. It may be postulated that transient augmentation of central dopaminergic tone resulted in inhibition of PRL secretion early after concussion and that disinhibition of PRL release occurred when central dopaminergic tone subsequently returned to baseline levels. This novel observation provides evidence for dopaminergic dysfunction after concussion that may be tracked by determination of serum PRL levels.

  17. 泌乳素检测与早产相关性研究%Correlation Study on Prolactin Testing and Preterm Delivery



    Objective To explore the role of prolactin (PRL) level of vaginal secretion in predicting preterm delivery through examining PRL level of pregnant women who gave preterm birth. Methods Examined PRL level of 50 preterm pregnant women as observation group and 50 normal pregnant women as control group using EIA (Enzyme Immunoassay) and car ied out analysis and comparison between them.Results The positive rate of PRL in observation group was higher than that in control group,which suggested statistical y significance( <0.05);the preterm birth rate of patients whose PRL test result was positive was higher than that of patients who were PRL-negative,suggesting statistical y significance ( <0.01).Conclusion PRL positivity could be a biochemical indicator of preterm delivery prediction.%目的通过对早产孕妇患者阴道分泌物中泌乳素(PRL)水平测量,探讨阴道分泌物中泌乳素(PRL)水平在预测早产中的作用。方法利用EIA法检测50例早产孕妇宫颈阴道分泌物泌乳素水平和50例对照组宫颈阴道分泌物泌乳素水平,并进行分析和对比。结果早产组PRL阳性率高于对照组,差异有统计学意义(<0.05);PRL检测呈阳性的患者早产率高于PRL阴性患者,差异有统计学意义(<0.01)。结论母体阴道分泌物泌乳素阳性可能是预测早产的生化指标。

  18. In vitro seasonal variations of LH, FSH and prolactin secretion of the male rat are dependent on the maternal pineal gland.

    Díaz, E; Vázquez, N; Fernández, C; Jiménez, V; Esquifino, A; Díaz, B


    The maternal pineal gland is involved in the seasonal rhythms entrainment. We evaluate the effect of maternal pinealectomy (PIN-X), also melatonin replacement (PIN-X+MEL) during pregnancy on "in vitro" gonadotropins and prolactin seasonal variations. Male offspring from control, PIN-X and PIN-X+MEL mother Wistar rats were studied at 31 and 60 days of age. In vitro LH release from controls was season-dependent during prepubertal and pubertal periods showing reduced values in winter. The mother pineal gland seems to be important in the entrainment of seasonal variations of in vitro pituitary LH release, since altered secretion showing very high values was observed in summer. Melatonin treatment to PIN-X mothers partially restored the LH response. The effect of pinealectomy upon LH secretion disappears at the pubertal phase. A different pattern was observed for FSH release, without seasonal variations at 31 or at 60 days of age in control offspring, but pinealectomy to mothers or melatonin treatment resulted in seasonal variations. Seasonal influence was also observed in the prolactin pituitary release of controls. PIN-X mother offspring showed delayed seasonal variations at 31 and 60 days of age. The effect of maternal melatonin treatment during pregnancy was observed up to 60 days of age.

  19. Prolactin and cancer: Has the orphan finally found a home?

    Bipin Kumar Sethi


    Full Text Available Prolactin has, for long, been associated with galactorrhea and infertility in women while its role in men is largely unknown. Recently, expression of prolactin in various other tissues like the breast, prostate, decidua, and the brain has been recognized. This has led to evaluation of paracrine and autocrine actions of prolactin at these tissues and a possible role in development of various cancers. Increased expression of PRL receptors has also been implicated in carcinogenesis. Breast cancer has the strongest association with increased prolactin and prolactin receptor levels. Prostate cancer also has reported significant association, while the role of prolactin in colorectal, gynecological, laryngeal, and hepatocellular cancers is more tenuous. Prolactin/prolactin receptor pathway has also been implicated in development of resistance to chemotherapy. Thus, the effects of this pathway in carcinogenesis seem widespread. At the same time, they also offer an exciting new approach to hormonal manipulation of cancers, especially the treatment-resistant cancers.

  20. Mammary gland copper transport is stimulated by prolactin through alterations in Ctr1 and Atp7A localization.

    Kelleher, Shannon L; Lönnerdal, Bo


    Milk copper (Cu) concentration declines and directly reflects the stage of lactation. Three Cu-specific transporters (Ctr1, Atp7A, Atp7B) have been identified in the mammary gland; however, the integrated role they play in milk Cu secretion is not understood. Whereas the regulation of milk composition by the lactogenic hormone prolactin (PRL) has been documented, the specific contribution of PRL to this process is largely unknown. Using the lactating rat as a model, we determined that the normal decline in milk Cu concentration parallels declining Cu availability to the mammary gland and is associated with decreased Atp7B protein levels. Mammary gland Cu transport was highest during early lactation and was stimulated by suckling and hyperprolactinemia, which was associated with Ctr1 and Atp7A localization at the plasma membrane. Using cultured mammary epithelial cells (HC11), we demonstrated that Ctr1 stains in association with intracellular vesicles that partially colocalize with transferrin receptor (recycling endosome marker). Atp7A was primarily colocalized with mannose 6-phosphate receptor (M6PR; late endosome marker), whereas Atp7B was partially colocalized with protein disulfide isomerase (endoplasmic reticulum marker), TGN38 (trans-Golgi network marker) and M6PR. Prolactin stimulated Cu transport as a result of increased Ctr1 and Atp7A abundance at the plasma membrane. Although the molecular mechanisms responsible for these posttranslational changes are not understood, transient changes in prolactin signaling play a role in the regulation of mammary gland Cu secretion during lactation.

  1. Prolactin receptor and signal transduction to milk protein genes

    Djiane, J.; Daniel, N.; Bignon, C. [Unite d`Endocrinologie Moleculaire, Jouy en Josas (France)] [and others


    After cloning of the mammary gland prolactin (PRL) receptor cDNA, a functional assay was established using co-transfection of PRL receptor cDNA together with a milk protein promoter/chloramphenicol acetyl transferase (CAT) construct in Chinese hamster ovary (CHO) cells. Different mutants of the PRL receptor were tested in this CAT assay to delimit the domains in the receptor necessary for signal transduction to milk protein genes. In CHO cells stably transfected with PRL receptor cDNA, high numbers of PRL receptor are expressed. By metabolic labeling and immunoprecipitation, expressed PRL receptor was identified as a single species of 100 kDa. Using these cells, we analyzed the effects of PRL on intracellular free Ca{sup ++} concentration. PRL stimulates Ca{sup ++} entry and induces secondary Ca{sup ++} mobilization. The entry of Ca{sup ++} is a result of an increase in K{sup +} conductance that hyperpolarizes the membranes. We have also analyzed tyrosine phosphorylation induced by PRL. In CHO cells stably transfected with PRL receptor cDNA, PRL induced a very rapid and transient tyrosine phosphorylation of a 100-kDa protein which is most probably the PRL receptor. The same finding was obtained in mammary membranes after PRL injection to lactating rabbits. Whereas tyrosine kinase inhibitors genistein and lavendustin were without effect, PRL stimulation of milk protein gene promoters was partially inhibited by 2 {mu}M herbimycin in CHO cells co-transfected with PRL receptor cDNA and the {Beta} lactoglobulin CAT construct. Taken together these observations indicate that the cytoplasmic domain of the PRL receptor interacts with one or several tyrosine kinases, which may represent early postreceptor events necessary for PRL signal transduction to milk protein genes. 14 refs., 4 figs.


    The availability of prolactin (PRL) to the neonatal brain is known to affect the development of the tuberoinfundibular (TIDA) neurons and, as a consequence, lead to alterations in subsequent PRL regulation. Without early lactational exposure to PRL (derived from the dam's milk), ...

  3. Altering prolactin concentrations in sows.

    Farmer, C


    Prolactin has a multiplicity of actions, but it is of particular importance in gestating and lactating animals. In sows, it is involved in the control of mammary development and also holds essential roles in the lactogenic and galactopoietic processes. Furthermore, low circulating concentrations of prolactin are associated with the agalactia syndrome. The crucial role of prolactin makes it important to understand the various factors that can alter its secretion. Regulation of prolactin secretion is largely under the negative control of dopamine, and dopamine agonists consistently decrease prolactin concentrations in sows. On the other hand, injections of dopamine antagonists can enhance circulating prolactin concentrations. Besides pharmacologic agents, many other factors can also alter prolactin concentrations in sows. The use of Chinese-derived breeds, for instance, leads to increased prolactin concentrations in lactating sows compared with standard European white breeds. Numerous husbandry and feeding practices also have a potential impact on prolactin concentrations in sows. Factors, such as provision of nest-building material prepartum, housing at farrowing, high ambient temperature, stress, transient weaning, exogenous thyrotropin-releasing factor, exogenous growth hormone-releasing factor, nursing frequency, prolonged photoperiod, fasting, increased protein and/or energy intake, altered energy sources, feeding high-fiber diets, sorghum ergot or plant extracts, were all studied with respect to their prolactinemic properties. Although some of these practices do indeed affect circulating prolactin concentrations, none leads to changes as drastic as those brought about by dopamine agonists or antagonists. It appears that the numerous factors regulating prolactin concentrations in sows are still not fully elucidated, and that studies to develop novel applicable ways of increasing prolactin concentrations in sows are warranted. Crown Copyright © 2015. Published

  4. PRL-3 activates mTORC1 in Cancer Progression.

    Ye, Zu; Al-Aidaroos, Abdul Qader Omer; Park, Jung Eun; Yuen, Hiu Fung; Zhang, Shu Dong; Gupta, Abhishek; Lin, Youbin; Shen, Han-Ming; Zeng, Qi


    PRL-3, a metastasis-associated phosphatase, is known to exert its oncogenic functions through activation of PI3K/Akt, which is a key regulator of the rapamycin-sensitive mTOR complex 1 (mTORC1), but a coherent link between PRL-3 and activation of mTOR has not yet been formally demonstrated. We report a positive correlation between PRL-3 expression and mTOR phospho-activation in clinical tumour samples and mouse models of cancer and demonstrate that PRL-3 increased downstream signalling to the mTOR substrates, p70S6K and 4E-BP1, by increasing PI3K/Akt-mediated activation of Rheb-GTP via TSC2 suppression. We also show that PRL-3 increases mTOR translocation to lysosomes via increased mTOR binding affinity to Rag GTPases in an Akt-independent manner, demonstrating a previously undescribed mechanism of action for PRL-3. PRL-3 also enhanced matrix metalloproteinase-2 secretion and cellular invasiveness via activation of mTOR, attributes which were sensitive to rapamycin treatment. The downstream effects of PRL-3 were maintained even under conditions of environmental stress, suggesting that PRL-3 provides a strategic survival advantage to tumour cells via its effects on mTOR.

  5. The role of prolactin in fish reproduction.

    Whittington, Camilla M; Wilson, Anthony B


    Prolactin (PRL) has one of the broadest ranges of functions of any vertebrate hormone, and plays a critical role in regulating aspects of reproduction in widely divergent lineages. However, while PRL structure, mode of action and functions have been well-characterised in mammals, studies of other vertebrate lineages remain incomplete. As the most diverse group of vertebrates, fish offer a particularly valuable model system for the study of the evolution of reproductive endocrine function. Here, we review the current state of knowledge on the role of prolactin in fish reproduction, which extends to migration, reproductive development and cycling, brood care behaviour, pregnancy, and nutrient provisioning to young. We also highlight significant gaps in knowledge and advocate a specific bidirectional research methodology including both observational and manipulative experiments. Focusing research efforts towards the thorough characterisation of a restricted number of reproductively diverse fish models will help to provide the foundation necessary for a more explicitly evolutionary analysis of PRL function.

  6. Expression of prolactin receptor and response to prolactin stimulation of human NK cell lines

    Rui SUN; Ai Ling LI; Hai Ming WEI; Zhi Gang TIAN


    We have previously shown a critical role of prolactin (PRL) during maturation and anti-tumor effects of murine natural killer (NK) cells in vitro and in vivo. We extended that study by exploring the ability of human NK cell lines (NK-92 and YT cell) to express PRL receptor (PRL-R) and to respond to PRL stimulation in vitro. Both human NK cell lines constitutively expressed PRL-R on membrane and mRNA transcripts,NK-92 cells contained higher level of PRL-R than YT cells,which correlated to the enhanced capacity of the cells to proliferate and to lyse target cells in response to PRL stimulation in the presence of trace amount of IL-2 or IL-15 in vitro. Two differences between IL-2 and IL-15 in functioning on human NK cells were for the first time observed. PRL synergized with IL-15 to improve proliferation of NK cells in a dose-dependent manner without double peak manifesting like IL-2. Although PRL enhanced the cytotoxicity of IL-2 or IL- 15 activated NK cells,it exerted the function through up-regulating gene expression of perforin without influence of FasL in IL-2-stimulated NK cells,while in IL-15-stimulated NK cells,PRL did the function through up-regulating gene expression of both perforin and FasL but not IFNγ. PRL increased expressions of IL-2Rα on membrane and of IL-2 mRNA in cells,indicating that PRL up-regulated NK cell function by improving positive feedback between IL-2 and IL-2R. The similar results were also observed in network between IL-15 and IL-15R. These data indicate a potential role of PRL in human NK cell modulation.

  7. Discovery of conventional prolactin from the holocephalan elephant fish, Callorhinchus milii.

    Yamaguchi, Yoko; Takagi, Wataru; Kuraku, Shigehiro; Moriyama, Shunsuke; Bell, Justin D; Seale, Andre P; Lerner, Darren T; Grau, E Gordon; Hyodo, Susumu


    The conventional prolactin (PRL), also known as PRL1, is an adenohypophysial hormone that critically regulates various physiological events in reproduction, metabolism, growth, osmoregulation, among others. PRL1 shares its evolutionary origin with PRL2, growth hormone (GH), somatolactin and placental lactogen, which together form the GH/PRL hormone family. Previously, several bioassays implied the existence of PRL1 in elasmobranch pituitaries. However, to date, all attempts to isolate PRL1 from chondrichthyans have been unsuccessful. Here, we cloned PRL1 from the pituitary of the holocephalan elephant fish, Callorhinchus milii, as the first report of chondrichthyan PRL1. The putative mature protein of elephant fish PRL1 (cmPRL1) consists of 198 amino acids, containing two conserved disulfide bonds. The orthologous relationship of cmPRL1 to known vertebrate PRL1s was confirmed by the analyses of molecular phylogeny and gene synteny. The cmPRL1 gene was similar to teleost PRL1 genes in gene synteny, but was distinct from amniote PRL1 genes, which most likely arose in an early amphibian by duplication of the ancestral PRL1 gene. The mRNA of cmPRL1 was predominantly expressed in the pituitary, but was considerably less abundant than has been previously reported for bony fish and tetrapod PRL1s; the copy number of cmPRL1 mRNA in the pituitary was less than 1% and 0.1% of that of GH and pro-opiomelanocortin mRNAs, respectively. The cells expressing cmPRL1 mRNA were sparsely distributed in the rostral pars distalis. Our findings provide a new insight into the studies on molecular and functional evolution of PRL1 in vertebrates. Copyright © 2015 Elsevier Inc. All rights reserved.

  8. Analysis of the Result of Detecting Prolactine (PRL) in 1086 Cases of Infertility and Menstruation Abnormality%1086例不孕不育及月经异常患者催乳激素(PRL)检测结果分析

    邵细琴; 廖巧如; 邹智伦



  9. Effects of central infusion of ghrelin on food intake and plasma levels of growth hormone, luteinizing hormone, prolactin, and cortisol secretion in sheep.

    Iqbal, Javed; Kurose, Yohei; Canny, Benedict; Clarke, Iain J


    Ghrelin is an endogenous ligand for the GH secretagogue/ghrelin receptor (GHS-R) and stimulates feeding behavior and GH levels in rodents and humans. A preprandial increase in plasma ghrelin levels is seen in sheep on programmed feeding, followed by a postprandial rise in plasma GH levels, but effects on food intake and endocrine function are not defined in this ruminant species. We administered ghrelin to female sheep in various modes and measured effects on voluntary food intake (VFI) and plasma levels of GH, LH, prolactin, and cortisol. Whether administered intracerebroventricularly or iv, ghrelin consistently failed to stimulate VFI. On the other hand, ghrelin invariably increased plasma GH levels and alpha,beta-diaminopropanoic acid-octanoyl3 human ghrelin was more potent than ovine ghrelin. Bolus injection of ghrelin into the third cerebral ventricle reduced plasma LH levels but did not affect levels of prolactin or cortisol. These findings suggested that the preprandial rise in plasma ghrelin that is seen in sheep on programmed feeding does not influence VFI but is likely to be important in the postprandial rise in GH levels. Thus, ghrelin does not appear to be a significant regulator of ingestive behavior in this species of ruminant but acts centrally to indirectly regulate GH and LH secretion.

  10. Prolactin blood test

    ... test; Amenorrhea - prolactin test; Breast leakage - prolactin test; Prolactinoma - prolactin test; Pituitary tumor - prolactin test ... hypothyroidism ) Kidney disease Pituitary tumor that makes prolactin (prolactinoma) Other pituitary tumors and diseases in the area ...

  11. Diurnal secretion of ghrelin, growth hormone, insulin binding proteins, and prolactin in normal weight and overweight subjects with and without the night eating syndrome.

    Birketvedt, Grethe S; Geliebter, Allan; Kristiansen, Ingrid; Firgenschau, Yngve; Goll, Rasmus; Florholmen, Jon R


    was observed in healthy overweight (ns). We conclude that in both NES groups and in healthy overweight subjects more or less attenuated ghrelin and GH secretions were observed, whereas divergent secretions were observed for prolactin.

  12. Prolactin induces apoptosis of lactotropes in female rodents.

    Jimena Ferraris

    Full Text Available Anterior pituitary cell turnover occurring during female sexual cycle is a poorly understood process that involves complex regulation of cell proliferation and apoptosis by multiple hormones. In rats, the prolactin (PRL surge that occurs at proestrus coincides with the highest apoptotic rate. Since anterior pituitary cells express the prolactin receptor (PRLR, we aimed to address the actual role of PRL in the regulation of pituitary cell turnover in cycling females. We showed that acute hyperprolactinemia induced in ovariectomized rats using PRL injection or dopamine antagonist treatment rapidly increased apoptosis and decreased proliferation specifically of PRL producing cells (lactotropes, suggesting a direct regulation of these cell responses by PRL. To demonstrate that apoptosis naturally occurring at proestrus was regulated by transient elevation of endogenous PRL levels, we used PRLR-deficient female mice (PRLRKO in which PRL signaling is totally abolished. According to our hypothesis, no increase in lactotrope apoptotic rate was observed at proestrus, which likely contributes to pituitary tumorigenesis observed in these animals. To decipher the molecular mechanisms underlying PRL effects, we explored the isoform-specific pattern of PRLR expression in cycling wild type females. This analysis revealed dramatic changes of long versus short PRLR ratio during the estrous cycle, which is particularly relevant since these isoforms exhibit distinct signaling properties. This pattern was markedly altered in a model of chronic PRLR signaling blockade involving transgenic mice expressing a pure PRLR antagonist (TGΔ1-9-G129R-hPRL, providing evidence that PRL regulates the expression of its own receptor in an isoform-specific manner. Taken together, these results demonstrate that i the PRL surge occurring during proestrus is a major proapoptotic signal for lactotropes, and ii partial or total deficiencies in PRLR signaling in the anterior pituitary

  13. Prolactin induces apoptosis of lactotropes in female rodents.

    Ferraris, Jimena; Zárate, Sandra; Jaita, Gabriela; Boutillon, Florence; Bernadet, Marie; Auffret, Julien; Seilicovich, Adriana; Binart, Nadine; Goffin, Vincent; Pisera, Daniel


    Anterior pituitary cell turnover occurring during female sexual cycle is a poorly understood process that involves complex regulation of cell proliferation and apoptosis by multiple hormones. In rats, the prolactin (PRL) surge that occurs at proestrus coincides with the highest apoptotic rate. Since anterior pituitary cells express the prolactin receptor (PRLR), we aimed to address the actual role of PRL in the regulation of pituitary cell turnover in cycling females. We showed that acute hyperprolactinemia induced in ovariectomized rats using PRL injection or dopamine antagonist treatment rapidly increased apoptosis and decreased proliferation specifically of PRL producing cells (lactotropes), suggesting a direct regulation of these cell responses by PRL. To demonstrate that apoptosis naturally occurring at proestrus was regulated by transient elevation of endogenous PRL levels, we used PRLR-deficient female mice (PRLRKO) in which PRL signaling is totally abolished. According to our hypothesis, no increase in lactotrope apoptotic rate was observed at proestrus, which likely contributes to pituitary tumorigenesis observed in these animals. To decipher the molecular mechanisms underlying PRL effects, we explored the isoform-specific pattern of PRLR expression in cycling wild type females. This analysis revealed dramatic changes of long versus short PRLR ratio during the estrous cycle, which is particularly relevant since these isoforms exhibit distinct signaling properties. This pattern was markedly altered in a model of chronic PRLR signaling blockade involving transgenic mice expressing a pure PRLR antagonist (TGΔ1-9-G129R-hPRL), providing evidence that PRL regulates the expression of its own receptor in an isoform-specific manner. Taken together, these results demonstrate that i) the PRL surge occurring during proestrus is a major proapoptotic signal for lactotropes, and ii) partial or total deficiencies in PRLR signaling in the anterior pituitary may result in

  14. Role of prolactin in B cell regulation in multiple sclerosis.

    Correale, Jorge; Farez, Mauricio F; Ysrraelit, María Célica


    The role of prolactin in MS pathogenesis was investigated. Prolactin levels were higher in MS subjects both during remission and exacerbation compared to control subjects. Prolactin increased JAK2 expression and Stat phosphorylation on B cells, up-regulated anti-MOG antibody secreting cell numbers, BAFF levels, and Bcl-2expression, and down-regulated expression of Trp63. Prolactin levels correlated positively with anti-MOG secreting cell numbers, and negatively with induced apoptotic B cells. Additionally, prolactin decreased B cell receptor-mediated activation threshold, and induced CD40 expression in B cells. These findings suggest that prolactin promotes B cell autoreactivity in MS through different mechanisms.

  15. Effects of sulpiride on prolactin and mRNA levels of steroid 5alpha-reductase isozymes in adult rat brain.

    Sánchez, Pilar; Torres, Jesús M; Vílchez, Pablo; Del Moral, Raimundo G; Ortega, Esperanza


    Prolactin (PRL) promotes maternal behavior (MB), a complex pattern of behavior aimed at maximizing offspring survival. 3alpha,5alpha-reduced neurosteroids may also regulate MB. Indeed, PRL, 3alpha,5alpha-reduced neurosteroids, and 5alpha-reductase (5alpha-R), the key enzyme in the biosynthesis of these neuroactive steroids, are all increased in stress situations These facts led us to hypothesize a possible interrelation between PRL levels and 5alpha-R. In the present study we quantified mRNA levels of both 5alpha-R isozymes in prefrontal cortex of male and female rats after administration of sulpiride, an inductor of PRL secretion. Our results demonstrated that mRNA levels of both 5alpha-R isozymes were significantly increased in male and female rats by sulpiride, directly or via sulpiride-induced hyperprolactinemia. Since 3alpha,5alpha-reduced neurosteroids and PRL exert anxiolytic effects in response to stress, these molecules and 5alpha-R may possibly participate in a common pathway of significant adaptation to stress situations.

  16. Recombinant Human Prolactin Protects against Irradiation Induced Myelosuppression

    Weici Zhang; Rui Sun; Jianhua Zhang; Jian Zhang; Zhigang Tian


    Prolactin is a multifunctional hormone that exerts many separate functions and acts as an important connection between the endocrine and immune systems. There are increasing researches implicating the role of prolactin in hematopoiesis. Enhanced erythropoiesis in pregnant women and direct erythropoietic effects in vitro of plasma either from pregnant or lactating mice have been reported. Furthermore, regression of erythroblastic leukemia has been observed in a significant number of rats after hypophysectomy. In this study, the effects of recombinant human prolactin (rhPRL) on hematopoiesis were assessed in irradiated mice. Mice were treated with rhPRL for five consecutive days after exposure to a lethal dose or a sub-dose irradiation. Prolonged survival rate and increased erythropoiesis were observed in the irradiation-induced myelosuppressive mice. It was concluded that rhPRL might act on erythropoiesis and could be a potential candidate for the treatment of irradiation-induced myelosuppresion in clinic. Cellular & Molecular Immunology.

  17. Prolactin receptor and osteogenic induction of prolactin in human periodontal ligament fibroblasts.

    Surarit, Rudee; Krishnamra, Nateetip; Seriwatanachai, Dutmanee


    Prolactin is an important hormone involved in the interaction between maternal, extraembryonic, and fetal tissues that remains in high levels during the entire duration of pregnancy. Although many systemic alterations occur during pregnancy, such as hormonal changes, that are known to be associated with periodontitis and tooth loss, PRL function in human periodontal ligament fibroblasts (HPDLF) had never been studied. Herein, we investigated the role of PRL in the regulation of HPDLF proliferation and differentiation. HPDLF were cultured in differentiating medium with various concentrations of PRL. The present study demonstrated that HPDLF and primary human PDL cells that were extracted for orthodontic purpose expressed both short and long isoforms of PRLR mRNA and its proteins. An incubation with of high concentration of PRL (600 and 1,000 ng/mL) modestly decreased the HPDLF number. In contrast, PRL at a non-reproductive level (10 ng/mL) and pregnant level (100 ng/mL) significantly upregulated the markers of osteogenesis, such as RUNX2, BMP2, and POSTN, but not SOX9. Mineral nodule formation was induced, whereas proteoglycan accumulation was reduced by PRL suggesting that HPDLF were undergoing differentiation into preosteoblastic cells. In conclusion, the presence of hPRLR in human PDL together with PRL-induced upregulation of osteogenic markers strongly suggested a direct regulatory role of PRL in PDL and periodontal tissue development.

  18. Prolactin and prolactin receptor expression in cervical intraepithelial neoplasia and cancer.

    Ascencio-Cedillo, Rafael; López-Pulido, Edgar Ivan; Muñoz-Valle, José Francisco; Villegas-Sepúlveda, Nicolás; Del Toro-Arreola, Susana; Estrada-Chávez, Ciro; Daneri-Navarro, Adrian; Franco-Topete, Ramón; Pérez-Montiel, Delia; García-Carrancá, Alejandro; Pereira-Suárez, Ana Laura


    Prolactin receptor (PRLR) overexpression could play a role in tumorigenesis. The aim of this study was to determine prolactin (PRL) and PRLR expression in biopsies from patients with precursor lesions and uterine cervical cancer. PRLR expression was analyzed in 63 paraffin-embedded biopsies of uterine cervical tissue. In total, eleven low-grade squamous intraepithelial lesions (LSIL), 23 high-grade squamous intraepithelial lesions (HSIL), 21 uterine cervical cancers (UCC) and 8 normal epithelium (NE) were examined using immunoperoxidase staining and Western blot analysis. Additionally, PRL expression was identified in human cervical cancer serum and tissues. The PRLR expression was found to be significantly increased in cervical cancer in comparison with normal tissue and precursor lesions (P prolactin expression was similar in precursor lesions and cervical cancer by Western blot analysis. Our data suggest a possible role for PRLR in the progression of cervical cancer.

  19. [Interest in prolactin levels in galactorrhea].

    Bessioud, Moncef; Mamlouk, Lilia; Djait, Riadh; Ben Aïssa, Rim; Gueddana, Nésiha


    The action of prolactin (PRL) in supra-physiological levels on the ovaries or on the hypothalamic-pituitary axis for the release of gonadotropins leads to a reversible inhibition of the cyclic functioning of the pituitary gland and of the ovaries. The consequences are either the production of immature follicles marked by anovulatory or dysovulatory cycles, or the absence of follicle production marked by amenorrhea. Thus, prolactin plays a major role in the productive system by its lactotropic and antigonadotropic effects. Through this study we intend to try to determine the diagnostic value of the association of the cyclic dysfunctions with galactorrhea by measuring the prolactin levels in 2236 patients complaining of galactorrhea. Measurements of FSH and LH levels were also performed in 236 women among those consulting for infertility associated with galactorrhea. The results obtained showed that galactorrhea was associated with prolactenemia in only 17% of cases and of the ovaries was proportional to the prolactin in blood.

  20. Prolactin stimulates precursor cells in the adult mouse hippocampus.

    Tara L Walker

    Full Text Available In the search for ways to combat degenerative neurological disorders, neurogenesis-stimulating factors are proving to be a promising area of research. In this study, we show that the hormonal factor prolactin (PRL can activate a pool of latent precursor cells in the adult mouse hippocampus. Using an in vitro neurosphere assay, we found that the addition of exogenous PRL to primary adult hippocampal cells resulted in an approximate 50% increase in neurosphere number. In addition, direct infusion of PRL into the adult dentate gyrus also resulted in a significant increase in neurosphere number. Together these data indicate that exogenous PRL can increase hippocampal precursor numbers both in vitro and in vivo. Conversely, PRL null mice showed a significant reduction (approximately 80% in the number of hippocampal-derived neurospheres. Interestingly, no deficit in precursor proliferation was observed in vivo, indicating that in this situation other niche factors can compensate for a loss in PRL. The PRL loss resulted in learning and memory deficits in the PRL null mice, as indicated by significant deficits in the standard behavioral tests requiring input from the hippocampus. This behavioral deficit was rescued by direct infusion of recombinant PRL into the hippocampus, indicating that a lack of PRL in the adult mouse hippocampus can be correlated with impaired learning and memory.

  1. Responses of cortisol and prolactin to sexual excitement and stress in stallions and geldings.

    Colborn, D R; Thompson, D L; Roth, T L; Capehart, J S; White, K L


    Sexual stimulation induces rapid secretion of cortisol and prolactin (PRL) in stallions. Experiment 1 was designated to determine whether stallions associated location and(or) procedure with previous sexual stimulation in that location. After a control period on d 1, four stallions were exposed to an estrous mare for 5 min on d 2. On d 3, 4, 5, and 6, the same procedure was followed with no mare present. Concentrations of PRL and cortisol increased (P less than .05) after mare exposure on d 2 but did not vary (P greater than .05) on d 1, 3, 4, 5, or 6. In Exp. 2, six stallions were used to determine the short-term effects of 1) sexual stimulation, 2) acute physical exercise, 3) restraint via a twitch (twitching), 4) epinephrine administration, and 5) no stimulation on plasma concentrations of PRL and cortisol. Stallions received one treatment per day separated by 2 d of no treatment. Concentrations of cortisol increased (P less than .05) within 10 min after sexual stimulation, exercise, twitching, and epinephrine administration but not during control bleedings. Concentrations of PRL increased (P less than .05) immediately after sexual stimulation, exercise, and twitching but not after epinephrine administration or during control bleeding. In Exp. 3, the same five treatments were administered to six geldings. Concentrations of cortisol increased (P less than .05) after epinephrine administration, exercise, and twitching but not after sexual stimulation or during control bleedings. Concentrations of PRL increased (P less than .05) after exercise and sexual stimulation.(ABSTRACT TRUNCATED AT 250 WORDS)

  2. Effect of various partial separations of the litters from their mother on plasma prolactin levels of lactating rats.

    Bánky, Z; Nagy, G M; Halász, B


    Removal of the pups results in an abrupt and marked depression in plasma prolactin (PRL) level of the lactating mother. The present studies were undertaken to investigate what kind of sensory input (smell, sound, visual, touch etc.) from the pups is essential for the mother to avoid the pituitary PRL response to pup-removal. Therefore, various partial separations were made and their effect on plasma PRL levels tested: a. The pups were placed into a small glass having holes on its cover; b. they were put into a long measuring tube not covered; c. the pups were placed into the feeding trough made of a wireframe; d. a dividing wall made of glass or metal was slowly let down when the mother spontaneously went away from her pups; e. the nipples were covered by a cotton plaster. Pituitary PRL responses were almost identical after all these separations and similar to that one obtained after removal of the pups from the cage. In addition, separation of the mother resulted in a rise in plasma corticosterone concentrations. The findings suggest that the pup-removal induced inhibition of PRL secretion is a very complex event for the mother and cannot be prevented by partial separations when the mother can see, smell her pups, or hear them or even can touch them with her nose. We assume that separation of the pups is a stress for the mother and cannot simply be due to the lack of just one kind of sensory input from the pups. This assumption is in line with our recent observations indicating that in lactating rat stress causes a decrease in plasma PRL level.

  3. Prolactin May Not Play a Role in Primary Antiphospholipid (Hughes') Syndrome

    Manoel Tavares Neves Junior; Carlos Ewerton Maia Rodrigues; Jozelio Freire de Carvalho


    The relationship between prolactin (PRL) and the immune system has been demonstrated in the last two decades and has opened new windows in the field of immunoendocrinology. However, there are scarce reports about PRL in primary antiphospholipid syndrome (pAPS). The objective of this study was to evaluate PRL levels in patients with pAPS compared to healthy controls and to investigate their possible clinical associations. Fifty-five pAPS patients according to Sapporo criteria were age- and sex...

  4. Overexpression of PRL7D1 in Leydig Cells Causes Male Reproductive Dysfunction in Mice.

    Liu, Yaping; Su, Xingyu; Hao, Jie; Chen, Maoxin; Liu, Weijia; Liao, Xiaogang; Li, Gang


    Prolactin family 7, subfamily d, member 1 (PRL7D1) is found in mouse placenta. Our recent work showed that PRL7D1 is also present in mouse testis Leydig cells, and the expression of PRL7D1 in the testis exhibits an age-related increase. In the present study, we generated transgenic mice with Leydig cell-specific PRL7D1 overexpression to explore its function during male reproduction. Prl7d1 male mice exhibited subfertility as reflected by reduced sperm counts and litter sizes. The testes from Prl7d1 transgenic mice appeared histologically normal, but the frequency of apoptotic germ cells was increased. Prl7d1 transgenic mice also had lower testosterone concentrations than wild-type mice. Mechanistic studies revealed that Prl7d1 transgenic mice have defects in the testicular expression of steroidogenic acute regulatory protein (STAR) and hydroxy-delta-5-steroid dehydrogenase, 3 beta- and steroid delta-isomerase cluster (HSD3B). Further studies revealed that PRL7D1 overexpression affected the expression of transferrin (TF) in Sertoli cells. These results suggest that PRL7D1 overexpression could lead to increased germ cell apoptosis and exert an inhibitory effect on testosterone production in Leydig cells by reducing the expression of certain steroidogenic-related genes. In addition, PRL7D1 appears to have important roles in the function of Sertoli cells, which, in turn, affects male fertility. We conclude that the expression level of PRL7D1 is associated with the reproductive function of male mice.

  5. LPXRFamide peptide stimulates growth hormone and prolactin gene expression during the spawning period in the grass puffer, a semi-lunar synchronized spawner.

    Shahjahan, Md; Doi, Hiroyuki; Ando, Hironori


    Gonadotropin-inhibitory hormone (GnIH) plays as a multifunctional neurohormone that controls reproduction in birds and mammals. LPXRFamide (LPXRFa) peptide, the fish ortholog of GnIH, has been shown to regulate the secretion of not only gonadotropin (GTH) but also growth hormone (GH) and prolactin (PRL), which are potentially important for gonadal function. To investigate the role of LPXRFa peptide on reproduction of the grass puffer, which spawns in semilunar cycles, we examined changes in the levels of gh and prl expression over the several months during the reproductive cycle, and the effects of goldfish LPXRFa peptide-1 (gfLPXRFa-1) on their expression were examined using primary pituitary cultures. The expression levels of both gh and prl showed significant changes during the reproductive cycle in both sexes with one peak in the spawning and pre-spawning periods for gh and prl, respectively. Particularly, gh showed substantial increase in expression in the spawning and post-spawning periods, indicative of its essentiality in the advanced stage of reproduction. gfLPXRFa-1 stimulated the expression of both gh and prl but there was a marked difference in response between them: gfLPXRFa-1 stimulated gh expression at a relatively low dose but little effect was observed on prl. Combined with the previous results of daily and circadian oscillations of lpxrfa expression, the present results suggest that LPXRFa peptide is important in the control of the cyclic reproduction by serving as a multifunctional hypophysiotropic factor that regulates the expression of gh and prl as well as GTH subunit genes.

  6. Gene expression of lymphocyte prolactin receptor was suppressed in lactating mothers.

    Maeda, Hironobu; Izumi, Shun-ichiro; Kato, Yukio; Cai, Li-yi; Kato, Takako; Suzuki, Takahiro; Nakamura, Eri; Sugiyama, Taro; Fuda, Takayo; Takahashi, Kazumi; Kondo, Akane; Matsumoto, Tadashi; Ishimoto, Hitoshi


    Prolactin (PRL) receptor (PRL-R) was proven to be ubiquitously expressed by cells in the immune system, while the physiological role of PRL was established in milk production in mammary glands. We analyzed the mRNA content of PRL-R in human lymphocytes in normo- and hyperprolactinemic conditions to document the presence of functioning PRL-R of human lymphocytes. Blood samples were obtained prior to treatment, and with written informed consent, from outpatients with ovarian dysfunction and hyperprolactinemia (n = 8; 19 ~ 41 y/o), from breast-feeding mothers after normal delivery (n = 12; 27 ~ 36 y/o), and from healthy volunteers: men (n = 9; 33 ~ 40 y/o) and women (n = 9; 26 ~ 36 y/o). Subsequently, total RNA was prepared from the lymphocytes separated. The quantity of PRL-R mRNA was examined by reverse transcription and polymerase chain reaction and normalized with a simultaneously measured amount of b actin. The resultant mRNA level of PRL-R was analyzed for its correlation with serum concentration of PRL measured by immunoassay. PRL-R mRNA levels of lymphocytes were significantly suppressed in lactating mothers, while there was a statistically significant negative correlation between PRL-R mRNA and serum PRL levels. However, there was no significant difference of PRL-R mRNA in the pathological condition of outpatients with ovarian dysfunction and/or hyperprolactinemia. While a few investigators reported the extra-mammary regulation on PRL-R by PRL, our data suggest that the PRL-R levels of circulating lymphocytes could be down-regulated by the elevated serum levels of PRL and that pituitary PRL may participate in regulating the expression of PRL-R genes on cells of the human immune system, especially in physiological circumstances such as in the postpartum period.

  7. Prolactin inhibits the apoptosis of chondrocytes induced by serum starvation.

    Zermeño, C; Guzmán-Morales, J; Macotela, Y; Nava, G; López-Barrera, F; Kouri, J B; Lavalle, C; de la Escalera, G Martínez; Clapp, C


    The apoptosis of chondrocytes plays an important role in endochondral bone formation and in cartilage degradation during aging and disease. Prolactin (PRL) is produced in chondrocytes and is known to promote the survival of various cell types. Here we show that articular chondrocytes from rat postpubescent and adult cartilage express the long form of the PRL receptor as revealed by immunohistochemistry of cartilage sections and by RT-PCR and Western blot analyses of the isolated chondrocytes. Furthermore, we demonstrate that PRL inhibits the apoptosis of these same chondrocytes cultured in low-serum. Chondrocyte apoptosis was measured by hypodiploid DNA content determined by flow cytometry and by DNA fragmentation evaluated by the ELISA and the TUNEL methods. The anti-apoptotic effect of PRL was dose-dependent and was prevented by heat inactivation. These data demonstrate that PRL can act as a survival factor for chondrocytes and that it has potential preventive and therapeutic value in arthropathies characterized by cartilage degradation.

  8. Prolactin protects retinal pigment epithelium by inhibiting sirtuin 2-dependent cell death.

    Meléndez García, Rodrigo; Arredondo Zamarripa, David; Arnold, Edith; Ruiz-Herrera, Xarubet; Noguez Imm, Ramsés; Baeza Cruz, German; Adán, Norma; Binart, Nadine; Riesgo-Escovar, Juan; Goffin, Vincent; Ordaz, Benito; Peña-Ortega, Fernando; Martínez-Torres, Ataúlfo; Clapp, Carmen; Thebault, Stéphanie


    The identification of pathways necessary for retinal pigment epithelium (RPE) function is fundamental to uncover therapies for blindness. Prolactin (PRL) receptors are expressed in the retina, but nothing is known about the role of PRL in RPE. Using the adult RPE 19 (ARPE-19) human cell line and mouse RPE, we identified the presence of PRL receptors and demonstrated that PRL is necessary for RPE cell survival via anti-apoptotic and antioxidant actions. PRL promotes the antioxidant capacity of ARPE-19 cells by reducing glutathione. It also blocks the hydrogen peroxide-induced increase in deacetylase sirtuin 2 (SIRT2) expression, which inhibits the TRPM2-mediated intracellular Ca(2+) rise associated with reduced survival under oxidant conditions. RPE from PRL receptor-null (prlr(-/-)) mice showed increased levels of oxidative stress, Sirt2 expression and apoptosis, effects that were exacerbated in animals with advancing age. These observations identify PRL as a regulator of RPE homeostasis.

  9. Prolactin protects retinal pigment epithelium by inhibiting sirtuin 2-dependent cell death

    Rodrigo Meléndez García


    Full Text Available The identification of pathways necessary for retinal pigment epithelium (RPE function is fundamental to uncover therapies for blindness. Prolactin (PRL receptors are expressed in the retina, but nothing is known about the role of PRL in RPE. Using the adult RPE 19 (ARPE-19 human cell line and mouse RPE, we identified the presence of PRL receptors and demonstrated that PRL is necessary for RPE cell survival via anti-apoptotic and antioxidant actions. PRL promotes the antioxidant capacity of ARPE-19 cells by reducing glutathione. It also blocks the hydrogen peroxide-induced increase in deacetylase sirtuin 2 (SIRT2 expression, which inhibits the TRPM2-mediated intracellular Ca2+ rise associated with reduced survival under oxidant conditions. RPE from PRL receptor-null (prlr−/− mice showed increased levels of oxidative stress, Sirt2 expression and apoptosis, effects that were exacerbated in animals with advancing age. These observations identify PRL as a regulator of RPE homeostasis.

  10. The role of the prolactin/vasoinhibin axis in rheumatoid arthritis: an integrative overview.

    Clapp, Carmen; Adán, Norma; Ledesma-Colunga, María G; Solís-Gutiérrez, Mariana; Triebel, Jakob; Martínez de la Escalera, Gonzalo


    Rheumatoid arthritis (RA) is a chronic, autoimmune, inflammatory disease destroying articular cartilage and bone. The female preponderance and the influence of reproductive states in RA have long linked this disease to sexually dimorphic, reproductive hormones such as prolactin (PRL). PRL has immune-enhancing properties and increases in the circulation of some patients with RA. However, PRL also suppresses the immune system, stimulates the formation and survival of joint tissues, acquires antiangiogenic properties upon its cleavage to vasoinhibins, and protects against joint destruction and inflammation in the adjuvant-induced model of RA. This review addresses risk factors for RA linked to PRL, the effects of PRL and vasoinhibins on joint tissues, blood vessels, and immune cells, and the clinical and experimental data associating PRL with RA. This information provides important insights into the pathophysiology of RA and highlights protective actions of the PRL/vasoinhibin axis that could lead to therapeutic benefits.

  11. Reevaluation of the proposed autocrine proliferative function of prolactin in breast cancer

    Nitze, Louise Maymann; Galsgaard, Elisabeth Douglas; Din, Nanni


    synthesised PRL in breast cancer. We analysed the expression of PRL in human breast cancer tumours using qPCR analysis and in situ hybridization (ISH). PRL mRNA expression was very low or undetectable in the majority of samples in three cDNA arrays representing samples from 144 breast cancer patients...... and in 13 of 14 breast cancer cell lines when analysed by qPCR. In accordance, PRL expression did not reach detectable levels in any of the 19 human breast carcinomas or 5 cell lines, which were analysed using a validated ISH protocol. Two T47D-derived breast cancer cell lines were stably transfected......The pituitary hormone prolactin (PRL) has been implicated in tumourigenesis. Expression of PRL and its receptor (PRLR) was reported in human breast epithelium and breast cancer cells. It was suggested that PRL may act as an autocrine/paracrine growth factor. Here, we addressed the role of locally...

  12. The in vitro effect of prolactin on the growth, motility and expression of prolactin receptors in larvae of Toxocara canis.

    Chávez-Güitrón, L E; Morales-Montor, J; Muñoz-Guzmán, M A; Nava-Castro, K E; Ramírez-Álvarez, H; Moreno-Méndoza, N A; Hernández-Cervantes, R; Alba-Hurtado, F


    The in vitro effect of prolactin (PRL) on the growth and motility of Toxocara canis larvae was assessed. Additionally, the expression and location of prolactin receptors (PRL-Rs) were determined in the larvae. Larvae of T. canis were incubated with different concentrations of PRL for different periods of time. The stimulated larvae accelerated their enlargement and increased their motility. The mean percentage of PRL-R+ cells in non-stimulated larvae, measured by flow cytometry was 7.3±0.3%. Compared with non-stimulated larvae, the mean fluorescence intensity (p<0.05) increased in larvae incubated with 40ng/mL of PRL for 10 days. A 465-bp length fragment was amplified from larvae gDNA by PCR. The sequence of this fragment showed 99% similarity with the gene fragment that codes for the PRL-R of the domestic dog. A high concentration of PRL-Rs was immune-located in the posterior region of the larval intestine; therefore, the intestinal cells in this region were most likely the targets for this hormone. Based on these results, PRL-Rs were identified in T. canis larvae, and the in vitro stimulation with PRL increased the number of these receptors, accelerated the growth and modified the activity of larvae. All of the above suggest that T. canis larvae are evolutionarily adapted to recognize the PRL of their definitive host and furthermore might explain the reactivation of tissue-arrested larvae during the gestation of bitches, which does not occur in gestating females of other species.

  13. A major prolactin-binding complex on human milk fat globule membranes contains cyclophilins A and B: the complex is not the prolactin receptor.

    Lorenson, Mary Y; Ueda, Eric K; Chen, KuanHui E; Walker, Ameae M


    Prolactin (PRL) in milk influences maturation of gastrointestinal epithelium and development of both the hypothalamo-pituitary and immune systems of offspring. Here, we demonstrate that most PRL in human milk is part of a novel, high-affinity, multicomponent binding complex found on the milk fat globule membrane and not in whey. To examine properties of the complex, a sensitive ELISA was developed such that human PRL (hPRL) binding to the complex was measured by loss of hPRL detectability; thus, as much as 50 ng of hPRL was undetectable in the presence of 10 μl of human milk. Using the same methodology, no comparable complex formation was observed with human serum or amniotic fluid. hPRL complexation in milk was rapid, time dependent, and cooperative. Antibodies to or competitors of the hPRL receptor (placental lactogen and growth hormone) showed the hPRL receptor was not involved in the complex. However, hPRL complexation was antagonized by cyclosporine A and anti-cyclophilins. The complex was very stable, resisting dissociation in SDS, urea, and dithiothreitol. Western analysis revealed an ∼75-kDa complex that included hPRL, cyclophilins A and B, and a 16-kDa cyclophilin A. Compared with noncomplexed hPRL, complexed hPRL in whole milk showed similar activation of STAT5 but markedly delayed activation of ERK. Alteration of signaling suggests that complex formation may alter hPRL biological activity. This is the first report of a unique, multicomponent, high-capacity milk fat reservoir of hPRL; all other analyses of milk PRL have utilized defatted milk.

  14. Prolactin and hostility in hospitalised patients and healthy women: A systematic review and meta-analysis.

    Barry, J A; Moran, E; Thomas, M; Hardiman, P J


    The aim of this systematic review and meta-analysis was to assess any difference in the self-ratings of hostility in mentally healthy women with different levels of prolactin (PRL). Electronic databases (PubMed, MEDLINE, EMBASE and the Cochrane Library) were searched up to 2nd July 2012 for published literature comparing hostility levels in women with different levels of PRL. Keyword pairs ('prolactin' and 'aggression', 'prolactin' and 'hostil*', 'prolactin' and 'anger', and 'prolactin' and 'angry') were entered simultaneously. From 1065 resulting titles, and one unpublished study, 214 articles underwent full-text review by authors JB and EM. Studies were selected based on clinical relevance. Eight comparative studies consisting of 242 female patients with high PRL levels, 207 female patients with normal PRL levels and 127 healthy controls with normal PRL levels were included. Data were analysed using the inverse variance method with a random-effects model. Analysis revealed significantly higher hostility in patients with high PRL compared with that in healthy control women (Z = 1.94, p < 0.05; Hedges' g = 0.72; 95% confidence interval [CI]: -0.01-1.45), significantly higher hostility in patient controls compared with that in healthy controls (Z = 1.94, p < 0.05; Hedges' g = 0.47; 95% CI: 0.00-0.94) and non-significantly higher hostility levels in patients with high PRL compared with that in patients with normal PRL levels (Z = 1.45, p < 0.15; Hedges' g = 0.38; 95% CI: -0.13-0.89). In this meta-analysis, hostility appears to be accounted for partly by PRL levels and also partly by patient status, perhaps due to the stress of being a patient. Methodological considerations and implications for patient care are discussed.

  15. Prolactin stimulates integrin-mediated adhesion of circulating mononuclear cells to endothelial cells.

    Montes de Oca, Pável; Macotela, Yazmín; Nava, Gabriel; López-Barrera, Fernando; de la Escalera, Gonzalo Martínez; Clapp, Carmen


    Attachment of leukocytes to endothelial cells is an essential step for the extravasation and recruitment of cells at sites of inflammation. The pituitary hormone prolactin (PRL) is involved in the inflammatory process. Here, we show that treatment with PRL of human peripheral blood mononuclear cells (PBMC) stimulates their adhesion to human umbilical vein endothelial cells (HUVEC) activated by interleukin-1beta. Stimulation of adhesion by PRL is mediated via integrins leukocyte functional antigen-1 (LFA-1) and very late antigen-4 (VLA-4), because immunoneutralization of both integrins prevents PRL action. Also, PRL promotes the adhesion of PBMC to immobilized intercellular adhesion molecule-1 and fibronectin, ligands for LFA-1 and VLA-4, respectively. Stimulation of integrin-mediated cell adhesion by PRL may involve the activation of chemokine receptors, because PRL upregulates the expression of the G-protein-coupled chemokine receptor CXCR3 in PBMC, and pertussis toxin, a specific G-protein inhibitor, blocks PRL stimulation of PBMC adhesion to HUVEC. In addition, PRL stimulates tyrosine phosphorylation pathways leading to leukocyte adhesion. PRL triggered the tyrosine phosphorylation of Janus kinase-2, of signal transducer and activator of transcription-3 and 5, and of the focal adhesion protein paxillin. Furthermore, genistein, a tyrosine kinase inhibitor, blocked PRL-stimulated adhesion of PBMC and Jurkat T-cells to HUVEC. These results suggest that PRL promotes integrin-mediated leukocyte adhesion to endothelial cells via chemokine receptors and tyrosine phosphorylation signaling pathways.

  16. Prolactin regulates transcription of the ion uptake Na+/Cl- cotransporter (ncc) gene in zebrafish gill

    Breves, Jason P.; Serizier, Sandy B.; Goffin, Vincent; McCormick, Stephen D.; Karlstrom, Rolf O.


    Prolactin (PRL) is a well-known regulator of ion and water transport within osmoregulatory tissues across vertebrate species, yet how PRL acts on some of its target tissues remains poorly understood. Using zebrafish as a model, we show that ionocytes in the gill directly respond to systemic PRL to regulate mechanisms of ion uptake. Ion-poor conditions led to increases in the expression of PRL receptor (prlra), Na+/Cl− cotransporter (ncc; slc12a10.2), Na+/H+ exchanger (nhe3b; slc9a3.2), and epithelial Ca2+ channel (ecac; trpv6) transcripts within the gill. Intraperitoneal injection of ovine PRL (oPRL) increased ncc and prlra transcripts, but did not affect nhe3b or ecac. Consistent with direct PRL action in the gill, addition of oPRL to cultured gill filaments stimulated ncc in a concentration-dependent manner, an effect blocked by a pure human PRL receptor antagonist (Δ1-9-G129R-hPRL). These results suggest that PRL signaling through PRL receptors in the gill regulates the expression of ncc, thereby linking this pituitary hormone with an effector of Cl− uptake in zebrafish for the first time.

  17. Prolactin regulates transcription of the ion uptake Na+/Cl- cotransporter (ncc) gene in zebrafish gill.

    Breves, Jason P; Serizier, Sandy B; Goffin, Vincent; McCormick, Stephen D; Karlstrom, Rolf O


    Prolactin (PRL) is a well-known regulator of ion and water transport within osmoregulatory tissues across vertebrate species, yet how PRL acts on some of its target tissues remains poorly understood. Using zebrafish as a model, we show that ionocytes in the gill directly respond to systemic PRL to regulate mechanisms of ion uptake. Ion-poor conditions led to increases in the expression of PRL receptor (prlra), Na(+)/Cl(-) cotransporter (ncc; slc12a10.2), Na(+)/H(+) exchanger (nhe3b; slc9a3.2), and epithelial Ca(2+) channel (ecac; trpv6) transcripts within the gill. Intraperitoneal injection of ovine PRL (oPRL) increased ncc and prlra transcripts, but did not affect nhe3b or ecac. Consistent with direct PRL action in the gill, addition of oPRL to cultured gill filaments stimulated ncc in a concentration-dependent manner, an effect blocked by a pure human PRL receptor antagonist (Δ1-9-G129R-hPRL). These results suggest that PRL signaling through PRL receptors in the gill regulates the expression of ncc, thereby linking this pituitary hormone with an effector of Cl(-) uptake in zebrafish for the first time. Copyright © 2013. Published by Elsevier Ireland Ltd.

  18. Episodic evolution of prolactin gene in primates

    LI Ying; DUAN Ziyuan; JIA Lu; ZHANG Yaping


    In the present study, we obtained exon 2―5 of prolactin (PRL) gene from four primate species by PCR and sequencing. Adding other genes available in GenBank, we calculate amino acid substitution rates for prolactin gene in primate. Comparison of nonsynonymous substitution rate to synonymous substitution rate ratios shows no evidence of positive selection for any lineage of primate prolactin gene. According to this and the facts that (I) no sites under positive selection are inferred by using maximum-likelihood method; (ii) among 32 amino acid replacement that occurred along the rapid evolutionary phase, only two are included in the 40 functionally important residues, indicating that amino acid replacement tends to occur in those functionally unimportant residues; (iii) partial of prolactin function is replaced by placental lactogen in primate at the rapid evolutionary phase of prolactin gene, we thus deem that it is relaxation of purifying selection to some extent rather than positive selection that enforces the rapid evolution of primate prolactin gene.

  19. [Prolactin as a modulator of antiparasitic immunity].

    Płociński, Przemysław; Dzitko, Katarzyna; Długońska, Henryka


    Prolactin (PRL) is a polypeptide hormone of the pituitary origin, that expresses over 300 separate biological activities, including its involvement in the regulation of immune functions. The hormone's immune capacities are related, among others, to comitogenic activity, prevention of immune cell apoptosis, stimulation of interleukins and antibodies production. Prolactin acts as a potent positive modulator of immunity to some protozoan parasites. It is well established that the hormone stimulates IFN-gamma and many other TH1-type cytokines production during Toxoplasma gondii, Leishmania sp. and Acanthamoeba castellanii infections. Recent studies suggest that human prolactin may be a regulator of antiparasitic activity against Plasmodium falciparum. On the other hand pregnancy-associated hyperprolactinemia may have a relevant contribution to reactivation of latent infections caused by many helminthic parasites, like Ancylostoma sp. or Necator sp. It is possibly connected with the process of transmammary transmission of hookworm infection to breast-fed newborns. Moreover, an increase in endogenous circulating prolactin during late pregnancy and lactation in ewes infected with Haemonchus contortus, promotes the phenomenon of periparturient egg rise. High prolactin levels have also been seen in dairy cattle suffering from other trichostrongylids infections. In this article we have discussed the role of prolactin as an important regulator of immunity to parasites.

  20. Prolactin 177, prolactin 188, and extracellular osmolality independently regulate the gene expression of ion transport effectors in gill of Mozambique tilapia.

    Inokuchi, Mayu; Breves, Jason P; Moriyama, Shunsuke; Watanabe, Soichi; Kaneko, Toyoji; Lerner, Darren T; Grau, E Gordon; Seale, Andre P


    This study characterized the local effects of extracellular osmolality and prolactin (PRL) on branchial ionoregulatory function of a euryhaline teleost, Mozambique tilapia (Oreochromis mossambicus). First, gill filaments were dissected from freshwater (FW)-acclimated tilapia and incubated in four different osmolalities, 280, 330, 380, and 450 mosmol/kg H2O. The mRNA expression of Na(+)/K(+)-ATPase α1a (NKA α1a) and Na(+)/Cl(-) cotransporter (NCC) showed higher expression with decreasing media osmolalities, while Na(+)/K(+)/2Cl(-) cotransporter 1a (NKCC1a) and PRL receptor 2 (PRLR2) mRNA levels were upregulated by increases in media osmolality. We then incubated gill filaments in media containing ovine PRL (oPRL) and native tilapia PRLs (tPRL177 and tPRL188). oPRL and the two native tPRLs showed concentration-dependent effects on NCC, NKAα1a, and PRLR1 expression; Na(+)/H(+) exchanger 3 (NHE3) expression was increased by 24 h of incubation with tPRLs. Immunohistochemical observation showed that oPRL and both tPRLs maintained a high density of NCC- and NKA-immunoreactive ionocytes in cultured filaments. Furthermore, we found that tPRL177 and tPRL188 differentially induce expression of these ion transporters, according to incubation time. Together, these results provide evidence that ionocytes of Mozambique tilapia may function as osmoreceptors, as well as directly respond to PRL to modulate branchial ionoregulatory functions.

  1. Prolactin and growth hormone responses to hypoglycemia in patients with systemic sclerosis and psoriatic arthritis.

    Rovensky, Jozef; Raffayova, Helena; Imrich, Richard; Radikova, Zofia; Penesova, Adela; Macho, Ladislav; Lukac, Jozef; Matucci-Cerinic, Marco; Vigas, Milan


    This study compared prolactin (PRL) and growth hormone (GH) responses to hypoglycemia in premenopausal females with systemic sclerosis (SSc) and psoriatic arthritis (PsA) with those in matched healthy controls. No differences were found in glucose and GH responses to hypoglycemia in both groups of patients compared to controls. SSc patients had lower PRL response (P < 0.05) to hypoglycemia compared to controls. PRL response tended to be lower also in PsA patients, however the difference did not reach level of statistical significance (P = 0.11). The present study showed decreased PRL response to hypoglycemia in premenopausal females with SSc.

  2. Identification of Polymorphisms in the Enhancer Region of the Bovine Prolactin Gene and Association with Fertility in Beef Cows

    Objectives were to investigate the polymorphic nature of the enhancer region of the bovine prolactin (PRL) gene and determine the association of these polymorphisms with fertility in beef cows. Primers were designed to amplify a 500 base pair fragment 892 to 1392 bases upstream of the bovine PRL gen...

  3. The prolactin and growth hormone families: Pregnancy-specific hormones/cytokines at the maternal-fetal interface

    Soares Michael J


    Abstract The prolactin (PRL) and growth hormone (GH) gene families represent species-specific expansions of pregnancy-associated hormones/cytokines. In this review we examine the structure, expression patterns, and biological actions of the pregnancy-specific PRL and GH families.

  4. The prolactin and growth hormone families: Pregnancy-specific hormones/cytokines at the maternal-fetal interface

    Soares Michael J


    Full Text Available Abstract The prolactin (PRL and growth hormone (GH gene families represent species-specific expansions of pregnancy-associated hormones/cytokines. In this review we examine the structure, expression patterns, and biological actions of the pregnancy-specific PRL and GH families.

  5. The progesterone and estrogen modify the uterine prolactin and prolactin receptor expression of hyperprolactinemic mice.

    do Amaral, Vinícius Cestari; Carvalho, Kátia Candido; Maciel, Gustavo Arantes Rosa; Simoncini, Tommaso; da Silva, Priscilla Ludovico; Marcondes, Rodrigo Rodrigues; Soares, José Maria; Baracat, Edmund Chada


    The aim of this study was to evaluate the effects of metoclopramide-induced hyperprolactinemia on the prolactin (PRL) and PRL receptor's expression in the uterus of mice. For this purpose, 49 Swiss mice were divided into the following groups: GrSS (non-ovariectomized mice given vehicle); GrMET (non-ovariectomized mice treated with metoclopramide); OvSS (ovariectomized mice given vehicle); OvMET (ovariectomized mice treated with metoclopramide); OvMET+17βE (ovariectomized mice treated with metoclopramide and 17β estradiol); OvMET+MP (ovariectomized mice treated with metoclopramide and micronized progesterone); OvMET+17βE+MP (ovariectomized mice treated with metoclopramide and a solution of 17β estradiol and micronized progesterone). Immunohistochemical analyzes were evaluated semi-quantitatively. Our results showed that GrMET, OvMET+MP, and OvMET+17βE+MP presented strong PRL expression. OvMET and OvMET+17βE presented mild reaction, while GrSS and OvSS presented weak reaction. Concerning PRL receptor, OvMET+MP and OvMET+17βE+MP showed strong reaction; GrMET, OvSS, and OvMET+17βE showed mild reaction; and GrSS and OvMET showed weak reaction. These findings suggest that progesterone alone or in combination with estrogen may increase the expression of uterine PRL and PRL receptor.

  6. 60 YEARS OF NEUROENDOCRINOLOGY: The hypothalamo-prolactin axis

    Grattan, David R.


    The hypothalamic control of prolactin secretion is different from other anterior pituitary hormones, in that it is predominantly inhibitory, by means of dopamine from the tuberoinfundibular dopamine neurons. In addition, prolactin does not have an endocrine target tissue, and therefore lacks the classical feedback pathway to regulate its secretion. Instead, it is regulated by short loop feedback, whereby prolactin itself acts in the brain to stimulate production of dopamine and thereby inhibi...

  7. Xenoestrogens at picomolar to nanomolar concentrations trigger membrane estrogen receptor-alpha-mediated Ca2+ fluxes and prolactin release in GH3/B6 pituitary tumor cells.

    Wozniak, Ann L; Bulayeva, Nataliya N; Watson, Cheryl S


    Xenoestrogens (XEs) are widespread in our environment and are known to have deleterious effects in animal (and perhaps human) populations. Acting as inappropriate estrogens, XEs are thought to interfere with endogenous estrogens such as estradiol (E2) to disrupt normal estrogenic signaling. We investigated the effects of E2 versus several XEs representing organochlorine pesticides (dieldrin, endosulfan, o',p'-dichlorodiphenylethylene), plastics manufacturing by-products/detergents (nonylphenol, bisphenol A), a phytoestrogen (coumestrol), and a synthetic estrogen (diethylstilbestrol) on the pituitary tumor cell subline GH3/B6/F10, previously selected for expression of high levels of membrane estrogen receptor-alpha. Picomolar to nanomolar concentrations of both E2 and XEs caused intracellular Ca2+ changes within 30 sec of administration. Each XE produced a unique temporal pattern of Ca2+ elevation. Removing Ca2+ from the extracellular solution abolished both spontaneous and XE-induced intracellular Ca2+ changes, as did 10 microM nifedipine. This suggests that XEs mediate their actions via voltage-dependent L-type Ca2+ channels in the plasma membrane. None of the Ca2+ fluxes came from intracellular Ca2+ stores. E2 and each XE also caused unique time- and concentration-dependent patterns of prolactin (PRL) secretion that were largely complete within 3 min of administration. PRL secretion was also blocked by nifedipine, demonstrating a correlation between Ca2+ influx and PRL secretion. These data indicate that at very low concentrations, XEs mediate membrane-initiated intracellular CCa2+ increases resulting in PRL secretion via a mechanism similar to that for E2, but with distinct patterns and potencies that could explain their abilities to disrupt endocrine functions.

  8. 血清PRL水平与MRI扫描垂体催乳素瘤的对比分析及临床应用%Comparative Analysis and Clinical Application of Serum PRL and MRI Scan on Pituitary Prolactinoma

    朱梅; 张勇; 彭虹; 邱红; 袁鹏; 阮书平


    目的:通过血清催乳素(PRL)含量与MRI扫描垂体催乳素瘤的对照研究,观察垂体催乳素瘤的特征,可进一步评价垂体催乳素瘤的生物学行为.方法:搜集确诊垂体催乳素瘤患者66例,同时行垂体MRI常规序列扫描及同位增强扫描.结果:微腺瘤患者中女性多见;好发在垂体前叶后部两侧.大腺瘤患者中男性多见;性腺功能减低发生率高;侵袭性腺瘤发生率高、复发率高.催乳素瘤的大小与血清PRL水平呈直线相关性(r=0.4372,P<0.01).结论:血清PRL增高,结合MRI动态增强扫描可准确显示垂体催乳素瘤的形态及位置,对照研究可初步评估肿瘤的生物学行为,为临床诊断治疗提供重要依据.%Objective Through the serum prolactin level and MRI scan pituitary prolactinoma case-control study,observation of pituitary prolactin-secreting tumor characteristics,further evaluation of pituitary prolactinoma biological behavior.Methods To collect the undiagnosed pituitary prolactinoma patients 66 cases,at the same time of pituitary MRI routine sequence scanning and parity enhanced scan.Results Microadenoma of most of the patients were females,occurred in the anterior pituitary of the two side of the back.Large adenomas in patients with male gonadal dysfunction;High incidence of invasive adenomas;high incidence rate,high recurrence rate.Prolactin-secreting tumor size and serum level of PRL showed a linear correlation(r=0.4372,P<0.01).Conclusion Serum PRL increased,combining with dynamic enhanced MRI scan can accurately display the PRL of pituitary prolactinoma shape and position,casecontrol study preliminary assessment of tumor biological behavior,and provide important basis for clinical diagnosis and treatment.

  9. Effects of metoclopramide-induced hyperprolactinemia on the prolactin and prolactin receptor expression of murine adrenal.

    do Amaral, Vinícius Cestari; da Silva, Priscilla Ludovico; Carvalho, Kátia Candido; Simoncini, Tommaso; Maciel, Gustavo Arantes Rosa; Soares-Jr, José Maria; Baracat, Edmund Chada


    The aim of this study was to evaluate the effects of metoclopramide-induced hyperprolactinemia on the prolactin (PRL) and prolactin receptor's (PRLR) expression in the adrenal. For this purpose, a total of 12 animals with intact ovaries were allocated to two groups: G1 (saline solution) and G2 (metoclopramide). A total of 30 oophorectomized animals was randomized to five subgroups: G3 (saline solution), G4 (metoclopramide), G5 (metoclopramide + 17β-estradiol), G6 (metoclopramide + progesterone), and G7 (metoclopramide + 17β-estradiol + progesterone). Immunohistochemical analyses were evaluated semi-quantitatively. For PRLR, the area fraction of labeled cells (ALC) varied from 1 (0-10%) to 3 (> 50%). Based on the mean of the immunostaining intensity, G2 and G4 showed strong expression; G6 and G7 presented a mild reaction; and G1, G3, and G5 exhibited a weak reaction. Concerning PRL, the ALC varied from 1 (0-10%) to 3 (> 50%), and groups G6 and G7 showed a strong reaction; G2, G4, and G5 showed a mild reaction; and G1 and G3 exhibited a weak reaction. These findings suggest that metoclopramide-induced hyperprolactinemia increases PRL expression in the adrenal glands of mice. Furthermore, progesterone alone or in association with estrogen also increases PRL expression, but to a lesser extent.

  10. Increased serum level of prolactin is related to autoantibody production in systemic lupus erythematosus.

    Yang, J; Li, Q; Yang, X; Li, M


    Prolactin (PRL) is known to aid effector B cells and augment autoimmunity, but the role of PRL in systemic lupus erythematosus (SLE) is not fully elucidated. The aim of this study was to determine the correlation between the serum levels of PRL and autoantibody production in SLE. Blood levels of PRL, anti-double-stranded DNA (ds-DNA) antibody, immunoglobulin M (IgM) and immunoglobulin G (IgG) were determined in samples from 30 adult patients with SLE and 25 healthy controls. The relationships between the serum level of PRL and SLE disease activity, as well as the titres of the ds-DNA antibody, IgM and IgG were determined. The serum level of PRL was higher in the SLE patients than in the healthy controls. PRL concentration increased during SLE flares-ups and decreased following disease remission. There was a positive correlation between the PRL concentration and serum levels of IgM, IgG and ds-DNA antibody titre. These data suggest that the serum level of PRL was closely related to the antibody production and disease activity of SLE patients. PRL concentration was dramatically reduced upon the remission of disease activity, indicating that PRL levels might be a promising predictor of SLE disease severity. © The Author(s) 2015.

  11. Prolactin as a biomarker for treatment response and tardive dyskinesia in schizophrenia subjects: old thoughts revisited from a genetic perspective.

    Souza, Renan P; Meltzer, Herbert Y; Lieberman, Jeffrey A; Voineskos, Aristotle N; Remington, Gary; Kennedy, James L


    Previous studies investigated whether prolactin (PRL) serum level was a biomarker of antipsychotic response, schizophrenia symptomatology, and tardive dyskinesia. Most of the findings support that antipsychotic drugs modulate PRL levels but PRL is not a steady indicator. Recent results suggest a genetic effect of PRL and PRL receptor (PRLR) polymorphisms in PRL levels indicating that independently of antipsychotic therapy subjects could have altered PRL levels due to their genetic background.We evaluated whether PRL and PRLR variants were associated with treatment outcome and tardive dyskinesia. We observed no association of PRL/PRLR polymorphism with treatment response (best genotypic results include PRL rs849885 and PRLR rs4703509 permuted p=0.326). Regarding tardive dyskinesia, the major allele of PRL rs37364 was nominally associated with risk for tardive dyskinesia in the European ancestry sub-sample (permuted p=0.183). Although we reported no significant associations, it is definitely worthy of investigation to see if together (genetic variants in the PRL system and PRL serum measures) could be a reliable biomarker for antipsychotic response and TD prevalence. Our results suggest that more studies in this context are required to shed light in the molecular mechanisms underlying antipsychotic response and tardive dyskinesia occurrence.

  12. Discovery of the improved antagonistic prolactin variants by library screening.

    Liu, Yun; Gong, Wei; Breinholt, Jens; Nørskov-Lauritsen, Leif; Zhang, Jinchao; Ma, Qinhong; Chen, Jianhe; Panina, Svetlana; Guo, Wei; Li, Tengkun; Zhang, Jingyuan; Kong, Meng; Liu, Zibing; Mao, Jingjing; Christensen, Leif; Hu, Sean; Wang, Lingyun


    Prolactin (PRL), a potent growth stimulator of the mammary epithelium, has been suggested to be a factor contributing to the development and progression of breast and prostate cancer. Several PRL receptor (PRLR) antagonists have been identified in the past decades, but their in vivo growth inhibitory potency was restricted by low receptor affinity, rendering them pharmacologically unattractive for clinical treatment. Thus, higher receptor affinity is essential for the development of improved PRLR antagonistic variants with improved in vivo potency. In this study, we generated Site 1 focused protein libraries of human G129R-PRL mutants and screened for those with increased affinity to the human PRLR. By combining the mutations with enhanced affinities for PRLR, we identified a novel G129R-PRL variant with mutations at Site 1 that render nearly 50-fold increase in the antagonistic potency in vitro.

  13. Prolactin mediates neuroprotection against excitotoxicity in primary cell cultures of hippocampal neurons via its receptor.

    Vergara-Castañeda, E; Grattan, D R; Pasantes-Morales, H; Pérez-Domínguez, M; Cabrera-Reyes, E A; Morales, T; Cerbón, M


    Recently it has been reported that prolactin (PRL) exerts a neuroprotective effect against excitotoxicity in hippocampus in the rat in vivo models. However, the exact mechanism by which PRL mediates this effect is not completely understood. The aim of our study was to assess whether prolactin exerts neuroprotection against excitotoxicity in an in vitro model using primary cell cultures of hippocampal neurons, and to determine whether this effect is mediated via the prolactin receptor (PRLR). Primary cell cultures of rat hippocampal neurons were used in all experiments, gene expression was evaluated by RT-qPCR, and protein expression was assessed by Western blot analysis and immunocytochemistry. Cell viability was assessed by using the MTT method. The results demonstrated that PRL treatment of neurons from primary cultures did not modify cell viability, but that it exerted a neuroprotective effect, with cells treated with PRL showing a significant increase of viability after glutamate (Glu)--induced excitotoxicity as compared with neurons treated with Glu alone. Cultured neurons expressed mRNA for both PRL and its receptor (PRLR), and both PRL and PRLR expression levels changed after the excitotoxic insult. Interestingly, the PRLR protein was detected as two main isoforms of 100 and 40 kDa as compared with that expressed in hypothalamic cells, which was present only as a 30 kDa variant. On the other hand, PRL was not detected in neuron cultures, either by western blot or by immunohistochemistry. Neuroprotection induced by PRL was significantly blocked by specific oligonucleotides against PRLR, thus suggesting that the PRL role is mediated by its receptor expressed in these neurons. The overall results indicated that PRL induces neuroprotection in neurons from primary cell cultures.

  14. Experimental Modification of Rat Pituitary Prolactin Cell Function During and After Spaceflight

    Hymer, W. C.; Salada, T.; Avery, L.; Grindeland, R. E.


    Experimental modification of rat pituitary prolactin cell function during and after spaceflight. This study was done to evaluate the effects of microgravity on prolactin (PRL) cells of the male rat pituitary gland. We used the identical passive closed-vial cell culture system that was described for the culture of growth hormone cells (W C. Hymer, R. E. Grindeland, T. Salada, P. Nye, E. Grossman, and R Lane). After an 8-day spaceflight, all flight media (containing released PRL), as well as extracts (containing intracellular PRL), contained significantly lower amounts of immunoreactive PRL than their corresponding ground control samples. On the other hand, these same samples, when assessed for their biological activities by two different in vitro lymphocyte assays, yielded disparate results that may reflect posttranslational modifications to the hormone molecule. Other data showed that: (1) the apparent molecular weights of released PRL molecules were not altered by microgravity; but (2) the region from which the PRL cells came (dorsal or ventral) made a significant difference in the amount and activity of PRL released from the flight cells. Because there is much current interest in the role that PRL may play in the regulation of the immune system and because changes in both cellular and humoral immunity accompany spaceflight, this study could help define future microgravity research in this area.

  15. Ovarian and PGF2α responses to stimulation of endogenous PRL pulses during the estrous cycle in mares.

    Pinaffi, F L V; Khan, F A; Silva, L A; Beg, M A; Ginther, O J


    The effects of a PRL-stimulating substance (sulpiride) on PRL and PGF2α secretion and on luteal and ovarian follicular dynamics were studied during the estrous cycle in mares. A control group (n = 9) and a sulpiride group (Sp; n = 10) were used. Sulpiride (25 mg) was given every 8 h from Day 13 postovulation to the next ovulation. Repeated sulpiride treatment did not appear to maintain PRL concentrations at 12-h intervals beyond Day 14. Therefore, the hypothesis that a long-term increase in PRL altered luteal and follicular end points was not testable. Hourly samples were collected from the hour of a treatment (Hour 0) to Hour 8 on Day 14. Concentrations of PRL increased to maximum at Hour 4 in the Sp group. The PRL pulses were more prominent (P PRL. A novel observation was that the peak of a PRL pulse occurred at the same hour or 1 h later than the peak of a PGFM pulse in 8 of 8 PGFM pulses in the controls and in 6 of 10 pulses in the Sp group (P PRL pulses. The hypothesis that sulpiride treatment during the equine estrous cycle increases concentrations of PRL and the prominence of PRL pulses was supported.

  16. Principles of the prolactin/vasoinhibin axis.

    Triebel, Jakob; Bertsch, Thomas; Bollheimer, Cornelius; Rios-Barrera, Daniel; Pearce, Christy F; Hüfner, Michael; Martínez de la Escalera, Gonzalo; Clapp, Carmen


    The hormonal family of vasoinhibins, which derive from the anterior pituitary hormone prolactin, are known for their inhibiting effects on blood vessel growth, vasopermeability, and vasodilation. As pleiotropic hormones, vasoinhibins act in multiple target organs and tissues. The generation, secretion, and regulation of vasoinhibins are embedded into the organizational principle of an axis, which integrates the hypothalamus, the pituitary, and the target tissue microenvironment. This axis is designated as the prolactin/vasoinhibin axis. Disturbances of the prolactin/vasoinhibin axis are associated with the pathogenesis of retinal and cardiac diseases and with diseases occurring during pregnancy. New phylogenetical, physiological, and clinical implications are discussed.

  17. 60 YEARS OF NEUROENDOCRINOLOGY: The hypothalamo-prolactin axis.

    Grattan, David R


    The hypothalamic control of prolactin secretion is different from other anterior pituitary hormones, in that it is predominantly inhibitory, by means of dopamine from the tuberoinfundibular dopamine neurons. In addition, prolactin does not have an endocrine target tissue, and therefore lacks the classical feedback pathway to regulate its secretion. Instead, it is regulated by short loop feedback, whereby prolactin itself acts in the brain to stimulate production of dopamine and thereby inhibit its own secretion. Finally, despite its relatively simple name, prolactin has a broad range of functions in the body, in addition to its defining role in promoting lactation. As such, the hypothalamo-prolactin axis has many characteristics that are quite distinct from other hypothalamo-pituitary systems. This review will provide a brief overview of our current understanding of the neuroendocrine control of prolactin secretion, in particular focusing on the plasticity evident in this system, which keeps prolactin secretion at low levels most of the time, but enables extended periods of hyperprolactinemia when necessary for lactation. Key prolactin functions beyond milk production will be discussed, particularly focusing on the role of prolactin in inducing adaptive responses in multiple different systems to facilitate lactation, and the consequences if prolactin action is impaired. A feature of this pleiotropic activity is that functions that may be adaptive in the lactating state might be maladaptive if prolactin levels are elevated inappropriately. Overall, my goal is to give a flavour of both the history and current state of the field of prolactin neuroendocrinology, and identify some exciting new areas of research development.

  18. Primary Hypothyroidism With Markedly High Prolactin



    Full Text Available Secondary Pituitary enlargement due to primary hypothyroidism is not a common manifestation. The loss of thyroxin feedback inhibition in primary hypothyroidism causes overproduction of thyroid-releasing hormone (TRH, which results in secondary pituitary enlargement.TRH has a weak stimulatory effect on lactotroph cells of pituitary, so mild to moderate rise in prolactin (PRL level is expected. We report a 67 years old female who presented with a large pituitary mass and very high level of TSH with a significant rise in PRL level. In this case the diagnosis of seller mass was challenging, it was difficult to distinguish between pituitary prolactinoma and primary hypothyroidism with secondary pituitary hyperplasia. The thyroid hormone replacement proved that hyperprolactinemia was due to hyperplasia of the pituitary gland.Hence, the correct diagnosis and thyroid hormone therapy can prevent unnecessary treatment with dopamine agonist.

  19. Primary Hypothyroidism with Markedly High Prolactin

    Ansari, Mohd Saleem; Almalki, Mussa H.


    Secondary pituitary enlargement due to primary hypothyroidism is not a common manifestation. The loss of thyroxin feedback inhibition in primary hypothyroidism causes overproduction of thyrotropin-releasing-hormone (TRH), which results in secondary pituitary enlargement. TRH has a weak stimulatory effect on the lactotroph cells of the pituitary, so a mild to moderate increase in prolactin (PRL) levels is expected. We report the case of a 67-year-old female who presented with a large pituitary mass and a very high level of TSH in association with a significant rise in PRL level. In this case, diagnosing a sellar mass was challenging; it was difficult to distinguish between pituitary prolactinoma and primary hypothyroidism with secondary pituitary hyperplasia. Thyroid hormone replacement proved that this patient’s hyperprolactinemia was due to hyperplasia of the pituitary gland. As such, making the correct diagnosis and initiating thyroid hormone therapy can prevent unnecessary treatment with dopamine agonists. PMID:27199892

  20. Are Prolactin Levels in Drug-Naive Schizophrenia Patients A Clinical Indicator?

    Demet Yalcin


    Aim: The relationship between serum prolactin (PRL) levels in patients with schizophrenia and the psychopathology, risk of relapse, symptom severity, the side effects after antipsychotics and schizophrenia subtypes are known. The aim of this study is to examine the serum PRL level difference between drug naive schizophrenia patients and healthy control group and between schizophrenia subtypes. Material and Method: 45 untreated volunteer participant between the ages of 18-55 who applied to Ank...

  1. Significance of hyperprolactinemia for cytomorphologic features of breast secretions

    Radojković Danijela


    Full Text Available Background/Aim. Nipple discharge syndrome is a clinical entity capable of presenting various disorders such is mammary infection (nonpuerperal and puerperal mastitis, intraductal papillomas, fibrodenoma, breast cancer and hyperprolactinemia syndrome. The aim of the study was to determine differencies in cytological features of mammary secretion in patients with hyperprolactinemia and those with normal serum prolactin levels and to define the role of growth hormone, follicle-stimulating hormone, luteinizing hormone and thyroid-stimulating hormone in creating cellular profile of breast secretion. Methods. The study included 50 patients with nipple discharge syndrome. The patients were devided into the clinical group (27 patients with hyperprolactinemia and nipple discharge and the control group I (23 patients with normal serum prolactin and nipple discharge. The control group II included the patients of the clinical group achiving normalised serum prolactin levels after the treatment of hyperprolactinemia. Serum prolactin, follicle-stimulating hormone and luteinizing hormone levels were assessed by RIA using commercial kits IRMA hPRL, hLH and hFSH, (INEP, Zemun, Serbia while serum growth hormone and thyroid-stimulating hormone levels were assessed by RIA using commercial kits LKB-wallac. Cytologic evaluation of samples, taken from all the patients with mammary secretion, was done using standard techniques of staining Haemathoxilin-eozine and May- Grünwald/Giemsa. Results. Our results showed a significantly higher presence of lipid and protein material in clinical group, in comparison with the control group I (p < 0.01. Also, our data demonstrated significantly higher number of ductal epithelial cells (p < 0.05 and ductal histiocities (p < 0.001 in the clinical group, compared with the control group I. Macrophagies frequency was proportionally higher in clinical group (44.44% compared the control group I (17.39%. Erythrocites were significantly

  2. Crystal structure of an affinity-matured prolactin complexed to its dimerized receptor reveals the topology of hormone binding site 2

    Broutin, Isabelle; Jomain, Jean-Baptiste; Tallet, Estelle;


    We report the first crystal structure of a 1:2 hormone.receptor complex that involves prolactin (PRL) as the ligand, at 3.8-A resolution. Stable ternary complexes were obtained by generating affinity-matured PRL variants harboring an N-terminal tail from ovine placental lactogen, a closely relate...

  3. Variation in the coding and 3’ untranslated regions of the porcine prolactin receptor short form modifies protein expression and function

    The actions of prolactin (PRL) are mediated by both long (LF) and short isoforms (SF) of the PRL receptor (PRLR). Here, we report on a genetic and functional analysis of the porcine PRLR (pPRLR) SF. Three single nucleotide polymorphisms (SNPs) within exon 11 of the pPRLR-SF give rise to four amino a...

  4. Expression of autocrine prolactin and the short isoform of prolactin receptor are associated with inflammatory response and apoptosis in monocytes stimulated with Mycobacterium bovis proteins.

    López-Rincón, Gonzalo; Mancilla, Raúl; Pereira-Suárez, Ana L; Martínez-Neri, Priscila A; Ochoa-Zarzosa, Alejandra; Muñoz-Valle, José Francisco; Estrada-Chávez, Ciro


    Increased levels of prolactin (PRL) have recently been associated with carcinogenesis and the exacerbation of autoimmune diseases, and might be involved in the progression of tuberculosis (TB). To investigate the relationship between PRL and prolactin receptor (PRLr) expression with inflammatory response and apoptosis in monocytes, we used THP-1 cells stimulated with antigens of the Mycobacterium bovis AN5 strain culture filtrate protein (CFP-M. bovis). Western blot (WB), real-time Polymerase chain reaction (PCR), and immunocytochemistry were performed to identify both PRL and PRLr molecules. PRL bioactivity and proinflammatory cytokine detection were assessed. The results showed that PRL and PRLr messenger RNA (mRNA) were synthesized in THP-1 monocytes induced with CFP-M. bovis at peaks of 176- and 404-fold, respectively. PRL forms of 60 and 80kDa and PRLr isoforms of 40, 50, and 65kDa were also identified as time-dependent, while 60-kDa PRL, as well as 40-, and 50-kDa PRLr, were found as soluble forms in culture media and later in the nucleus of THP-1 monocytes. PRL of 60kDa released by monocytes exhibited bioactivity in Nb2 cells, and both synthesized PRL and synthesized PRLr were related with nitrite and proinflammatory cytokine levels proapoptotic activity in CFP-M. bovis-induced monocytes. Our results suggest the overexpression of a full-autocrine loop of PRL and PRLr in monocytes that enhances the inflammatory response and apoptosis after priming with M. bovis antigens.

  5. Functionally reciprocal mutations of the prolactin signalling pathway define hairy and slick cattle.

    Littlejohn, Mathew D; Henty, Kristen M; Tiplady, Kathryn; Johnson, Thomas; Harland, Chad; Lopdell, Thomas; Sherlock, Richard G; Li, Wanbo; Lukefahr, Steven D; Shanks, Bruce C; Garrick, Dorian J; Snell, Russell G; Spelman, Richard J; Davis, Stephen R


    Lactation, hair development and homeothermy are characteristic evolutionary features that define mammals from other vertebrate species. Here we describe the discovery of two autosomal dominant mutations with antagonistic, pleiotropic effects on all three of these biological processes, mediated through the prolactin signalling pathway. Most conspicuously, mutations in prolactin (PRL) and its receptor (PRLR) have an impact on thermoregulation and hair morphology phenotypes, giving prominence to this pathway outside of its classical roles in lactation.

  6. Repeated administration of meta-chlorophenylpiperazine or 1-(2,5-dimethoxy-4-iodophenyl)-2-aminopropane produces tolerance to its stimulatory effect on adrenocorticotropin hormone but not prolactin or corticosterone secretion in rats.

    Mazzola-Pomietto, P; Aulakh, C S; Huang, S J; Murphy, D L


    In an attempt to clarify whether m-chlorophenylpiperazine-(m-CPP) and 1-(2,5-dimethoxy-4-iodophenyl)-2-aminopropane-(DOI) induced increases in plasma adrenocorticotropin hormone, corticosterone and prolactin secretion are mediated by the same or different mechanisms, we studied the time course of development of tolerance to the neuroendocrine effects of m-CPP (2.5 mg/kg/day) and DOI (2.5 mg/kg/day) in rats and, furthermore, also evaluated possible cross-tolerance in responses to m-CPP and DOI. We observed the development of tolerance in adrenocorticotropin hormone responses after a single i.p. injection of m-CPP. However, there was no cross-tolerance to DOI when chronic (13 days) m-CPP-treated animals were challenged with DOI (2.5 mg/kg). Injections of DOI (2.5 mg/kg) for six days were required before tolerance developed to the effect of DOI on adrenocorticotropin hormone. Furthermore, cross-tolerance was observed when DOI-treated animals (2.5 mg/kg/day x 6) were challenged with m-CPP (2.5 mg/kg) on day 7. In contrast, daily administration of m-CPP and DOI for 13 days did not produce tolerance to their stimulating effects on corticosterone and prolactin secretion. Hypothalamic levels of 5-hydroxyindoleacetic acid but not 5-HT were significantly reduced after acute or subchronic administration of both m-CPP and DOI. Furthermore, no change in the approximate 50% reduction in 5-hydroxyindoleacetic acid after m-CPP was observed after subchronic administration of this drug. These findings suggest that separate mechanisms mediate m-CPP and DOI-induced adrenocorticotropin hormone secretion in rats.

  7. Further studies on the role of cholecystokinin-A and B receptors in secretion of anterior pituitary hormones in male rats.

    Peuranen, E; Vasar, E; Koks, S; Volke, V; Lang, A; Rauhala, P; Männistö, P T


    We compared the effects of unselective cholecystokinin (CCK) agonists (caerulein and CCK-8s) and a CCKB agonist CCK-4 on the secretion of thyrotropin (TSH), growth hormone (GH) and prolactin (PRL) in male rats. The subcutaneous (s.c.) administration of caerulein and CCK-8s suppressed dose-dependently TSH and GH levels. In contrast, when given into the 3rd brain ventricle (i.c.v.) caerulein dose-dependently elevated the GH levels. Next the importance of the afferent vagal nerves was studied in the action of caerulein and CCK-4. Subdiaphragmatic vagotomy itself decreased cold-stimulated TSH levels but abolished the suppressing effect of intraperitoneal (i.p.), and apparently also that of the i.c.v. caerulein. GH and PRL levels were altered neither by vagotomy nor caerulein. CCK-4 did not affect hormone levels. Atropine and butylscopolamine (i.p.) themselves did not alter TSH, PRL or GH secretion in intact rats. Neither did they reverse the effect of caerulein on TSH. In conclusion, CCKA receptors dominate in TSH and CCKB receptors in GH regulation. CCKA receptors in the gastrointestinal tract, related to the nervus vagus are mediating the inhibitory effect of caerulein upon TSH secretion but inhibition of GH secretion does not depend on the nervus vagus. CCKB receptors in the brain stem or near the 3rd brain ventricle are responsible for stimulation of GH secretion.

  8. The ′hook effect′ on serum prolactin estimation in a patient with macroprolactinoma.

    Unnikrishnan A


    Full Text Available Large quantities of antigen in an immunoassay system impair antigen-antibody binding, resulting in low antigen determination. This is called the ′high dose hook effect′. We report this phenomenon in a patient with a large macroprolactinoma. In this patient, the correct estimate of serum prolactin (PRL was obtained only after appropriate dilution of serum. We suggest that in order to avoid the high dose hook effect, the serum PRL be estimated in appropriate dilution in all patients with large pituitary tumours. This is particularly important when the clinical suspicion of high PRL is strong, as in women with amenorrhoea-galactorrhoea and men with long standing hypogonadism.

  9. Prolactin potentiates the activity of acid-sensing ion channels in female rat primary sensory neurons.

    Liu, Ting-Ting; Qu, Zu-Wei; Ren, Cuixia; Gan, Xiong; Qiu, Chun-Yu; Hu, Wang-Ping


    Prolactin (PRL) is a polypeptide hormone produced and released from the pituitary and extrapituitary tissues. It regulates activity of nociceptors and causes hyperalgesia in pain conditions, but little is known the molecular mechanism. We report here that PRL can exert a potentiating effect on the functional activity of acid-sensing ion channels (ASICs), key sensors for extracellular protons. First, PRL dose-dependently increased the amplitude of ASIC currents with an EC50 of (5.89 ± 0.28) × 10(-8) M. PRL potentiation of ASIC currents was also pH dependent. Second, PRL potentiation of ASIC currents was blocked by Δ1-9-G129R-hPRL, a PRL receptor antagonist, and removed by intracellular dialysis of either protein kinase C inhibitor GF109203X, protein interacting with C-kinase 1(PICK1) inhibitor FSC-231, or PI3K inhibitor AS605240. Third, PRL altered acidosis-evoked membrane excitability of DRG neurons and caused a significant increase in the amplitude of the depolarization and the number of spikes induced by acid stimuli. Four, PRL exacerbated nociceptive responses to injection of acetic acid in female rats. Finally, PRL displayed a stronger effect on ASIC mediated-currents and nociceptive behavior in intact female rats than OVX female and male rats and thus modulation of PRL may be gender-dependent. These results suggest that PRL up-regulates the activity of ASICs and enhances ASIC mediated nociceptive responses in female rats, which reveal a novel peripheral mechanism underlying PRL involvement in hyperalgesia.

  10. Prolactin receptor attenuation induces zinc pool redistribution through ZnT2 and decreases invasion in MDA-MB-453 breast cancer cells

    Bostanci, Zeynep, E-mail: [The Pennsylvania State University, Department of Nutritional Sciences, 209 Chandlee Lab, University Park, PA 16802 (United States); The Pennsylvania State University Milton S. Hershey Medical Center, Department of Surgery, 500 University Dr., Hershey, PA 17033 (United States); Alam, Samina, E-mail: [The Pennsylvania State University, Department of Nutritional Sciences, 209 Chandlee Lab, University Park, PA 16802 (United States); The Pennsylvania State University Milton S. Hershey Medical Center, Department of Surgery, 500 University Dr., Hershey, PA 17033 (United States); Soybel, David I., E-mail: [The Pennsylvania State University, Department of Nutritional Sciences, 209 Chandlee Lab, University Park, PA 16802 (United States); The Pennsylvania State University Milton S. Hershey Medical Center, Department of Surgery, 500 University Dr., Hershey, PA 17033 (United States); The Pennsylvania State University College of Medicine, Department of Cell and Molecular Physiology, 500 University Dr., Hershey, PA 17033 (United States); Kelleher, Shannon L., E-mail: [The Pennsylvania State University, Department of Nutritional Sciences, 209 Chandlee Lab, University Park, PA 16802 (United States); The Pennsylvania State University Milton S. Hershey Medical Center, Department of Surgery, 500 University Dr., Hershey, PA 17033 (United States); The Pennsylvania State University College of Medicine, Department of Cell and Molecular Physiology, 500 University Dr., Hershey, PA 17033 (United States)


    Prolactin receptor (PRL-R) activation regulates cell differentiation, proliferation, cell survival and motility of breast cells. Prolactin (PRL) and PRL-R over-expression are strongly implicated in breast cancer, particularly contributing to tumor growth and invasion in the more aggressive estrogen-receptor negative (ER−) disease. PRL-R antagonists have been suggested as potential therapeutic agents; however, mechanisms through which PRL-R antagonists exert their actions are not well-understood. Zinc (Zn) is a regulatory factor for over 10% of the proteome, regulating critical cell processes such as proliferation, cell signaling, transcription, apoptosis and autophagy. PRL-R signaling regulates Zn metabolism in breast cells. Herein we determined effects of PRL-R attenuation on cellular Zn metabolism and cell function in a model of ER-, PRL-R over-expressing breast cancer cells (MDA-MB-453). PRL-R attenuation post-transcriptionally increased ZnT2 abundance and redistributed intracellular Zn pools into lysosomes and mitochondria. ZnT2-mediated lysosomal Zn sequestration was associated with reduced matrix metalloproteinase 2 (MMP-2) activity and decreased invasion. ZnT2-mediated Zn accumulation in mitochondria was associated with increased mitochondrial oxidation. Our results suggest that PRL-R antagonism in PRL-R over-expressing breast cancer cells may reduce invasion through the redistribution of intracellular Zn pools critical for cellular function. - Highlights: • PRL-R attenuation increased ZnT2 expression. • PRL-R attenuation increased lysosomal and mitochondrial Zn accumulation. • PRL-R attenuation decreased MMP-2 and invasion. • PRL-R antagonists may modulate lysosomal and mitochondrial Zn pools.

  11. Identification of bovine prolactin in seminal fluid, and expression and localization of the prolactin receptor and prolactin-inducible protein in the testis and epididymis of bulls exposed to ergot alkaloids.

    Pratt, S L; Calcatera, S M; Stowe, H M; Dimmick, M A; Schrick, F N; Duckett, S K; Andrae, J G


    The objectives of this study were to determine (1) the presence and expression levels of bovine prolactin receptor (PRLR) and prolactin-inducible protein (PIP) in bovine testis and epididymis, and (2) the presence and concentrations of prolactin (PRL) present in seminiferous fluid in bulls consuming diets with (E+) or without (E-) ergot alkaloids. Bulls (n = 8) were sacrificed after 126 days (group A) of E+ or E- treatment or 60 days after all bulls (n = 6) were switched to the E- ration (group B). End point and real-time quantitative reverse transcription-polymerase chain reaction and immunohistochemistry were conducted on testis and epididymis samples to establish the presence and relative expression of PRLR and PIP. Seminal fluid samples obtained from bulls consuming E- and E+ diets were subjected to RIA for PRL. Both PIP and PRLR were present in testis and epididymis as determined by reverse transcription-polymerase chain reaction and immunohistochemistry. Prolactin-inducible protein mRNA abundance was affected by time of slaughter in testis and epididymis head, respectively (P Prolactin receptor mRNA expression was affected by time of slaughter in the epididymis (P < 0.05) and differed in testis samples because of treatment (P < 0.05). Radioimmunoassay establishes the presence of PRL in seminal fluid; however, differences in the concentration of PRL over two separate studies were inconsistent, possibly because of differences in diet. The presence and localization of the PRLR are consistent with expression data reported for other species, and the presence of PIP and PRL in seminal fluid is consistent with data generated in humans.

  12. Actions of Prolactin in the Brain: From Physiological Adaptations to Stress and Neurogenesis to Psychopathology

    Torner, Luz


    Prolactin (PRL) is one of the most versatile hormones known. It is considered an adaptive hormone due to the key roles it plays in the modulation of the stress response and during pregnancy and lactation. Within the brain, PRL acts as a neuropeptide to promote physiological responses related to reproduction, stress adaptation, neurogenesis, and neuroprotection. The action of PRL on the nervous system contributes to the wide array of changes that occur in the female brain during pregnancy and result in the attenuation of the hypothalamic–pituitary–adrenal axis. Together, all these changes promote behavioral and physiological adaptations of the new mother to enable reproductive success. Brain adaptations driven by PRL are also important for the regulation of maternal emotionality and well-being. PRL also affects the male brain during the stress response, but its effects have been less studied. PRL regulates neurogenesis both in the subventricular zone and in the hippocampus. Therefore, alterations in the PRL system due to stress or exposure to substances that reduce neurogenesis or other conditions, could contribute to maladaptive responses and pathological behavioral outcomes. Here, we review the PRL system and the role it plays in the modulation of stress response and emotion regulation. We discuss the effects of PRL on neurogenesis and neuroprotection, the putative neuronal mechanisms underlying these effects, and their contribution to the onset of psychopathological states such as depression. PMID:27065946

  13. Non-classical effects of prolactin on the innate immune response of bovine mammary epithelial cells: Implications during Staphylococcus aureus internalization.

    Medina-Estrada, Ivan; Alva-Murillo, Nayeli; López-Meza, Joel E; Ochoa-Zarzosa, Alejandra


    Staphylococcus aureus has the ability to invade mammary epithelial cells (bMECs) causing mastitis. This event depends primarily on the α5β1 integrin in the host cell. In addition, bMECs are a target for the hormone prolactin (PRL), which can regulate β1 integrin-dependent actions related to differentiation and lactation. Previously, we demonstrated that bovine PRL (bPRL, 5 ng/ml) stimulates S. aureus internalization into bMECs. TLR2 is important during S. aureus infections, but its activation by PRL has not yet been established. The objective of this study was to determine the role of α5β1 integrin and TLR2 during S. aureus internalization into bMECs stimulated with bPRL. We demonstrated that the prolactin-stimulated internalization of S. aureus decreases in response to the blockage of α5β1 integrin (∼ 80%) and TLR2 (∼ 80%). bPRL increases the membrane abundance (MA) of α5β1 integrin (∼ 20%) and induces TLR2 MA (∼ 2-fold). S. aureus reduces the α5β1 integrin MA in bMECs treated with bPRL (∼ 75%) but induces TLR2 MA in bMECs (∼ 3-fold). Bacteria and bPRL did not modify TLR2 MA compared with the hormone alone. S. aureus induces the activation of the transcription factor AP-1, which was inhibited in bMECs treated with bPRL and infected. In general, bPRL induces both pro- and anti-inflammatory responses in bMECs, which are abated in response to bacterial challenge. Interestingly, the canonical Stat-5 transcription factor was not activated in the challenged bMECs and/or treated with bPRL. Taken together, these results support novel functions of prolactin as a modulator of the innate immune response that do not involve the classical prolactin pathway.

  14. Effects of amisulpride on sexual function and prolactin secretion in male patients with schizophrenia%氨磺必利对男性精神分裂症患者性功能和催乳素的影响

    程林; 李泽爱; 朱春燕; 潘多


    Objective To investigate the influence of amisulpride treatment on sexual function and prolactin secre-tion in male schizophrenia. Methods 60 patients of schizophrenia were randomly divided into two groups, each of which received either amisulpride (30 cases) or aripiprazole(30 cases) treatment for 8 weeks. The Arizona sexual experience scale ( ASEX ) was self-evaluated before and after 8 weeks treatment , respectively . The positive and negative symptom scales ( PANSS ) were used to evaluate treatment efficacy while side effects were assessed by treatment emergent symptom scale ( TESS) and prolactin levels were measured in the same time. Results After 8 weeks treatment, ASEX scores, sex drive scores, sexually aroused scores, orgasms satisfying scores, prolactin lev-els were significantly higher than before in the patients receiving amisulpride. No significant difference was in arip-iprozole group. The therapeutic effects were nearly equivalent; and the side effects of both were weak. Prolactin levels had significantly positive correlation with ASEX scores within the whole patients and amisulpride group after 8 weeks treatment. No significant correlation was detected between amisulpride dosage and either sex function or pro-lactin levels . Conclusion Amisulpride has stronger effects in sexual function and serum prolactin of male schizo-phrenia patients.%目的探讨氨磺必利对男性精神分裂症患者性功能与催乳素的影响。方法将60例精神分裂症患者随机分为氨磺必利组30例和阿立哌唑组30例,治疗8周,分别于治疗前,治疗后第8周采用亚利桑那性体验量表( ASEX)自评,同时评定阳性与阴性症状量表( PANSS)及治疗时出现的症状量表( TESS),检查血清催乳素。结果治疗第8周末,氨磺必利组ASEX总分及性冲动因子分、性唤起因子分、性高潮满意度因子分、血浆催乳素均较治疗前升高(P0.05);两组患者疗效相当,副反应均较轻;血

  15. PAK1 translocates into nucleus in response to prolactin but not to estrogen

    Oladimeji, Peter, E-mail:; Diakonova, Maria, E-mail:


    Tyrosyl phosphorylation of the p21-activated serine–threonine kinase 1 (PAK1) has an essential role in regulating PAK1 functions in breast cancer cells. We previously demonstrated that PAK1 serves as a common node for estrogen (E2)- and prolactin (PRL)-dependent pathways. We hypothesize herein that intracellular localization of PAK1 is affected by PRL and E2 treatments differently. We demonstrate by immunocytochemical analysis that PAK1 nuclear translocation is ligand-dependent: only PRL but not E2 stimulated PAK1 nuclear translocation. Tyrosyl phosphorylation of PAK1 is essential for this nuclear translocation because phospho-tyrosyl-deficient PAK1 Y3F mutant is retained in the cytoplasm in response to PRL. We confirmed these data by Western blot analysis of subcellular fractions. In 30 min of PRL treatment, only 48% of pTyr-PAK1 is retained in the cytoplasm of PAK1 WT clone while 52% re-distributes into the nucleus and pTyr-PAK1 shuttles back to the cytoplasm by 60 min of PRL treatment. In contrast, PAK1 Y3F is retained in the cytoplasm. E2 treatment causes nuclear translocation of neither PAK1 WT nor PAK1 Y3F. Finally, we show by an in vitro kinase assay that PRL but not E2 stimulates PAK1 kinase activity in the nuclear fraction. Thus, PAK1 nuclear translocation is ligand-dependent: PRL activates PAK1 and induces translocation of activated pTyr-PAK1 into nucleus while E2 activates pTyr-PAK1 only in the cytoplasm. - Highlights: • Prolactin but not estrogen causes translocation of PAK1 into nucleus. • Tyrosyl phosphorylation of PAK1 is required for nuclear localization. • Prolactin but not estrogen stimulates PAK1 kinase activity in nucleus.

  16. Immunological properties of prolactin and studies on a gonadotropin binding inhibitor

    Chang, Y.S.


    The physiological role of prolactin in horses has not yet been well defined. With the availability of highly purified ePRL for inducing antibody formation in rabbits and for radiolabeling with Na/sup 125/I, a very sensitive (0.4-0.6 ng/ml) and highly specific homologous RIA for ePRL was developed. A heterologous RIA using /sup 125/I-labeled ovine PRL and anti-ePRL antiserum was also developed and compared to the homologous RIA for ePRL. Of the two systems, it is concluded that this homologous RIA system is more suitable and more reliable for measuring prolactin concentration in horse serum samples. Until now, biochemical information on PRL has not been available for reptilian species. Sea turtle (Chelonia mydas) prolactin was purified from pituitary extracts by selective precipitation, DEAE-cellulose chromatography and gel filtration. Similar to other species of PRL, sea turtle PRL is a 22,000-24,000 daltons protein and contains a high content of glutamic acid, aspartic acid, serine and leucine, the N-terminal amino acid residue. Gonadotropin (FSH) binding inhibitor was partially purified from sheep testes by ammonium sulfate fractionation and ion exchange chromatography. The FSH-BI (molecular weight: 50,000 daltons, estimated by gel filtration) contains a protein moiety necessary for binding inhibitory activity. The inhibition of the binding of /sup 125/I-labeled ovine FSH to its receptor by the FSH-BI is not competitive. Both in vivo and in vitro biological studies of FSH-BI preparations in rats indicated various effects on FSH and LH activities at the gonadal level. These findings suggest a physiological role for FSH-BI in the regulation of reproduction.

  17. Uncoupling clutch size, prolactin, and luteinizing hormone using experimental egg removal.

    Ryan, Calen P; Dawson, Alistair; Sharp, Peter J; Williams, Tony D


    Clutch size is a key avian fitness and life history trait. A physiological model for clutch size determination (CSD), involving an anti-gonadal effect of prolactin (PRL) via suppression of luteinizing hormone (LH), was proposed over 20 years ago, but has received scant experimental attention since. The few studies looking at a PRL-based mechanistic hypothesis for CSD have been equivocal, but recent experiments utilizing a pharmacological agent to manipulate PRL in the zebra finch (Taeniopygia guttata) found no support for a role of this hormone in clutch size determination. Here, we take a complementary approach by manipulating clutch size through egg removal, examining co-variation in PRL and LH between two breeding attempts, as well as through experimentally-extended laying. Clutch size increased for egg removal females, but not controls, but this was not correlated with changes in PRL or LH. There were also no differences in PRL between egg removal females and controls, nor did PRL levels during early, mid- or late-laying of supra-normal clutches predict clutch size. By uncoupling PRL, LH and clutch size in our study, several key predictions of the PRL-based mechanistic model for CSD were not supported. However, a positive correlation between PRL levels late in laying and days relative to the last egg (clutch completion) provides an alternative explanation for the equivocal results surrounding the conventional PRL-based physiological model for CSD. We suggest that females coordinate PRL-mediated incubation onset with clutch completion to minimize hatching asynchrony and sibling hierarchy, a behavior that is amplified in females laying larger clutches.

  18. Migratory fat deposition in European quail: a role for prolactin?

    Boswell, T; Sharp, P J; Hall, M R; Goldsmith, A R


    The present study addresses the role of prolactin as a regulator of migratory fattening in European quail (Coturnix coturnix). Plasma prolactin levels in captive birds undergoing migratory fattening in an outdoor aviary and in the laboratory were measured by radioimmunoassay with an antibody raised against recombinant-derived chicken prolactin. No strong association between prolactin and migratory fattening was apparent, and prolactin levels were more closely related to daylength, with the highest concentrations being reached on long days. Plasma prolactin profiles were similar in intact and castrated male quail. Prolactin was secreted in a daily rhythm, with the highest concentrations occurring early in the photophase. However, when birds were food-restricted for 50 days during a migratory phase, there was no difference in fat deposition between birds food-deprived for the first half of the daily photophase compared with those deprived for the second half. Fattening was reduced in the food-restricted birds relative to ad libitum-fed controls, but there was no difference in plasma prolactin levels between the groups. Injections of ovine prolactin (4 mg/kg) significantly increased food intake and body mass of birds maintained on long days, but there were no differences in fattening between birds injected in the morning compared with those injected in the afternoon. Collectively, these results do not support a major role for prolactin in the regulation of migratory fat deposition in European quail.

  19. Quantitative assessment of female prolactin-secreting pituitary microadenomas with dynamic enhanced MR imaging%动态增强MRI定量诊断女性垂体泌乳素微腺瘤

    刘兰祥; 刘德丰; 崔玉杰


    Objective To quantitatively analyze dynamic MR parameters of female normal adenohypophysis and prolactin-secreting pituitary microadenomas, and to explore the optimal diagnostic threshold of these parameters for prolactin-secre-ting pituitary microadenomas. Methods Dynamic enhanced MR imaging was performed in 30 normal female adenohypophysis and 30 patients with female prolactin-secreting pituitary microadenoma. The shape of time-signal intensity curve (TIC), the peak time, the slop and enhance rate were statistically compared between normal adenohypophysis and microadenomas, while the diagnostic threshold of prolactin-secreting pituitary microadeoma was determined with ROC, the sensitivity and specificity were calculated as well. Results Taking peak time of 66 s as the threshold of pituitary microadenoma, the diagnostic sensitivity and specificity was 76. 70% and 84. 40%. When the slop of enhancement curves of 2. 015 was taken as the threshold, the sensitivity and specificity was 88. 50% and 67. 10% , respectively. Taking combined peak time, slop and enhance rate of 0. 566 as the threshold, the sensitivity and specificity was 92. 20% and 87. 53%, respectively. Conclusion Peak time 66 s, slop of enhancement 2. 015 and combined peak time, slop and enhance rate 0. 566 can be regarded as the threshold of dynamic enhanced MR imaging in diagnosis of pituitary microadenoma.%目的 定量分析动态增强MRI诊断女性垂体泌乳素微腺瘤的各参数指标,探索各参数的最佳阈值.方法 分析30例女性垂体泌乳素微腺瘤及30名健康女性腺垂体动态增强MRI,比较泌乳素微腺瘤与正常腺垂体时间-信号强度曲线(TIC)的形态、达峰时间、强化率、强化斜率.采用ROC法确定垂体泌乳素微腺瘤的诊断阈值,并计算诊断敏感度、特异度.结果 当以达峰时间66 s作为诊断阈值时,其敏感度为76.70%,特异度为84.40%;以强化斜率为2.015作为诊断阈值时,其敏感度为88.50

  20. A novel first exon directs hormone-sensitive transcription of the pig prolactin receptor

    Endocrine, paracrine, and autocrine prolactin (PRL) acts through its receptor (PRLR) to confer a wide range of biological functions, including its established role during lactation.We have identified a novel first exon of the porcine PRLR that gives rise to three different mRNA transcripts. Transcri...


    Maternal Atrazine (ATR) alters hypothalamic dopamine (HYP-DA) and serum prolactin (sPRL) in male pups. 1Christopher Langdale, 2Tammy Stoker and 2Ralph Cooper. 1 Dept. of Cell Biology, North Carolina State University College of Veterinary Medicine, Raleigh, NC. 2 Endocrinology ...

  2. Prolactin and Psychopathology in Schizophrenia: A Literature Review and Reappraisal

    Ravi Philip Rajkumar


    Full Text Available Secretion of the anterior pituitary hormone prolactin can be significantly increased by antipsychotic drugs, leading to a range of adverse effects in patients with schizophrenia. However, there is evidence from a variety of studies that prolactin may also be related to symptom profile and treatment response in these patients, and recent work has identified variations in prolactin secretion even in drug-free patients. In this paper, a selective review of all relevant studies pertaining to prolactin and schizophrenia, including challenge and provocation studies, is presented. The implications of this work are discussed critically. A tentative model, which synthesizes these findings and argues for a significant role for prolactin in the development of schizophrenia, is outlined.

  3. Prolactin and psychopathology in schizophrenia: a literature review and reappraisal.

    Rajkumar, Ravi Philip


    Secretion of the anterior pituitary hormone prolactin can be significantly increased by antipsychotic drugs, leading to a range of adverse effects in patients with schizophrenia. However, there is evidence from a variety of studies that prolactin may also be related to symptom profile and treatment response in these patients, and recent work has identified variations in prolactin secretion even in drug-free patients. In this paper, a selective review of all relevant studies pertaining to prolactin and schizophrenia, including challenge and provocation studies, is presented. The implications of this work are discussed critically. A tentative model, which synthesizes these findings and argues for a significant role for prolactin in the development of schizophrenia, is outlined.

  4. Regulation of prolactin receptor (PRLR) gene expression in insulin-producing cells. Prolactin and growth hormone activate one of the rat prlr gene promoters via STAT5a and STAT5b

    Galsgaard, E D; Møldrup, Annette; Nielsen, Jens Høiriis


    Expression of the prolactin receptor (PRLR) gene is increased in pancreatic islets during pregnancy and in vitro in insulin-producing cells by growth hormone (GH) and prolactin (PRL). The 5'-region of the rat PRLR gene contains at least three alternative first exons that are expressed tissue......-specifically because of differential promoter usage. We show by reverse transcription-polymerase chain reaction analysis that both exon 1A- and exon 1C-containing PRLR transcripts are expressed in rat islets and that human (h)GH, ovine (o)PRL, and bovine (b)GH increase exon 1A expression 6.5 +/- 0. 8-fold, 6.8 +/- 0...

  5. Tissue-specific alterations of PRL-1 and PRL-2 expression in cancer.

    Dumaual, Carmen M; Sandusky, George E; Soo, Han Weng; Werner, Sean R; Crowell, Pamela L; Randall, Stephen K


    The PRL-1 and PRL-2 phosphatases have been implicated as oncogenic, however the involvement of these molecules in human neoplasms is not well understood. To increase understanding of the role PRL-1 and PRL-2 play in the neoplastic process, in situ hybridization was used to examine PRL-1 and PRL-2 mRNA expression in 285 normal, benign, and malignant human tissues of diverse origin. Immunohistochemical analysis was performed on a subset of these. PRL-1 and PRL-2 mRNA expression was also assessed in a small set of samples from a variety of diseases other than cancer. Where possible, associations with clinicopathological characteristics were evaluated. Alterations in PRL-1 or -2 expression were a frequent event, but the nature of those alterations was highly tumor type specific. PRL-1 was significantly overexpressed in 100% of hepatocellular and gastric carcinomas, but significantly under-expressed in 100% of ovarian, 80% of breast, and 75% of lung tumors. PRL-2 expression was significantly increased in 100% of hepatocellular carcinomas, yet significantly downregulated in 54% of kidney carcinomas. PRL-1 expression was correlated to patient gender in the bladder and to patient age in the brain and skeletal muscle. PRL-1 expression was also associated with tumor grade in the prostate, ovary, and uterus. These results suggest a pleiotropic role for PRL-1 and PRL-2 in the neoplastic process. These molecules may associate with tumor progression and serve as clinical markers of tumor aggressiveness in some tissues, but be involved in inhibition of tumor formation or growth in others.

  6. Overexpression of des(1-3)hIGF-I in the mammary gland during prolonged lactation enhances milk yield and elevates prolactin secretion

    During prolonged lactation, the mammary gland loses the capacity to synthesize and secrete the large amounts of milk that are produced during early lactation. This loss occurs despite the continued presence of a suckling stimulus and complete removal of mammary secretions. The decline in milk synthe...

  7. Convergent evolution of endometrial prolactin expression in primates, mice, and elephants through the independent recruitment of transposable elements.

    Emera, Deena; Casola, Claudio; Lynch, Vincent J; Wildman, Derek E; Agnew, Dalen; Wagner, Günter P


    Prolactin (PRL) is a multifunctional signaling molecule best known for its role in regulating lactation in mammals. Systemic PRL is produced by the anterior pituitary, but extrapituitary PRL has also been detected in many tissues including the human endometrium. Prolactin is essential for pregnancy in rodents and one of the most dramatically induced genes in the endometrium during human pregnancy. The promoter for human endometrial Prl is located about 5.8 kb upstream of the pituitary promoter and is derived from a transposable element called MER39. Although it has been shown that prolactin is expressed in the pregnant endometrium of a few mammals other than humans, MER39 has been described as primate specific. Thus, in an effort to understand mechanisms of prolactin regulatory evolution, we sought to determine how uterine prolactin is transcribed in species that lack MER39. Using a variety of complementary strategies, including reverse transcriptase-polymerase chain reaction, 5' rapid amplification of cDNA ends, and whole-transcriptome sequencing, we show that endometrial Prl expression is not a shared character of all placental mammals, as it is not expressed in rabbits, pigs, dogs, or armadillos. We show that in primates, mice, and elephants, prolactin mRNA is transcribed in the pregnant endometrium from alternative promoters, different from the pituitary promoter and different from each other. Moreover, we demonstrate that the spider monkey promoter derives from the long terminal repeat (LTR) element MER39 as in humans, the mouse promoter derives from the LTR element MER77, and the elephant promoter derives from the lineage-specific LINE retrotransposon L1-2_LA. We also find surprising variation of transcriptional start sites within these transposable elements and of Prl splice variants, suggesting a high degree of flexibility in the promoter architecture even among closely related species. Finally, the three groups shown here to express endometrial prolactin

  8. Prolactin and teleost ionocytes: new insights into cellular and molecular targets of prolactin in vertebrate epithelia

    Breves, Jason P.; McCormick, Stephen D.; Karlstrom, Rolf O.


    The peptide hormone prolactin is a functionally versatile hormone produced by the vertebrate pituitary. Comparative studies over the last six decades have revealed that a conserved function for prolactin across vertebrates is the regulation of ion and water transport in a variety of tissues including those responsible for whole-organism ion homeostasis. In teleost fishes, prolactin was identified as the “freshwater-adapting hormone”, promoting ion-conserving and water-secreting processes by acting on the gill, kidney, gut and urinary bladder. In mammals, prolactin is known to regulate renal, intestinal, mammary and amniotic epithelia, with dysfunction linked to hypogonadism, infertility, and metabolic disorders. Until recently, our understanding of the cellular mechanisms of prolactin action in fishes has been hampered by a paucity of molecular tools to define and study ionocytes, specialized cells that control active ion transport across branchial and epidermal epithelia. Here we review work in teleost models indicating that prolactin regulates ion balance through action on ion transporters, tight-junction proteins, and water channels in ionocytes, and discuss recent advances in our understanding of ionocyte function in the genetically and embryonically accessible zebrafish (Danio rerio). Given the high degree of evolutionary conservation in endocrine and osmoregulatory systems, these studies in teleost models are contributing novel mechanistic insight into how prolactin participates in the development, function, and dysfunction of osmoregulatory systems across the vertebrate lineage.

  9. Serum prolactin is associated with apoptosis in men with human immunodeficiency virus infection.

    Parra, A; Ramírez-Peredo, J; Larrea, F; Pérez-Romano, B; Cabrera, V; Torres, I; Reyes-Núñez, V; Ruiz-Argüelles, G; Ruiz-Argüelles, A


    We examined the in vivo and in vitro production of prolactin (PRL) in 20 untreated HIV-infected men compared to 14 uninfected men and its association with the cell cycle and apoptosis. Compared to uninfected men, the HIV-infected men had: (i) higher fasting serum bioactive (BIO) PRL; (ii) lower serum immunoreactive (RIA) and BIO-PRL responses to intravenous metoclopramide; (iii) greater BIO-RIA PRL ratio both fasting and during intravenous metoclopramide; (iv) lower percentage of non-stimulated PBMC in the G0/G1 phase, but a higher percentage in the S phase, of the cell cycle with normal response to Concanavalin-A; and (v) higher in vitro production of BIO-PRL by non-stimulated PBMC, which was blocked after Concanavalin-A. Fasting serum BIO-PRL positively correlated with the percent of non-stimulated PBMC in S + G2/M phases. The percentage of apoptotic PBMC negatively correlated with CD4+ T lymphocytes and with the area under the serum RIA-PRL curve, but positively correlated with the area under the curve for the BIO/RIA ratio. These results suggest that in these HIV-infected men: (i) a diminished dopaminergic tone may exist, as an adaptive mechanism attempting to survive; and (ii) BIO-PRL may participate as a cofactor in the stimulation of T-cell proliferation.

  10. mRNA expression patterns for GH, PRL, SL, IGF-I and IGF-II during altered feeding status in rabbitfish, Siganus guttatus.

    Ayson, Felix G; de Jesus-Ayson, Evelyn Grace T; Takemura, Akihiro


    Feeding time is a major synchronizer of many physiological rhythms in many organisms. Alteration in the nutritional status, specifically fasting, also affects the secretion rhythms of growth hormone (GH) and insulin-like growth factor-I (IGF-I). In this study, we investigated whether the expression patterns for the mRNAs of GH, prolactin (PRL) and somatolactin (SL) in the pituitary gland, and insulin-like growth factor I and II (IGF-I and IGF-II) in the liver of juvenile rabbitfish (Siganus guttatus) follow a rhythm according to feeding time and whether these hormone rhythms changes with starvation. Hormone mRNA levels were determined by real time PCR. The daily expression pattern for the mRNAs of GH, PRL and SL was not altered whether food was given in the morning (10:00 h) or in the afternoon (15:00 h). The daily GH mRNA expression pattern, however, was affected when food was not available for 3 days. In contrast, the daily expression pattern for IGF-I mRNA reaches its peak at roughly 5-6h after feeding. This pattern, however, was not observed with IGF-II mRNA. During 15-day starvation, GH mRNA levels in starved fish were significantly higher than the control fish starting on the 9th day of starvation until day 15. The levels returned to normal after re-feeding. In contrast to GH, PRL mRNA levels in starved fish were significantly lower than the control group starting on the 6th day of starvation until 3 days after re-feeding. SL mRNA levels were not significantly different between the control and starved group at anytime during the experiment. Both IGF-I and IGF-II mRNA levels in starved group were significantly higher than the control fish on the 3rd and 6th day of starvation. mRNA levels of both IGF-I and II in the starved fish decreased starting on the 9th day of starvation. While IGF-I mRNA levels in the starved group continued to decrease as starvation progressed, IGF-II mRNA levels were not significantly different from the control during the rest of the

  11. Glucose administration does not modulate prolactin response to exercise, TRH or haloperidol injection.

    Vigas, M; Jezová, D


    Glucose was found to exert an In vitro regulatory effect on prolactin secretion. Its role in the modulation of stimulated secretion of prolactin in man is, however, not clear. To evaluate the effect of hyperglycaemia on prolactin release, three stimulatory tests with different mechanisms of stimulation were employed. Healthy male subjects served as volunteers during submaximal exercise, TRH test (0.2 mg i.v.) and administration of haloperidol (2 mg i.v.). Glucose (100 g in 400 ml) or an equal volume of water was given 30 min before the tests. Blood for glucose and prolactin analysis was taken via an indwelling catheter. The plasma prolactin concentration increased in response to each of the stimuli applied. However, the prolactin increase during hyperglycaemia did not differ from values obtained in tests performed in normoglycaemia after water administration. These results indicate that prolactin release in healthy man is not modulated by hyperglycaemia.

  12. Prolactin variants in ram adenohypophyses vary with season

    Stroud, C. M.; Deaver, D. R.; Peters, J. L.; Loeper, D. C.; Toth, B. E.; Derr, J. A.; Hymer, W. C.


    Secretion of PRL in sheep is affected by photoperiod being highest during the spring and summer, lowest in fall and winter. The objectives of this study were to determine if 1) the production of variant forms of PRL, and 2) immuno- and bioactivities of PRL (iPRL and bPRL) differ during times of the year selected to represent periods of low, transitional and high PRL secretion. Twelve mature rams were maintained on pasture and killed in October, December, and April (n = 4/month). Individual pituitary glands were dispersed, cells obtained, and fixed for immunocytochemical flow cytometry, extracted with 0.01 N NaHCO3 or cultured in serum-free, defined media. The Mr of PRL extracted from cells immediately following dispersion ranged from 14-140K, with significantly more bands greater than 40K being detected from rams sacrificed in December than from those killed in October and April (P less than 0.01). No bands of PRL greater than 25K were observed when samples were reduced with beta-mercaptoethanol prior to electrophoresis, indicating that the high Mr forms were disulfide-linked aggregates. Culture media from October and April contained variants of PRL that ranged from 22-40K but those greater than 25K were generally not observed from cells harvested during December. Extracts of cells after 24 h in culture contained fewer high Mr species during December than had been present in initial extracts from that month. In contrast, during April more high Mr intracellular forms were present after culture than had been detected prior to culture during that month. The percentage of lactotrophs averaged 50.0 +/- 2.5, 47.4 +/- 5.7, and 59.4 +/- 5.5 for October, December, and April, respectively. Initial lactotroph content (pg/lactotroph) of iPRL was higher (P = 0.06) in April (46.0 +/- 17.0) when compared to October and December (8.0 +/- 2.0 and 20.0 +/- 10.0, respectively). In contrast, the bPRL content of initial extracts was higher (P = 0.05) in December (267.0 +/- 68.0) than

  13. Hostility is associated with a heightened prolactin response to meta-chlorophenylpiperazine in abstinent cocaine addicts.

    Handelsman, L; Kahn, R S; Sturiano, C; Rinaldi, P J; Gabriel, S; Schmeidler, J P; Bernstein, D P; Siever, L; Cooper, T B


    The prolactin (PRL) response to the administration of serotonin (5HT) agonists is an index of central nervous system 5HT activity. This index is blunted in association with hostile aggression in personality and depressive disorder patients without substance abuse. We tested whether the PRL response to the oral administration of the partial 5HT agonist meta-chlorophenylpiperazine (MCPP), 0.35 mg/kg, was associated with a measure of trait hostility, the Buss Durkee Hostility Inventory (BDHI), in cocaine addicts who were completing a 3-week detoxification and rehabilitation program. We also tested whether the cocaine addicts differed from healthy volunteers on their PRL, cortisol (CORT) or temperature responses to MCPP. The PRL response to MCPP was positively associated with the total score on the BDHI. There were, however, no differences in the neuroendocrine or temperature responses to MCPP between the cocaine-dependent group and the healthy volunteers once age effects were controlled for.

  14. Opposite association of serum prolactin and survival in patients with colon and rectal carcinomas: influence of preoperative radiotherapy.

    Barrera, Marcos Gutiéerrez De La; Trejo, Belem; Luna-Péerez, Pedro; López-Barrera, Fernándo; Escalera, Gonzalo Martínez De La; Clapp, Carmen


    Prolactin (PRL) is a pleiotropic hormone associated with the progression of various cancers, including colorectal cancer (CRC). Here we investigate whether the association of serum PRL concentration and survival is affected by tumor location and preoperative radiotherapy (PRERT) in patients with CRC cancer. Serum PRL was determined in 82 CRC patients without previous treatment. Patients with PRL concentrations at and above the 75th percentile (high PRL) or below this level (low PRL), had a significant correlation with overall survival determined using the Kaplan-Meier method. In colon cancer, there was an increased risk of mortality when PRL values were at and above the highest quartile (22% vs. 73%; P = 0.01). In contrast, in rectal cancer, high PRL values were associated with a significant overall survival advantage (88% vs. 44%; P = 0.05), which became more significant (100% vs. 34%; P = 0.005) when only rectal cancer patients receiving PRERT were compared. These findings suggest that tumor location and adjuvant radiotherapy influence the association between circulating PRL and survival in CRC.

  15. Studies on the regulatory effect of Peony-Glycyrrhiza Decoction on prolactin hyperactivity and underlying mechanism in hyperprolactinemia rat model.

    Wang, Di; Wang, Wei; Zhou, Yulin; Wang, Juan; Jia, Dongxu; Wong, Hei Kiu; Zhang, Zhang-Jin


    Clinical trials have demonstrated the beneficial effects of Peony-Glycyrrhiza Decoction (PGD) in alleviating antipsychotic-induced hyperprolactinemia (hyperPRL) in schizophrenic patients. In previous experiment, PGD suppressed prolactin (PRL) level in MMQ cells, involving modulating the expression of D2 receptor (DRD2) and dopamine transporter (DAT). In the present study, hyperPRL female rat model induced by dopamine blocker metoclopramide (MCP) was applied to further confirm the anti-hyperpPRL activity of PGD and underlying mechanism. In MCP-induced hyperPRL rats, the elevated serum PRL level was significantly suppressed by either PGD (2.5-10 g/kg) or bromocriptine (BMT) (0.6 mg/kg) administration for 14 days. However, in MCP-induced rats, only PGD restored the under-expressed serum progesterone (P) to control level. Both PGD and BMT administration restore the under-expression of DRD2, DAT and TH resulted from MCP in pituitary gland and hypothalamus. Compared to untreated group, hyperPRL animals had a marked reduction on DRD2 and DAT expression in the arcuate nucleus. PGD (10 g/kg) and BMT (0.6 mg/kg) treatment significant reversed the expression of DRD2 and DAT. Collectively, the anti-hyperPRL activity of PGD associates with the modulation of dopaminergic neuronal system and the restoration of serum progesterone level. Our finding supports PGD as an effective agent against hyperPRL.

  16. Validity of a radioimmunoassay for serum and pituitary prolactin in adult male rats. Effects of bromocriptine and thyrotropin-releasing hormone

    Andre, M. Grizard, G.; Boucher, D. (Faculte de Medecine, 63 - Clermont-Ferrand (France))


    Validity of a radioimmunoassay for rat prolactin (PRL) in serum and pituitary is analysed in adult male rats. Data are presented bearing on the accuracy, precision and sensitivity of the method. Serum levels and pituitary content are respectively ranged from 2,56 to 28,03 ng PRL RP/sub 2/ ml/sup -1/ and from 7,36 to 21,44 PRL RP/sub 2/ per gland in intact animals. Treatment with bromocriptine (10 days) results in a decrease of serum PRL levels and pituitary PRL contents. In progesterone-estradiol benzoate pretreated rats, serum PRL levels are increased 20 min after the injection of TRH.

  17. Notch2 controls prolactin and insulin-like growth factor binding protein-1 expression in decidualizing human stromal cells of early pregnancy.

    Gerlinde R Otti

    Full Text Available Decidualization, the transformation of the human uterine mucosa into the endometrium of pregnancy, is critical for successful implantation and embryonic development. However, key regulatory factors controlling differentiation of uterine stromal cells into hormone-secreting decidual cells have not been fully elucidated. Hence, we herein investigated the role of the Notch signaling pathway in human decidual stromal cells (HDSC isolated from early pregnancy samples. Immunofluorescence of first trimester decidual tissues revealed expression of Notch2 receptor and its putative, membrane-anchored interaction partners Jagged1, Delta-like (DLL 1 and DLL4 in stromal cells whereas other Notch receptors and ligands were absent from these cells. During in vitro differentiation with estrogen/progesterone (E2P4 and/or cyclic adenosine monophosphate (cAMP HDSC constitutively expressed Notch2 and weakly downregulated Jagged1 mRNA and protein, measured by quantitative PCR (qPCR and Western blotting, respectively. However, increased levels of DLL1 and DLL4 were observed in the decidualizing cultures. Transfection of a Notch luciferase reporter and qPCR of the Notch target gene hairy and enhancer of split 1 (HES1 revealed an induction of canonical Notch activity during in vitro differentiation. In contrast, treatment of HDSC with a chemical Notch/γ-secretase inhibitor decreased cAMP/E2P4-stimulated Notch luciferase activity, HES1 transcript levels and mRNA expression of the decidual marker genes prolactin (PRL and insulin-like growth factor binding protein 1 (IGFBP1. Similarly, siRNA-mediated gene silencing or antibody-mediated blocking of Notch2 diminished HES1, PRL and IGFBP1 mRNA levels as well as secreted PRL protein. In summary, the data suggest that canonical, Notch2-dependent signaling plays a role in human decidualization.

  18. The novel somatostatin analog SOM230 is a potent inhibitor of hormone release by growth hormone- and prolactin-secreting pituitary adenomas in vitro

    L.J. Hofland (Leo); A-J. van der Lely (Aart-Jan); S.W.J. Lamberts (Steven); A. Beckers (Albert); J. van der Hoek (Joost); P.M. van Koetsveld (Peter); W.W. de Herder (Wouter); M. Waaijers (Marlijn); D. Sprij-Mooij (Diana); C. Bruns (Christian); G. Weckbecker (Gisbert); R.A. Feelders (Richard)


    textabstractTo determine the inhibitory profile of the novel somatostatin (SRIF) analog SOM230 with broad SRIF receptor binding, we compared the in vitro effects of SOM230, octreotide (OCT), and SRIF-14 on hormone release by cultures of different types of secreting pituitary adenom

  19. [Prolactin and male fertility].

    Schreiber, G; Börner, A; Lauterbach, H; Thiel, W


    On 68 selected patients with disturbances of the potentia generandi et/sive coeundi (25 males with healthy metabolism and 43 males with diabetes) as well as 14 control persons PRL, LH, FSH, testosterone and oestradiol were determined radioimmunologically and the results were ascribed to sexological, clinical, spermatological and testo-histological findings. A statistically secure correlation was found between PRL values and disturbance of the libido as well as the presence of a gynaecomasty. PRL did not correlate with the spermatological variables volume of ejaculate, relative and absolute number of spermatozoa and motility. PRL did also not correlate with the testohistological findings. A relation between PRL and the peptide hormones LH and FSH as well as the steroid hormones testosterone and oestradiol could not be ascertained. Therefore the diagnostic values of a PRL determination is much limited; the pertinency of a hyperprolactinaemia may be increased by the proof of the symptoms reduction of libido and gynaecomasty with simultaneous disturbance of fertility. In our opinion the definition of hyperprolactinaemia needs revision, since at only determination of the basal value of more than 800 mU/l no more frequently pathologically andrological findings are to be observed than below 200 mU/l.

  20. Vasoinhibins: a family of N-terminal prolactin fragments that inhibit angiogenesis and vascular function.

    Clapp, Carmen; González, Carmen; Macotela, Yazmín; Aranda, Jorge; Rivera, José C; García, Celina; Guzmán, Jessica; Zamorano, Miriam; Vega, Claudia; Martín, Cecilia; Jeziorski, Michael C; de la Escalera, Gonzalo Martínez


    Antiangiogenic molecules derived from prolactin (PRL) are not a single entity, but rather a family of peptides with different molecular masses, all containing the N-terminal region of PRL. Cleavage of PRL by cathepsin-D or by matrix metalloproteases generates N-terminal fragments that act on endothelial cells to suppress vasodilation and angiogenesis and promote vascular regression. N-terminal PRL fragments have been identified in cartilage and retina, where angiogenesis is highly restricted. In vivo experiments demonstrate that these PRL fragments exert a tonic and essential suppression of retinal blood vessel growth and dilation. Similar PRL fragments have been detected in the pituitary gland, a highly vascularized organ where the control of vascular growth may differ from that in tissues where angiogenesis is highly restricted. We have previously proposed the name vasoinhibins to describe the collection of N-terminal PRL fragments having blood vessel-blocking activity, and here we discuss their promise as factors to control vascular function in health and disease.

  1. Long-term effects of radiotherapy for acromegaly on circulating prolactin

    Ciccarelli, E.; Corsello, S.M.; Besser, G.M.; Wass, J.A.H. (Department of Endocrinology, St. Bartholomew' s Hospital, West Smithfield, London (UK)); Plowman, P.N.; Jones, A.E. (Department of Radiotherapy, St. Bartholomew' s Hospital, West Smithfield, London (UK)); Touzel, R.; Rees, L.H. (Department of Chemical Endocrinology, St. Bartholomew' s Hospital, West Smithfield, London (UK))


    In 61 acromegalic patients, serum PRL was assessed (off medical treatment) before and 2 to 12 (mean 6 p) years after external beam radiotherapy. Before radiotherapy elevated PRL levels were present in 22 of 35 males (63%) and 12 of 26 females (46%) and were above 1000 mU/l in 11 males and 5 females. When studied for up to 5 years after radiotherapy, 22 or 23 (96%) patients who had not had surgery and who had normal PRL preradiotherapy showed an increased PRL level and this was also seen in 17 or 27 (63%) who had hyperprolactinaemic initially. In contrast, 10 of 27 patients (37%) who had elevated pre-radiotherapy levels (all greater than 1000 mU/l) had a reduction in PRL values after radiotherapy. In all 11 patients who underwent surgery before radiotherapy, an increase in PRL was seen after radiotherapy. In the 21 patients followed for 10--12 years, the peak PRL value occurred 1--6 years after radiotherapy. After this, a progressive reduction of PRL to normal was seen. Normal levels were reached 4 to 10 years after radiotherapy. No correlation was found between pretreatment PRL values and final GH values in the whole group, nor between changes in PRL and the development of Impaired ACTH or TSH secretion. Thus, different patterns of PRL behaviour suggest that radiotherapy treatment may either produce hyperprolactinemia from mild hypothalamic damage or ablate PRL secreting cells if they were present in the tumour before treatment. These changes do not predict final GH results or the development of hypopituitarism after radiotherapy. (author).

  2. Expression of prolactin receptors in normal canine mammary tissue, canine mammary adenomas and mammary adenocarcinomas

    Michel Erika


    Full Text Available Abstract Background Mammary tumors represent the most common neoplastic disease in female dogs. Recently, the promoting role of prolactin (PRL in the development of human breast carcinoma has been shown. Possible proliferative, anti-apoptotic, migratory and angiogenic effects of PRL on human mammary cancer cells in vitro and in vivo were suggested. The effects of PRL are mediated by its receptor, and alterations in receptor expression are likely to play a role in tumor development. Currently, not much data is available about prolactin receptor (PRLR expression in canine mammary tumors. To set the basis for investigations on the role of PRL in mammary tumorigenesis in this species, prolactin receptor expression was evaluated by semi-quantitative real time PCR and immunohistochemistry on 10 formalin-fixed, paraffin-embedded samples each of canine non-neoplastic mammary tissue, mammary adenomas and adenocarcinomas. Results The highest PRLR expression levels were found in normal mammary tissue, while adenomas, and to an even higher degree adenocarcinomas, showed a significant decrease in prolactin receptor expression. Compared to normal tissue, PRLR mRNA was reduced 2.4 fold (p = 0.0261 in adenomas and 4.8 fold (p = 0.008 in adenocarcinomas. PRLR mRNA expression was significantly lower in malignant than in benign lesions (p = 0.0165. Immunohistochemistry demonstrated PRLR expression in all three tissue types with signals mostly limited to epithelial cells. Conclusions Malignant transformation of mammary tissue was associated with a decline in prolactin receptor expression. Further studies are warranted to address the functional significance of this finding.

  3. Association of Psoriasis Severity with Serum Prolactin, Thyroid Hormones, and Cortisol before and after Treatment

    Reza M. Robati


    Full Text Available Background. Prolactin (PRL level is proposed to be associated with the severity of psoriasis although the previous studies reported different results. Objective. To find the association between PRL levels and severity of psoriasis before and after treatment. In addition, we aimed to find a difference in prolactin, thyroid stimulating hormone (TSH, thyroid hormones (T3 and T4, and cortisol levels between patients with psoriasis and normal controls. Methods. First, the levels of hormones were measured in 30 patients with psoriasis and 30 matched controls. The severity was assessed by psoriasis area and severity index (PASI. Then, patients were treated, and PASI was assessed every week until achieving PASI-75 response. At this time, the hormones were measured again and compared to the baseline. Results. No statistical significant difference was observed in the mean PRL, T3, T4, TSH, and cortisol levels between cases and controls. Comparing to the baseline, a significant decrease in PRL levels and a significant increase in T3 and serum cortisol levels were observed after treatment (P<0.05, while the changes in other hormones were not significant. Conclusion. After treatment, PRL significantly decreased, and T3 and cortisol levels significantly increased. No correlation between hormone levels and improvement of PASI score existed.

  4. Effect of Prolactin on Systemic Lupus Erythematosus%催乳素对系统性红斑狼疮的影响



    Prolactin( PRL)is a kind oi pure proteohormone secreted by adenohypophysis eosinophilic granulocyte, which is composed oi 199 amino-arid residues and has an relation between modulation oi secretion and hypothalamus. It plays a main role in mammotrophic and lactogenic efferts,also in maintaining lactation. Evidence also supports an association between prolactin levels and the activity oi human autoimmune disorders such as systemic lupus erythematosus, rheumatoid arthritis, and Reiter's syndrome etc. . Here is to make a review on the roles oi prolactin in systemic lupus erythematosus,and its correlation with the activity oi the disease.%催乳素是腺垂体嗜酸粒细胞分泌的一种纯蛋白激素,由199个氨基酸残基所组成,分泌的调节与下丘脑有关.主要作用是发挥亲乳腺效应,刺激乳腺泌乳,并维持泌乳状态.研究显示,催乳素水平与人类一些自身免疫紊乱疾病的活跃性密切相关,这类疾病包括系统性红斑狼疮、类风湿关节炎、瑞特综合征等.现对催乳素在系统性红斑狼疮发病中的作用及与系统性红斑狼疮活跃性的关系进行综述.

  5. Prolactin transport into mouse brain is independent of prolactin receptor.

    Brown, Rosemary S E; Wyatt, Amanda K; Herbison, Ryan E; Knowles, Penelope J; Ladyman, Sharon R; Binart, Nadine; Banks, William A; Grattan, David R


    The anterior pituitary hormone prolactin exerts important physiologic actions in the brain. However, the mechanism by which prolactin crosses the blood-brain barrier and enters the brain is not completely understood. On the basis of high expression of the prolactin receptor in the choroid plexus, it has been hypothesized that the receptor may bind to prolactin in the blood and translocate it into the cerebrospinal fluid (CSF). This study aimed to test this hypothesis by investigating transport of (125)I-labeled prolactin ((125)I-prolactin) into the brain of female mice in the presence and absence of the prolactin receptor (PRLR(-/-)). Peripherally administered prolactin rapidly activates brain neurons, as evidenced by prolactin-induced phosphorylation of signal transducer and activator of transcription 5 (pSTAT5) in neurons within 30 min of administration. The transport of prolactin into the brain was saturable, with transport effectively blocked only by a very high dose of unlabeled ovine prolactin. Transport was regulated, as in lactating mice with chronically elevated levels of prolactin, the rate of (125)I-prolactin transport into the brain was significantly increased compared to nonlactating controls. There was no change in the rate of (125)I-prolactin transport into the brain in PRLR(-/-) mice lacking functional prolactin receptors compared to control mice, indicating transport is independent of the prolactin receptor. These data suggest that prolactin transport into the brain involves another as yet unidentified transporter molecule. Because CSF levels of (125)I-prolactin were very low, even up to 90 min after administration, the data suggest that CSF is not the major route by which blood prolactin gains access to neurons in the brain.

  6. Interplay between progesterone and prolactin in mammary development and implications for breast cancer.

    Lee, Heather J; Ormandy, Christopher J


    Progesterone and prolactin remodel mammary morphology during pregnancy by acting on the mammary epithelial cell hierarchy. The roles of each hormone in mammary development have been well studied, but evidence of signalling cross-talk between progesterone and prolactin is still emerging. Factors such as receptor activator of NFkB ligand (RANKL) may integrate signals from both hormones to orchestrate their joint actions on the epithelial cell hierarchy. Common targets of progesterone and prolactin signalling are also likely to integrate their pro-proliferative actions in breast cancer. Therefore, a thorough understanding of the interplay between progesterone and prolactin in mammary development may reveal therapeutic targets for breast cancer. This review summarises our understanding of Pg and PRL action in mammary gland development before focusing on molecular mechanisms of signalling cross-talk and the implications for breast cancer. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  7. Prolactin Levels Correlate with Abnormal B Cell Maturation in MRL and MRL/lpr Mouse Models of Systemic Lupus Erythematosus-Like Disease

    Maria Victoria Legorreta-Haquet


    Full Text Available Prolactin (PRL plays an important role in modulating the immune response. In B cells, PRL enhances antibody production, including antibodies with self-specificity. In this study, our aims were to determine the level of PRL receptor expression during bone-marrow B-cell development and to assess whether the presence of high PRL serum concentrations influences absolute numbers of developing populations and disease outcome in lupus-prone murine models. We observed that the PRL-receptor is expressed in early bone-marrow B-cell; the expression in lupus-prone mice, which had the highest level of expression in pro-B cells and immature cells, differed from that in wild-type mice. These expression levels did not significantly change in response to hyperprolactinemia; however, populations of pro-B and immature cells from lupus-prone strains showed a decrease in the absolute numbers of cells with high PRL-receptor expression in response to PRL. Because immature self-reactive B cells are constantly being eliminated, we assessed the expression of survival factor BIRC5, which is more highly expressed in both pro-B and immature B-cells in response to PRL and correlates with the onset of disease. These results identify an important role of PRL in the early stages of the B-cell maturation process: PRL may promote the survival of self-reactive clones.

  8. Prolactin Levels Correlate with Abnormal B Cell Maturation in MRL and MRL/lpr Mouse Models of Systemic Lupus Erythematosus-Like Disease

    Legorreta-Haquet, Maria Victoria; Flores-Fernández, Rocio; Blanco-Favela, Francisco; Fuentes-Pananá, Ezequiel M; Chávez-Sánchez, Luis; Hernández-González, Rafael; Tesoro-Cruz, Emiliano; Arriaga-Pizano, Lourdes; Chávez-Rueda, Adriana Karina


    Prolactin (PRL) plays an important role in modulating the immune response. In B cells, PRL enhances antibody production, including antibodies with self-specificity. In this study, our aims were to determine the level of PRL receptor expression during bone-marrow B-cell development and to assess whether the presence of high PRL serum concentrations influences absolute numbers of developing populations and disease outcome in lupus-prone murine models. We observed that the PRL-receptor is expressed in early bone-marrow B-cell; the expression in lupus-prone mice, which had the highest level of expression in pro-B cells and immature cells, differed from that in wild-type mice. These expression levels did not significantly change in response to hyperprolactinemia; however, populations of pro-B and immature cells from lupus-prone strains showed a decrease in the absolute numbers of cells with high PRL-receptor expression in response to PRL. Because immature self-reactive B cells are constantly being eliminated, we assessed the expression of survival factor BIRC5, which is more highly expressed in both pro-B and immature B-cells in response to PRL and correlates with the onset of disease. These results identify an important role of PRL in the early stages of the B-cell maturation process: PRL may promote the survival of self-reactive clones. PMID:24454471

  9. Prolactin is associated with metabolic risk and cortisol in 1007 women with polycystic ovary syndrome

    Glintborg, Dorte; Altinok, Magda; Mumm, Hanne


    .001). In the patient population prolactin levels were inversely associated with age, smoking status, waist circumference, total cholesterol, triglyceride and low-density lipoprotein (LDL) and positively associated with high-density lipoprotein, estradiol, total testosterone, dehydroepiandrosterone sulfate, 17....../or PCOS and 116 healthy, age-matched controls were included. Prolactin levels were measured in blood samples taken in the morning after a minimum of 2 h awakening time. Macroprolactinemia was excluded by the precipitation of serum with polyethylene glycol in patients with increased prolactin levels...... estrogen levels were low (follicular phase) could be related to the lower levels of prolactin. Furthermore, as prolactin is secreted in a pulsatile manner, several measures of prolactin may be needed to further investigate associations between prolactin and metabolic risk. WIDER IMPLICATIONS...

  10. Chlorpromazine, haloperidol, metoclopramide and domperidone release prolactin through dopamine antagonism at low concentrations but paradoxically inhibit prolactin release at high concentrations.

    Besser, G. M.; Delitala, G.; Grossman, A.; Stubbs, W. A.; Yeo, T.


    1. The effects of chlorpromazine, haloperidol, metoclopramide and domperidone on the release of prolactin from perfused columns of dispersed rat anterior pituitary cells were studied. 2. Chlorpromazine, haloperidol, metoclopramide and domperidone antagonized the dopamine-mediated inhibition of prolactin release at low concentrations. 3. Each dopamine antagonist displaced the dose-response curve for dopamine-induced suppression of prolactin release to the right in a parallel manner. 4. At higher concentrations, the four drugs became less effective as dopamine antagonists. 5. At high concentrations in the absence of dopamine, chlorpromazine, haloperidol, metoclopramide and domperidone paradoxically suppressed prolactin secretion by an unknown mechanism. PMID:6110459

  11. Increased levels of prolactin receptor expression correlate with the early onset of lupus symptoms and increased numbers of transitional-1 B cells after prolactin treatment

    Ledesma-Soto Yadira


    Full Text Available Abstract Background Prolactin is secreted from the pituitary gland and other organs, as well as by cells such as lymphocytes. Prolactin has an immunostimulatory effect and is associated with autoimmune diseases that are characterised by abnormal B cell activation, such as systemic lupus erythematosus (SLE. Our aim was to determine if different splenic B cell subsets express the prolactin receptor and if the presence of prolactin influences these B cell subsets and correlates with development of lupus. Results Using real-time PCR and flow cytometry, we found that different subsets of immature (transitional and mature (follicular, marginal zone B cells express different levels of the prolactin receptor and are differentially affected by hyperprolactinaemia. We found that transitional B cells express the prolactin receptor at higher levels compared to mature B cells in C57BL/6 mice and the lupus-prone MRL/lpr and MRL mouse strains. Transitional-1 (T1 B cells showed a higher level of prolactin receptor expression in both MRL/lpr and MRL mice compared to C57BL/6 mice. Hyperprolactinaemia was induced using metoclopramide, which resulted in the development of early symptoms of SLE. We found that T1 B cells are the main targets of prolactin and that prolactin augments the absolute number of T1 B cells, which reflects the finding that this B cell subpopulation expresses the highest level of the prolactin receptor. Conclusions We found that all B cell subsets express the prolactin receptor but that transitional B cells showed the highest prolactin receptor expression levels. Hyperprolactinaemia in mice susceptible to lupus accelerated the disease and increased the absolute numbers of T1 and T3 B cells but not of mature B cells, suggesting a primary effect of prolactin on the early stages of B cell maturation in the spleen and a role of prolactin in B cell differentiation, contributing to SLE onset.

  12. EGF stimulates Pit-1 independent transcription of the human prolactin pituitary promoter in human breast cancer SK-BR-3 cells through its proximal AP-1 response element.

    Manfroid, Isabelle; Van de Weerdt, Cécile; Baudhuin, Ariane; Martial, Joseph A; Muller, Marc


    Normal and neoplastic human mammary gland cells are targets for the proliferative action of prolactin. These cells also synthesize prolactin, thereby inducing an autocrine/paracrine proliferative loop. We present the first extensive analysis of the transcriptional regulation of the human prolactin gene (hPRL) in human mammary tumor cells, SK-BR-3. We show that the pituitary promoter is functional in these cells in the absence of the pituitary-specific factor Pit-1. Expression of exogenous Pit-1 or epidermal growth factor (EGF) treatment stimulates the transfected hPRL pituitary promoter and the endogenous hPRL expression. EGF stimulation is mediated by increased synthesis of c-fos and c-jun, resulting in AP-1 binding to the proximal hPRL pituitary promoter. This regulation involves the EGF receptor, possibly ErbB2 that is highly expressed in SK-BR-3 cells, and a PI3K/JNK pathway. The stimulation of hPRL gene transcription by EGF in mammary cells may include hPRL in a complex regulatory network controlling growth of human mammary cells.

  13. Prokaryotic Expression and Polyclonal Antibody Preparation of PRL3

    SHEN Xing-gui; LI Wan-nan; WANG Jing; JIANG Yi-qun; LI Qing-shan; FU Xue-qi


    Phosphatase of regenerating liver 3(PRL3), which belongs to the superfamily of protein tyrosine phosphatases (PTPs), represents a group of low molecular weight PTPs that participate in tumorigenesis and metastasis processes.Presented here are the results of cloning, prokaryotic expression, purification, and polyclonal antibody preparation of PRL3. To obtain a specific polyclonal antibody against PRL3, the authors have prepared GST-PRL3 to immunize rabbits and purify an anti-PRL3 polyclonal antibody by negative selection affinity columns. Western blot analysis shows that the anti-PRL3 polyclonal antibody has a specific binding ability with PRL3 protein. The anti-PRL3 polyclonal antibody provides a good tool to further study the function of PRL3.

  14. The effects of prolactin and gonadotropin on luteal function and morphology in the cyclic golden hamster.

    Kon, Hiroe; Kishi, Hisashi; Arai, Koji Y; Shinoda, Motoo; Watanabe, Gen; Taya, Kazuyoshi


    The present study was conducted to evaluate the endocrinological effects of the pituitary on luteal maintenance and regression in the cyclic golden hamster (Mesocritus auratus). After hypophysectomy (Hypox) at 0900 h on day 1 of the estrous cycle (the day of ovulation), the animals received injection of prolactin (PRL) or PRL plus equine chorionic gonadotropin (eCG). They were decapitated at 1500 h on day 3 of the cycle, and trunk blood was collected for measurement of progesterone (P4). Corpora lutea (CLs) were dissected from one ovary for DNA ladder detection by electrophoresis, determination of DNA fragmentation ratio by fluorometric measurement method and measurement of P4. The other ovary was used for histological observation. After the Hypox, the daily injection of 1 mg ovine PRL restrained the DNA fragmentation ratio and number of apoptotic cell in the CLs. The PRL treatment maintained the luteal morphology and increased the luteal P4 concentration, but not in the plasma P4 concentration. In addition to PRL, injection of 2 IU eCG after the Hypox also restrained the DNA fragmentation ratio and number of apoptotic cells in the CLs to the level of a pregnant animal. The PRL plus eCG treatment maintained the luteal morphology in the same manner as the PRL only treatment and increased not only the luteal but also the plasma P4 concentration. These results suggest that PRL restrains luteal apoptosis and maintains luteal morphology and that the combination of PRL and eCG restrains not only structural but also functional luteal regression in the cyclic hamster.

  15. Chondroregulatory action of prolactin on proliferation and differentiation of mouse chondrogenic ATDC5 cells in 3-dimensional micromass cultures

    Seriwatanachai, Dutmanee [Center of Calcium and Bone Research (COCAB), Faculty of Science, Mahidol University, Bangkok (Thailand); Krishnamra, Nateetip [Center of Calcium and Bone Research (COCAB), Faculty of Science, Mahidol University, Bangkok (Thailand); Department of Physiology, Faculty of Science, Mahidol University, Bangkok (Thailand); Charoenphandhu, Narattaphol, E-mail: [Center of Calcium and Bone Research (COCAB), Faculty of Science, Mahidol University, Bangkok (Thailand); Department of Physiology, Faculty of Science, Mahidol University, Bangkok (Thailand)


    Highlights: Black-Right-Pointing-Pointer Mouse chondrogenic ATDC5 cells expressed PRL receptor mRNAs and proteins. Black-Right-Pointing-Pointer Low PRL concentration (10 ng/mL) increased chondrocyte viability and differentiation. Black-Right-Pointing-Pointer Higher PRL concentrations ( Greater-Than-Or-Slanted-Equal-To 100 ng/mL) decreased viability and increased apoptosis. -- Abstract: A recent investigation in lactating rats has provided evidence that the lactogenic hormone prolactin (PRL) increases endochondral bone growth and bone elongation, presumably by accelerating apoptosis of hypertrophic chondrocytes in the growth plate and/or subsequent chondrogenic matrix mineralization. Herein, we demonstrated the direct chondroregulatory action of PRL on proliferation, differentiation and apoptosis of chondrocytes in 3-dimensional micromass culture of mouse chondrogenic ATDC5 cell line. The results showed that ATDC5 cells expressed PRL receptor (PRLR) transcripts, and responded typically to PRL by downregulating PRLR expression. Exposure to a low PRL concentration of 10 ng/mL, comparable to the normal levels in male and non-pregnant female rats, increased chondrocyte viability, differentiation, proteoglycan accumulation, and mRNA expression of several chondrogenic differentiation markers, such as Sox9, ALP and Hspg2. In contrast, high PRL concentrations of Greater-Than-Or-Slanted-Equal-To 100 ng/mL, comparable to the levels in pregnancy or lactation, decreased chondrocyte viability by inducing apoptosis, with no effect on chondrogenic marker expression. It could be concluded that chondrocytes directly but differentially responded to non-pregnant and pregnant/lactating levels of PRL, thus suggesting the stimulatory effect of PRL on chondrogenesis in young growing individuals, and supporting the hypothesis of hypertrophic chondrocyte apoptosis in the growth plate of lactating rats.

  16. Vasoactive intestinal polypeptide and thyrotropin-releasing hormone stimulate newly synthesized, not stored, prolactin

    Maas, D.L.; Arnaout, M.A.; Martinson, D.R.; Erdmann, M.D.; Hagen, T.C. (Medical College of Wisconsin, Milwaukee (USA))


    Experiments were designed to determine whether vasoactive intestinal polypeptide (VIP), reported to stimulate basal PRL secretion, affects PRL processing by lactotrophs. Initially, rat anterior pituitary quarters were incubated for 2 h with (3H)leucine, with and without 10(-5) M VIP, and immunoreactive and immunoprecipitable rPRL were measured during 56 mM KCl perifusion to determine total and 3H-labeled PRL, respectively. Inclusion of VIP increased immunoreactive PRL, decreased immunoprecipitable PRL, and, therefore, decreased the specific activity of labeled PRL. These results suggested an enhanced release of newly synthesized PRL before KCl depolarization, thus decreasing the release of labeled PRL. To discriminate between the two PRL pools, newly synthesized and storage, pituitary quarters were incubated with and without 10(-5) M VIP for 4 h with (14C)leucine, 2 h in cold medium and 2 h with (3H)leucine. Immunoprecipitable PRL was measured during perifusion with 56 mM KCl. Data were depicted as the 3H/14C disintegrations per min ratio of PRL released/3H/14C disintegrations per min of total tissue to account for any differences in tissue labeling. This ratio was greater for tissue labeled in the presence of VIP. To determine whether VIP, as a secretagogue, differentiates between the newly synthesized and storage pools, VIP was added after pulse chase, as previously described. No preferential release was observed between the two groups. Finally, using the same (3H)- and (14C)leucine-labeling protocol with and without 10(-5) M VIP, tissue was perifused with medium 199 for 1 h, with 10(-5) M TRH for 30 min, with medium 199 for 30 min, and with 56 mM KCl for 1 h. Inclusion of VIP increased the 3H/14C released/3H/14C total tissue ratio during basal perifusion and TRH exposure.

  17. Prolactin inhibits a major tumor-suppressive function of wild type BRCA1.

    Chen, Kuan-Hui Ethan; Walker, Ameae M


    Even though mutations in the tumor suppressor, BRCA1, markedly increase the risk of breast and ovarian cancer, most breast and ovarian cancers express wild type BRCA1. An important question is therefore how the tumor-suppressive function of normal BRCA1 is overcome during development of most cancers. Because prolactin promotes these and other cancers, we investigated the hypothesis that prolactin interferes with the ability of BRCA1 to inhibit the cell cycle. Examining six different cancer cell lines with wild type BRCA1, and making use of both prolactin and the growth-inhibiting selective prolactin receptor modulator, S179D PRL, we demonstrate that prolactin activation of Stat5 results in the formation of a complex between phospho-Stat5 and BRCA1. Formation of this complex does not interfere with nuclear translocation or binding of BRCA1 to the p21 promoter, but does interfere with the ability of BRCA1 to transactivate the p21 promoter. Overexpression of a dominant-negative Stat5 in prolactin-stimulated cells resulted in increased p21 expression. We conclude that prolactin inhibits a major tumor-suppressive function of BRCA1 by interfering with BRCA1's upregulation of expression of the cell cycle inhibitor, p21.

  18. Prolactin induces interleukin-6 expression in PBMCs of rheumatoid ar-thritis patients%泌乳素促进类风湿关节炎患者外周血单个核细胞分泌白细胞介素-6∗

    唐莼; 李昀; 林小军; 叶静华; 李伟念; 何志翔; 李芳菲; 蔡小燕


    目的::探讨类风湿关节炎( RA)患者血清泌乳素( PRL)水平与疾病活动程度的关系,以及PRL促进外周血单个核细胞(PBMCs)分泌白细胞介素-6(IL-6)的机制。方法:收集我院2015年3月至9月40例初治RA患者临床及实验室资料。采用化学发光免疫分析法( CLIA)检测血清PRL水平,ELISA检测IL-6水平,RT-qPCR 检测泌乳素受体( PRLR) mRNA的表达,Western blot法检测MAPK通路相关蛋白p-p38的蛋白水平。结果:RA患者血清PRL水平明显升高(P<0.01),活动期RA患者PRL水平明显高于非活动期RA患者(P<0.01)。 PRL水平与DAS28评分、ESR和CRP呈正相关(P<0.01)。 RA患者PBMCs中PRLR水平明显升高(P<0.01)。 PRL可诱导PBMCs分泌IL-6,siRNA沉默PRLR或采用MAPK通路抑制剂可抑制IL-6的产生。结论: RA患者血清PRL升高与DAS28评分、ESR和CRP呈正相关,PRL可作为预测RA严重程度的指标。 PRL通过与PRLR相互作用,激活p38 MAPK通路,从而促进IL-6分泌。%AIM:To investigate the correlation between serum prolactin ( PRL) levels and disease activity in rheumatoid arthritis (RA) patients, and the regulatory role of PRL in interleukin-6 (IL-6) release from peripheral blood mononuclear cells ( PBMCs) , and to explore the MAPK-related mechanism of IL-6 release in PBMCs. METHODS: The clinicopathologic and hematologic parameters of 40 new-onset RA patients in the Department of Rheumatology of our hospi-tal between March and September 2015 were collected. Chemilumineseent immunoassay ( CLIA) was used to detect the ser-um PRL levels in the 40 RA patients and 20 healthy controls. The levels of IL-6 secretion by the PBMCs were evaluated u-sing ELISA. Quantitative real-time PCR was employed to examine the mRNA expression of prolactin receptor (PRLR). MAPK pathway protein p-p38 levels were evaluated by Western blot. RESULTS:Serum PRL level in the RA patients was significantly higher than that in the healthy controls (P<0. 01). Serum PRL level in

  19. Ovariectomized Sprague-Dawley and Long-Evans rats release prolactin differently in response to estrogen

    Lawson, D.M.; Sensui, N.; Gala, R.R.


    Mature female Sprague-Dawley (SD) and Long-Evans (LE) rats were ovariectomized (OVX), and given a single sc injection of either 25 or 100 polyestradiol phosphate (PEP); seven days later blood samples were withdrawn at two hour intervals from 1100 to 2100 hours to detect the presence of an afternoon surge of prolactin (PRL). Other groups of OVX rats of both strains also treated with PEP were sampled before and at 2, 5, 10 and 30 min after iv administration of 1 synthetic thyrotropin releasing hormone (TRH). Pituitary (AP) and uterine weights were determined following sacrifice one day after TRH treatment. The AP homogenates and plasma samples were assayed for PRL by radioimmunoassay. Rats of both strains had afternoon PRL surges and in both strains the magnitude and/or duration of the surges were enhanced by the higher dose of PEP. However, within each PEP dose LE rats released significantly more PRL during the surge than did SD drats. Rats of both strains also rleased PRL in response to TRH and this response was enhanced in both strains by the higher of the two doses of PEP. These data not only show that strain differences exist in estrogen-induced or mediated PRL release in the rat but also indicate that the differences are not uniform.

  20. Oxytocin and prolactin release after hypertonic saline administration in melatonin-treated male Syrian hamsters

    Juszczak, M.; Steger, R.W.; Fadden, C.; Bartke, A. [Southern Illinois Univ., Carbondale, IL (United States)


    The aim of the present investigations was to examine the effects of melatonin (Mel) on oxytocin (OT) release under conditions of osmotic stimulation, brought about by hypertonic saline administration, as well as to determine whether osmotically stimulated OT release in Mel-treated Syrian hamster is associated with alterations in the release of prolactin (PRL) and in norepinephrine (NE) and dopamine (DA) content in the hypothalamus. In both Mel- and vehicle-treated hamsters, injection of hypertonic saline was followed by a significant decrease in OT content in the pituitary neurointermediate lobe (NIL) and elevation of plasma OT and PRL levels. Melatonin injections had no significant affect on NIL OT content in either isotonic- or hypertonic-saline treated animals. Pretreatment with Mel did not alter plasma OT or PRL levels in isotonic saline-injected animals. However, Mel facilitated the release of OT, but prevented the release of PRL after hypertonic saline administration. Melatonin treatment reduced hypothalamic NE content (but not that of DA) in isotonic-saline treated animals. After osmotic stimulation, hypothalamic content of NE and DA was significantly lower in Mel-treated than in vehicle-treated animals. Data from the present study suggest that the osmotically-stimulated release of OT and PRL seems to be related to the activation of noradrenergic rather than dopaminergic transmission. Both dopaminergic and noradrenergic transmission may be, however, involved in mediating the effects of Mel on the osmotically-activated OT and PRL release. (author). 48 refs, 3 figs.

  1. Inhibitory activity of the peptides derived from buffalo prolactin on angiogenesis

    Jaeok Lee; Syamantak Majumder; Suvro Chatterjee; Kambadur Muralidhar


    The peptide fragments obtained by cathepsin digestion of purified buffalo prolactin (buPRL) monomer have been characterized using SDS-PAGE and FPLC with regard to size and pI. Their antiangiogenic activity was tested in chick embryo chorioallantoic membrane (CAM) assay and the human endothelial cells wound healing assay. Antiangiogenic activity was observed in cathepsin-cleaved fragments from buPRL. Further, a peptide sequence 45A-46Q-47G-48K-49G-50F-51I-52T-53M-54A-55L-56N-57S-58C, which matched with human somatostatin (hSST), a known antiangiogenic factor, was located in the second loop between the first and second α-helices in the threedimensional structure of buPRL, obtained by homology modelling. The synthetic peptide matching with SST sequence was found to exhibit antiangiogenic activity in both in vitro and ex vivo assays. It was also observed that all the peptides related to buPRL could antagonize the vascular endothelial growth factor (VEGF) and bradykinin (BK)-dependent production of endothelial nitric oxide (NO), which is a pre-requisite for endothelial tube formation. It is concluded therefore that an internal sequence in buPRL and peptide fragments derived from cathepsin-digested buPRL exhibit antiangiogenic activities.

  2. Emodin inhibits migration and invasion of DLD-1 (PRL-3) cells via inhibition of PRL-3 phosphatase activity.

    Han, Young-Min; Lee, Su-Kyung; Jeong, Dae Gwin; Ryu, Seong Eon; Han, Dong Cho; Kim, Dae Keun; Kwon, Byoung-Mog


    Anthraquinones have been reported as phosphatase inhibitors. Therefore, anthraquinone derivatives were screened to identify a potent phosphatase inhibitor against the phosphatase of regenerating liver-3 (PRL-3). Emodin strongly inhibited phosphatase activity of PRL-3 with IC(50) values of 3.5μM and blocked PRL-3-induced tumor cell migration and invasion in a dose-dependent manner. Emodin rescued the phosphorylation of ezrin, which is a known PRL-3 substrate. The results of this study reveal that emodin is a PRL-3 inhibitor and a good lead molecule for obtaining a selective PRL-3 inhibitor.

  3. Generation of conditional knockout alleles for PRL-3.

    Yan, Hong; Kong, Dong; Ge, Xiaomei; Gao, Xiang; Han, Xiao


    Phosphatase of regenerating liver-3 (PRL-3) is a member of the protein tyrosine phosphatase (PTP) superfamily and is highly expressed in cancer metastases. For better understanding of the role of PRL-3 in tumor metastasis, we applied a rapid and efficient method for generating PRL-3 floxed mice and investigated its phenotypes. A BAC retrieval strategy was applied to construct the PRL-3 conditional gene-targeting vector. Exon 4 was selected for deletion to generate a nonfunctional prematurely terminated short peptide as it will cause a frame-shift mutation. Conditional knockout PRL-3 mice were generated by using the Cre-loxP system and were validated by Southern blot and RT-PCR analysis. Further analysis revealed the phenotype characteristics of PRL-3 knockout mice and wildtype mice. In this study, we successfully constructed the PRL-3 conditional knockout mice, which will be helpful to clarify the roles of PRL-3 and the mechanisms in tumor metastasis.

  4. 羊驼垂体催乳素(PRL)基因全长cDNA的克隆及序列分析%Cloning and Sequence Analysis of the Full-length cDNA of PRL Gene from Alpaca Pituitary

    薛霖莉; 董常生; 赫晓燕; 范瑞文; 王海东; 曹靖; 郝欢庆


    In order to provide theoretical basis for studying biological function and application of alpaca prolactin (PRL), the alpaca PRL cDNA sequence were cloned and analyzed.According to the known cDNA sequences from mammals, alpaca PRL primers was designed and the full-length cDNA of PRL from alpaca pituitary was cloned by RT-PCR and RACE techniques.The size of full-length cDNA of PRL from alpaca pituitary was 959 bp and it contained an open reading frame (ORF) of 687 bp which encoded PRL precursor protein with 229 AA.PRL precursor protein was a single-chain polypeptide composed of 30-AA signal peptide and 199-AA mature peptide.The spatial structure of alpaca PRL protein was similar to human GH.The result of the sequence alignment showed that the amino acids composition of alpaca PRL was similar to most mammals, but the methionine at 81-AA (51-AA for mature peptide) might lead to different spatial structure which might impact functions of alpaca PRL.A phylogenetic tree constructed basing on the amino acid sequences of alpaca PRL and other organisms showed that the relationships between alpaca PRL and camel PRL were closest and that the evolution speed of alpaca was very slow with no ' episodic' evolution pattern as most mammals such as primates, rodents and ruminant.%获得并分析羊驼PRL基因cDNA全序列结构,为研究羊驼催乳素(PRL)的各种生物学作用和生产应用提供理论依据.根据已知的不同哺乳动物的PRL基因cDNA序列,设计羊驼PRL引物,运用RT-PCR方法和cDNA末端快速扩增(RACE)技术获得羊驼PRL基因cDNA全序列.羊驼PRL基因cDNA序列全长959 bp,编码区为687bp,编码229个氨基酸的PRL碰前体蛋白.预测羊驼PRL蛋白质的空间结构类似人生长激素(GH),但在81位(成熟肽为51位)为蛋氨酸可能导致蛋白空间结构的不同而影响羊驼PRL的功能;序列比对结果表明,羊驼PRL的cDNA序列与大多数哺乳动物相似.构建的基因进化树分析结果显示,羊驼PRL与骆

  5. Prolactin levels and autoantibodies in female patients with systemic lupus erythematosus.

    Kozáková, D; Rovenský, J; Cebecauer, L; Bosák, V; Jahnová, E; Vigas, M


    We investigated the relationships between prolactin (PRL) levels and antibody occurrence in systemic lupus erythematosus (SLE). No significant association between PRL levels and the majority of the autoantibodies studied (anti-U1 RNP, anti-rRNP, anti-Sm, anti-dsDNA, anti-DNP, auto-LCA, anti-EACA) could be confirmed (P > 0.05), anti-Ro/SSA antibodies being an exception. Our results showed significantly increased frequencies of these antibodies in the group of female SLE patients with normal PRL levels (< 20 micrograms/L): anti Ro/SSA in 53% (P < 0.025, chi 2 = 5.80, RR = 4.0) and anti-Ro/SSA + anti-Ro/La in 60% (P < 0.05, chi 2 = 4.05) compared with female SLE patients with hyperprolactinemia.

  6. Leptin stimulates pituitary prolactin release through an extracellular signal-regulated kinase-dependent pathway

    Tipsmark, Christian K; Strom, Christina N; Bailey, Sean T


    Leptin was initially identified as a regulator of appetite and weight control centers in the hypothalamus, but appears to be involved in a number of physiological processes. This study was carried out to examine the possible role of leptin in regulating prolactin (PRL) release using the teleost...... pituitary model system. This advantageous system allows isolation of a nearly pure population of lactotropes in their natural, in situ aggregated state. The rostral pars distalis were dissected from tilapia pituitaries and exposed to varying concentrations of leptin (0, 1, 10, 100 nM) for 1 h. Release...... of PRL was stimulated by leptin in a potent and concentration-dependent manner. A time-course experiment showed that the strongest response in PRL release with leptin occurs within the first hour (approximately sixfold), and stimulation was sustained after 16 h (approximately twofold). Many...

  7. Molecular performance of Prl and Gh/Igf1 axis in the Mediterranean meager, Argyrosomus regius, acclimated to different rearing salinities.

    Mohammed-Geba, Khaled; González, Antonio Astola; Suárez, Rubén Ayala; Galal-Khallaf, Asmaa; Martos-Sitcha, Juan Antonio; Ibrahim, Hany Mohammed; Martínez-Rodríguez, Gonzalo; Mancera, Juan Miguel


    Aquaculture industry in the Mediterranean region exhibits a growing interest for the Mediterranean meager Argyrosomus regius. Some preliminary works showed a good growth performance of the species in nearly isosmotic salinities. However, the patterns of alteration of prolactin (Prl) as well as growth hormone (Gh)/insulin growth factor-1 (Igf1) axis at the molecular level are not yet described in this species. Therefore, we cloned and sequenced partial cDNAs for pituitary prolactin (prl) and growth hormone (gh), hepatic insulin-like growth factor (igf1), and β-actin (actb). Expression patterns of these transcripts were tested in juveniles of A. regius acclimated to four different environmental salinities: (1) 5 ‰ (hyposmotic); (2) 12 ‰ (isosmotic); (3) 38 ‰ (hyperosmotic; seawater control); and (4) 55 ‰ (extremely hyperosmotic). All investigated transcripts shared high sequence identities with their counterparts in other perciformes. prl mRNA levels showed inverse pattern with increasing salinities. gh mRNA enhanced significantly in both 12 and 55 ‰ salinity groups in comparison with the control group, while igf1 showed its maximum expression levels under the nearly isosmotic environment. The results indicated clear sensitivity of prl, gh and igf1 to changes in environmental salinity, which can possibly control the euryhalinity capacity of this species.

  8. Relationship between prolactin, reproductive experience, and parental care in a biparental songbird, the zebra finch (Taeniopygia guttata).

    Smiley, Kristina O; Adkins-Regan, Elizabeth


    Hormonal systems have long been thought to play an important role in stimulating the onset of parental behavior, a critical component of reproductive success in a variety of taxa. Elevations in the peptide hormone prolactin (PRL) have been repeatedly positively correlated with the onset and maintenance of parental care across vertebrate species. A causal role for PRL in parental care has been established in several mammalian species, but less evidence for a causal role of PRL and parental care exists in birds. The zebra finch, a socially monogamous, biparental songbird, is an exceptionally useful animal model to study parental care and other close social relationships. Both sexes share parental care equally, exhibit the same parental behaviors, and show a marked improvement in breeding success with experience. We hypothesize that PRL is critically involved in the expression of zebra finch parental care and predict that circulating PRL levels will increase with breeding experience. To begin testing this, we measured plasma PRL concentrations in 14 male-female zebra finch pairs (N=28) across two breeding cycles, using a repeated measures design. PRL was measured in the birds' first, reproductively inexperienced, breeding cycle beginning at courtship and extending through chick fledging. PRL was measured again during the birds' second, reproductively experienced, breeding cycle, beginning with egg laying until chick fledging. We found that plasma PRL is significantly elevated from non-breeding concentrations during late incubation and early post-hatch care and that this elevation is greater in the reproductively experienced cycle compared to the inexperienced cycle. Findings of this study will be used to inform hypotheses and predictions for future experimental manipulations of PRL during parental care.

  9. Circulating angiogenic factors and urinary prolactin as predictors of adverse outcomes in women with preeclampsia.

    Leaños-Miranda, Alfredo; Campos-Galicia, Inova; Ramírez-Valenzuela, Karla Leticia; Chinolla-Arellano, Zarela Lizbeth; Isordia-Salas, Irma


    Preeclampsia is characterized by an imbalance in angiogenic factors. Urinary prolactin (PRL) levels and its antiangiogenic PRL fragments have been associated with disease severity. In this study, we assessed whether these biomarkers are associated with an increased risk of adverse maternal and perinatal outcomes in preeclamptic women. We studied 501 women with preeclampsia attended at a tertiary care hospital. Serum concentrations of soluble fms-like tyrosine kinase-1 (sFlt-1), placental growth factor (PlGF), and soluble endoglin (sEng), as well as urinary PRL levels, were measured by enzymed-linked immunosorbent assay. Antiangiogenic PRL fragments were determined by immunoblotting. The risk for any adverse maternal outcome and for having a small-for-gestational-age infant was higher among women with sFlt-1/PlGF ratios, sEng, and urinary PRL level values in the highest quartile (odds ratios ≥ 2.7), compared with the lowest quartile. Both urinary PRL levels and the presence of antiangiogenic PRL fragments were more closely associated with the risk of specific adverse maternal outcomes (placental abruption, hepatic hematoma or rupture, acute renal failure, pulmonary edema, maternal death, and need for endotracheal intubation, positive inotropic drug support, and hemodialysis; odds ratios ≥ 5.7 and ≥ 4.7, respectively) than either sFlt-1/PlGF ratio or sEng alone. We concluded that in preeclamptic women at the time of initial evaluation, sFlt-1/PlGF ratio and sEng are associated with increased risk of combined adverse maternal outcomes. However, urinary PRL concentrations and its antiangiogenic fragments appear to be better predictors of an adverse maternal outcome and may be useful for risk stratification in preeclampsia.

  10. A Pit-1 Binding Site Adjacent to E-box133 in the Rat PRL Promoter is Necessary for Pulsatile Gene Expression Activity.

    Bose, Sudeep; Ganguly, Surajit; Kumar, Sachin; Boockfor, Fredric R


    Recent evidence reveals that prolactin gene expression (PRL-GE) in mammotropes occurs in pulses, but the molecular process(es) underlying this phenomenon remains unclear. Earlier, we have identified an E-box (E-box133) in the rat PRL promoter that binds several circadian elements and is critical for this dynamic process. Preliminary analysis revealed a Pit-1 binding site (P2) located immediately adjacent to this E-box133 raising the possibility that some type of functional relationship may exist between these two promoter regions. In this study, using serum shocked GH3 cell culture system to synchronize PRL-GE activity, we determined that Pit-1 gene expression occurred in pulses with time phases similar to that for PRL. Interestingly, EMSA analysis not only confirmed Pit-1 binding to the P2 site, but also revealed an interaction with factor(s) binding to the adjacent E-box133 promoter element. Additionally, down-regulation of Pit-1 by siRNA reduced PRL levels during pulse periods. Thus, using multiple evidences, our results demonstrate clearly that the Pit-1 P2 site is necessary for PRL-GE elaboration. Furthermore, the proximity of this critical Pit-1 binding site (P2) and the E-box133 element coupled with the evidences of a site-to-site protein interactions suggest that the process of PRL-GE pulse activity might involve more dynamic and intricate cross-talks between promoter elements that may span some, or all, of the proximal region of the PRL promoter in driving its pulsatile expression.

  11. 经蝶窦显微手术与伽玛刀治疗泌乳素微腺瘤的疗效对比%Comparative study of transsphenoidal microsurgery and gamma knife radiosurgery in the treatment of prolactin-secreting microadenoma

    苏海波; 刘灵慧; 陈善成; 赖睿佳


    Objective To compare the therapeutic effects of transsphenoidal microsurgery (TSM) and gamma knife radiosurgery (GKR) for prolactin-secreting microadenoma. Methods Clinical data of 104 patients with prolactin-secreting microadenoma were analyzed retrospectively. TSM was performed in 50 cases (TSM group) and GKR in 54 (GKR group). The clinical effects of TSM and GKR were evaluated according to the following aspects: clinical symptom relief rate, serum prolactin level, complication rate and MRI images. Results The clinical symptom relief rate was 94% in TSM group and 92.6% in GKR group, and there was no significant difference between TSM group and GKR group (P>0.05). Compared with preoperation, the serum prolactin levels in two groups significantly decreased postoperatively (P<0.01). Compared with GKR group, the serum prolactin levels decreased more quickly in TSM group (P<0.01). The complication rate was 30.0% in TSM group and 13.0% in GKR group, and there was a significant difference between the two groups (P<0.05). Conclusions TSM and GKR for prolactin-secreting microadenoma have their respective advantages and disadvantages. TSM can make the serum prolactin levels decrease more quickly, while GKR can get less and milder complications,thus being safer than TSM.%目的 对比经蝶窦显微外科手术与伽玛刀治疗泌乳素微腺瘤的疗效.方法 回顾性分析104例泌乳素微腺瘤的临床资料.采用经蝶窦显微手术(手术组)50例,伽玛刀治疗(伽玛刀组)54例.通过比较两组临床症状缓解率、泌乳索水平、并发症发生率及MRI表现,综合评价两组疗效.结果 临床症状缓解率手术组为94%,伽玛刀组为92.6%,两组差异无统计学意义(P>0.05).与术前比较,两组术后初期泌乳素水平均明显改善(P<0.01);与伽玛刀组比较,手术组术后泌乳素水平下降更快(P<0.01).并发症发生率手术组为30.0%,伽玛刀组为13.0%,两组差异具有统计学意义(P<0.05).结论

  12. Measurement of Prolactin and Estradiol to Estimate Menses Return of Breastfeeding Mothers

    Bi-hua JIN; He-lian YU; Min-fei JIN; Xue-liang DU; Shu-rong YANG; Jing-chuan WU


    Objective To determine whether the measurement of serum prolactin (PRL) and estradiol (E2) is effective and reliable to estimate the returning time of menses during breastfeedingMethods Serum PRL and E2 were measured in 703 breastfeeding mothers during the period of 2, 3, 4, 5 and 6~9 months postpartum. Radio-immunoassay (RIA) was used to measure the levels of PRL and E2.The cervical mucus, sexual behaviors and vagina bleeding were also monitored since 56 d after postpantum.Results (1) The average level of serum PRL and E2 was 8.16, 3.66, 0.69 in the fully breastfeeding, mixed-feeding and bottle-feeding groups respectively. It showed that 92.55% mother returned menses within 6 months of postpartum in the bottle-feeding group. (2) According to the results, the levels of serum Prolactin and Estradiol were related to the feeding ways, but not completely related to the duration of postpartum. (3) By using the ratio of PRL to E2 to estimate the time of menses return among the breastfeeding mothers, we found that when the ratio became 0.60, the subjects' menses would returen. The sensitivity and the specificity of this method were 89.85% and 90.68% respectively.Conclusion The measurement of serum PRL and E2 is a simple, effective and reliable method to estimate the return time of menses during breastfeeding period. If possible, it should be promoted for clinical use to prepare for their fertility return.

  13. Are Prolactin Levels in Drug-Naive Schizophrenia Patients A Clinical Indicator?

    Demet Yalcin


    Full Text Available Aim: The relationship between serum prolactin (PRL levels in patients with schizophrenia and the psychopathology, risk of relapse, symptom severity, the side effects after antipsychotics and schizophrenia subtypes are known. The aim of this study is to examine the serum PRL level difference between drug naive schizophrenia patients and healthy control group and between schizophrenia subtypes. Material and Method: 45 untreated volunteer participant between the ages of 18-55 who applied to Ankara Numune Training and Research Hospital, in patient and outpatient departments of Psychiatry, diagnosed with schizophrenia with the DSM IV-TR classification were included to study before getting treated. Participants were given sociodemographic information form; Axis-II for definitions Semi-Structured Clinical Interview, the Positive and Negative Syndrome Scale (PANSS and Global Assessment of Functioning Scale (GAF and biochemical measurements were made. Results: The mean serum PRL levels in drug naive patients with schizophrenia were higher compared to the control group (p = 0.004. When patients with schizophrenia divided in to two groups as “paranoid” and “non-paranoid”, the mean serum prolactin levels among these groups were significantly different (p = 0.000. There was no significant relationship between serum PRL levels and GAF scores (P = 0.116 or PANSS total scores (P = 0.676 in patients with drug naive schizophrenia. Discussion: The difference between mean serum PRL levels in drug naive schizophrenia patients and schizophrenia subtypes are consistent with studies in the literature. As to use PRL levels as a marker in the clinic, further studies are needed.

  14. Prolactin Rescues Immature B-Cells from Apoptosis Induced by B-Cell Receptor Cross-Linking.

    Flores-Fernández, Rocio; Blanco-Favela, Francisco; Fuentes-Pananá, Ezequiel M; Chávez-Sánchez, Luis; Gorocica-Rosete, Patricia; Pizaña-Venegas, Alberto; Chávez-Rueda, Adriana Karina


    Prolactin has an immunomodulatory effect and has been associated with B-cell-triggered autoimmune diseases, such as systemic lupus erythematosus (SLE). In mice that develop SLE, the PRL receptor is expressed in early bone marrow B-cells, and increased levels of PRL hasten disease manifestations, which are correlated with a reduction in the absolute number of immature B-cells. The aim of this work was to determine the effect of PRL in an in vitro system of B-cell tolerance using WEHI-231 cells and immature B-cells from lupus prone MRL/lpr mice. WEHI-231 cells express the long isoform of the PRL receptor, and PRL rescued the cells from cell death by decreasing the apoptosis induced by the cross-linking of the B-cell antigen receptor (BCR) as measured by Annexin V and active caspase-3. This decrease in apoptosis may have been due to the PRL and receptor interaction, which increased the relative expression of antiapoptotic Bcl-xL and decreased the relative expression of proapoptotic Bad. In immature B-cells from MRL/lpr mice, PRL increased the viability and decreased the apoptosis induced by the cross-linking of BCR, which may favor the maturation of self-reactive B-cells and contribute to the onset of disease.

  15. Prolactin Rescues Immature B-Cells from Apoptosis Induced by B-Cell Receptor Cross-Linking

    Flores-Fernández, Rocio; Blanco-Favela, Francisco; Fuentes-Pananá, Ezequiel M.; Chávez-Sánchez, Luis; Gorocica-Rosete, Patricia; Pizaña-Venegas, Alberto; Chávez-Rueda, Adriana Karina


    Prolactin has an immunomodulatory effect and has been associated with B-cell-triggered autoimmune diseases, such as systemic lupus erythematosus (SLE). In mice that develop SLE, the PRL receptor is expressed in early bone marrow B-cells, and increased levels of PRL hasten disease manifestations, which are correlated with a reduction in the absolute number of immature B-cells. The aim of this work was to determine the effect of PRL in an in vitro system of B-cell tolerance using WEHI-231 cells and immature B-cells from lupus prone MRL/lpr mice. WEHI-231 cells express the long isoform of the PRL receptor, and PRL rescued the cells from cell death by decreasing the apoptosis induced by the cross-linking of the B-cell antigen receptor (BCR) as measured by Annexin V and active caspase-3. This decrease in apoptosis may have been due to the PRL and receptor interaction, which increased the relative expression of antiapoptotic Bcl-xL and decreased the relative expression of proapoptotic Bad. In immature B-cells from MRL/lpr mice, PRL increased the viability and decreased the apoptosis induced by the cross-linking of BCR, which may favor the maturation of self-reactive B-cells and contribute to the onset of disease. PMID:27314053

  16. Prolactin Rescues Immature B-Cells from Apoptosis Induced by B-Cell Receptor Cross-Linking

    Rocio Flores-Fernández


    Full Text Available Prolactin has an immunomodulatory effect and has been associated with B-cell-triggered autoimmune diseases, such as systemic lupus erythematosus (SLE. In mice that develop SLE, the PRL receptor is expressed in early bone marrow B-cells, and increased levels of PRL hasten disease manifestations, which are correlated with a reduction in the absolute number of immature B-cells. The aim of this work was to determine the effect of PRL in an in vitro system of B-cell tolerance using WEHI-231 cells and immature B-cells from lupus prone MRL/lpr mice. WEHI-231 cells express the long isoform of the PRL receptor, and PRL rescued the cells from cell death by decreasing the apoptosis induced by the cross-linking of the B-cell antigen receptor (BCR as measured by Annexin V and active caspase-3. This decrease in apoptosis may have been due to the PRL and receptor interaction, which increased the relative expression of antiapoptotic Bcl-xL and decreased the relative expression of proapoptotic Bad. In immature B-cells from MRL/lpr mice, PRL increased the viability and decreased the apoptosis induced by the cross-linking of BCR, which may favor the maturation of self-reactive B-cells and contribute to the onset of disease.

  17. Rotating night shift work, sleep quality, selected lifestyle factors and prolactin concentration in nurses and midwives.

    Bukowska, Agnieszka; Sobala, Wojciech; Peplonska, Beata


    The pattern of secretion of many hormones, including prolactin, is dependent on the circadian rhythm. Night shift work involves exposure to artificial light at night and sleep deficiency, which in turn can affect prolactin synthesis. The aim of this study was to evaluate a possible association between night shift work characteristics, sleep quality, lifestyle factors and prolactin concentration, using data from a cross-sectional study of nurses and midwives. A cross-sectional study was conducted among 327 nurses and midwives currently working on rotating night shifts, and 330 nurses and midwives working during the day (aged 40-60 years) (388 premenopausal and 269 postmenopausal). Information about night shift work characteristics, lifestyle, reproductive factors, sleep pattern and other covariates was collected through a face-to-face interview, and from a one-week work and sleep diary completed by the subjects. Weight and height were measured. Prolactin concentration was measured in the morning blood sample using the electrochemiluminesence immunoassay method. Associations were analyzed using linear regression models adjusted for important confounders. Analyses were carried out separately in pre- and postmenopausal women. None of the night shift work or sleep characteristics was significantly associated with prolactin concentration. Prolactin concentration was significantly (p prolactin among premenopausal women, but inversely among postmenopausal. Age was related to prolactin among postmenopausal women only. Our study indicates that rotating night shift work is not associated with prolactin concentration. Smoking, parity, time of blood collection and age among postmenopausal women were significant determinants of prolactin.

  18. Hyperprolactinemia (Prolactin Excess)

    ... When men or women who are not pregnant produce breast milk. Hypothyroidism : Underactive thyroid. Pituitary : A walnut-sized gland that sits at the bottom of the brain and releases hormones related to reproduction and growth. Prolactin inhibiting factor (PIF): A hormone that stops ...

  19. Multiple metals predict prolactin and thyrotropin (TSH) levels in men

    Meeker, John D., E-mail: [Department of Environmental Health Sciences, University of Michigan School of Public Health, 6635 SPH Tower, 109 S. Observatory St., Ann Arbor, MI 48109 (United States); Rossano, Mary G. [Department of Animal and Food Sciences, University of Kentucky, Lexington, KY (United States); Protas, Bridget [Department of Epidemiology, Michigan State University, East Lansing, MI (United States); Diamond, Michael P.; Puscheck, Elizabeth [Department of Obstetrics and Gynecology, Wayne State University, Detroit, MI (United States); Daly, Douglas [Grand Rapids Fertility and IVF, Grand Rapids, MI (United States); Paneth, Nigel [Department of Obstetrics and Gynecology, Michigan State University, East Lansing, MI (United States); Wirth, Julia J. [Department of Epidemiology, Michigan State University, East Lansing, MI (United States); Department of Obstetrics and Gynecology, Michigan State University, East Lansing, MI (United States)


    Exposure to a number of metals can affect neuroendocrine and thyroid signaling, which can result in adverse effects on development, behavior, metabolism, reproduction, and other functions. The present study assessed the relationship between metal concentrations in blood and serum prolactin (PRL) and thyrotropin (TSH) levels, markers of dopaminergic, and thyroid function, respectively, among men participating in a study of environmental influences on male reproductive health. Blood samples from 219 men were analyzed for concentrations of 11 metals and serum levels of PRL and TSH. In multiple linear regression models adjusted for age, BMI and smoking, PRL was inversely associated with arsenic, cadmium, copper, lead, manganese, molybdenum, and zinc, but positively associated with chromium. Several of these associations (Cd, Pb, Mo) are consistent with limited studies in humans or animals, and a number of the relationships (Cr, Cu, Pb, Mo) remained when additionally considering multiple metals in the model. Lead and copper were associated with non-monotonic decrease in TSH, while arsenic was associated with a dose-dependent increase in TSH. For arsenic these findings were consistent with recent experimental studies where arsenic inhibited enzymes involved in thyroid hormone synthesis and signaling. More research is needed for a better understanding of the role of metals in neuroendocrine and thyroid function and related health implications.

  20. One-Year Follow-Up of Serum Prolactin Level in Schizophrenia Patients Treated with Blonanserin: A Case Series.

    Takahashi, Sakae; Suzuki, Masahiro; Uchiyama, Makoto


    In our previous study, a prolactin elevation was more frequently in risperidone than in blonanserin; however, it was more often in blonanserin than in olanzapine. Therefore, while a rate of PRL rising is low to moderate, hyperprolactinemia is a considerable adverse effect in the blonanserin treatment. In this study, to examine detailed characteristics of hyperprolactinemia of blonanserin, we analyzed the prolactin data in six schizophrenic patients who were switched to blonanserin from other antipsychotics and followed for one year. As a result, blonanserin dose was clearly associated with serum prolactin level. The average prolactin level was almost normal when the mean blonanserin dosage was 8.0 mg/day. Regardless of the dose decrease of blonanserin, there were no remarkable changes in symptoms and social functions. Based on our findings, we conclude that low dose blonanserin medication may be useful for schizophrenia maintenance treatment without hyperprolactinemia and a high rate of relapse.

  1. Human Prolactin Improves Engraftment and Reconstitution of Human Peripheral Blood Lymphocytes in SCID Mice

    Rui Sun; Jian Zhang; Cai Zhang; Jianhua Zhang; Shujuan Liang; Anyuan Sun; Junfu Wang; Zhigang Tian


    Recombinant human prolactin (rhPRL) was administered to huPBL-SCID mice to determine its effects on human immunologic reconsfitution and function. The huPBL-SCID mice were given 10 μg I.p. Injection of rhPRL every other day for a total of 10 injections after huPBL were transferred. The results demonstrated that rhPRL improved the engraftment of lymphocytes into thymus, lymph nodes and spleens, showing that the cellularities of these organs increased although the cellularities tended to vary depending on the donor. The amounts of human T cells (HLA-ABC+/CD3+) increased greatly in thymus (14.2 folds), spleen (4.16 folds) and lymph nodes (40.18 folds) after rhPRL injections. The amounts of human B cells (HLA-ABC+/CD19+) also increased greatly in lymph nodes (42.5 folds) and spleen (5.78 folds). The lymph node cells from the rhPRL-treated huPBL-SCID mice were more sensitive to PHA stimulation ([3H] thymidine incorporation). The supernatant of PHA-stimulated PBL from rhPRL-treated huPBL/SCID chimerism contained more cytokines (IFN-γ and IL-2). The natural cytotoxicity against human sensitive target cells, K562 cells, from spleen and bone marrow of hPBL/SCID chimerism was significantly enhanced by rhPRL administration. The lymph node cells were stimulated with LPS in vitro for 3 days and the lymphocytes from the rhPRL-treated huPBL-SCID mice were more sensitive to mitogen stimulation. Both serum total IgG level and IgM level of rhPRL-treated huPBL/SCID chimerism were increased, and even without DT-rechallenge the base line of DT-specific IgG was elevated after rhPRL treatment in huPBL-SCID mice. Thus, rhPRL stimulation promotes reconstitution of human immune system in huPBL-SCID mice.

  2. Human Prolactin Improves Engraftment and Reconstitution of Human Peripheral Blood Lymphocytes in SCID Mice

    RuiSun; JianZhang; CaiZhang; JianhuaZhang; ShujuanLiang; AnyuanSun; JunfuWang; ZhigangTian


    Recombinant human prolactin (rhPRL) was administered to huPBL-SCID mice to determine its effects on human immunologic reconstitution and function. The huPBL-SCID mice were given 10 μg i.p. injection of rhPRL every other day for a total of 10 injections after huPBL were transfered. The results demonstrated that rhPRL improved the engraftment of lymphocytes into thymus, lymph nodes and spleens, showing that the cellularities of these organs increased although the cellularities tended to vary depending on the donor. The amounts of human T cells (HLA-ABC+/CD3+) increased greatly in thymus (14.2 folds), spleen (4.16 folds) and lymph nodes (40.18 folds) after rhPRL injections. The amounts of human B cells (HLA-ABC+/CD19+) also increased greatly in lymph nodes (42.5 folds) and spleen (5.78 folds). The lymph node cells from the rhPRL-treated huPBL-SCID mice were more sensitive to PHA stimulation (〔3H〕thymidine incorporation). The supernatant of PHA-stimulated PBL from rhPRL-treated huPBL/SCID chimerism contained more cytokines (IFN-γ and IL-2). The natural cytotoxicity against human sensitive target cells, K562 cells, from spleen and bone marrow of hPBL/SCID chimerism was significantly enhanced by rhPRL administration. The lymph node cells were stimulated with LPS in vitro for 3 days and the lymphocytes from the rhPRL-treated huPBL-SCID mice were more sensitive to mitogen stimulation. Both serum total IgG level and IgM level of rhPRL-treated huPBL/SCID chimerism were increased, and even without DT-rechallenge the base line of DT-specific IgG was elevated after rhPRL treatment in huPBL-SCID mice. Thus, rhPRL stimulation promotes reconstitution of human immune system in huPBL-SCID mice. Cellular & Molecular Immunology. 2004;1(2):129-136.

  3. Proliferation and mRNA expression of absorptive villous cell markers and mineral transporters in prolactin-exposed IEC-6 intestinal crypt cells.

    Teerapornpuntakit, Jarinthorn; Wongdee, Kannikar; Thongbunchoo, Jirawan; Krishnamra, Nateetip; Charoenphandhu, Narattaphol


    During pregnancy and lactation, prolactin (PRL) enhances intestinal absorption of calcium and other minerals for fetal development and milk production. Although an enhanced absorptive efficiency is believed to mainly result from the upregulation of mineral transporters in the absorptive villous cells, some other possibilities, such as PRL-enhanced crypt cell proliferation and differentiation to increase the absorptive area, have never been ruled out. Here, we investigated cell proliferation and mRNA expression of mineral absorption-related genes in the PRL-exposed IEC-6 crypt cells. As expected, the cell proliferation was not altered by PRL. Inasmuch as the mRNA expressions of villous cell markers, including dipeptidylpeptidase-4, lactase and glucose transporter-5, were not increased, PRL was not likely to enhance crypt cell differentiation into the absorptive villous cells. In contrast to the previous findings in villous cells, PRL was found to downregulate the expression of calbindin-D(9k), claudin-3 and occludin in IEC-6 crypt cells, while having no effect on transient receptor potential vanilloid family channels-5/6, plasma membrane Ca(2+)-ATPase (PMCA)-1b and Na(+)/Ca(2+) exchanger-1 expression. In conclusion, IEC-6 crypt cells did not respond to PRL by increasing proliferation or differentiation into villous cells. The present results thus supported the previous hypothesis that PRL enhanced mineral absorption predominantly by increasing transporter expression and activity in the absorptive villous cells. Copyright © 2012 John Wiley & Sons, Ltd.

  4. Polymorphism in the serotonin transporter gene and moderators of prolactin response to meta-chlorophenylpiperazine in African-American cocaine abusers and controls.

    Mannelli, Paolo; Patkar, Ashwin A; Peindl, Kathleen; Tharwani, Haresh; Gopalakrishnan, Raman; Hill, Kevin P; Berrettini, Wade H


    Serotonin (5-HT) function is altered in several psychiatric disorders, including cocaine dependence (CD), and its role in impulsive-aggressive behaviors has been widely studied. However, the relationship between psychopathological and behavioral dimensions and mechanisms of 5-HT alterations remains unclear. We investigated the relationship of a polymorphism in the 5' promoter region of the serotonin transporter gene (5-HTTLPR) with prolactin (PRL) response to meta-chlorophenylpiperazine (m-CPP) in a sample of 68 African-American individuals, 35 CD subjects and 33 controls. We also examined whether measures of impulsivity, hostility and sensation seeking influenced the relationship between the 5-HTTLPR polymorphism and PRL response to m-CPP in this sample. Individuals with the SS genotype showed significantly heightened PRL response to the challenge compared with the LL and LS genotypes. No influence of gender or substance abuse condition was observed. Hostility was associated with blunted PRL response in the total sample. Cocaine abuse was the most significant moderator of DeltaPRL (peak PRL-baseline PRL), and the interaction of genetic, behavioral and psychopathological measures helped predict most of the observed DeltaPRL (62.5%). Although these results need replication, variation in the 5-HTTLPR gene appears to influence measures of 5-HT function and interact with disease state and personality dimensions to account for 5-HT disturbances in African-American populations.

  5. Gonadotropin-releasing hormone stimulates prolactin release from lactotrophs in photoperiodic species through a gonadotropin-independent mechanism.

    Henderson, Helen L; Hodson, David J; Gregory, Susan J; Townsend, Julie; Tortonese, Domingo J


    Previous studies have provided evidence for a paracrine interaction between pituitary gonadotrophs and lactotrophs. Here, we show that GnRH is able to stimulate prolactin (PRL) release in ovine primary pituitary cultures. This effect was observed during the breeding season (BS), but not during the nonbreeding season (NBS), and was abolished by the application of bromocriptine, a specific dopamine agonist. Interestingly, GnRH gained the ability to stimulate PRL release in NBS cultures following treatment with bromocriptine. In contrast, thyrotropin-releasing hormone, a potent secretagogue of PRL, stimulated PRL release during both the BS and NBS and significantly enhanced the PRL response to GnRH during the BS. These results provide evidence for a photoperiodically modulated functional interaction between the GnRH/gonadotropic and prolactin axes in the pituitary gland of a short day breeder. Moreover, the stimulation of PRL release by GnRH was shown not to be mediated by the gonadotropins, since immunocytochemical, Western blotting, and PCR studies failed to detect pituitary LH or FSH receptor protein and mRNA expressions. Similarly, no gonadotropin receptor expression was observed in the pituitary gland of the horse, a long day breeder. In contrast, S100 protein, a marker of folliculostellate cells, which are known to participate in paracrine mechanisms within this tissue, was detected throughout the pituitaries of both these seasonal breeders. Therefore, an alternative gonadotroph secretory product, a direct effect of GnRH on the lactotroph, or another cell type, such as the folliculostellate cell, may be involved in the PRL response to GnRH in these species.

  6. Investigation of Prolactin Receptor Activation and Blockade Using Time-Resolved Fluorescence Resonance Energy Transfer

    Estelle eTallet


    Full Text Available The prolactin receptor (PRLR is emerging as a therapeutic target in oncology. Knowledge-based drug design led to the development of a pure PRLR antagonist (Del1-9-G129R-hPRL that was recently shown to prevent PRL-induced mouse prostate tumorogenesis. In humans, the first gain-of-function mutation of the PRLR (PRLRI146L was recently identified in breast tumor patients. At the molecular level, the actual mechanism of action of these two novel players in the PRL system remains elusive. In this study, we addressed whether constitutive PRLR activation (PRLRI146L or PRLR blockade (antagonist involved alteration of receptor oligomerization and/or of inter-chain distances compared to unstimulated and PRL-stimulated PRLR. Using a combination of various biochemical and spectroscopic approaches (co-IP, blue-native electrophoresis, BRET1, we demonstrated that preformed PRLR homodimers are altered neither by PRL- or I146L-induced receptor triggering, nor by antagonist-mediated blockade. These findings were confirmed using a novel time-resolved fluorescence resonance energy transfer (TR-FRET technology that allows monitoring distance changes between cell-surface tagged receptors. This technology revealed that PRLR blockade or activation did not involve detectable distance changes between extracellular domains of receptor chains within the dimer. This study merges with our previous structural investigations suggesting that the mechanism of PRLR activation solely involves intermolecular contact adaptations leading to subtle intramolecular rearrangements.

  7. Enhancement of Human Prolactin Synthesis by Sodium Butyrate Addition to Serum-Free CHO Cell Culture

    Herbert Rodrigues Goulart


    Full Text Available Sodium butyrate (NaBu has been used as a productivity enhancer for the synthesis of recombinant proteins in Chinese hamster ovary (CHO cells. Thus, the influence of NaBu on the production of recombinant human prolactin (hPRL from CHO cells was investigated for the first time. CHO cell cultures were submitted to a treatment with different concentrations of NaBu (0.25 to 4 mM. Quantitative and qualitative analyses by reverse-phase high-performance liquid chromatography (RP-HPLC and Western blot or SDS-PAGE, carried out directly on CHO-conditioned medium, showed that the highest hPRL expression was obtained with 1 mM NaBu. In vitro biological assays based on noble rat lymphoma (Nb2 and mouse pro-B lymphoma (Ba/F3-LLP cells were carried out on purified hPRL. Its bioactivity in the presence of NaBu was not apparently different from that of the First International Reference Reagent of recombinant hPRL (WHO 97/714. Our results show that NaBu increased the synthesis of recombinant hPRL in CHO cells, apparently without compromising either its structure or function.

  8. Prolactin May Not Play a Role in Primary Antiphospholipid (Hughes' Syndrome

    Manoel Tavares Neves Junior


    Full Text Available The relationship between prolactin (PRL and the immune system has been demonstrated in the last two decades and has opened new windows in the field of immunoendocrinology. However, there are scarce reports about PRL in primary antiphospholipid syndrome (pAPS. The objective of this study was to evaluate PRL levels in patients with pAPS compared to healthy controls and to investigate their possible clinical associations. Fifty-five pAPS patients according to Sapporo criteria were age- and sex-matched with 41 healthy subjects. Individuals with secondary causes of hyperprolactinemia (HPRL were excluded; demographic, biometric, and clinical data, PRL levels, antiphospholipid antibodies, inflammatory markers, and other routine laboratory findings were analyzed. PRL levels were similar between pAPS and healthy controls (8.94±7.02 versus 8.71±6.73 ng/mL, P=.876. Nine percent of the pAPS patients and 12.1% of the control subjects presented HPRL (P=.740. Comparison between the pAPS patients with hyper- and normoprolactinemia revealed no significant differences related to anthropometrics, clinical manifestations, medications, smoking, and antiphospholipid antibodies (P>.05. This study showed that HPRL does not seem to play a role in clinical manifestations of the pAPS, differently from other autoimmune rheumatic diseases.

  9. Psychological Stress-Derived Prolactin Modulates Occludin Expression in Vaginal Epithelial Cells to Compromise Barrier Function

    Xueyan Li


    Full Text Available Background/Aims: The causative factors of the vaginitis are not fully understood yet. Epithelial barrier dysfunction plays a critical role in the pathogenesis of vaginitis. This study aims to investigate the role of prolactin (PRL in the causing the vaginal epithelial barrier dysfunction. Methods: Adult rats were treated with water-avoid-stress. The serum levels of PRL were determined by ELISA. T84 cell (T84 cells; a vaginal epithelial cell line monolayers were prepared to be used assessing the epithelial barrier functions. The expression of occludin in T84 cells was assessed by Chromatin immunoprecipitation assay, methylation specifIc PCR, real time quantitative RT-PCR and Western blotting. Results: The results showed that psychological stress markedly increased the serum levels of PRL in the rat vaginal epithelia. Exposure of T84 cells to PRL in the culture markedly increased the phosphorylation of STAT3 and suppressed the expression of occludin in the cells; the transepithelial electric resistance was decreased and the permeability to a macromolecular tracer was increased in the T84 monolayers, which was mimicked by blocking STAT3, or abolished by over expression of occludin in the epithelial cells. Conclusions: Psychological stress-derived PRL induces vaginal epithelial barrier dysfunction by inhibiting the expression of occludin.

  10. Circulating breeding and pre-breeding prolactin and LH are not associated with clutch size in the zebra finch (Taeniopygia guttata).

    Ryan, Calen P; Dawson, Alistair; Sharp, Peter J; Meddle, Simone L; Williams, Tony D


    Clutch size is a fundamental predictor of avian fitness, widely-studied from evolutionary and ecological perspectives, but surprisingly little is known about the physiological mechanisms regulating clutch size variation. The only formal mechanistic hypothesis for avian clutch-size determination predicts an anti-gonadal effect of circulating prolactin (PRL) via the inhibition of luteinizing hormone (LH), and has become widely-accepted despite little experimental support. Here we investigated the relationship between pre-breeding and breeding plasma PRL and LH and clutch-size in captive-breeding female zebra finches (Taeniopygia guttata). Using a repeated-measures design, we followed individual females from pre-breeding, through multiple breeding attempts, and attempted to decrease PRL using the D2-receptor agonist, bromocriptine. Clutch size was independent of variation in pre-breeding PRL or LH, although pre-breeding LH was negatively correlated with the time between pairing and the onset of laying. Clutch size was independent of variation in plasma PRL on all days of egg-laying. Bromocriptine treatment had no effect on plasma PRL, but in this breeding attempt clutch size was also independent of plasma PRL. Finally, we found no evidence for an inverse relationship between plasma PRL and LH levels, as predicted if PRL had inhibitory effects via LH. Thus, our data fail to provide any support for the involvement of circulating PRL in clutch size determination. These findings suggest that alternative models for hormonal control of avian clutch size need to be considered, perhaps involving downstream regulation of plasma PRL at the level of the ovary, or other hormones that have not been considered to date.

  11. Differences in the activity of prolactin cells in male and female fresh water teleostMastacembelus armatus (Lacepede) during gonadal cycle

    Sushant Kumar Verma; Abdul Alim


    Objective:To determine the differences in the activity of pituitary prolactin cells between male and female fresh water teleostMastacembelus armatus(M. armatus) during their reproductive cycle.Methods:Fishes were sampled every month throughout the year.They were dissected, gonads weighed for the determination ofGSI.Blood samples were collected for estimation of plasma calcium,17β-estradiol of females and testosterone of males and prolactin.Nuclear diameter ofPRL cells, diameter of oocyte and testicular lobule was measured by image analyzer microscope.An experiment was also conducted in which female and male fishes were injected with17β-estradiol and17 alpha-methyltestosterone respectively and the blood samples were analyzed for plasma calcium, prolactin and sex steroids levels.Results:Negligible change in plasma calcium and prolactin level and little variation in nuclear diameter ofPRL cells were recorded throughout the year in relation to testicular cycle as well as after17 alpha-methyltestosterone administration in male.Variations in level of plasma calcium and prolactin and a large range of difference in nuclear diameter ofPRL cells were noted during ovarian cycle as well as after17β-estradiol administration in female.Conclusion:Difference in the activity ofPRL cells was noted between male and femaleM. armatus.It act as hypercalcemic factor in females whose level increase along with maturation of ovary with the influence of increasing level of17β-estradiol from ovarian follicles to fulfill the increased demand of calcium for vitellogenesis and thus directly effecting reproduction.No such role of prolactin was observed for male fishes.

  12. Role of thyrotropin-releasing hormone in prolactin-producing cell models.

    Kanasaki, Haruhiko; Oride, Aki; Mijiddorj, Tselmeg; Kyo, Satoru


    Thyrotropin-releasing hormone (TRH) is a hypothalamic hypophysiotropic neuropeptide that was named for its ability to stimulate the release of thyroid-stimulating hormone in mammals. It later became apparent that it exerts a number of species-dependent hypophysiotropic activities that regulate other pituitary hormones. TRH also regulates the synthesis and release of prolactin, although whether it is a physiological regulator of prolactin that remains unclear. Occupation of the Gq protein-coupled TRH receptor in the prolactin-producing lactotroph increases the turnover of inositol, which in turn activates the protein kinase C pathway and the release of Ca(2+) from storage sites. TRH-induced signaling events also include the activation of extracellular signal-regulated kinase (ERK) and induction of MAP kinase phosphatase, an inactivator of activated ERK. TRH stimulates prolactin synthesis through the activation of ERK, whereas prolactin release occurs via elevation of intracellular Ca(2+). We have been investigating the role of TRH in a pituitary prolactin-producing cell model. Rat pituitary somatolactotroph GH3 cells, which produce and release both prolactin and growth hormone (GH), are widely used as a model for the study of prolactin- and GH-secreting cells. In this review, we describe the general action of TRH as a hypophysiotropic factor in vertebrates and focus on the role of TRH in prolactin synthesis using GH3 cells.

  13. Therapeutic potential of PRL-3 targeting and clinical significance of PRL-3 genomic amplification in gastric cancer

    Nishimiya Hiroshi


    Full Text Available Abstract Background Phosphatase of regenerating liver-3 (PRL-3 has deserved attention as a crucial molecule in the multiple steps of metastasis. In the present study, we examined the mechanisms regulating PRL-3 expression, and assessed the clinical potential of PRL-3-targeted therapy in gastric cancer. Methods PRL-3 genomic amplification was analyzed using quantitative-polymerase chain reaction and/or fluorescence in situ hybridization in 77 primary gastric tumors. The anticancer activity of PRL-3 inhibitor (1-4-bromo-2-benzylidene rhodanine treatment was evaluated against cancer cells with different genetic and expression status. Results PRL-3 genomic amplification was closely concordant with high level of its protein expression in cell lines, and was found in 20% (8/40 among human primary tumors with its expression, which were all stage III/IV disease (40%, 8/20, but in none (0/37 among those without expression. Additionally, PRL-3 genomic amplification was associated with metastatic lymph node status, leading to advanced stage and thereby poor outcomes in patients with lymph node metastasis (P = 0.021. PRL-3 small interfering RNA robustly repressed metastatic properties, including cell proliferation, invasion, and anchorage-independent colony formation. Although neither PRL-3 genomic amplification nor expression level was responsible for the sensitivity to PRL-3 inhibitor treatment, the inhibitor showed dose-dependent anticancer efficacy, and remarkably induced apoptosis on all the tested cell lines with PRL-3 expression. Conclusions We have for the first time, demonstrated that PRL-3 genomic amplification is one of the predominant mechanisms inducing its expression, especially in more advanced stage, and that PRL-3-targeted therapy may have a great potential against gastric cancer with its expression.

  14. Characterization of the protein tyrosine phosphatase PRL from Entamoeba histolytica.

    Ramírez-Tapia, Ana Lilia; Baylón-Pacheco, Lidia; Espíritu-Gordillo, Patricia; Rosales-Encina, José Luis


    Protein tyrosine phosphatase of regenerating liver (PRL) is a group of phosphatases that has not been broadly studied in protozoan parasites. In humans, PRLs are involved in metastatic cancer, the promotion of cell migration and invasion. PTPs have been increasingly recognized as important effectors of host-pathogen interactions. We characterized the only putative protein tyrosine phosphatase PRL (PTP EhPRL) in the eukaryotic human intestinal parasite Entamoeba histolytica. Here, we reported that the EhPRL protein possessed the classical HCX5R catalytic motif of PTPs and the CAAX box characteristic of the PRL family and exhibited 31-32% homology with the three human PRL isoforms. In amebae, the protein was expressed at low but detectable levels. The recombinant protein (rEhPRL) had enzymatic activity with the 3-o-methyl fluorescein phosphate (OMFP) substrate; this enzymatic activity was inhibited by the PTP inhibitor o-vanadate. Using immunofluorescence we showed that native EhPRL was localized to the cytoplasm and plasma membrane. When the trophozoites interacted with collagen, EhPRL relocalized over time to vesicle-like structures. Interaction with fibronectin increased the presence of the enzyme in the cytoplasm. Using RT-PCR, we demonstrated that EhPRL mRNA expression was upregulated when the trophozoites interacted with collagen but not with fibronectin. Trophozoites recovered from amoebic liver abscesses showed higher EhPRL mRNA expression levels than normal trophozoites. These results strongly suggest that EhPRL may play an important role in the biology and adaptive response of the parasite to the host environment during amoebic liver abscess development, thereby participating in the pathogenic mechanism.

  15. Intestinal mucosal changes and upregulated calcium transporter and FGF-23 expression during lactation: Contribution of lactogenic hormone prolactin.

    Wongdee, Kannikar; Teerapornpuntakit, Jarinthorn; Sripong, Chanakarn; Longkunan, Asma; Chankamngoen, Wasutorn; Keadsai, Chutiya; Kraidith, Kamonshanok; Krishnamra, Nateetip; Charoenphandhu, Narattaphol


    As the principal lactogenic hormone, prolactin (PRL) not only induces lactogenesis but also enhances intestinal calcium absorption to supply calcium for milk production. How the intestinal epithelium res-ponses to PRL is poorly understood, but it is hypothesized to increase mucosal absorptive surface area and calcium transporter expression. Herein, lactating rats were found to have greater duodenal, jejunal and ileal villous heights as well as cecal crypt depths than age-matched nulliparous rats. Morphometric analyses in the duodenum and cecum showed that their mucosal adaptations were diminished by bromocriptine, an inhibitor of pituitary PRL release. PRL also upregulated calcium transporter expression (e.g., TRPV6 and PMCA1b) in the duodenum of lactating rats. Since excessive calcium absorption could be detrimental to lactating rats, local negative regulator of calcium absorption, e.g., fibroblast growth factor (FGF)-23, should be increased. Immunohistochemistry confirmed the upregulation of FGF-23 protein expression in the duodenal and cecal mucosae of lactating rats, consistent with the enhanced FGF-23 mRNA expression in Caco-2 cells. Bromocriptine abolished this lactation-induced FGF-23 expression. Additionally, FGF-23 could negate PRL-stimulated calcium transport across Caco-2 monolayer. In conclusion, PRL was responsible for the lactation-induced mucosal adaptations, which were associated with compensatory increase in FGF-23 expression probably to prevent calcium hyperabsorption.

  16. Differential stimulation pathways of progesterone secretion from newly formed corpora lutea in rats treated with ethylene glycol monomethyl ether, sulpiride, or atrazine.

    Taketa, Yoshikazu; Yoshida, Midori; Inoue, Kaoru; Takahashi, Miwa; Sakamoto, Yohei; Watanabe, Gen; Taya, Kazuyoshi; Yamate, Jyoji; Nishikawa, Akiyoshi


    Ethylene glycol monomethyl ether (EGME), sulpiride, and atrazine are known ovarian toxicants, which increase progesterone (P4) secretion and induce luteal cell hypertrophy following repeated administration. The aim of this study was to define the pathways by which these compounds exerted their effects on the ovary and hypothalamic-pituitary-gonadal (HPG) axis. In the ovary, changes in the steroidogenic activity of new and old corpora lutea (CL) were addressed. EGME (300 mg/kg), sulpiride (100 mg/kg), or atrazine (300 mg/kg) were orally given daily for four times from proestrus to diestrus in normal cycling rats. Treatment with all chemicals significantly increased serum P4 levels, and EGME as well as sulpiride induced increases in prolactin (PRL) levels. In new CL, at both the gene and the protein levels, all three chemicals upregulated the following steroidogenic factors: scavenger receptor class B type I, steroidogenic acute regulatory protein, P450 cholesterol side-chain cleavage, and 3β-hydroxysteroid dehydrogenase (HSD) and downregulated the luteolytic gene, 20α-HSD. Coadministration of EGME and bromocriptine, a D2 agonist, completely inhibited PRL but not P4 secretion. Additionally, steroidogenic factor expression levels were upregulated, and 20α-HSD level was downregulated in new CL. These results suggest that EGME both directly and indirectly stimulates P4 production in luteal cells, whereas sulpiride elevates P4 through activation of PRL secretion in the pituitary. Atrazine may directly activate new CL by stimulating steroidogenic factor expressions. The present study suggests that multiple pathways mediate the effects of EGME, sulpiride, and atrazine on the HPG axis and luteal P4 production in female rats in vivo.

  17. Differences in the activity of prolactin cells in male and female fresh water teleost Mastacembelus armatus (Lacepede during gonadal cycle

    Sushant Kumar Verma


    Conclusion: Difference in the activity of PRL cells was noted between male and female M. armatus. It act as hypercalcemic factor in females whose level increase along with maturation of ovary with the influence of increasing level of 17 β-estradiol from ovarian follicles to fulfill the increased demand of calcium for vitellogenesis and thus directly effecting reproduction. No such role of prolactin was observed for male fishes.

  18. Effects of antipsychotics on bone mineral density and prolactin levels \\ud in patients with schizophrenia: a 12-month prospective study


    Objective: Effects of conventional and atypical antipsychotics on bone mineral density (BMD) and serum prolactin levels (PRL) were examined in patients with schizophrenia.\\ud \\ud Methods: One hundred and sixty-three first-episode inpatients with schizophrenia were recruited, to whom one of three conventional antipsychotics (perphenazine, sulpiride, and chlorpromazine) or one of three atypical antipsychotics (clozapine, quetiapine, and aripiprazole)\\ud was prescribed for 12 months as appropria...

  19. Effects of deletion of the prolactin receptor on ovarian gene expression

    Kelly Paul A


    Full Text Available Abstract Prolactin (PRL exerts pleiotropic physiological effects in various cells and tissues, and is mainly considered as a regulator of reproduction and cell growth. Null mutation of the PRL receptor (R gene leads to female sterility due to a complete failure of embryo implantation. Pre-implantatory egg development, implantation and decidualization in the mouse appear to be dependent on ovarian rather than uterine PRLR expression, since progesterone replacement permits the rescue of normal implantation and early pregnancy. To better understand PRL receptor deficiency, we analyzed in detail ovarian and corpora lutea development of PRLR-/- females. The present study demonstrates that the ovulation rate is not different between PRLR+/+ and PRLR-/- mice. The corpus luteum is formed but an elevated level of apoptosis and extensive inhibition of angiogenesis occur during the luteal transition in the absence of prolactin signaling. These modifications lead to the decrease of LH receptor expression and consequently to a loss of the enzymatic cascades necessary to produce adequate levels of progesterone which are required for the maintenance of pregnancy.

  20. Effect of hypothalamic surgery on prolactin release induced by 5-hydroxytryptophan (5-HTP) in rats.

    Ohgo, S; Kato, Y; Chihara, K; Imura, H; Maeda, K


    Intravenous injections of varying doses of 5-HTP (1, 3 and 5 mg/100 g body wt), a precursor of serotonin, caused a significant and dose-related increase in plasma prolactin concentrations in urethane-anesthetized rats. Increases in plasma prolactin concentrations caused by 5-HTP (1 mg/100 g body wt iv) were abolished by the concomitant administration of L-DOPA (2 mg/100 g body wt iv). Plasma prolactin levels were also significantly elevated following the injection of 5-HTP in rats with complete hypothalamic deafferentation, whereas 5-HTP had no significant effect on plasma prolactin levels in rats with extensive hypothalamic ablation. These results suggest that 5-HTP causes prolactin secretion by stimulating the serotoninergic mechanism in the hypothalamus.

  1. Expression of p53, Ki-67 and c-erb B2 in growth hormone-and/or prolactin-secreting pituitary adenomas Expressão de p53, Ki-67 e c-erb B2 em adenomas hipofisários secretores de prolactina e/ou hormônio de crescimento

    Carlos Henrique A. Botelho


    Full Text Available The subcellular events implicated on the formation and behavior of pituitary adenomas are not fully understood. In this study we investigated the presence of p53, Ki-67 and c-erb B2 in 38 pituitary adenomas with immunohistochemical positivity for GH and prolactin (n=26; 68.4%, for prolactin (n=9; 23.7% and for GH (n=3. 7.8%. The analyses revealed the following results: 24 (63.2% tumors expressed variable positivity for c-erb B2, 11 (28.9% expressed p53 positivity and 11 (28.9% tumors were variably positive for Ki-67. Our results demonstrated a high percentage of GH/prolactin-, prolactin- and GH-secreting tumors with immunohistochemical positivity for c-erb B2. Once this membrane receptor is related to growth factors EGF and TGFalpha and both have a definite effect on tumor growth, our data suggest a possible role for c-erb B2 on the evolution of these tumors.Os eventos subcelulares implicados na formação e comportamento dos adenomas hipofisários não são completamente compreendidos. Neste estudo nós investigamos a presença de p53, Ki-67 e c-erb B2 em 38 adenomas hipofisários com positividade imuno-histoquímica para GH e prolactina (n=26, 68,4%, para prolactina (n=9, 23,7% e para GH (n=3, 7,8%. A análise revelou os seguintes resultados: 24 tumores (63,2% expressaram positividade variável para c-erb B2, 11 (28,9% expressaram positividade para p53 e 11 tumores (28,9% foram variavelmente positivos para Ki-67. Nossos resultados demonstraram elevada percentagem de tumores secretores de GH/prolactina, prolactina e GH com positividade imuno-histoquímica para c-erb B2. Desde que este receptor de membrana está relacionado aos fatores de crescimento EGF e TGFalfa e ambos têm efeito definido no crescimento tumoral, nossos dados sugerem possível função para o c-erb B2 na evolução destes tumores.

  2. Characterization of Δ7/11, a functional prolactin-binding protein

    Fleming, JM; Ginsburg, E; McAndrew, CW; Heger, CD; Cheston, L; Rodriguez-Canales, J; Vonderhaar, BK; Goldsmith, P


    Prolactin is essential for normal mammary gland development and differentiation, and has been shown to promote tumor cell proliferation and chemotherapeutic resistance. Soluble isoforms of the prolactin receptor have been reported to regulate prolactin bioavailability by functioning as “prolactin binding proteins.” Included in this category is Δ7/11, a product of alternate splicing of the prolactin receptor primary transcript. However, the direct interactions of prolactin withΔ7/11, and the resulting effect on cell behavior, have not been investigated. Herein, we demonstrate the ability of Δ7/11 to bind prolactin using a novel proximity ligation assay and traditional immunoprecipitation techniques. Biochemical analyses demonstrated that Δ7/11 was heavily glycosylated, similar to the extracellular domain of the primary prolactin receptor, and that glycosylation regulated the cellular localization and secretion of Δ7/11. Low levels of Δ7/11 were detected in serum samples of healthy volunteers, but were undetectable in human milk samples. Expression of Δ7/11 was also detected in six of the 62 primary breast tumor biopsies analyzed; however, no correlation was found with Δ7/11 expression and tumor histotype or other patient demographics. Functional analysis demonstrated the ability of Δ7/11 to inhibit prolactin-induced cell proliferation as well as alter prolactin-induced rescue of cell cycle arrest/early senescence events in breast epithelial cells. Collectively, these data demonstrate that Δ7/11 is a novel regulatory mechanism of prolactin bioavailability and signaling. PMID:23048206

  3. Excitatory and inhibitory effects of prolactin release activated by nerve stimulation in rat anterior pituitary

    Gao Li-Zhi


    Full Text Available Abstract Background A series of studies showed the presence of substantial amount of nerve fibers and their close relationship with the anterior pituitary gland cells. Our previous studies have suggested that aside from the classical theory of humoral regulation, the rat anterior pituitary has direct neural regulation on adrenocorticotropic hormone release. In rat anterior pituitary, typical synapses are found on every type of the hormone-secreting cells, many on lactotrophs. The present study was aimed at investigating the physiological significance of this synaptic relationship on prolactin release. Methods The anterior pituitary of rat was sliced and stimulated with electrical field in a self-designed perfusion chamber. The perfusate was continuously collected in aliquots and measured by radioimmunoassay for prolactin levels. After statistic analysis, differences of prolactin concentrations within and between groups were outlined. Results The results showed that stimulation at frequency of 2 Hz caused a quick enhancement of prolactin release, when stimulated at 10 Hz, prolactin release was found to be inhibited which came slower and lasted longer. The effect of nerve stimulation on prolactin release is diphasic and frequency dependent. Conclusions The present in vitro study offers the first physiological evidence that stimulation of nerve fibers can affect prolactin release in rat anterior pituitary. Low frequency stimulation enhances prolactin release and high frequency mainly inhibits it.

  4. Luteinizing hormone (LH) and prolactin-releasing pituitary tumor: possible malignant transformation of the LH cell line.

    Spertini, F; Deruaz, J P; Perentes, E; Pelet, B; Gomez, F


    A pituitary tumor was diagnosed in a prepubertal 13-yr-old girl, who had elevated plasma LH (58 mIU/ml) and PRL (93 ng/ml) levels; decreased GH, ACTH, and FSH secretion; and diabetes insipidus. After surgery, plasma LH and PRL declined, but not to normal levels. Conventional external radiotherapy to the pituitary was immediately followed by a decrease in LH to prepubertal values (0.7 mIU/ml), while PRL levels became normal only after a long course of bromocriptine therapy. The pituitary tumor was composed of two distinct cell types: small polygonal cells, which were PRL positive by immunohistochemistry, and clusters of pleomorphic large frequently mitotic polynucleated cells, which were LH positive, some of them also being positive for the alpha-subunit or beta LH but not for beta FSH. Four years after surgery and radiotherapy, the patient deteriorated neurologically. Computed tomographic scan showed widespread frontal and periventricular tumor, which had the histological features of a poorly differentiated carcinoma. No PRL, LH, or alpha- or beta-subunits were detectable on immunocytochemistry. While the PRL-positive cells of the pituitary tumor displayed the histological and clinical features of PRL adenomas, the morphological characteristics of LH cells and the sharp decline of plasma LH levels after radiotherapy were suggestive of malignant transformation. In this context, the later brain tumor could have been the result of subependymal spread of the pituitary tumor after it lost its hormone-secreting capacity.

  5. The hypothalamic-pituitary response in SLE. Regulation of prolactin, growth hormone and cortisol release.

    Rovenský, J; Blazícková, S; Rauová, L; Jezová, D; Koska, J; Lukác, J; Vigas, M


    It has been suggested that neuroendocrine regulation plays an important role in the pathogenesis and activation of autoimmune diseases. The aim of this investigation was to clarify the hypothalamic-pituitary response to a well-defined stimulus under standardised conditions in patients with SLE. Plasma concentrations of prolactin (PRL), growth hormone (GH) and cortisol were determined in venous blood drawn through an indwelling cannula during insulin-induced hypoglycaemia (0.1 U/kg b.w., i.v.) in ten patients and in 12 age-, gender- and weight-matched healthy subjects. Basal PRL concentrations were higher in patients vs healthy controls (12 vs 6 ng/ml, P < 0.01), though still within the physiological range. Insulin-induced plasma PRL and GH were significantly increased both in patients and healthy subjects; however, the increments or areas under the curves were not different in the two groups. Plasma cortisol response showed moderate attenuation in patients. Sensitivity of pituitary lactotrothrops to thyrotropin-releasing hormone (TRH) administration (200 microg, i.v.) was the same in patients and control subjects. In SLE patients with low activity of the disease the sensitivity of pituitary PRL release to TRH administration remained unchanged. The hypothalamic response to stress stimulus (hypoglycaemia) was comparable in patients and healthy subjects.

  6. Discovery and Evaluation of PRL Trimer Disruptors for Novel Anticancer Agents.

    Bai, Yunpeng; Yu, Zhi-Hong; Zhang, Zhong-Yin


    Overexpression of PRL phosphatases (PRL1, PRL2, and PRL3) has been found in a variety of late-stage tumors and their distant metastatic sites. Therefore, the oncogenic PRL phosphatases represent intriguing targets for cancer therapy. There is considerable interest in identifying small molecule inhibitors targeting PRLs as novel anticancer agents. However, it has been difficult to acquire phosphatase activity-based PRL inhibitors due to the unusual wide and shallow catalytic pockets of PRLs revealed by crystal structure studies. Here, we present a novel method to identify PRL1 inhibitors by targeting the PRL1 trimer interface and the procedure to characterize their biochemical and cellular activity.

  7. Ovine prolactin and human growth hormone derivatives. Specific modification of their alpha-amino groups.

    Caridad, J J; Nowicki, C; Santomé, J A; Wolfenstein-Todel, C


    The alpha-amino group of ovine prolactin (oPRL) and human growth hormone (hGH) was selectively modified by transamination with glyoxylic acid. No difference was found in the binding capacity of transaminated oPRL to rat liver lactogenic receptors with respect to its control, although both samples showed a decrease in its binding capacity with reference to the native hormone. This decrease was due to conformational changes caused by the reaction conditions and not by the transamination itself, as shown by the circular dichroism spectra. Transaminated hGH retained the full binding capacity of the hormone. These results suggest that the alpha-amino group is not relevant for the binding to lactogenic liver receptors in both lactogenic hormones.

  8. TSH and PRL, side-effect markers in aripiprazole treatment: adjunctive aripiprazole-induced thyrotropin oversuppression in a young man with schizophrenia.

    Ohta, Hidenobu; Inoue, Satoru; Hara, Koichiro; Watanabe, Akihiko


    A 26-year-old Japanese man was admitted to our unit with exacerbated paranoid schizophrenia. Prior to his admission, daily administration of olanzapine had been sufficient to maintain a partial remission of his schizophrenia, but due to an exacerbation of his delusions, he had then also been prescribed aripiprazole, which had been followed by no improvement in symptoms and a gradual further exacerbation of auditory delusions. Physical examinations, brain MRI and neurophysiological assessment were unremarkable. Blood analysis, however, revealed extremely low thyroid-stimulating hormone (TSH) and prolactin-releasing hormone (PRL) concentration. Interestingly, after aripiprazole discontinuation, he returned to partial remission with an increase in plasma TSH and PRL concentration. © BMJ Publishing Group Ltd (unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  9. Human decidual stromal cells secrete soluble pro-apoptotic factors during decidualization in a cAMP-dependent manner.

    Leno-Durán, E; Ruiz-Magaña, M J; Muñoz-Fernández, R; Requena, F; Olivares, E G; Ruiz-Ruiz, C


    Is there a relationship between decidualization and apoptosis of decidual stromal cells (DSC)? Decidualization triggers the secretion of soluble factors that induce apoptosis in DSC. The differentiation and apoptosis of DSC during decidualization of the receptive decidua are crucial processes for the controlled invasion of trophoblasts in normal pregnancy. Most DSC regress in a time-dependent manner, and their removal is important to provide space for the embryo to grow. However, the mechanism that controls DSC death is poorly understood. The apoptotic response of DSC was analyzed after exposure to different exogenous agents and during decidualization. The apoptotic potential of decidualized DSC supernatants and prolactin (PRL) was also evaluated. DSC lines were established from samples of decidua from first trimester pregnancies. Apoptosis was assayed by flow cytometry. PRL production, as a marker of decidualization, was determined by enzyme-linked immunosorbent assay. DSCs were resistant to a variety of apoptosis-inducing substances. Nevertheless, DSC underwent apoptosis during decidualization in culture, with cAMP being essential for both apoptosis and differentiation. In addition, culture supernatants from decidualized DSC induced apoptosis in undifferentiated DSC, although paradoxically these supernatants decreased the spontaneous apoptosis of decidual lymphocytes. Exogenously added PRL did not induce apoptosis in DSC and an antibody that neutralized the PRL receptor did not decrease the apoptosis induced by supernatants. Further studies are needed to examine the involvement of other soluble factors secreted by decidualized DSC in the induction of apoptosis. The present results indicate that apoptosis of DSC occurs in parallel to differentiation, in response to decidualization signals, with soluble factors secreted by decidualized DSC being responsible for triggering cell death. These studies are relevant in the understanding of how the regression of decidua

  10. Effects of salinity and prolactin on gene transcript levels of ion transporters, ion pumps and prolactin receptors in Mozambique tilapia intestine.

    Seale, Andre P; Stagg, Jacob J; Yamaguchi, Yoko; Breves, Jason P; Soma, Satoshi; Watanabe, Soichi; Kaneko, Toyoji; Cnaani, Avner; Harpaz, Sheenan; Lerner, Darren T; Grau, E Gordon


    Euryhaline teleosts are faced with significant challenges during changes in salinity. Osmoregulatory responses to salinity changes are mediated through the neuroendocrine system which directs osmoregulatory tissues to modulate ion transport. Prolactin (PRL) plays a major role in freshwater (FW) osmoregulation by promoting ion uptake in osmoregulatory tissues, including intestine. We measured mRNA expression of ion pumps, Na(+)/K(+)-ATPase α3-subunit (NKAα3) and vacuolar type H(+)-ATPase A-subunit (V-ATPase A-subunit); ion transporters/channels, Na(+)/K(+)/2Cl(-) co-transporter (NKCC2) and cystic fibrosis transmembrane conductance regulator (CFTR); and the two PRL receptors, PRLR1 and PRLR2 in eleven intestinal segments of Mozambique tilapia (Oreochromis mossambicus) acclimated to FW or seawater (SW). Gene expression levels of NKAα3, V-ATPase A-subunit, and NKCC2 were generally lower in middle segments of the intestine, whereas CFTR mRNA was most highly expressed in anterior intestine of FW-fish. In both FW- and SW-acclimated fish, PRLR1 was most highly expressed in the terminal segment of the intestine, whereas PRLR2 was generally most highly expressed in anterior intestinal segments. While NKCC2, NKAα3 and PRLR2 mRNA expression was higher in the intestinal segments of SW-acclimated fish, CFTR mRNA expression was higher in FW-fish; PRLR1 and V-ATPase A-subunit mRNA expression was similar between FW- and SW-acclimated fish. Next, we characterized the effects of hypophysectomy (Hx) and PRL replacement on the expression of intestinal transcripts. Hypophysectomy reduced both NKCC2 and CFTR expression in particular intestinal segments; however, only NKCC2 expression was restored by PRL replacement. Together, these findings describe how both acclimation salinity and PRL impact transcript levels of effectors of ion transport in tilapia intestine.

  11. Growth hormone, prolactin and cortisol response to exercise in patients with depression

    Krogh, Jesper; Nordentoft, Merete; Mohammad-Nezhad, Mahdi


    BACKGROUND: A blunted growth hormone and prolactin response to pharmacological stress test have previously been found in depressed patients, as well as an increased cortisol response to psychosocial stress. This study investigated these hormones in response to acute exercise using an incremental...... bicycle test. METHOD: A cross-sectional comparison of cortisol, growth hormone, and prolactin in depressed (n=137) and healthy (n=44) subjects during rest and in response to an incremental bicycle test. Secondly, we tested the depressed patients again after a 4-month randomized naturalistic exercise...... controls. The effect of acute exercise stress on PRL (p=.56) did not differ between depressed and healthy subjects. Apart from a decrease in GH response in the strength-training group (p=.03) the pragmatic exercise intervention did not affect resting hormonal levels, or the response to acute exercise...

  12. Expression and clinical role of protein of regenerating liver (PRL) phosphatases in ovarian carcinoma.

    Reich, Reuven; Hadar, Shany; Davidson, Ben


    The present study analyzed the expression and clinical role of the protein of regenerating liver (PRL) phosphatase family in ovarian carcinoma. PRL1-3 mRNA expression was studied in 184 tumors (100 effusions, 57 primary carcinomas, 27 solid metastases) using RT-PCR. PRL-3 protein expression was analyzed in 157 tumors by Western blotting. PRL-1 mRNA levels were significantly higher in effusions compared to solid tumors (p PRL-1 and PRL-2 were overexpressed in pleural compared to peritoneal effusions (p = 0.001). PRL-3 protein expression was significantly higher in primary diagnosis pre-chemotherapy compared to post-chemotherapy disease recurrence effusions (p = 0.003). PRL-1 mRNA expression in effusions correlated with longer overall survival (p = 0.032), and higher levels of both PRL-1 and PRL-2 mRNA correlated with longer overall survival for patients with pre-chemotherapy effusions (p = 0.022 and p = 0.02, respectively). Analysis of the effect of laminin on PRL-3 expression in ovarian carcinoma cells in vitro showed dose-dependent PRL-3 expression in response to exogenous laminin, mediated by Phospholipase D. In contrast to previous studies associating PRL-3 with poor outcome, our data show that PRL-3 expression has no clinical role in ovarian carcinoma, whereas PRL-1 and PRL-2 expression is associated with longer survival, suggesting that PRL phosphatases may be markers of improved outcome in this cancer.

  13. Prolactin-induced neuroprotection against glutamate excitotoxicity is mediated by the reduction of [Ca2+]i overload and NF-κB activation

    Rivero-Segura, Nadia A.; Flores-Soto, Edgar; García de la Cadena, Selene; Coronado-Mares, Isabel; Gomez-Verjan, Juan C.; Ferreira, Diana G.; Cabrera-Reyes, Erika Alejandra; Lopes, Luísa V.; Massieu, Lourdes


    Prolactin (PRL) is a peptidic hormone that displays pleiotropic functions in the organism including different actions in the brain. PRL exerts a neuroprotective effect against excitotoxicity produced by glutamate (Glu) or kainic acid in both in vitro and in vivo models. It is well known that Glu excitotoxicity causes cell death through apoptotic or necrotic pathways due to intracellular calcium ([Ca2+] i) overload. Therefore, the aim of the present study was to assess the molecular mechanisms by which PRL maintains cellular viability of primary cultures of rat hippocampal neurons exposed to Glu excitotoxicity. We determined cell viability by monitoring mitochondrial activity and using fluorescent markers for viable and dead cells. The intracellular calcium level was determined by a fluorometric assay and proteins involved in the apoptotic pathway were determined by immunoblot. Our results demonstrated that PRL afforded neuroprotection against Glu excitotoxicity, as evidenced by a decrease in propidium iodide staining and by the decrease of the LDH activity. In addition, the MTT assay shows that PRL maintains normal mitochondrial activity even in neurons exposed to Glu. Furthermore, the Glu-induced intracellular [Ca2+]i overload was attenuated by PRL. These data correlate with the reduction found in the level of active caspase-3 and the pro-apoptotic ratio (Bax/Bcl-2). Concomitantly, PRL elicited the nuclear translocation of the transcriptional factor NF-κB, which was detected by immunofluorescence and confocal microscopy. To our knowledge, this is the first report demonstrating that PRL prevents Glu excitotoxicity by a mechanism involving the restoration of the intracellular calcium homeostasis and mitochondrial activity, as well as an anti-apoptotic action possibly mediated by the activity of NF-κB. Overall, the current results suggest that PRL could be of potential therapeutic advantage in the treatment of neurodegenerative diseases. PMID:28475602

  14. 中西医结合治疗垂体泌乳素微腺瘤疗效分析%Efficacy Analysis of Integrative Medicine Treatment for Prolactin-secreting Pituitary Microadenoma

    凌聪; 胡细玲; 何海勇; 蔡梅钦


    Objective : To explore normative , more effective medication for pituitary prolactinoma via the comparision of Traditional Chinese medicine combined with Bromocriptine and single Bromocriptine treating the pituitary prolactinoma. Methods : 50 selected female patients with prolactinoma were divided into two groups , 25 patients in each group. The two groups accepted the treatment of Traditional Chinese medicine combined Bromocriptine respectively, and the decrease of the prolactin levels, curative rate, effective rate and incidence of side effectives were analyzed statistically. Results : The prolactin levels of the two groups were significantly different 3 months after treatment, not significantly different 6 months or 9 months after treatment. The prolactin levels of the groups were significantly different before and after treatment respectively. The curative rate was significantly different, and the effective rate was not significantly different. Conclusion : Traditional Chinese medicine combined with Bromocriptine and single Bromocriptine are effective on decreasing prolactin level. Traditional Chinese medicine combined Bromocriptin is more effective in meliorating menses and asisting pregnancy than single Bromocriptin.%目的:通过对中医联合溴隐亭和单纯溴隐亭治疗垂体泌乳素微腺瘤的效果比较,探讨规范、更有效的垂体泌乳素微腺瘤的药物治疗方法.方法:将入选的50例垂体泌乳素微腺瘤女性患者随机分成两组,每组25例.两组病人分别接受中药加溴隐亭和单纯溴隐亭治疗.比较两种治疗方法在降低催乳素水平、治愈率、有效率和不良反应发生率等方面的差异,并做相应的统计学处理.结果:两组治疗后催乳素水平在治疗后3个月有显著差异,在6个月和9个月均无显著差异;两组治疗前后的催乳素水平均有显著差异;两组的治愈率有显著差异,有效率无显著差异.结论:中西医结合与单纯西药对降低

  15. Dexamethasone counteracts the effect of prolactin on islet function: implications for islet regulation in late pregnancy.

    Weinhaus, A J; Bhagroo, N V; Brelje, T C; Sorenson, R L


    Islets undergo a number of up-regulatory changes to meet the increased demand for insulin during pregnancy, including increased insulin secretion and beta-cell proliferation. It has been shown that elevated lactogenic hormone is directly responsible for these changes, which occur in a phasic pattern, peaking on day 15 of pregnancy and returning to control levels by day 20 (term). As placental lactogen levels remain elevated through late gestation, it was of interest to determine whether glucocorticoids (which increase during late gestation) could counteract the effects of lactogens on insulin secretion, beta-cell proliferation, and apoptosis. We found that insulin secretion measured over 24 h in culture and acute secretion measured over 1 h in response to high glucose were increased at least 2-fold by PRL treatment after 6 days in culture. Dexamethasone (DEX) treatment had a significant inhibitory effect on secretion in a dose-dependent manner at concentrations greater than 1 nM. At 100 nM, a concentration equivalent to the plasma corticosteroid level during late pregnancy, DEX inhibited secretion to below control levels. The addition of DEX (>1 nM) inhibited secretion from PRL-treated islets to levels similar to those produced by DEX treatment alone. Bromodeoxyuridine (10 microM) staining for the final 24 h of a 6-day culture showed that PRL treatment increased cell proliferation 6-fold over the control level. DEX treatment alone (1-1000 nM) did not reduce cell division below the control level, but significantly inhibited the rate of division in PRL-treated islets. YoYo-1, an ultrasensitive fluorescent nucleic acid stain, was added (1 microM; 8 h) to the medium after 1-3 days of culture to examine cell death. Islets examined under confocal microscopy showed that DEX treatment (100 nM) increased the number of cells with apoptotic nuclear morphologies. This was quantified by counting the number of YoYo-labeled nuclei per islet under conventional epifluorescence

  16. Prolactin: does it exert an up-modulation of the immune response in Trypanosoma cruzi-infected rats?

    Filipin, Marina Del Vecchio; Brazão, Vânia; Santello, Fabricia Helena; Caetano, Leony Cristina; Toldo, Míriam Paula Alonso; do Prado, José Clóvis


    During the course of infection by Trypanosoma cruzi, the host immune system is involved in distinct, complex interactions with the endocrine system, and prolactin (PRL) is one of several hormones involved in immunoregulation. Although intensive studies attempting to understand the mechanisms that underlie Chagas' disease have been undertaken, there are still some pieces missing from this complex puzzle. Because data are scarce concerning the role of PRL involvement in Chagas' disease and taking into account the existence of crosstalk between neuroendocrine hormones and the immune system, the current study evaluates a possible up-regulation of the cellular immune response triggered by PRL in T. cruzi-infected rats and the role of PRL in reversing immunosuppression caused by the parasitic infection. The data shown herein demonstrate that PRL induces the proliferation of T lymphocytes, coupled with an activation of macrophages and the production of nitric oxide (NO), leading to a reduction in the number of blood trypomastigotes during the peak of parasitemia. During the acute phase of T. cruzi infection, an enhancement of both CD3+CD4+ and CD3+CD8+ T cell populations were observed in infected groups, with the highest numbers of these T cell subsets found in the infected group treated with PRL. Because NO is a signaling molecule involved in a number of cellular interactions with components of the immune system and the neuroendocrine system, PRL can be considered an alternative hormone able to up-regulate the host's immune system, consequently lowering the pathological effects of a T. cruzi infection.


    于力群; 王厚鹏; 朱作言; 孙永华


    Growth hormone (GH) is a member of the GH/Prolactin (PRL) protein super family. It is secreted by anterior pituitary and critically involved in the regulation of cell proliferation, differentiation and migration. Using RT-PCR (re-verse-transcription PCR), our previous study revealed that both gh and its receptor gene ghra (growth hormone receptor a) were maternally expressed in zebrafish. This suggested that the GH/GHR signaling pathway might play an important role at the early stage of zebrafish development. To further study the function of GH/PRL signaling pathway in zebrafish embryogenesis, here we characterized and compared the expression patterns of gh/prl and their receptor family members in early embryonic development using real-time PCR and in situ hybridization. We found that the ligand family mem-bers, gh and somatolactin (smtl), and the receptor gene family members, ghra and ghrb, were maternally expressed in zebrafish. The analysis of spi2.1 promoter activity indicated the cross-interaction between various ligand family mem-bers and GHRa in the early embryos of zebrafish. Our results demonstrated the important role of the GH/PRL family signaling pathway in the early development of zebrafish.%为了进一步研究 GH/PRL 家族信号通路在鱼类早期胚胎发育中的作用,研究以斑马鱼为模型,通过Real-time PCR技术和原位杂交技术刻画并比较了GH/PRL家族成员及其受体家族成员在胚胎发育早期的表达模式。结果发现,在配体家族成员中,生长激素(Growth hormone, GH)和生长催乳素(Somatolactin, smtl)存在母源表达,在受体家族成员中, ghra、ghrb存在母源表达。利用荧光素酶分析spi2.1启动子活性的结果初步证明,在斑马鱼早期胚胎发育中,各配体家族成员与GHRa之间可以发生广泛的互作。这一系列结果对于我们认识GH/PRL家族信号通路在斑马鱼早期发育中的作用具有重要的指导意义。


    Mitrofanova O. V.


    Full Text Available Prolactin (PRL - is a peptide hormone. It effects on metabolic processes in mammals and birds. Indel genotype mutations in a prolactin gene were determined in 595 hens and cocks. Polymerase chain reaction (PCR were used. We studied four different breeds: Cornish, White Russian, Pushkin, Yurlov crower. Homozygous of insertion II, homozygous deletion of DD and heterozygous ID were observed in all groups. The differences in frequencies of genotypes and alleles were observed in all groups. Homozygotes II and allele I (frequency is 0,83 were the most common for Russian white chickens with high egg production and the lack of the instinct of incubation. Prolactin gene deletion was more common for beef Cornish. The frequency of D allele was 0,84. Pushkin chickens proved to be closer to the egg type. A significant number of heterozygotes with this mutation were noted in a population of Yurlov crower. It is recommended to use gene prolactin as a marker of productive indicators in chickens

  19. Short-Chain Fatty Acids Inhibit Growth Hormone and Prolactin Gene Transcription via cAMP/PKA/CREB Signaling Pathway in Dairy Cow Anterior Pituitary Cells

    Jian-Fa Wang


    Full Text Available Short-chain fatty acids (SCFAs play a key role in altering carbohydrate and lipid metabolism, influence endocrine pancreas activity, and as a precursor of ruminant milk fat. However, the effect and detailed mechanisms by which SCFAs mediate bovine growth hormone (GH and prolactin (PRL gene transcription remain unclear. In this study, we detected the effects of SCFAs (acetate, propionate, and butyrate on the activity of the cAMP/PKA/CREB signaling pathway, GH, PRL, and Pit-1 gene transcription in dairy cow anterior pituitary cells (DCAPCs. The results showed that SCFAs decreased intracellular cAMP levels and a subsequent reduction in PKA activity. Inhibition of PKA activity decreased CREB phosphorylation, thereby inhibiting GH and PRL gene transcription. Furthermore, PTX blocked SCFAs- inhibited cAMP/PKA/CREB signaling pathway. These data showed that the inhibition of GH and PRL gene transcription induced by SCFAs is mediated by Gi activation and that propionate is more potent than acetate and butyrate in inhibiting GH and PRL gene transcription. In conclusion, this study identifies a biochemical mechanism for the regulation of SCFAs on bovine GH and PRL gene transcription in DCAPCs, which may serve as one of the factors that regulate pituitary function in accordance with dietary intake.

  20. Effects of Parity and Serum Prolactin Levels on the Incidence and Regression of DMBA-Induced Tumors in OFA hr/hr Rats

    Corina V. Sasso


    Full Text Available Prolactin (PRL is a key player in the development of mammary cancer. We studied the effects of parity or hyperprolactinemia on mammary carcinogenesis in OFA hr/hr treated with 7,12-dimethylbenzanthracene. They were divided into three groups: nulliparous (Null, primiparous (PL, after pregnancy and lactation, and hyperprolactinemic rats (I, implanted in the arcuate nucleus with 17β-estradiol. The tumor incidence was similar in the three groups. However, a higher percentage of regressing tumors was evident in the PL group. Serum PRL, mammary development, and mammary β-casein content were higher in I rats compared to Null. The expression of hormone receptors was similar in the different groups. However, mammary tissue from PL rats bearing tumors had increased expression of PRL and estrogen alpha receptors compared to rats free of tumors. Our results suggest that serum PRL levels do not have relevance on the incidence of tumors, probably because the low levels of PRL in OFA rats are not further decreased by PL like in other strains. However, supraphysiological levels of PRL affect carcinogenesis. PL induces regression of the tumors due to the differentiation produced on the mammary cells. Alterations in the expression of hormonal receptors may be involved in progression and regression of tumors.

  1. 癫痫过程和抗癫痫药物治疗对泌乳素分泌的影响%Effect of seizures and antiepileptic drugs on prolactin secretions



    目的探讨癫痫发作和抗癫痫药物治疗对泌乳素(PRL)分泌的影响.方法利用RIA法测定癫痫发作前后和应用不同抗癫痫药物治疗的癫痫患者血清中PRL水平.结果癫痫发作后PRL分泌明显升高,发作后15minPRL分泌达到峰值,是基础PRL水平的5.1倍,发作后90min,有89.4%的病例PRL水平下降;癫痫发作后血清PRL水平的变化与 癫痫病灶位置无关;失神性癫痫发作后,血清PRL水平不升高或升高不明显,而其他类型的癫痫发作后均可引起血清PRL水平升高.苯妥英钠、丙戊酸钠单一治疗和马西平+丙戊酸钠+苯妥英钠联合治疗后,血清PRL水平降低,而纯中药治疗不影响垂体PRL的分泌.结论癫痫发作和抗癫痫药物治疗均明显影响垂体PRL的分泌.

  2. Thioredoxin-related protein 32 (TRP32) specifically reduces oxidized phosphatase of regenerating liver (PRL).

    Ishii, Tasuku; Funato, Yosuke; Miki, Hiroaki


    PRL family constitutes a unique class of phosphatases associated with metastasis. The phosphatase activity of PRL has been reported to be important for promoting metastasis, and it is inactivated by reversible oxidation of its catalytic cysteine. Here, we show that TRP32 specifically reduces PRL. Reduction of oxidized PRL in cells is inhibited by 2,4-dinitro-1-chlorobenzene, an inhibitor of TRX reductase. In vitro assays for the reduction of PRL show that only TRP32 can potently reduce oxidized PRL, whereas other TRX-related proteins linked to TRX reductase show little or no reducing activity. Indeed, TRP32 knockdown significantly prolongs the H2O2-induced oxidation of PRL. Binding analyses reveal that the unique C-terminal domain of TRP32 is required and sufficient for its direct interaction with PRL. These results suggest that TRP32 maintains the reduced state of PRL and thus regulates the biological function of PRL.

  3. Diet, prolactin, and breast cancer.

    Baghurst, P A; Carman, J A; Syrette, J A; Baghurst, K I; Crocker, J M


    Relationships between dietary nutrients and plasma prolactin concentration were studied in 249 women with a history of nonskin cancers among first-degree female relatives. For each quintile of nutrient density, the odds ratio (OR), relative to the lowest quintile, of having an elevated (above the median) prolactin concentration was estimated by logistic regression, taking into account parity, menopausal status, and current tobacco-smoking habits. For nutrient densities estimated from 24-h recall data there was a significant positive association between plasma prolactin concentration and increasing saturated fatty acid intake; the OR of elevated prolactin in the top quintile was 3.1 [95% confidence interval (CI) 1.2-8.1] and there was a negative association with vitamin C [OR in the top quintile 0.28, (95% CI 0.10-0.78)]. For usual nutrient densities (estimated by quantitative food frequency questionnaire) there was a statistically significant trend (P = 0.04) toward lower prolactin concentrations with increasing sodium density, and a marginally significant positive trend (P = 0.07) with increasing dietary density of refined sugars.

  4. HoxA-11 and FOXO1A cooperate to regulate decidual prolactin expression: towards inferring the core transcriptional regulators of decidual genes.

    Vincent J Lynch

    Full Text Available BACKGROUND: During the menstrual cycle, the ovarian steroid hormones estrogen and progesterone control a dramatic transcriptional reprogramming of endometrial stromal cells (ESCs leading to a receptive state for blastocyst implantation and the establishment of pregnancy. A key marker gene of this decidualization process is the prolactin gene. Several transcriptional regulators have been identified that are essential for decidualization of ESCs, including the Hox genes HoxA-10 and HoxA-11, and the forkhead box gene FOXO1A. While previous studies have identified downstream target genes for HoxA-10 and FOXO1A, the role of HoxA-11 in decidualization has not been investigated. Here, we show that HoxA-11 is required for prolactin expression in decidualized ESC. While HoxA-11 alone is a repressor on the decidual prolactin promoter, it turns into an activator when combined with FOXO1A. Conversely, HoxA-10, which has been previously shown to associate with FOXO1A to upregulate decidual IGFBP-1 expression, is unable to upregulate PRL expression when co-expressed with FOXO1A. By co-immunoprecipitation and chromatin immunoprecipitation, we demonstrate physical association of HoxA-11 and FOXO1A, and binding of both factors to an enhancer region (-395 to -148 relative to the PRL transcriptional start site of the decidual prolactin promoter. Because FOXO1A is induced upon decidualization, it serves to assemble a decidual-specific transcriptional complex including HoxA-11. These data highlight cooperativity between numerous transcription factors to upregulate PRL in differentiating ESC, and suggest that this core set of transcription factors physically and functionally interact to drive the expression of a gene battery upregulated in differentiated ESC. In addition, the functional non-equivalence of HoxA-11 and HoxA-10 with respect to PRL regulation suggests that these transcription factors regulate distinct sets of target genes during decidualization.

  5. Lack of rise in serum prolactin following yttrium-90 interstitial irradiation for acromegaly

    Clark, A.J.L.; Chahal, P.; Mashiter, K.; Joplin, G.F. (Royal Postgraduate Medical School, London (UK))


    The authors have investigated the possibility that the increase in serum PRL levels observed in patients with acromegaly treated with external irradiation could be due to damage to the hypothalamus or portal vessels, by comparing the effects of yttrium-90 interstitial irradiation, which is highly localised and does not normally extend to the hypothalamus, in a similar series of patients. These results are consistent with the hypothesis; a less likely explanation is that an overgrowth of radio-resistant PRL-secreting tumour cells is occurring after external irradiation, but not after yttrium-90 implantation.

  6. Use of antiserum to neurotensin reveals a physiological role for the peptide in rat prolactin release.

    Vijayan, E; Carraway, R; Leeman, S E; McCann, S M


    , inhibits prolactin secretion by the lactotropes. The direct stimulatory effect of the peptide on prolactin release after its presumed release into portal vessels also appears to be physiologically significant in female but not in male rats. PMID:3200862

  7. Regulatory elements controlling pituitary-specific expression of the human prolactin gene.

    Peers, B; Voz, M L; Monget, P; Mathy-Hartert, M; Berwaer, M; Belayew, A; Martial, J A


    We have performed transfection and DNase I footprinting experiments to investigate pituitary-specific expression of the human prolactin (hPRL) gene. When fused to the chloramphenicol acetyltransferase (CAT) reporter gene, 5,000 base pairs of the 5'-flanking sequences of the hPRL gene were able to drive high cat gene expression in prolactin-expressing GH3B6 cells specifically. Deletion analysis indicated that this pituitary-specific expression was controlled by three main positive regulatory regions. The first was located just upstream from the TATA box between coordinates -40 and -250 (proximal region). We have previously shown that three motifs of this region bind the pituitary-specific Pit-1 factor. The second positive region was located in the vicinity of coordinates -1300 to -1750 (distal region). DNase I footprinting assays revealed that eight DNA motifs of this distal region bound protein Pit-1 and that two other motifs were recognized by ubiquitous factors, one of which seems to belong to the AP-1 (jun) family. The third positive region was located further upstream, between -3500 and -5000 (superdistal region). This region appears to enhance transcription only in the presence of the distal region.

  8. Phosphocysteine in the PRL-CNNM pathway mediates magnesium homeostasis.

    Gulerez, Irina; Funato, Yosuke; Wu, Howie; Yang, Meng; Kozlov, Guennadi; Miki, Hiroaki; Gehring, Kalle


    PRLs (phosphatases of regenerating liver) are frequently overexpressed in human cancers and are prognostic markers of poor survival. Despite their potential as therapeutic targets, their mechanism of action is not understood in part due to their weak enzymatic activity. Previous studies revealed that PRLs interact with CNNM ion transporters and prevent CNNM4-dependent Mg(2+) transport, which is important for energy metabolism and tumor progression. Here, we report that PRL-CNNM complex formation is regulated by the formation of phosphocysteine. We show that cysteine in the PRL catalytic site is endogenously phosphorylated as part of the catalytic cycle and that phosphocysteine levels change in response to Mg(2+) levels. Phosphorylation blocks PRL binding to CNNM Mg(2+) transporters, and mutations that block the PRL-CNNM interaction prevent regulation of Mg(2+) efflux in cultured cells. The crystal structure of the complex of PRL2 and the CBS-pair domain of the Mg(2+) transporter CNNM3 reveals the molecular basis for the interaction. The identification of phosphocysteine as a regulatory modification opens new perspectives for signaling by protein phosphatases.

  9. Is a stable or decreasing prolactin level in a patient with prolactinoma a surrogate marker for lack of tumor growth?

    Alkabbani, Abdulrahman G; Mon, Sann Y; Hatipoglu, Betul; Kennedy, Laurence; Faiman, Charles; Weil, Robert J; Hamrahian, Amir H


    The optimal interval for follow-up imaging of patients with prolactinomas is unclear. We wish to determine the likelihood of tumor enlargement in patients with prolactinomas who have a stable or reduced prolactin (PRL) level over time, whether or not they are treated with a dopamine agonist (DA). We identified 80 patients with prolactinomas (34 men, 46 women) who had at least two paired sets of serum PRL levels and pituitary MRIs, 3 or more months apart. Patients with hyperprolactinemia due to drug or stalk effects were excluded. The median (range) age was 45 (25-77) years. Sixty-three patients (78.8%) were treated with DA. PRL levels (ng/mL) at the initial and latest sets were 114 (0.3-15,732) and 16 (0.3-1,204), respectively. In patients with identifiable tumors, the maximum tumor diameters (mm) at the initial and latest MRI studies were 12.5 (2-60) and 12.5 (2-39) respectively, with an interval of 2.9 (0.3-9.7) years. Sixty percent of patients (n = 48) had a macroadenoma. Forty-two (52.5%) patients had either disappearance of the tumor (n = 22) or reduction (n = 20) in tumor size. In the remainder, tumor size was stable in 35 but increased in 3 patients. One of these patients, observed off therapy had a concomitant rise in PRL level. The other 2 had evidence of pituitary hemorrhage with no PRL increase. Tumor growth in prolactinoma patients with a stable or decreasing PRL level, regardless of size, is a rare event. Repetitive pituitary imaging in these patients may not be warranted.

  10. Short communication: retinoic acid plus prolactin to synergistically increase specific casein gene expression in MAC-T cells.

    Lee, H Y; Heo, Y T; Lee, S E; Hwang, K C; Lee, H G; Choi, S H; Kim, N H


    Mammary alveolar (MAC-T) cells, an established bovine mammary epithelial cell line, are frequently used to investigate differentiation. A lactogenic phenotype in these cells is induced by treatment with a combination of hydrocortisone, insulin, and prolactin (PRL). The effect of the vitamin A derivative retinoic acid (RA), which induces differentiation in many cells, has not been studied in MAC-T cells. The objective of this study was to evaluate the differentiation potential of RA (1 μM) in MAC-T cells and to examine the effect of combined treatment with RA (1 μM) and PRL (5 μg/mL). Although RA treatment alone inhibited MAC-T cell proliferation, co-treatment of RA with PRL increased cell growth compared with the control group (treated with 1 μg/mL hydrocortisone and 5 μg/mL insulin). The ratio of Bcl to Bax mRNA was decreased in the RA treatment compared with RA+PRL or control. Retinoic acid-induced differentiation of MAC-T cells was associated with an increase in the mRNA expression of αS1-casein (3.9-fold), αS2-casein (4.5-fold), and β-casein (4.4-fold) compared with the control group. Expression of αS1-casein, αS2-casein, and β-casein was increased 12.9-fold, 11.9-fold, and 19.3-fold, respectively, following treatment with RA and PRL combined compared with the control group. These results demonstrate that RA induces differentiation of MAC-T cells and acts synergistically with PRL to increase specific casein gene expression.

  11. Role of nitric oxide in control of prolactin release by the adenohypophysis.

    Duvilanski, B H; Zambruno, C; Seilicovich, A; Pisera, D; Lasaga, M; Diaz, M C; Belova, N; Rettori, V; McCann, S M


    Nitric oxide synthase-containing cells were visualized in the anterior pituitary gland by immunocytochemistry. Consequently, we began an evaluation of the possible role of NO in the control of anterior pituitary function. Prolactin is normally under inhibitory hypothalamic control, and in vitro the gland secretes large quantities of the hormone. When hemipituitaries were incubated for 30 min in the presence of sodium nitroprusside, a releaser of NO, prolactin release was inhibited. This suppression was completely blocked by the scavenger of NO, hemoglobin. Analogs of arginine, such as NG-monomethyl-L-arginine (NMMA, where NG is the terminal guanidino nitrogen) and nitroarginine methyl ester, inhibit NO synthase. Incubation of hemipituitaries with either of these compounds significantly increased prolactin release. Since in other tissues most of the actions of NO are mediated by activation of soluble guanylate cyclase with the formation of cyclic GMP, we evaluated the effects of cyclic GMP on prolactin release. Cyclic GMP (10 mM) produced an approximately 40% reduction in prolactin release. Prolactin release in vivo and in vitro can be stimulated by several peptides, which include vasoactive intestinal polypeptide and substance P. Consequently, we evaluated the possible role of NO in these stimulations by incubating the glands in the presence of either of these peptides alone or in combination with NMMA. In the case of vasoactive intestinal polypeptide, the significant stimulation of prolactin release was augmented by NMMA to give an additive effect. In the case of substance P, there was a smaller but significant release of prolactin that was not significantly augmented by NMMA. We conclude that NO has little effect on the stimulatory action of these two peptides on prolactin release. Dopamine (0.1 microM), an inhibitor of prolactin release, reduced prolactin release, and this inhibitory action was significantly blocked by either hemoglobin (20 micrograms/ml) or

  12. Src-mediated phosphorylation of the tyrosine phosphatase PRL-3 is required for PRL-3 promotion of Rho activation, motility and invasion.

    Fiordalisi, James J; Dewar, Brian J; Graves, Lee M; Madigan, James P; Cox, Adrienne D


    The metastasis-associated tyrosine phosphatase PRL-3/PTP4A is upregulated in numerous cancers, but the mechanisms modulating PRL-3 activity other than its expression levels have not been investigated. Here we report evidence for both Src-dependent tyrosine phosphorylation of PRL-3 and Src-mediated regulation of PRL-3 biological activities. We used structural mutants, pharmacological inhibitors and siRNA to demonstrate Src-dependent phosphorylation of endogenous PRL-3 in SW480 colon cancer cells. We also demonstrated that PRL-3 was not tyrosine phosphorylated in SYF mouse embryo fibroblasts deficient in Src, Yes and Fyn unless Src was re-expressed. Further, we show that platelet-derived growth factor (PDGF) can stimulate PRL-3 phosphorylation in a Src-dependent manner. Finally, we show that PRL-3-induced cell motility, Matrigel invasion and activation of the cytoskeleton-regulating small GTPase RhoC were abrogated in the presence of the phosphodeficient PRL-3 mutant Y53F, or by use of a Src inhibitor. Thus, PRL-3 requires the activity of a Src kinase, likely Src itself, to promote these cancer-associated phenotypes. Our data establish a model for the regulation of PRL-3 by Src that supports the possibility of their coordinate roles in signaling pathways promoting invasion and metastasis, and supports simultaneous use of novel molecularly targeted therapeutics directed at these proteins.

  13. Effect of prolactin, beta-lactoglobulin, and kappa-casein genotype on milk yield in East Friesian sheep.

    Staiger, E A; Thonney, M L; Buchanan, J W; Rogers, E R; Oltenacu, P A; Mateescu, R G


    The effect of prolactin (PRL), beta-lactoglobulin (beta-LG), and kappa-casein (CSN3) on milk yield was estimated in an East Friesian dairy sheep population from Old Chatham Sheepherding Company, New York. Genotypes were determined by PCR amplification followed by digestion with HaeIII and RsaI for PRL and beta-LG, respectively, and by PCR amplification for CSN3. Monthly milking records and pedigree information were used to evaluate the effect of each polymorphism on milk yield. Results indicated that PRL genotype had a significant effect on milk yield. Ewes carrying one A allele produced 110.6g more milk per day than ewes with no A alleles. There was no statistical difference between ewes with only one A allele and ewes with 2 A alleles. No association among polymorphisms at the beta-LG and CSN3 loci and milk yield was found. The results presented in this study indicate that the PRL gene is a potential marker that could be used in selection programs for improving milk yield in dairy sheep.

  14. Dynamics of prolactin, gonadotropin, and of sex steroids in the blood serum of parturients during laser therapy

    Kovalyov, M. I.


    An investigation was made of the effect (lambda) equals 0.63 micrometers diode laser radiation with the energy density of 0.6 to 0.8 J cm-2 on parturients affected by nipples' rhagades. In our experiments, we determined the content of prolactin (PRL), follicle-stimulating hormone (FSH), luteinizing hormone (LH), estradiol (E2), and of progesterone (P) in the parturients' blood serum. It was found that laser radiation produced an insignificant effect on the prolactic (PRL) content in parturients with the normal lactation level. On the contrary, it produced a stimulating effect on the PRL level in parturients with hypogalactia. Possibly, laser radiation promoted the decrease in the FSH level in the parturients' blood serum. It was also found that this laser radiation produced an insignificant effect on the levels of LH, estradiol (E2), and of progesterone. Women subsequently affected by mastitis exhibited a significantly higher PRL level in their blood serum, as compared with women of the control group.

  15. Prolactin and breast cancer: The need to avoid undertreatment of serious psychiatric illnesses in breast cancer patients: A review.

    Froes Brandao, Denise; Strasser-Weippl, Kathrin; Goss, Paul E


    Hyperprolactinemia, defined as a sustained elevation of prolactin (PRL) levels greater than 530 mIU/L in women and greater than 424 mIU/L in men, has been implicated for a long time in breast cancer etiology and prognosis. Elevated PRL values (approximately 2-3 times higher than the reference values) are a common adverse effect of antipsychotic medications, especially with first-generation drugs, and most antipsychotics carry a standard warning regarding PRL elevations on their US product labels. These associations foster undertreatment of serious psychiatric illnesses in both otherwise healthy patients and cancer patients. This review assesses both the preclinical and clinical evidence that has led to the hypothesis of PRL's role in breast cancer risk or breast cancer progression. It is concluded that taken together, the published data are unconvincing and insufficient to deprive cancer patients in general and breast cancer patients specifically of potentially effective antipsychotic or antidepressant medications for serious psychiatric indications. We thus call on revised medication guidelines to avoid the existing undertreatment of serious psychiatric illnesses among cancer patients based on an unproven contraindication to psychiatric medications. Cancer 2016;122:184-188. © 2015 American Cancer Society.

  16. A predictive algorithm for evaluating elevated serum prolactin in patients with a sellar mass.

    Cheng, Jason S; Salinas, Ryan; Molinaro, Annette; Chang, Edward F; Kunwar, Sandeep; Blevins, Lewis; Aghi, Manish K


    Hyperprolactinemia occurs in patients with a prolactinoma and in those with a sellar mass compressing the pituitary stalk. Distinguishing these two diagnostic possibilities guides treatment with dopamine agonist therapy or surgical resection. We aimed to identify a simple, predictive algorithm to aid in the diagnosis of prolactinoma in patients with an elevated serum prolactin and a sellar mass. A case-control analysis of pathologically confirmed prolactinomas and non-endocrine secreting controls from the University of California, San Francisco was performed. From 2001 to 2011, this resulted in 177 patients with prolactinomas and 87 controls. Univariate and classification and regression tree (CART) analysis determined the significance of demographic variables, patient symptoms, laboratory values, and radiographic findings in distinguishing pathology. Additionally, a subset of patients with mildly elevated serum prolactin (25-125 ng/ml) was independently analyzed. Prolactinomas had a mean pre-operative prolactin of 858 ng/ml versus 17.57 ng/ml in controls (p10mm) compared to 74 (92.5%) of the controls (pprolactin (>41.5 ng/ml), age (prolactin (prolactin (>40 ng/ml) as key variables. These two factors correctly predicted 98.6% (69/70) of cases. Our model correctly classifies most patients with elevated serum prolactin and identifies those patients most amenable to surgical treatment.

  17. Analysis of cell-specificity and variegation of transgene expression driven by salmon prolactin promoter in stable lines of transgenic rainbow trout.

    Uzbekova, Svetlana; Amoros, Claire; Cauty, Chantale; Mambrini, Muriel; Perrot, Elizabeth; Hew, Choy L; Chourrout, Daniel; Prunet, Patrick


    In order to identify the specificity and functionality of salmon prolactin (sPRL) promoter, transgenic rainbow trout carrying a construct comprising the 2.4 kb fragment of the 5' flanking region of Atlantic Chinook sPRL gene fused either to the reporter genes cat (sPRL-cat) or lacZ (sPRL-lacZ) were produced. sPRL-cat in transgenic F0 fish expressed strongly CAT only in the pituitary gland. Transgenic in F1-F4 lines harbouring sPRL-lacZ expressed beta-galactosidase (beta-gal) only in the follicular PRL-producing cells of the adenohypophysis. We observed heterocellular, mosaic distribution of beta-gal within PRL cell population and enormous variation of lacZ expression level between the littermates in the same transgenic line. Regardless of the transgene copy number, age or sex of transgenic fish, beta-gal expression was lactotroph-specific but variegated in all the nine F2 hemizygous lines analysed. One line harbouring a multicopy integration was followed up to F4 generation: the transgene was transmitted without modifications. Analysis of genomic DNA from pituitaries showed that lacZ sequences were highly methylated. LacZ expression was low and its transcripts, analysed by in situ hybridisation, showed a mosaic distribution within the pituitary gland. These data suggest that variegated expression of lacZ can occur at the transcription level owing to the silencing effect of lacZ gene. After proving the tissue-specific expression of reporter genes driven by the sPRL promoter, we tried to obtain the genetic ablation of PRL-producing cells,by transferring the same construct comprising diphtheria toxin DT-A gene (tox). However, the high mortality rate of sPRL-tox transformed embryos has embedded this study and no transgenic fish expressing tox were produced. The appropriateness of using transgenic strategies to analyse gene function in Salmonids is discussed, especially the implications of the multicopy integration patterns and of the variegated transgene expression.

  18. Establishing a relationship between prolactin and altered fatty acid β-Oxidation via carnitine palmitoyl transferase 1 in breast cancer cells

    Gerstein Hertzel


    Full Text Available Abstract Background Mammary carcinomas have been associated with a high-fat diet, and the rate of breast cancer in overweight post-menopausal women is up to 50% higher than in their normal-weight counterparts. Epidemiological studies suggest that prolactin (PRL plays a role in the progression of breast cancer. The current study examined breast cancer as a metabolic disease in the context of altered fatty acid catabolism by examining the effect of PRL on carnitine palmitoyl transferase 1 (CPT1, an enzyme that shuttles long-chain fatty acids into the mitochondrial matrix for β-oxidation. The effect of PRL on the adenosine 5'-monophosphate-activated protein kinase (AMPK energy sensing pathway was also investigated. Methods MCF-7 and MDA-MB-231 breast cancer cells and 184B5 normal breast epithelial cells treated with 100 ng/ml of PRL for 24 hr were used as in vitro models. Real-time PCR was employed to quantify changes in mRNA levels and Western blotting was carried out to evaluate changes at the protein level. A non-radioactive CPT1 enzyme activity assay was established and siRNA transfections were performed to transiently knock down specific targets in the AMPK pathway. Results PRL stimulation increased the expression of CPT1A (liver isoform at the mRNA and protein levels in both breast cancer cell lines, but not in 184B5 cells. In response to PRL, a 20% increase in CPT1 enzyme activity was observed in MDA-MB-231 cells. PRL treatment resulted in increased phosphorylation of the α catalytic subunit of AMPK at Thr172, as well as phosphorylation of acetyl-CoA carboxylase (ACC at Ser79. A siRNA against liver kinase B1 (LKB1 reversed these effects in breast cancer cells. PRL partially restored CPT1 activity in breast cancer cells in which CPT1A, LKB1, or AMPKα-1 were knocked down. Conclusions PRL enhances fatty acid β-oxidation by stimulating CPT1 expression and/or activity in MCF-7 and MDA-MB-231 breast cancer cells. These PRL-mediated effects are

  19. Molecular evolution of prolactin in primates.

    Wallis, O Caryl; Mac-Kwashie, Akofa O; Makri, Georgia; Wallis, Michael


    Pituitary prolactin, like growth hormone (GH) and several other protein hormones, shows an episodic pattern of molecular evolution in which sustained bursts of rapid change contrast with long periods of slow evolution. A period of rapid change occurred in the evolution of prolactin in primates, leading to marked sequence differences between human prolactin and that of nonprimate mammals. We have defined this burst more precisely by sequencing the coding regions of prolactin genes for a prosimian, the slow loris (Nycticebus pygmaeus), and a New World monkey, the marmoset (Callithrix jacchus). Slow loris prolactin is very similar in sequence to pig prolactin, so the episode of rapid change occurred during primate evolution, after the separation of lines leading to prosimians and higher primates. Marmoset prolactin is similar in sequence to human prolactin, so the accelerated evolution occurred before divergence of New World monkeys and Old World monkeys/apes. The burst of change was confined largely to coding sequence (nonsynonymous sites) for mature prolactin and is not marked in other components of the gene sequence. This and the observations that (1) there was no apparent loss of function during the episode of rapid evolution, (2) the rate of evolution slowed toward the basal rate after this burst, and (3) the distribution of substitutions in the prolactin molecule is very uneven support the idea that this episode of rapid change was due to positive adaptive selection. In the slow loris and marmoset there is no evidence for duplication of the prolactin gene, and evidence from another New World monkey (Cebus albifrons) and from the chimpanzee and human genome sequences, suggests that this is the general position in primates, contrasting with the situation for GH genes. The chimpanzee prolactin sequence differs from that of human at two residues and comparison of human and chimpanzee prolactin gene sequences suggests that noncoding regions associated with regulating

  20. Metastasis-associated phosphatase PRL-2 regulates tumor cell migration and invasion.

    Wang, Y; Lazo, J S


    The phosphatase of regenerating liver (PRL) family, comprising PRL-1, PRL-2 and PRL-3, is a group of prenylated phosphatases that are candidate cancer biomarkers and therapeutic targets. Although several studies have documented that altered expression of PRL-1 or PRL-3 can influence cell proliferation, migration and invasion, there is a dearth of knowledge about the biological functions of PRL-2. Thus, in the current study we have evaluated the role of PRL-2 in cell migration and invasion in human cancer cells. We found that four human lung cancer cells, including A549 cells, overexpress PRL-2 when compared with normal lung cells. PRL-2 knockdown by RNA interference markedly inhibited cell migration and invasion, and this inhibition can be restored by overexpressing the short interference RNA (siRNA)-resistant vector HA-PRL-2m. PRL-2 suppression by siRNA decreased p130Cas and vinculin expression, and decreased extracellular signal-regulated kinase (ERK) phosphorylation, while increasing the phosphorylation of ezrin on tyrosine 146. We found no significant changes in total p53, Akt and c-Src expression levels or their phosphorylation status, suggesting that PRL-2 knockdown could inhibit tumor cell migration and invasion through a Src-independent p130Cas signaling pathway. Ectopic expression of wild-type PRL-2, a catalytic inactive C101S mutant and a C-terminal CAAX deletion revealed a requirement for both the PRL-2 catalytic functionality and prenylation site. Expression of wild-type but not mutant forms of PRL-2 caused ERK phosphorylation and nuclear translocation. These results support a model in which PRL-2 promotes cell migration and invasion through an ERK-dependent signaling pathway.

  1. Fetal Alcohol Exposure Reduces Dopamine Receptor D2 and Increases Pituitary Weight and Prolactin Production via Epigenetic Mechanisms.

    Omkaram Gangisetty

    Full Text Available Recent evidence indicated that alcohol exposure during the fetal period increases the susceptibility to tumor development in mammary and prostate tissues. Whether fetal alcohol exposure increases the susceptibility to prolactin-producing tumor (prolactinoma development in the pituitary was studied by employing the animal model of estradiol-induced prolactinomas in Fischer 344 female rats. We employed an animal model of fetal alcohol exposure that simulates binge alcohol drinking during the first two trimesters of human pregnancy and involves feeding pregnant rats with a liquid diet containing 6.7% alcohol during gestational day 7 to day 21. Control rats were pair-fed with isocaloric liquid diet or fed ad libitum with rat chow diet. Adult alcohol exposed and control female offspring rats were used in this study on the day of estrus or after estrogen treatment. Results show that fetal alcohol-exposed rats had increased levels of pituitary weight, pituitary prolactin (PRL protein and mRNA, and plasma PRL. However, these rats show decreased pituitary levels of dopamine D2 receptor (D2R mRNA and protein and increased pituitary levels of D2R promoter methylation. Also, they show elevated pituitary mRNA levels of DNA methylating genes (DNMT1, DNMT3b, MeCP2 and histone modifying genes (HDAC2, HDAC4, G9a. When fetal alcohol exposed rats were treated neonatally with a DNA methylation inhibitor 5-Aza deoxycytidine and/or a HDAC inhibitor trichostatin-A their pituitary D2R mRNA, pituitary weights and plasma PRL levels were normalized. These data suggest that fetal alcohol exposure programs the pituitary to increase the susceptibility to the development of prolactinomas possibly by enhancing the methylation of the D2R gene promoter and repressing the synthesis and control of D2R on PRL-producing cells.

  2. A tale of two rhythms: the emerging roles of oxytocin in rhythmic prolactin release.

    Bertram, R; Helena, C V; Gonzalez-Iglesias, A E; Tabak, J; Freeman, M E


    Hormone secretion often occurs in a pulsatile manner. In this review, we discuss two rhythms of in vivo prolactin release in female rats and the ongoing research that we and others have performed aiming to understand the mechanisms underlying them. The peptide hormone oxytocin appears to play an important role in both rhythms. One rhythm occurs during the first half of pregnancy, but can also be induced in ovariectomised rats. This is characterised by a circadian pattern with two prolactin surges per day. Two methods for triggering this rhythm are discussed, each utilising a unique physiological pathway that includes oxytocin action, presumably on pituitary lactotrophs. The second rhythm occurs during the oestrous cycle and is characterised by a surge of prolactin on the afternoon of pro-oestrus. We discuss recent findings that oxytocin is more effective at stimulating prolactin release from lactotrophs taken from animals on the afternoon of pro-oestrus than from those of animals on the morning of dioestrus 1, raising the possibility that this hormone plays a physiological role in the regulation of prolactin secretion during the oestrous cycle.

  3. Plasma Growth Hormone and Prolactin Levels in Healthy Sedentary Young Men after Short-Term Endurance Training under Hot Environment


    Pituitary hormones play an important role energy expenditure and body temperature regulation during exercise. The aim of the stu¬dy was to investigate the effect of two different endurance training in ambient temperature (30.76 ± 1.71oC and 57.92 ± 5.80% r.h.) on plasma growth hormone (GH) and prolactin (PRL) levels in non-trained healthy subjects. Twenty-four untrained healthy men participated in an 8-wk progressive two different endurance-training program. Subjects were divided into two gro...

  4. Regulation by the extracellular matrix (ECM) of prolactin-induced alpha s1-casein gene expression in rabbit primary mammary cells: role of STAT5, C/EBP, and chromatin structure.

    Jolivet, Geneviève; Pantano, Thaïs; Houdebine, Louis Marie


    The aim of the present study was to understand how the extracellular matrix (ECM) regulates at the gene level the prolactin (Prl)-induced signal transducer and activator of transcription 5 (STAT5)-dependent expression of the alpha s1-casein gene in mammary epithelial cells. CCAAT enhancer binding proteins (C/EBPs) are assumed regulators of beta-casein gene expression. Rabbit primary mammary cells express alpha s1-casein gene when cultured on collagen and not on plastic. Similar C/EBPbeta, C/EBPdelta, STAT5, and Prl-activated STAT5 were found under all culture conditions. Thus the ECM does not act through C/EBPs or STAT5. This was confirmed by transfections of rabbit primary mammary cells by a construct sensitive to ovine prolactin (oPrl) and ECM (6i TK luc) encompassing STAT5 and C/EBP binding sites. The mutation of C/EBPs binding sites showed that these sites were not mandatory for Prl-induced expression of the construct. Interestingly, chromatin immunoprecipitation by the anti-acetylhistone H4 antibody (ChIP) showed that the ECM (and not Prl) maintained a high amount of histone H4 acetylation upstream of the alpha s1-casein gene especially at the level of a distal Prl- and ECM-sensitive enhancer. Alpha6 integrin (a membrane receptor of laminin, the principal active component of the mammary ECM) was found at the surface of cells cultured on collagen but not on plastic. In cells cultured on collagen in the presence of anti-alpha6 integrin antibody, Prl-induced transcription of the endogenous alpha s1-casein gene was significantly reduced, without modifying C/EBPs and STAT5. Besides, histone H4 acetylation was reduced. Thus, we propose that the ECM regulates rabbit alpha s1-casein protein expression by local modification of chromatin structure, independently of STAT5 and C/EBPs.

  5. Association of polymorphisms in the promoter region of turkey prolactin with egg performance

    Fathi Mehrangiz


    Full Text Available The induction and regulation of broodiness is of the most important role of prolactin in avian species. In this study, the association between prolactin promoter region alleles and reproductive traits in Fars native turkey was investigated. These traits consisted of mean egg weight (MEW, number of egg (EN and egg mass, during the first laying period. In total, 115 laying turkeys, randomly selected from the flock of the Breeding Center for Fars Native turkey, and DNA was purificated from blood samples, 231 bp of prolactin promoter region was amplified and Genotype of Samples was determinate by PCR-SSCP technique were genotyped. Two alleles D and I were identified. Based on the results obtained, the frequency of D and I alleles were 0.67 and 0.33, respectively. Frequencies of DD, II and ID genotypes were 0.385, 0.044 and 0.571, respectively. The association analysis between the polymorphism PRL gene promoter region and egg performance was carried out. Significant relationship was found between genotypes with egg production (P<0.01. Individuals with II genotype produced higher egg production than DD and ID genotype. The results of current study showed that using information of genes related to egg production could be used to improve the performance of native turkey of East Azerbaijan province.

  6. PRL-3 expression in nasal sinus squamous cell carcinoma

    Zi-Hui Chen; Min-Ying Li


    Objective:To investigate the relationship between liver regeneration phosphatase-3 (PRL-3) with differentiation extent of nasal sinus squamous cell carcinoma, and molecular biological effects on the pathogenesis of nasal sinus squamous cell carcinoma to comprehend its relevance, so as to make early diagnosis of patients, and to give guidance to the prognosis. Methods:Immunohistochemistry was used to detect PRL-3 in 30 cases of different degrees of sinus nasal squamous cell carcinoma. 20 cases of normal nasal cavity of mucosa tissues were set as control. Results:The PRL-3 in all levels of sinonasal squamous cell carcinoma tissues, there was a significant difference compared with the normal nasal mucosa (P<0.05), squamous cell carcinoma and its expression increased with the grade with enhanced trend. Conclusions:PRL-3 expression increased significantly in sinonasal squamous cell carcinoma than in nasal polyp tissue, showed that it may be associated with squamous cell carcinoma of nasal sinus squamous cell carcinoma, may be the early event.

  7. Rhodanine-based PRL-3 inhibitors blocked the migration and invasion of metastatic cancer cells.

    Min, Garam; Lee, Su-Kyung; Kim, Hye-Nan; Han, Young-Min; Lee, Rhan-Hee; Jeong, Dae Gwin; Han, Dong Cho; Kwon, Byoung-Mog


    PRL-3, phosphatase of regenerating liver-3, plays a role in cancer progression through its involvement in invasion, migration, metastasis, and angiogenesis. We synthesized rhodanine derivatives, CG-707 and BR-1, which inhibited PRL-3 enzymatic activity with IC50 values of 0.8 μM and 1.1 μM, respectively. CG-707 and BR-1 strongly inhibited the migration and invasion of PRL-3 overexpressing colon cancer cells without exhibiting cytotoxicity. The specificity of the inhibitors on PRL-3 phosphatase activity was confirmed by the phosphorylation recovery of known PRL-3 substrates such as ezrin and cytokeratin 8. The compounds selectively inhibited PRL-3 in comparison with other phosphatases, and CG-707 regulated epithelial-to-mesenchymal transition (EMT) marker proteins. The results of the present study reveal that rhodanine is a specific PRL-3 inhibitor and a good lead molecule for obtaining a selective PRL-3 inhibitor.

  8. PRL-3 activates NF-κB signaling pathway by interacting with RAP1.

    Lian, Shenyi; Meng, Lin; Liu, Caiyun; Xing, Xiaofang; Song, Qian; Dong, Bin; Han, Yong; Yang, Yongyong; Peng, Lirong; Qu, Like; Shou, Chengchao


    Phosphatase of regenerating liver (PRL-3) promotes cancer metastasis through enhanced cell motility and invasiveness, however its role in tumorigenesis remains unclear. Herein, we reported that PRL-3 interacts with telomere-related protein RAP1. PRL-3 promotes the cytosolic localization of RAP1, which is counteracted by silencing of PRL-3. Immunohistochemical staining of colon cancer tissue array (n=170) revealed that high level of PRL-3 associates with cytosolic localization of RAP1 (p=0.01). Microarray analysis showed that PRL-3 regulates expression of diverse genes and enhances phosphorylation of p65 subunit of NF-κB in a RAP1-dependent manner. Furthermore, PRL-3 transcriptionally activates RAP1 expression, which is counteracted by ablating p65. Therefore, our results demonstrate PRL-3 as a novel regulator of NF-κB signaling pathway through RAP1.

  9. Characterization and polymorphism screening of IGF-I and prolactin genes in Nelore heifers

    Janete Apparecida Desidério Sena


    Full Text Available Insulin growth factor I (IGF-I and prolactin (PRL are peptide hormones that exert complementary effects on reproductive traits by acting on folliculogenesis. In view of the lack of information about the IGF-I and PRL genes in Bos indicus, the objective of this study was to partially characterize the promoter regions of these genes and to screen animals of different ages at first pregnancy for the presence of polymorphisms in these regions. In addition, we determined whether polymorphisms influence the regulation of the two hormone genes, evaluating their association with sexual precocity. The animals were divided into three groups according to age at first pregnancy: 1 100 heifers considered to be sexually precocious that became pregnant at 15-16 months of age, 2 100 heifers that became pregnant during the normal breeding season at 24 months of age, and 3 100 heifers that did not become pregnant until 24 months of age. For the IGF-I gene, PCR-RFLP-SnaBI analysis showed the presence of genotypes AB and BB at frequencies of 0.02 and 0.98, respectively. Sequencing of the IGF-I gene fragment revealed a single nitrogen base change from cytosine to thymine, corresponding to the restriction site of SnaBI. The polymorphisms identified in the 5’-flanking region of the IGF-I gene may serve as a basis for future studies of molecular markers in cattle. For the PRL gene, PCR-RFLP-HaeIII analysis showed the presence of only one migration pattern, a finding characterizing the region studied as monomorphic. The study of other regions in the IGF-I and PRL genes might provide molecular data that can be used in the future for the selection of sexually precocious animals.

  10. Function of Treg Cells Decreased in Patients With Systemic Lupus Erythematosus Due To the Effect of Prolactin.

    Legorreta-Haquet, María Victoria; Chávez-Rueda, Karina; Chávez-Sánchez, Luis; Cervera-Castillo, Hernando; Zenteno-Galindo, Edgar; Barile-Fabris, Leonor; Burgos-Vargas, Rubén; Álvarez-Hernández, Everardo; Blanco-Favela, Francisco


    Prolactin has different functions, including cytokine secretion and inhibition of the suppressor effect of regulatory T (Treg) cells in healthy individuals. Systemic lupus erythematosus (SLE) is an autoimmune disease characterized by defects in the functions of B, T, and Treg cells. Prolactin plays an important role in the physiopathology of SLE. Our objective was to establish the participation of prolactin in the regulation of the immune response mediated by Treg cells from patients with SLE. CD4CD25CD127 cells were purified using magnetic beads and the relative expression of prolactin receptor was measured. The functional activity was evaluated by proliferation assay and cytokine secretion in activated cells, in the presence and absence of prolactin. We found that both percentage and function of Treg cells decrease in SLE patients compared to healthy individuals with statistical significance. The prolactin receptor is constitutively expressed on Treg and effector T (Teff) cells in SLE patients, and this expression is higher than in healthy individuals. The expression of this receptor differs in inactive and active patients: in the former, the expression is higher in Treg cells than in Teff cells, similar to healthy individuals, whereas there is no difference in the expression between Treg and Teff cells from active patients. In Treg:Teff cell cocultures, addition of prolactin decreases the suppressor effect exerted by Treg cells and increases IFNγ secretion. Our results suggest that prolactin plays an important role in the activation of the disease in inactive patients by decreasing the suppressor function exerted by Treg cells over Teff cells, thereby favoring an inflammatory microenvironment.

  11. Function of Treg Cells Decreased in Patients With Systemic Lupus Erythematosus Due To the Effect of Prolactin

    Legorreta-Haquet, María Victoria; Chávez-Rueda, Karina; Chávez-Sánchez, Luis; Cervera-Castillo, Hernando; Zenteno-Galindo, Edgar; Barile-Fabris, Leonor; Burgos-Vargas, Rubén; Álvarez-Hernández, Everardo; Blanco-Favela, Francisco


    Abstract Prolactin has different functions, including cytokine secretion and inhibition of the suppressor effect of regulatory T (Treg) cells in healthy individuals. Systemic lupus erythematosus (SLE) is an autoimmune disease characterized by defects in the functions of B, T, and Treg cells. Prolactin plays an important role in the physiopathology of SLE. Our objective was to establish the participation of prolactin in the regulation of the immune response mediated by Treg cells from patients with SLE. CD4+CD25hiCD127−/low cells were purified using magnetic beads and the relative expression of prolactin receptor was measured. The functional activity was evaluated by proliferation assay and cytokine secretion in activated cells, in the presence and absence of prolactin. We found that both percentage and function of Treg cells decrease in SLE patients compared to healthy individuals with statistical significance. The prolactin receptor is constitutively expressed on Treg and effector T (Teff) cells in SLE patients, and this expression is higher than in healthy individuals. The expression of this receptor differs in inactive and active patients: in the former, the expression is higher in Treg cells than in Teff cells, similar to healthy individuals, whereas there is no difference in the expression between Treg and Teff cells from active patients. In Treg:Teff cell cocultures, addition of prolactin decreases the suppressor effect exerted by Treg cells and increases IFNγ secretion. Our results suggest that prolactin plays an important role in the activation of the disease in inactive patients by decreasing the suppressor function exerted by Treg cells over Teff cells, thereby favoring an inflammatory microenvironment. PMID:26844452

  12. Early Postnatal Administration of Growth Hormone Increases Tuberoinfundibular Dopaminergic Neuron Numbers in Ames Dwarf Mice

    Khodr, Christina E; Clark, Sara; Bokov, Alex F.; Richardson, Arlan; Strong, Randy; Hurley, David L.; Phelps, Carol J.


    Hypothalamic tuberoinfundibular dopaminergic (TIDA) neurons secrete dopamine, which inhibits pituitary prolactin (PRL) secretion. PRL has demonstrated neurotrophic effects on TIDA neuron development in PRL-, GH-, and TSH-deficient Ames (df/df) and Snell (dw/dw) dwarf mice. However, both PRL and PRL receptor knockout mice exhibit normal-sized TIDA neuron numbers, implying GH and/or TSH influence TIDA neuron development. The current study investigated the effect of porcine (p) GH on TIDA neuron...

  13. 蛋白质组学方法分析PRL-3功能相关蛋白%Comparative proteomics analysis of PRL-3 functionally related protein

    关玉峰; 刘璐; 伍衡; 来伟; 李守峰; 褚忠华


    目的 蛋白质组学方法分析转染肝再生磷酸酶-3(PRL-3)后结肠癌细胞LoVo的蛋白表达改变.方法 构建绿色荧光蛋白载体PAcGFP-C3-PRL-3并转染至结肠癌细胞LoVo中,获得稳定表达GFP-PRL-3的结肠癌细胞LoVo-PRL-3.Western blot检测转染后细胞的PRL-3表达.采用双向凝胶电泳(2-DE)分离LoVo-PRL-3细胞及转染空载体PAcGFP-C3的LoVo-Control细胞总蛋白,从中选取差异表达蛋白质点,通过基质辅助激光解吸电离飞行时间串联质谱(MALD I-TOF-TOF-MS)鉴定差异表达的蛋白质.结果 Western blot结果显示PRL-3在LoVo-PRL-3细胞中高表达,而未检测到在LoVo-Control细胞中表达.通过双向凝胶电泳图谱分析发现20个差异蛋白质斑点,质谱成功鉴定出17种蛋白.与LoVo-Control细胞比较,10种蛋白在LoVo-PRL-3细胞中高表达,而7种蛋白在LoVo-PRL-3细胞中表达降低.结论 成功鉴定出PRL-3功能相关蛋白,为进一步研究PRL-3促进结直肠癌转移机制奠定基础.%Objective To identify the protein expression patterns after the colon cancer cells LoVo transfected with phosphatase of regenerating liver-3 ( PRL-3 ) using a comparative proteomic approach. Methods The green fluorescent protein vector PAcGFP-C3 -PRL-3 was constructed and transfected into the colon cancer cells LoVo and colon cancer cells stably expressing GFP-PRL-3 (LoVo-PRL-3) were established. Western blotting was used to detect the expression levels of PRL-3 in LoVo-PRL-3 cells. 2-DE was applied to separate the whole proteins in LoVo-PRL-3 cells and LoVo control cells that trasfected with vectors PAcGFP-C3. The proteins with statistically significant differential expression between LoVo-PRL-3 and LoVo control cells were identified by matrix-assisted laser desorption/ionization tandem time-of-flight mass spectrometry (MALD I-TOF-TOF-MS). Results Western blotting showed that PRL-3 was highly expresssed in LoVo-PRL-3 cells, but undetectable in LoVo control cells. Twenty

  14. The protein tyrosine phosphatase PRL-2 interacts with the magnesium transporter CNNM3 to promote oncogenesis.

    Hardy, S; Uetani, N; Wong, N; Kostantin, E; Labbé, D P; Bégin, L R; Mes-Masson, A; Miranda-Saavedra, D; Tremblay, M L


    The three PRL (phosphatases of regenerating liver) protein tyrosine phosphatases (PRL-1, -2 and -3) have been identified as key contributors to metastasis in several human cancers, yet the molecular basis of their pro-oncogenic property is unclear. Among the subfamily of PRL phosphatases, overexpression of PRL-2 in breast cancer cells has been shown to promote tumor growth by a mechanism that remains to be uncovered. Here we show that PRL-2 regulates intracellular magnesium levels by forming a functional heterodimer with the magnesium transporter CNNM3. We further reveal that CNNM3 is not a phosphorylated substrate of PRL-2, and that the interaction occurs through a loop unique to the CBS pair domains of CNNM3 that exists only in organisms having PRL orthologs. Supporting the role of PRL-2 in cellular magnesium transport is the observation that PRL-2 knockdown results in a substantial decrease of cellular magnesium influx. Furthermore, in PRL-2 knockout mice, serum magnesium levels were significantly elevated as compared with control animals, indicating a pivotal role for PRL-2 in regulating cellular magnesium homeostasis. Although the expression levels of CNNM3 remained unchanged after magnesium depletion of various cancer cell lines, the interaction between endogenous PRL-2 and CNNM3 was markedly increased. Importantly, xenograft tumor assays with CNNM3 and a mutant form that does not associate with PRL-2 confirm that CNNM3 is itself pro-oncogenic, and that the PRL-2/CNNM3 association is important for conferring transforming activities. This finding is further confirmed from data in human breast cancer tissues showing that CNNM3 levels correlate positively with both PRL-2 expression and the tumor proliferative index. In summary, we demonstrate that oncogenic PRL-2 controls tumor growth by modulating intracellular magnesium levels through binding with the CNNM3 magnesium transporter.

  15. Stimulation of receptor-associated kinase, tyrosine kinase, and MAP kinase is required for prolactin-mediated macromolecular biosynthesis and mitogenesis in Nb2 lymphoma.

    Carey, G B; Liberti, J P


    Lactogens [prolactin (Prl) and growth hormone] stimulate phosphorylation of the 40S ribosomal protein, S6, in Nb2 cells by mechanisms that do not involve participation of cAMP or protein kinase A, protein kinase C, or cGMP-dependent protein kinase. However, inhibition of tyrosine kinase (TK) abrogates Prl-mediated macromolecular biosynthesis. Inasmuch as lactogen signaling may involve sequential activation of protein kinases, the effect of Prl on the well-characterized mitogen-activated protein kinase (MAPK) and S6 kinase (S6K), the enzyme responsible for S6 phosphorylation in vivo, and their relationship to Nb2 macromolecular biosynthesis and mitogenesis were investigated. The results show that MAPK stimulation is transient (peak activity, 30 min) and precedes that of S6K, which reaches a maximum at 1.5-2 h, and slowly returns towards control levels at 6 h. Both staurosporine which inhibits GH receptor-associated kinase (JAK2) and genistein (GEN), an inhibitor of membrane-associated and cytoplasmic TKs, abrogate Prl-stimulated TK, MAPK, and S6K. Rapamycin (RAP), a specific inhibitor of p70S6K, completely blocks S6K but does not affect TK and MAPK. TK and MAPK activity correlates with Prl-stimulated anabolism, i.e., protein and DNA synthesis and mitogenesis. Thus, concentrations of STR and GEN which abrogate TK and MAPK inhibit anabolism virtually 100%. However, RAP, which inhibits S6K (ca. 100%) but not TK or MAPK, only delays Prl-mediated anabolism. These results indicate that Prl signaling in Nb2 cells involves a protein kinase cascade and that regulation of receptor-associated kinase, TK, and MAPK correlates with anabolism. The role of S6K (and S6 phosphorylation) appears to be ancillary.

  16. Are sexual side effects of prolactin-raising antipsychotics reducible to serum prolactin?

    Knegtering, Henderikus; van den Bosch, Rob; Castelein, Stynke; Bruggeman, Richard; Sytema, Sjoerd; van Os, Jim


    Objective: To assess the degree to which sexual side effects (SSE) are associated with prolactin-raising antipsychotics, and to what degree such SSE are reducible to serum prolactin levels. Method: A large sample (n = 264) of patients treated for 6 weeks with protactin-raising and prolactin-sparing

  17. Are sexual side effects of prolactin-raising antipsychotics reducible to serum prolactin?

    Knegtering, Henderikus; van den Bosch, Rob; Castelein, Stynke; Bruggeman, Richard; Sytema, Sjoerd; van Os, Jim


    Objective: To assess the degree to which sexual side effects (SSE) are associated with prolactin-raising antipsychotics, and to what degree such SSE are reducible to serum prolactin levels. Method: A large sample (n = 264) of patients treated for 6 weeks with protactin-raising and prolactin-sparing

  18. Drosophila PRL-1 is a growth inhibitor that counteracts the function of the Src oncogene.

    Pagarigan, Krystle T; Bunn, Bryce W; Goodchild, Jake; Rahe, Travis K; Weis, Julie F; Saucedo, Leslie J


    Phosphatase of Regenerating Liver (PRL) family members have emerged as molecular markers that significantly correlate to the ability of many cancers to metastasize. However, contradictory cellular responses to PRL expression have been reported, including the inhibition of cell cycle progression. An obvious culprit for the discrepancy is the use of dozens of different cell lines, including many isolated from tumors or cultured cells selected for immortalization which may have missing or mutated modulators of PRL function. We created transgenic Drosophila to study the effects of PRL overexpression in a genetically controlled, organismal model. Our data support the paradigm that the normal cellular response to high levels of PRL is growth suppression and furthermore, that PRL can counter oncogenic activity of Src. The ability of PRL to inhibit growth under normal conditions is dependent on a CAAX motif that is required to localize PRL to the apical edge of the lateral membrane. However, PRL lacking the CAAX motif can still associate indiscriminately with the plasma membrane and retains its ability to inhibit Src function. We propose that PRL binds to other membrane-localized proteins that are effectors of Src or to Src itself. This first examination of PRL in a model organism demonstrates that PRL performs as a tumor suppressor and underscores the necessity of identifying the conditions that enable it to transform into an oncogene in cancer.

  19. Oncogenic function and prognostic significance of protein tyrosine phosphatase PRL-1 in hepatocellular carcinoma.

    Jin, Shaowen; Wang, Kaimei; Xu, Kang; Xu, Junyao; Sun, Jian; Chu, Zhonghua; Lin, Dechen; Koeffler, Phillip H; Wang, Jie; Yin, Dong


    Our SNP-Chip data demonstrated 7/60 (12%) hepatocellular carcinoma (HCC) patients had PRL-1 copy number amplification. However, its biological functions and signaling pathways in HCC are deficient. Here, we investigated its oncogenic function and prognostic significance in HCC. PRL-1 protein levels were examined in 167 HCC samples by immunohistochemisty (IHC). The relationship of PRL-1 expression and clinicopathological features was assessed by correlation, Kaplan-Meier and Cox regression analyses. The oncogenic function of PRL-1 in HCC cells and its underlying mechanism were investigated by ectopic overexpression and knockdown model. PRL-1 levels in primary HCC and metastatic intravascular cancer thrombus were also determined by IHC. PRL-1 levels were frequently elevated in HCC tissues (81%), and elevated expression of PRL-1 was significantly associated with more aggressive phenotype and poorer prognosis in HCC patients (pPRL-1 markedly enhanced HCC cells migration and invasion. Furthermore, the oncogenic functions of PRL-1 were mediated by PI3K/AKT/GSK3β signaling pathway through inhibiting E-cadherin expression. Finally, PRL-1 protein levels in metastatic cancer thrombus were higher than that in primary HCC tissues (pPRL-1 in HCC invasion and metastasis implicating PRL-1 as a potential prognostic marker as well as therapeutic target in HCC.

  20. Growth hormone and prolactin responses to bolus and sustained infusions of GRH-1-40-OH in man.

    Goldman, J A; Molitch, M E; Thorner, M O; Vale, W; Rivier, J; Reichlin, S


    To determine whether GRH stimulates PRL secretion we studied the effects of iv bolus injections and prolonged infusions of GRH 1-40-OH on PRL and GH serum levels in normal volunteers. Eight patients with acromegaly, two of whom had elevated basal levels of PRL, were also tested with single bolus injections. Six normal subjects given 3.3 micrograms/kg bolus injections of GRH showed a mean increment of GH of 22.0 +/- 1.7 ng/ml (mean +/- SE). A small rise in PRL was noted in 5 of the 6 subjects (mean peak level of 6.4 +/- 1.9 ng/ml vs basal level of 3.3 +/- 0.4 ng/ml, p less than 0.05). During the continuous intusion of GRH (10 ng/kg/min), GH levels rose gradually from a mean baseline of 1.1 +/- 0.1 ng/ml to a mean peak of 30.0 +/- 7.2 ng/ml at about 2 h and then slowly declined to a nadir of 4.2 +/- 0.4 ng/ml at 330 min. PRL levels did not rise significantly during the infusion. To determine whether the decline in GH levels in the face of continued infusion was due to loss of GH responsiveness, a 3.3 micrograms/kg bolus of GRH was given during the nadir at 330 min; this GH increment was significantly less than that obtained by the GRH bolus injection without the infusion (12.9 +/- 3.5 ng/ml vs 22.0 +/- 1.7 ng/ml, p less than 0.05). The PRL response to the GRH bolus was the same during the infusion of GRH as before. In each of 8 acromegalic patients (including two who had initially elevated basal PRL levels) GRH led to an increase in both GH and PRL levels. PRL and GH levels spontaneously fluctuated in parallel in 4 acromegalic cases studied with repeated samples over 6 h during placebo administration. These experiments show that GRH has significant, though weak, PRF effect in normals and that it is more potent PRF in acromegalic patients. Furthermore, the effects on GH and PRL of a sustained infusion of GRH for 5 1/2 h are both qualitatively and quantitatively different. These results suggest that the GRH effect is exerted either on different pituitary receptors for

  1. [Prolactin and thyrotropin after stimulation by thyrotropin releasing hormone a study under long-term administration of oral contraceptives (author's transl)].

    Bellmann, O; Bröschen-Zywietz, C; Fichte, K


    The longtime application of oral contraceptives is assumed to elevate serum prolactin levels under non-stimulated conditions. We therefore examined whether oral contraceptives also will augment prolactin secretion after stimulation, e.g. by thyrotropin releasing hormone (TRH). After TRH stimulation the time sequence of secretion both of prolactin (HPRL) and thyroid stimulating hormone (TSH) was determined. Three groups of women were tested in a non-randomized study: group 1 without any hormonal medication (= controls), group 2 taking an oral contraceptives containing cyproterone acetate, group 3 using an oral contraceptive containing d-norgestrel. HPRL secretion was similar in all three groups, the same held true for TSH. A possible correlation between the secretion of HPRL and TSH was examined in the control group. No such correlation was found. The secretion patterns of both hormones also were different. In addition, the basic levels of both HPRL and TSH did not seem to influence the response after stimulation.

  2. A Novel Nectin-mediated Cell Adhesion Apparatus That Is Implicated in Prolactin Receptor Signaling for Mammary Gland Development.

    Kitayama, Midori; Mizutani, Kiyohito; Maruoka, Masahiro; Mandai, Kenji; Sakakibara, Shotaro; Ueda, Yuki; Komori, Takahide; Shimono, Yohei; Takai, Yoshimi


    Mammary gland development is induced by the actions of various hormones to form a structure consisting of collecting ducts and milk-secreting alveoli, which comprise two types of epithelial cells known as luminal and basal cells. These cells adhere to each other by cell adhesion apparatuses whose roles in hormone-dependent mammary gland development remain largely unknown. Here we identified a novel cell adhesion apparatus at the boundary between the luminal and basal cells in addition to desmosomes. This apparatus was formed by the trans-interaction between the cell adhesion molecules nectin-4 and nectin-1, which were expressed in the luminal and basal cells, respectively. Nectin-4 of this apparatus further cis-interacted with the prolactin receptor in the luminal cells to enhance the prolactin-induced prolactin receptor signaling for alveolar development with lactogenic differentiation. Thus, a novel nectin-mediated cell adhesion apparatus regulates the prolactin receptor signaling for mammary gland development.

  3. Increased serum prolactin in borderline personality disorder.

    Atmaca, Murad; Korkmaz, Sevda; Ustundag, Bilal; Ozkan, Yusuf


    Although there is an important interaction between serotonergic system, prolactin and suicidal behavior, and impulsivity, no investigation examined the prolactin values in borderline personality disorder in which suicidal behavior and impulsivity are core symptom dimensions. In this context, in the present investigation, we planned to measure serum prolactin levels in the patients with borderline personality disorder. The study comprised 15 patients with borderline personality disorder and 15 healthy controls. Prolactin values were measured in both patients and control subjects. The patients had abnormally higher mean value of prolactin compared to those of healthy controls (48.66 ± 36.48 mg/dl for patients vs. 15.20 ± 7.81 mg/dl for healthy controls). There was no correlation between prolactin values and any demographic variables for both the patients and control subjects. In conclusion, our present results suggest that prolactin values increased in the patients with borderline personality disorder and are required to be replicated by more comprehensive and detailed further studies to decipher the exact roles of prolactin increase.

  4. Phosphatase PRL-3 is a direct regulatory target of TGFbeta in colon cancer metastasis.

    Jiang, Yanjun; Liu, Xiao-Qiong; Rajput, Ashwani; Geng, Liying; Ongchin, Melanie; Zeng, Qi; Taylor, Gregory S; Wang, Jing


    Metastasis causes most deaths from cancer yet mechanistic understanding and therapeutic options remain limited. Overexpression of the phosphatase PRL-3 (phosphatase of regenerating liver) is associated with metastasis of colon cancer. Here, we show that PRL-3 is a direct target of signaling by TGFβ, which is broadly implicated in progression and metastasis. We found that suppression of PRL-3 expression by TGFβ was mediated by Smad-dependent inhibition of PRL-3 transcription at the level of promoter activity. PRL-3 activation stimulated PI3K/AKT signaling that caused resistance to stress-induced apoptosis. PRL-3 overexpression promoted metastatic colonization in an orthotopic mouse model of colon cancer, whereas PRL-3 knockdown reduced metastatic potential. Altered metastatic phenotypes were not derivative of primary tumor development or local invasion but could be attributed to PRL-3-mediated cell survival. Our findings suggest that inhibiting PRL-3 expression might be an important mechanism through which TGFβ suppresses metastasis in colon cancer. In addition, our findings suggest that loss of TGFβ signaling, which occurs commonly during colon cancer progression, is sufficient to activate a PRL-3-mediated cell survival pathway that can selectively promote metastasis. Therefore, a major implication of our findings is that PRL-3 antagonists may offer significant value for antimetastatic therapy in patients with colon cancer.

  5. Increased expression of the PRL-3 gene in human oral squamous cell carcinoma and dysplasia tissues.

    Hassan, Nur Mohammad Monsur; Hamada, Jun-ichi; Kameyama, Takeshi; Tada, Mitsuhiro; Nakagawa, Koji; Yoshida, Shoko; Kashiwazaki, Haruhiko; Yamazaki, Yutaka; Suzuki, Yukiko; Sasaki, Akira; Nagatsuka, Hitoshi; Inoue, Nobuo; Moriuchi, Tetsuya


    Phosphatase of regenerating liver (PRL) belongs to a class of the protein tyrosine phosphatase family, which is known so far to consist of 3 members, PRL-1, PRL-2, and PRL-3. The aim of this study was to uncover the role of PRL genes in development of oral malignancy. We analyzed expression levels of the 3 PRL genes in 50 human oral squamous cell carcinomas (OSCCs), 11 dysplasia and 12 normal mucosa tissues by a real-time RT-PCR method. PRL-3 but not PRL-1 or PRL-2 expressions were significantly higher in OSCC and dysplasia than in normal mucosa tissues. Additionally, PRL-3 expressions were significantly higher in OSCC tissues harboring dominant-negative p53 or recessive p53 mutation than in those harboring wild-type p53. These results suggest that PRL-3 plays a role in oral cancer development and can be useful as a marker of pre-malignant and malignant lesion of oral mucosa.

  6. Anti-cytomegalovirus activity of the anthraquinone atanyl blue PRL.

    Alam, Zohaib; Al-Mahdi, Zainab; Zhu, Yali; McKee, Zachary; Parris, Deborah S; Parikh, Hardik I; Kellogg, Glen E; Kuchta, Alison; McVoy, Michael A


    Human cytomegalovirus (CMV) causes significant disease in immunocompromised patients and serious birth defects if acquired in utero. Available CMV antivirals target the viral DNA polymerase, have significant toxicities, and suffer from resistance. New drugs targeting different pathways would be beneficial. The anthraquinone emodin is proposed to inhibit herpes simplex virus by blocking the viral nuclease. Emodin and related anthraquinones are also reported to inhibit CMV. In the present study, emodin reduced CMV infectious yield with an EC50 of 4.9μM but was cytotoxic at concentrations only twofold higher. Related anthraquinones acid blue 40 and alizarin violet R inhibited CMV at only high concentrations (238-265μM) that were also cytotoxic. However, atanyl blue PRL inhibited infectious yield of CMV with an EC50 of 6.3μM, significantly below its 50% cytotoxic concentration of 216μM. Atanyl blue PRL reduced CMV infectivity and inhibited spread. When added up to 1h after infection, it dramatically reduced CMV immediate early protein expression and blocked viral DNA synthesis. However, it had no antiviral activity when added 24h after infection. Interestingly, atanyl blue PRL inhibited nuclease activities of purified CMV UL98 protein with IC50 of 4.5 and 9.3μM. These results indicate that atanyl blue PRL targets very early post-entry events in CMV replication and suggest it may act through inhibition of UL98, making it a novel CMV inhibitor. This compound may provide valuable insights into molecular events that occur at the earliest times post-infection and serve as a lead structure for antiviral development.

  7. Exploring amino acid auxotrophy in Bifidobacterium bifidum PRL2010

    Chiara eFerrario


    Full Text Available The acquisition and assimilation strategies followed by members of the infant gut microbiota to retrieve nitrogen from the gut lumen are still largely unknown. In particular, no information on these metabolic processes is available regarding bifidobacteria, which are among the first microbial colonizers of the human intestine. Here, evaluation of amino acid auxotrophy and prototrophy of Bifidobacterium bifidum, with particular emphasis on B. bifidum strain PRL2010 (LMG S-28692, revealed a putative auxotrophy for cysteine. In addition, we hypothesized that cysteine plays a role in the oxidative stress response in B. bifidum. The use of glutathione as an alternative reduced sulfur compound did not alleviate cysteine auxotrophy of this strain, though it was shown to stimulate expression of the genes involved in cysteine biosynthesis, reminiscent of oxidative stress response. When PRL2010 was grown on a medium containing complex substrates, such as whey proteins or casein hydrolysate, we noticed a distinct growth-promoting effect of these compounds. Transcriptional analysis involving B. bifidum PRL2010 cultivated on whey proteins or casein hydrolysate revealed that the biosynthetic pathways for cysteine and methionine are modulated by the presence of casein hydrolysate. Such findings support the notion that certain complex substrates may act as potential prebiotics for bifidobacteria in their ecological niche.

  8. Purification and Characterization of PRL Protein Tyrosine Phosphatases

    LI Zhao-fa; WANG Yan; LI Qing-shan; ZHAO Zhi-zhuang Joe; FU Xue-qi; LI Yu-lin; LI Yi-lei


    PRLs constitute a subfamily of protein tyrosine phosphatases(PTPs). In the present paper are reported the molecular cloning, expression, purification, and characterization of all the three members of the PRL enzymes in human and the only PRL in C.elegans. These enzymes were expressed as glutathione S-transferase(GST) fusion proteins in DE3pLysS E.coli cells, and the recombinant fusion proteins were purified on glutathione-Sepharose affinity columns. Having been cleaved with thrombin, GST-free enzymes were further purified on an S-100 Sepharose gel filtration column. The purified proteins show single polypeptide bands on SDS-polyacrylamide gel electrophoresis. With para-nitrophenyl phosphate(p-NPP) as a substrate, PRLs exhibit classical Michaelis-Menten kinetics with Vmax values two orders of magnitude smaller than those of classic PTPs. The responses of PRLs to ionic strength, metal ions and phosphatase inhibitors are similar to those of other characterized PTPs, but their optimal pH values are different. These data thus reveal distinct common biochemical properties of PRL subfamily PTPs as well.

  9. Mediation of ACTH and prolactin responses to 5-HTP by 5-HT2 receptors.

    Gartside, S E; Cowen, P J


    Serotonin has a facilitatory role in the role of prolactin and adrenocorticotropin (ACTH) secretion. The serotonin precursor 5-hydroxy-L-tryptophan (5-HTP) dose dependently (30-100 mg/kg i.p.) increased plasma prolactin and ACTH in the male rat. Prolactin and ACTH responses to 5-HTP (100 mg/kg) were attenuated by pretreatment with the non-selective 5-HT receptor antagonist, metergoline (0.5 mg/kg), and by the selective 5-HT2 receptor antagonists, ritanserin (0.4 mg/kg), ketanserin (2.5 mg/kg), ICI (5.0 mg/kg) and spiperone (1.0 mg/kg). The 5-HT1 receptor antagonists, propranolol (40 mg/kg) and pindolol (4.0 mg/kg), failed to antagonize the prolactin and ACTH responses to 5-HTP (100 mg/kg), as did the selective 5-HT3 receptor antagonist, BRL 43694 (1.0 mg/kg). The results suggest that the prolactin and ACTH responses to 5-HTP in the male rat are mediated by 5-HT2 receptors.

  10. 21 CFR 862.1625 - Prolactin (lactogen) test system.


    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Prolactin (lactogen) test system. 862.1625 Section... Systems § 862.1625 Prolactin (lactogen) test system. (a) Identification. A prolactin (lactogen) test system is a device intended to measure the anterior pituitary polypeptide hormone prolactin in serum...

  11. Gamma irradiation effects on human growth hormone producing pituitary adenoma tissue. An analysis of morphology and hormone secretion in an in vitro model system

    Anniko, M. (Karolinska sjukhuset, Stockholm (Sweden). Dept. of Oto-Rhino-Laryngology); Arndt, J. (Karolinska sjukhuset, Stockholm (Sweden). Dept. of Radiophysics, Radiumhemmet); Raehn, T. (Karolinska sjukhuset, Stockholm (Sweden). Dept. of Neurosurgery); Werner, S. (Karolinska sjukhuset, Stockholm (Sweden). Dept. of Endocrinology)


    Irradiation-induced effects on pituitary cell morphology and secretion of growth hormone (GH) and prolactin (PRL) have been analysed using an in vitro system. Specimens for organ culture were were obtained from three patients with pituitary tumours causing acromegaly but with different clinical activity of disease. Specimens were followed in vitro 1 h - 6 days after single-dose gamma irradiation (/sup 60/Co) with 70 100 and 150 Gy, respectively. These doses are used in clinical work for the stereotactic radiosuregery of pituitary adenomas. Considerable fluctuations in hormone secretion/release occurred during the first 24h after irradiation. All three tumours showed individual differences concern ing irradiation-induced morphological damage. Only a minor variation occurred between specimens from the same tumour. An individual sensitivity to irradiation of pituitary tumours in vitro is documented. The great number of surviving pituitary tumour cells one week after irradiation-many with an intact ultrastructure and containing hormone granules-indicated an initial high degree of radioresistance.

  12. Expressions and Significances of PRL-3 and RhoC in A549 Cell

    Ping ZHANG


    Full Text Available Background and objective The expression of phosphatase of regenerating liver-3 (PRL-3 is correlated with Ras homologue C (RhoC in non-small cell lung cancer (NSCLC, suggesting that they have interactions. The aim of this study is to investigate the functions of PRL-3 and RhoC in the migration of A549 cell and the potential mechanism of PRL-3 and RhoC in carcinogenesis and cancer development. Methods PRL-3Ab and RhoCAb were used to block the functions of PRL-3 and RhoC respectively. Wound healing assay was applied to detect the migration of A549 cell and the expression levels of PRL-3 and RhoC were detected by RT-PCR. Results The migration of A549 cell decreased after blockage of PRL-3 and RhoC. The expression of RhoC decreased when PRL-3 was blocked without any changes on the expression of PRL-3. Conclusion PRL-3, RhoC could increase cell migration in A549 cells.

  13. Overexpression of the protein tyrosine phosphatase PRL-2 correlates with breast tumor formation and progression.

    Hardy, Serge; Wong, Nau Nau; Muller, William J; Park, Morag; Tremblay, Michel L


    The PRL-1, PRL-2, and PRL-3 phosphatases are prenylated protein tyrosine phosphatases with oncogenic activity that are proposed to drive tumor metastasis. We found that PRL-2 mRNA is elevated in primary breast tumors relative to matched normal tissue, and also dramatically elevated in metastatic lymph nodes compared with primary tumors. PRL-2 knockdown in metastatic MDA-MB-231 breast cancer cells decreased anchorage-independent growth and cell migration, suggesting that the malignant phenotype of these cells is mediated at least in part through PRL-2 signaling. In different mouse mammary tumor-derived cell lines overexpressing PRL-2, we confirmed its role in anchorage-independent growth and cell migration. Furthermore, injection of PRL-2-overexpressing cells into the mouse mammary fat pad promoted extracellular signal-regulated kinase 1/2 activation and tumor formation. MMTV-PRL-2 transgenic mice engineered to overexpress the enzyme in mammary tissue did not exhibit spontaneous tumorigenesis, but they exhibited an accelerated development of mammary tumors initiated by introduction of an MMTV-ErbB2 transgene. Together, our results argue that PRL-2 plays a role in breast cancer progression.

  14. Novel Anticancer Agents Based on Targeting the Trimer Interface of the PRL Phosphatase.

    Bai, Yunpeng; Yu, Zhi-Hong; Liu, Sijiu; Zhang, Lujuan; Zhang, Ruo-Yu; Zeng, Li-Fan; Zhang, Sheng; Zhang, Zhong-Yin


    Phosphatase of regenerating liver (PRL) oncoproteins are phosphatases overexpressed in numerous types of human cancer. Elevated levels of PRL associate with metastasis and poor clinical outcomes. In principle, PRL phosphatases offer appealing therapeutic targets, but they remain underexplored due to the lack of specific chemical probes. In this study, we address this issue by exploiting a unique property of PRL phosphatases, namely, that they may function as homotrimers. Starting from a sequential structure-based virtual screening and medicinal chemistry strategy, we identified Cmpd-43 and several analogs that disrupt PRL1 trimerization. Biochemical and structural analyses demonstrate that Cmpd-43 and its close analogs directly bind the PRL1 trimer interface and obstruct PRL1 trimerization. Cmpd-43 also specifically blocks the PRL1-induced cell proliferation and migration through attenuation of both ERK1/2 and Akt activity. Importantly, Cmpd-43 exerted potent anticancer activity both in vitro and in vivo in a murine xenograft model of melanoma. Our results validate a trimerization-dependent signaling mechanism for PRL and offer proof of concept for trimerization inhibitors as candidate therapeutics to treat PRL-driven cancers. Cancer Res; 76(16); 4805-15. ©2016 AACR.

  15. Metastasis-associated PRL-3 induces EGFR activation and addiction in cancer cells.

    Al-Aidaroos, Abdul Qader Omer; Yuen, Hiu Fung; Guo, Ke; Zhang, Shu Dong; Chung, Tae-Hoon; Chng, Wee Joo; Zeng, Qi


    Metastasis-associated phosphatase of regenerating liver-3 (PRL-3) has pleiotropic effects in driving cancer progression, yet the signaling mechanisms of PRL-3 are still not fully understood. Here, we provide evidence for PRL-3-induced hyperactivation of EGFR and its downstream signaling cascades in multiple human cancer cell lines. Mechanistically, PRL-3-induced activation of EGFR was attributed primarily to transcriptional downregulation of protein tyrosine phosphatase 1B (PTP1B), an inhibitory phosphatase for EGFR. Functionally, PRL-3-induced hyperactivation of EGFR correlated with increased cell growth, promigratory characteristics, and tumorigenicity. Moreover, PRL-3 induced cellular addiction to EGFR signaling, as evidenced by the pronounced reversion of these oncogenic attributes upon EGFR-specific inhibition. Of clinical significance, we verified elevated PRL-3 expression as a predictive marker for favorable therapeutic response in a heterogeneous colorectal cancer (CRC) patient cohort treated with the clinically approved anti-EGFR antibody cetuximab. The identification of PRL-3-driven EGFR hyperactivation and consequential addiction to EGFR signaling opens new avenues for inhibiting PRL-3-driven cancer progression. We propose that elevated PRL-3 expression is an important clinical predictive biomarker for favorable anti-EGFR cancer therapy.

  16. Prolactin rs1341239 T allele may have protective role against the brick tea type skeletal fluorosis

    Li, Bing-Yun; Yang, Yan-Mei; Liu, Yang; Sun, Jing; Ye, Yan; Liu, Xiao-Na; Liu, Hong-Xu; Sun, Zhen-Qi; Li, Mang; Cui, Jing; Sun, Dian-Jun; Gao, Yan-Hui


    Objective Prolactin (PRL) has been reported to be associated with increased bone turnover, and increased bone turnover is also a feature of skeletal fluorosis (SF). Autocrine/paracrine production of PRL is regulated by the extrapituitary promoter and a polymorphism in the extrapituitary PRL promoter at -1149 (rs1341239) is associated with disturbances of bone metabolism in other diseases. Here, we have investigated the possibility that the rs1341239 polymorphism is associated with SF, which results from the consumption of brick tea. Design We conducted a cross-sectional study in Sinkiang, Qinghai, Inner Mongolia in China. Demography survey questionnaires were completed and physical examination and X-ray diagnoses were used to diagnose SF. Brick tea water fluoride intake (IF) and urinary fluoride (UF) were tested by an F-ion selective electrode method. A Sequenom MassARRAY system was used to determine PRL gene polymorphisms. Results Subjects who were younger than 45 years of age and carried the T allele had a significantly decreased risk of SF [OR = 0.279 (95%CI, 0.094–0.824)] compared to those carrying the homozygous G allele. This phenomenon was only observed in Kazakh subjects [OR = 0.127 (95%CI, 0.025–0.646)]. Kazakh females who carried T alleles has a decreased risk of SF [OR = 0.410 (95%CI, 0.199–0.847)]. For Kazakh subjects which IF is less than 3.5 mg/d, a decreased risk of SF was observed among the participants who carried T alleles [OR = 0.118 (95%CI, 0.029–0.472)]. Overall, subjects with 1.6–3.2 mg/L UF and carried T alleles had a significantly decreased risk of SF [OR = 0.476 (95%CI, 0.237–0.955)] compared to homozygous G allele carriers. This phenomenon was only observed in Kazakh subjects [OR = 0.324 (95%CI, 0.114–0.923)]. Conclusions Our results suggested that the PRL rs1341239 T allele decreases the risk of brick tea SF. PMID:28152004

  17. Prolactin and growth hormone in fish osmoregulation

    Sakamoto, T.; McCormick, S.D.


    Prolactin is an important regulator of multiple biological functions in vertebrates, and has been viewed as essential to ion uptake as well as reduction in ion and water permeability of osmoregulatory surfaces in freshwater and euryhaline fish. Prolactin-releasing peptide seems to stimulate prolactin expression in the pituitary and peripheral organs during freshwater adaptation. Growth hormone, a member of the same family of hormones as prolactin, promotes acclimation to seawater in several teleost fish, at least in part through the action of insulin-like growth factor I. In branchial epithelia, development and differentiation of the seawater-type chloride cell (and their underlying biochemistry) is regulated by GH, IGF-I, and cortisol, whereas the freshwater-type chloride cell is regulated by prolactin and cortisol. In the epithelia of gastrointestinal tract, prolactin induces cell proliferation during freshwater adaptation, whereas cortisol stimulates both cell proliferation and apoptosis. We propose that control of salinity acclimation in teleosts by prolactin and growth hormone primarily involves regulation of cell proliferation, apoptosis, and differentiation (the latter including upregulation of specific ion transporters), and that there is an important interaction of these hormones with corticosteroids. ?? 2005 Elsevier Inc. All rights reserved.

  18. Dense collagen-I matrices enhance pro-tumorigenic estrogen-prolactin crosstalk in MCF-7 and T47D breast cancer cells.

    Craig E Barcus

    Full Text Available Breast cancers that express estrogen receptor alpha (ERα+ constitute the majority of breast tumors. Estrogen is a major driver of their growth, and targeting ER-mediated signals is a largely successful primary therapeutic strategy. Nonetheless, ERα+ tumors also result in the most breast cancer mortalities. Other factors, including altered characteristics of the extracellular matrix such as density and orientation and consequences for estrogen crosstalk with other hormones such as prolactin (PRL, may contribute to these poor outcomes. Here we employed defined three dimensional low density/compliant and high density/stiff collagen-I matrices to investigate the effects on 17β-estradiol (E2 activity and PRL/E2 interactions in two well-characterized ERα+/PRLR+ luminal breast cancer cell lines in vitro. We demonstrate that matrix density modulated E2-induced transcripts, but did not alter the growth response. However, matrix density was a potent determinant of the behavioral outcomes of PRL/E2 crosstalk. High density/stiff matrices enhanced PRL/E2-induced growth mediated by increased activation of Src family kinases and insensitivity to the estrogen antagonist, 4-hydroxytamoxifen. It also permitted these hormones in combination to drive invasion and modify the alignment of collagen fibers. In contrast, low density/compliant matrices allowed modest if any cooperation between E2 and PRL to growth and did not permit hormone-induced invasion or collagen reorientation. Our studies demonstrate the power of matrix density to determine the outcomes of hormone actions and suggest that stiff matrices are potent collaborators of estrogen and PRL in progression of ERα+ breast cancer. Our evidence for bidirectional interactions between these hormones and the extracellular matrix provides novel insights into the regulation of the microenvironment of ERα+ breast cancer and suggests new therapeutic approaches.

  19. Dense Collagen-I Matrices Enhance Pro-Tumorigenic Estrogen-Prolactin Crosstalk in MCF-7 and T47D Breast Cancer Cells

    Barcus, Craig E.; Holt, Elizabeth C.; Keely, Patricia J.; Eliceiri, Kevin W.; Schuler, Linda A.


    Breast cancers that express estrogen receptor alpha (ERα+) constitute the majority of breast tumors. Estrogen is a major driver of their growth, and targeting ER-mediated signals is a largely successful primary therapeutic strategy. Nonetheless, ERα+ tumors also result in the most breast cancer mortalities. Other factors, including altered characteristics of the extracellular matrix such as density and orientation and consequences for estrogen crosstalk with other hormones such as prolactin (PRL), may contribute to these poor outcomes. Here we employed defined three dimensional low density/compliant and high density/stiff collagen-I matrices to investigate the effects on 17β-estradiol (E2) activity and PRL/E2 interactions in two well-characterized ERα+/PRLR+ luminal breast cancer cell lines in vitro. We demonstrate that matrix density modulated E2-induced transcripts, but did not alter the growth response. However, matrix density was a potent determinant of the behavioral outcomes of PRL/E2 crosstalk. High density/stiff matrices enhanced PRL/E2-induced growth mediated by increased activation of Src family kinases and insensitivity to the estrogen antagonist, 4-hydroxytamoxifen. It also permitted these hormones in combination to drive invasion and modify the alignment of collagen fibers. In contrast, low density/compliant matrices allowed modest if any cooperation between E2 and PRL to growth and did not permit hormone-induced invasion or collagen reorientation. Our studies demonstrate the power of matrix density to determine the outcomes of hormone actions and suggest that stiff matrices are potent collaborators of estrogen and PRL in progression of ERα+ breast cancer. Our evidence for bidirectional interactions between these hormones and the extracellular matrix provides novel insights into the regulation of the microenvironment of ERα+ breast cancer and suggests new therapeutic approaches. PMID:25607819

  20. Pituitary regulation of corpus luteum progesterone secretion in cyclic rats.

    Sánchez-Criado, J E; López, F; Aguilar, E


    Pituitary LH and PRL secretion during the early postovulatory period of the rat estrous cycle seem to affect the corpus luteum (CL) autonomy to secrete progesterone. Thus, while PRL would act luteotropically, LH would be luteolytic. To further investigate these facts, 4-day cyclic rats, treated with either 1 mg bromocriptine (CB) or 0.25 ml 70% ethanol (ETOH) at 1600 h on estrus, were injected with 0.5 ml of either an anti-LH serum (LHAS) or normal horse serum (NHS) at 0800 h on metestrus. Rats treated at 0800 h on metestrus with both, CB and LHAS, were also used. To verify through a different procedure the effect of LH and/or PRL deprivation in estrous cycle CL progesterone secretion, hypophysectomy (HYPOX) and sham HYPOX (SHAM) were done at 0800 h on metestrus in either CB- or ETOH-injected rats at 1600 h on estrus. Hypophysectomized rats at 1600 h on estrus were also used. Progesterone secretion was prolonged up to 0800 h on diestrus in those rats deprived of LH from 0800 h on metestrus (ETOH/LHAS, -/CB + LHAS, ETOH/HYPOX) compared with controls (ETOH/NHS, ETOH/SHAM). This luteotropic effect was absent in those rats lacking estrous afternoon PRL (CB/LHAS, CB/HYPOX, HYPOX/-). No effect on CL progesterone secretion was detected in those rats exclusively deprived of PRL on the afternoon of estrus (CB/NHS, CB/SHAM). These results suggest that in the absence of the protective effects of PRL secretion on the afternoon of estrus, rat CL become extremely sensitive to the luteolytic effects of early diestrous LH levels, and this results in 4-day estrous cycles.

  1. Variance of serum prolactin in controlled ovarian stimulafion%控制性卵巢刺激治疗中血清催乳素水平的变化特点

    梁晓燕; 熊永崂; 庄广伦


    Objective To investigate the variance of peripheral blood prolactin(PRL)in controlled ovarian stimulation.Methods Seventy-two patients,with totally 106 cycles receiving a long protocol of gonadotropin-releasing hormone agonist combined with gonadotropin(Gn)were randomly enrolled in this retrospective study.During controlled ovarian stimulation,peripheral blood hormones were measured by chemiluminescent microparticle immunoassay.Results Prolactin was positively correlated with estradiol (r=0.5897.P<0.01)while there was no significant correlation between luteinizing hormone and PRLProgesterone had a positive relation with prolactin(r=0.1412,P<0.01).Conclusions During controlled ovarian stimulation,prolactin secretion is not affected by Gn but may be stimulated by estradiol.Progesterone has a positive relation with prolactin.%目的 探讨控制性卵巢刺激(COS)治疗中血清催乳素水平的变化特点.方法 收集接收体外受精-胚胎移植的患者72例,共115个周期,采用促性腺激素释放激素激动剂结合促性腺激素(Gn)长、短方案促排卵治疗,定时经阴道B超监测卵泡发育情况及子宫内膜厚度,并采用酶联免疫发光法检测不同时间点血清雌二醇、黄体生成素(LH)、孕酮和催乳素的水平,分析患者雌二醇、LH、孕酮水平与催乳素水平之间的相关性.结果 对催乳素与雌二醇水平进行相关和回归分析发现,随着雌二醇水平的上升,催乳素水平有显著上升的趋势,两者呈显著正相关关系(r=0.5897,P<0.01).对催乳素与孕酮水平进行相关和回归分析发现,孕酮水平随催乳素水平的升高而升高,两者呈显著正相关关系(r=0.1412,P<0.01).但是LH水平与催乳素水平之间未见明显关联.结论 在控制性卵巢刺激治疗中,催乳素的分泌不受Gn的影响,而雌二醇水平的升高可能刺激催乳素的分泌,且催乳素与孕酮水平呈正相关关系.

  2. Effect of supplemental light on growth, prolactin, progesterone and luteinizing hormone in water buffalo ( Bubalus bubalis)

    Perera, K. S.; Gwazdauskas, F. C.; Akers, R. M.; McGilliard, M. L.


    Fifty non-pregnant Surti buffalo heifers aged between 17 and 42 months ( n=24, 24 months) were randomly assigned to groups subject to either natural daylight +4h supplemental light ( n=25) or natural day light ( n=25), to study changes in growth, serum prolactin (Prl), progesterone (P4) and luteinizing hormone (LH) to supplemental lighting. Ambient temperatures (T) and relative humidity (RH) generally were >27° C and <70% during the day-time, respectively. Light-supplemented heifers had 16.2 kg net body weight (BW) gain at 9 weeks compared to 20.8 kg for controls, but higher mean Prl after 6.5 weeks ( P<0.01), and higher P4 (0.41 vs 0.19 ng/ml; P<0.06) than control heifers. Older heifers had 39.7% greater BW ( P<0.01), but a net 4.3% BW gain compared to a 10.1% gain for younger heifers at 10 weeks. Older, light-supplemented heifers had higher mean P4 (0.63 vs 0.19 ng/ml; P<0.07) than the other groups. These weight and hormonal changes suggest that 4 h supplemental light can alter growth and endocrine function in buffaloes under similar planes of nutrition. While light supplementation did not have a positive effect on body wieght during the 10 week study, body weight and endocrine changes due to supplemental light may be important factors for initiation of reproductive cyclicity.

  3. The Beckman DxI 800 prolactin assay demonstrates superior specificity for monomeric prolactin.

    Byrne, Brendan


    Commercially available prolactin immunoassays detect macroprolactin to variable degrees. Best practice requires laboratories to assess the cross-reactivity of their prolactin assay with macroprolactin, and where appropriate, introduce a screen for the presence of macroprolactin. Our policy has been to reanalyse hyperprolactinaemic samples following polyethylene glycol (PEG) precipitation and to report the resultant value as the monomeric prolactin content of the sample. The goal of this study was to determine the need to continue PEG precipitation when prolactin measurements with the Wallac AutoDELFIA were replaced by the Beckman DxI 800.

  4. Prolactin-like activity of anti-prolactin receptor antibodies on casein and DNA synthesis in the mammary gland.

    Djiane, J; Houdebine, L M; Kelly, P A


    Prolactin receptors were partially purified from rabbit mammary gland membranes by using an affinity chromatography technique. Antibodies against this prolactin receptor preparation were obtained in guinea pig and sheep. Both antisera were able to inhibit the binding of 125I-labeled ovine prolactin to rabbit mammary gland membranes. When added to culture media of rabbit mammary explants, the anti-prolactin receptor antiserum inhibited the capacity of prolactin to initiate casein synthesis and...

  5. Atypical Antipsychotics on Prolactin Levels in Male Schizophrenics%非典型抗精神病药对男性精神分裂症患者泌乳素水平的影响

    余燕萍; 王朔


      目的:调查分析6种非典型抗精神病药对男性精神分裂症患者泌乳素水平的影响.方法:将360例精神分裂症患者按照服药情况平均分为6组,于基线时治疗4、8周末测定血清泌乳素水平(PRL).结果:基线时各组间泌乳素水平比较无统计学差异(P>0.05),8周末时与治疗前相比利培酮泌乳素水平增加最为明显(P0.05).结论:利培酮对泌乳素水平升高最为明显,阿立哌唑、齐拉西酮对泌乳素水平基本没有影响.%Objective:To investigate the impact of the six kinds of atypical antipsychotics on prolactin levels in male schizophrenics. Methods: 360 patients with schizophrenia were medication compliance were divided into six groups at baseline and treatment of 4,8 weekend serum prolactin level (PRL). Results:Baseline prolactin levels among the groups showed no significant difference (P> 0.05), the weekend of August before treatment Bili Pei ketone prolactin levels increased most significantly (P 0.05). Conclusions:Effects of risperidone on prolactin levels were the most obvious, Aripiprazole, ziprasidone on prolactin level did not affect the basic.

  6. Structure and backbone dynamics of vanadate-bound PRL-3: comparison of 15N nuclear magnetic resonance relaxation profiles of free and vanadate-bound PRL-3.

    Jeong, Ki-Woong; Kang, Dong-Il; Lee, Eunjung; Shin, Areum; Jin, Bonghwan; Park, Young-Guen; Lee, Chung-Kyoung; Kim, Eun-Hee; Jeon, Young Ho; Kim, Eunice Eunkyeong; Kim, Yangmee


    Phosphatases of regenerating liver (PRLs) constitute a novel class of small, prenylated phosphatases with oncogenic activity. PRL-3 is particularly important in cancer metastasis and represents a potential therapeutic target. The flexibility of the WPD loop as well as the P-loop of protein tyrosine phosphatases is closely related to their catalytic activity. Using nuclear magnetic resonance spectroscopy, we studied the structure of vanadate-bound PRL-3, which was generated by addition of sodium orthovanadate to PRL-3. The WPD loop of free PRL-3 extended outside of the active site, forming an open conformation, whereas that of vanadate-bound PRL-3 was directed into the active site by a large movement, resulting in a closed conformation. We suggest that vanadate binding induced structural changes in the WPD loop, P-loop, helices α4-α6, and the polybasic region. Compared to free PRL-3, vanadate-bound PRL-3 has a longer α4 helix, where the catalytic R110 residue coordinates with vanadate in the active site. In addition, the hydrophobic cavity formed by helices α4-α6 with a depth of 14-15 Å can accommodate a farnesyl chain at the truncated prenylation motif of PRL-3, i.e., from R169 to M173. Conformational exchange data suggested that the WPD loop moves between open and closed conformations with a closing rate constant k(close) of 7 s(-1). This intrinsic loop flexibility of PRL-3 may be related to their catalytic rate and may play a role in substrate recognition.

  7. PRL-3 promotes cell adhesion by interacting with JAM2 in colon cancer

    Lian, Shenyi; Meng, Lin; Xing, Xiaofang; Yang, Yongyong; Qu, Like; Shou, Chengchao


    Phosphatase of regenerating liver-3 (PRL-3), also termed PTP4A3, is a metastasis-related protein tyrosine phosphatase. Its expression levels are significantly correlated with the progression and survival of a wide range of malignant tumors. However, the mechanism by which PRL-3 promotes tumor invasion and metastasis is not clear. In the present study, the functions of PRL-3 were systemically analyzed in the key events of metastasis including, motility and adhesion. A cell wounding assay, cell spread assay and cell-matrix adhesion assay were carried out to analyze the cell movement and cell adhesion ability of colon cancer, immunoprecipitation and immunofluorescence assay was confirmed the interaction of PRL-3 and JAM2. It was demonstrated that PRL-3 promoted the motility of Flp-In-293 and LoVo colon cancer cells and increased the distribution of cell skeleton proteins on the cell protrusions. In addition, stably expressing PRL-3 reduced the spreading speed of colon cancer cells and cell adhesion on uncoated, fibronectin-coated and collagen I-coated plates. Mechanistically, junction adhesion molecular 2 (JAM2) was identified as a novel interacting protein of PRL-3. The findings of the present study revealed the roles of PRL-3 in cancer cell motility and adhesion process, and provided information on the possibility of PRL-3 increase cell-cell adhesion by associating with JAM2. PMID:27588115

  8. Snail as a key regulator of PRL-3 gene in colorectal cancer.

    Zheng, Ping; Meng, Hui-Min; Gao, Wei-Zhe; Chen, Lin; Liu, Xun-Hua; Xiao, Zheng-Quan; Liu, Yong-Xia; Sui, Hong-Mei; Zhou, Jun; Liu, Yu-Hong; Li, Jian-Ming


    The regulators of a key metastasis gene PRL-3 in colorectal cancer (CRC) are still largely unknown. We found three potential binding sites of Snail, a key transcriptional factor involved in the epithelial-mesenchymal transition (EMT), in the region of PRL-3 promoter (located at -642 to -383). Moreover, our results showed that one of the Snail binding sites (located at -624 to -619) was the key element to maintain promoter activity of human PRL-3 gene. The transcriptional activity of PRL-3 promoter was abolished after the Snail binding site (located at -624 to -619) was mutated. Both promoter activity and protein expression of PRL-3 in CRC cell lines could be regulated by Snail. In clinical samples of CRC and metastatic lymph node of CRC, expression of PRL-3 protein was correlated with expression of Snail protein. Functional studies using gene over-expression and knockdown methods indicated that Snail promoted proliferation, cell adhesion and migration of human CRC cells. In SW480 cells with PRL-3 stable knockdown, cell proliferation increased after Snail was up-regulated. Our data first reveal transcriptional factor Snail as a key regulator of PRL-3 in CRC. The link between Snail and PRL-3 suggests a new potential mechanism of Snail contributing to progression and metastasis of CRC.

  9. PRL-3 promotes cell adhesion by interacting with JAM2 in colon cancer.

    Lian, Shenyi; Meng, Lin; Xing, Xiaofang; Yang, Yongyong; Qu, Like; Shou, Chengchao


    Phosphatase of regenerating liver-3 (PRL-3), also termed PTP4A3, is a metastasis-related protein tyrosine phosphatase. Its expression levels are significantly correlated with the progression and survival of a wide range of malignant tumors. However, the mechanism by which PRL-3 promotes tumor invasion and metastasis is not clear. In the present study, the functions of PRL-3 were systemically analyzed in the key events of metastasis including, motility and adhesion. A cell wounding assay, cell spread assay and cell-matrix adhesion assay were carried out to analyze the cell movement and cell adhesion ability of colon cancer, immunoprecipitation and immunofluorescence assay was confirmed the interaction of PRL-3 and JAM2. It was demonstrated that PRL-3 promoted the motility of Flp-In-293 and LoVo colon cancer cells and increased the distribution of cell skeleton proteins on the cell protrusions. In addition, stably expressing PRL-3 reduced the spreading speed of colon cancer cells and cell adhesion on uncoated, fibronectin-coated and collagen I-coated plates. Mechanistically, junction adhesion molecular 2 (JAM2) was identified as a novel interacting protein of PRL-3. The findings of the present study revealed the roles of PRL-3 in cancer cell motility and adhesion process, and provided information on the possibility of PRL-3 increase cell-cell adhesion by associating with JAM2.

  10. Upregulation of metastasis-associated PRL-3 initiates chordoma in zebrafish.

    Li, Li; Shi, Hongshun; Zhang, Mingming; Guo, Xiaoling; Tong, Fang; Zhang, Wenliang; Zhou, Junyi; Wang, Haihe; Yang, Shulan


    The metastasis-associated phosphatase of regenerating liver-3 (PRL-3) plays multiple roles in progression of various human cancers; however, significance of its role during development has not been addressed. Here we cloned and characterized the expression pattern of zebrafish prl-3 transcript and showed that it is ubiquitiously expressed in the first 24 h of development with both maternal and zygotic expressions. The transcripts become progressively restricted to the notochord, vessels and the intestine by 96 h post-fertilization. Notably, overexpression of zebrafish Prl-3 (zPrl-3) and human PRL-3 induces notochord malformation in zebrafish. This phenotype resembles chordoma and is confirmed by associated misexpression of notochord-specific markers. Clinical significance of the PRL-3 in chordoma is strongly suggested by detection of PRL-3 antigen in clinical chordoma specimens. Collectively, our results uncovered that aberrant overexpression of PRL-3 could initiate chordoma in early development and suggest the use of PRL-3 could be used as a predictor and a therapeutic target for chordoma.

  11. Oncogenic roles of PRL-3 in FLT3-ITD induced acute myeloid leukaemia.

    Park, Jung Eun; Yuen, Hiu Fung; Zhou, Jian Biao; Al-Aidaroos, Abdul Qader O; Guo, Ke; Valk, Peter J; Zhang, Shu Dong; Chng, Wee Joo; Hong, Cheng William; Mills, Ken; Zeng, Qi


    FLT3-ITD mutations are prevalent mutations in acute myeloid leukaemia (AML). PRL-3, a metastasis-associated phosphatase, is a downstream target of FLT3-ITD. This study investigates the regulation and function of PRL-3 in leukaemia cell lines and AML patients associated with FLT3-ITD mutations. PRL-3 expression is upregulated by the FLT3-STAT5 signalling pathway in leukaemia cells, leading an activation of AP-1 transcription factors via ERK and JNK pathways. PRL-3-depleted AML cells showed a significant decrease in cell growth. Clinically, high PRL-3 mRNA expression was associated with FLT3-ITD mutations in four independent AML datasets with 1158 patients. Multivariable Cox-regression analysis on our Cohort 1 with 221 patients identified PRL-3 as a novel prognostic marker independent of other clinical parameters. Kaplan-Meier analysis showed high PRL-3 mRNA expression was significantly associated with poorer survival among 491 patients with normal karyotype. Targeting PRL-3 reversed the oncogenic effects in FLT3-ITD AML models in vitro and in vivo. Herein, we suggest that PRL-3 could serve as a prognostic marker to predict poorer survival and as a promising novel therapeutic target for AML patients.

  12. Localizing PRL-2 expression and determining the effects of dietary Mg(2+) on expression levels.

    Gungabeesoon, Jeremy; Tremblay, Michel L; Uetani, Noriko


    The phosphatase of regenerating liver (PRL) is a group of protein tyrosine phosphatases that play a key role in cancer progression and metastasis. We previously showed that PRL-2 modulates intracellular Mg(2+) levels and sustains cancer phenotypes by binding to the Mg(2+) transporter CNNM3. However, the physiological functions of PRL-2 in animals remain largely unknown. To better understand which cell types are associated with PRL-2 function, we characterized its expression in mouse tissues using a PRL-2 β-galactosidase reporter mouse model. Our results demonstrated that PRL-2 was ubiquitously expressed, with the highest expression levels observed in the hippocampal pyramidal neurons, ependymal cells, cone and rod photoreceptor cells, endocardium, vascular and bronchial smooth muscle, and collecting ducts in the kidney. On the other hand, PRL-2 expression was undetectable or very low in the parenchymal cells of the liver and pancreas. Our results also indicated that PRL-2 is involved in cell-type-specific Mg(2+) homeostasis and that PRL-2 expression is potentially inversely regulated by dietary Mg(2+) levels.

  13. LEO1 is regulated by PRL-3 and mediates its oncogenic properties in acute myelogenous leukemia.

    Chong, Phyllis S Y; Zhou, Jianbiao; Cheong, Lip-Lee; Liu, Shaw-Cheng; Qian, Jingru; Guo, Tiannan; Sze, Siu Kwan; Zeng, Qi; Chng, Wee Joo


    PRL-3, an oncogenic dual-specificity phosphatase, is overexpressed in 50% of acute myelogenous leukemia (AML) and associated with poor survival. We found that stable expression of PRL-3 confers cytokine independence and growth advantage of AML cells. However, how PRL-3 mediates these functions in AML is not known. To comprehensively screen for PRL3-regulated proteins in AML, we performed SILAC-based quantitative proteomics analysis and discovered 398 significantly perturbed proteins after PRL-3 overexpression. We show that Leo1, a component of RNA polymerase II-associated factor (PAF) complex, is a novel and important mediator of PRL-3 oncogenic activities in AML. We described a novel mechanism where elevated PRL-3 protein increases JMJD2C histone demethylase occupancy on Leo1 promoter, thereby reducing the H3K9me3 repressive signals and promoting Leo1 gene expression. Furthermore, PRL-3 and Leo1 levels were positively associated in AML patient samples (N=24; PPRL-3 oncogenic phenotypes in AML. Loss of Leo1 leads to destabilization of the PAF complex and downregulation of SOX2 and SOX4, potent oncogenes in myeloid transformation. In conclusion, we identify an important and novel mechanism by which PRL-3 mediates its oncogenic function in AML.

  14. Oestrogen requires the insulin-like growth factor-I receptor for stimulation of prolactin synthesis via mitogen-activated protein kinase.

    Arroba, A I; Frago, L M; Argente, J; Chowen, J A


    Sex steroids and growth factors interact at the intracellular level in a variety of tissues to control numerous physiological functions. Oestrogen is known to stimulate prolactin synthesis and secretion, but the effect of insulin-like growth factor (IGF)-I is less clear. We used GH3 cells, a somatolactotroph cell line, to study the interaction of 17beta-oestradiol (E(2)) and IGF-I on prolactin protein levels and the intracellular mechanisms involved. Cell cultures were treated with E(2) (10 nM) and/or IGF-I (10 ng/ml) for 8 h. The real-time reverse transcriptase-polymerase chain reaction, Western blot and enzyme-immunoassay were used to determine changes in prolactin mRNA and protein levels. At this time-point, there were no significant changes in cell number, prolactin mRNA expression, or the amount of secreted prolactin. However, E(2) increased intracellular prolactin concentrations. IGF-I alone had no effect, but blocked the stimulatory effect of E(2). MAPK (ERK1/2) activation, as determined by Western blot analysis, increased with both E(2) and IGF-I, but not with the combination of these factors. The MAPK inhibitor PD98059 blocked the ability of E(2) to increase intracellular prolactin concentrations. Similarly, the IGF-I receptor antagonist, JB1, blocked the effect of E(2) on prolactin synthesis and MAPK activation, as did the oestrogen receptor antagonist ICI182 780. These results suggest that, to stimulate prolactin synthesis, E(2) activates the MAPK cascade and that this requires the presence of both oestrogen and IGF-I receptors.

  15. Prolactin does not affect human platelet aggregation or secretion

    Reuwer, A.Q.; Nieuwland, R.; Fernandez, I.; Goffin, V.; van Tiel, C.M.; Schaap, M.C.L.; Berckmans, R.J.; Kastelein, J.J.P.; Twickler, M.T.B.


    Platelets play an important role in the development of plaque formation and in the events after rupture of the atherosclerotic plaque, leading to atherothrombosis. Multiple hormones, either in excess or when deficient, are involved in the development of atherothrombotic disease, but, to which extent

  16. Effects of ovariectomy or force feeding on the plasma concentrations of prolactin and luteinizing hormone in incubating turkey hens.

    Zadworny, D; Etches, R J


    The effect of ovariectomy (OVX) on plasma concentrations of prolactin (PRL) and luteinizing hormone (LH) in incubating turkey hens was studied. Neither the sham-operated nor the OVX hens exhibited any change in the pattern of incubation behavior as a result of the surgery. Plasma concentrations of estradiol decreased to less than approximately 3 pg/ml by 2 days after surgery in the OVX hens. There were no significant differences in plasma levels of PRL between the sham-operated and OVX hens throughout the study. The concentration of PRL did not change in either the sham-operated or OVX hens and was maintained at high levels after surgery and during incubation of the eggs. By 2 days after hens were placed into cages, plasma levels of PRL significantly decreased and were maintained at low levels in both groups. The concentration of LH did not change in either group during the two wk after surgery when the hens were incubating eggs. After the hens were placed into cages, the concentration of LH increased in the OVX hens and was maintained at significantly higher levels than in the sham-operated hens. By contrast, the concentration of LH increased within 4 days after OVX of out-of-lay but nonincubating hens. The delay in the postcastration increase in plasma level of LH in the OVX hens was not associated with anorexia of incubating hens, since plasma levels of LH were not affected by force-feeding unless plasma levels of PRI were suppressed by nest deprivation.(ABSTRACT TRUNCATED AT 250 WORDS)

  17. Prolactin increases hepatic Na+/taurocholate co-transport activity and messenger RNA post partum.

    Ganguly, T C; Liu, Y; Hyde, J F; Hagenbuch, B; Meier, P J; Vore, M


    We have shown that Na+/taurocholate co-transport activity is decreased in pregnancy, but rebounds post partum relative to non-pregnant controls, and that activity can be increased by treatment with ovine prolactin [Ganguly, Hyde and Vore (1993) J. Pharmacol. Exp. Ther. 267, 82-87]. To determine the basis for these effects, Na+/taurocholate co-transport was determined in purified basolateral liver plasma-membrane (bLPM) vesicles and compared with steady-state mRNA levels encoding the Na+/taurocholate-co-transporting polypeptide (Ntcp) in non-pregnant controls, pregnant rats (19-20 days pregnant), rats post partum (48 h post partum) and rats post partum treated with bromocriptine to inhibit prolactin secretion. Na+/taurocholate co-transport activity (nmol/5 s per mg of protein) in bLPM was decreased from 10.4 +/- 1.8 in non-pregnant controls to 7.9 +/- 0.6 in bLPM in pregnant rats, but rebounded to 17.5 +/- 1.3 post partum; treatment of rats post partum with bromocriptine to inhibit prolactin secretion decreased activity to 14.1 +/- 0.9. Northern and slot-blot analyses revealed similar changes in mRNA for Ntcp, so that a positive correlation was observed between Na+/taurocholate co-transport activity and Ntcp mRNA. Furthermore, treatment of ovariectomized rats with ovine prolactin increased Ntcp mRNA 10-fold compared with solvent-treated controls, consistent with the 2-fold increase in Vmax, for Na+/taurocholate co-transport in isolated hepatocytes. These data are the first to demonstrate endogenous physiological regulation by prolactin of Ntcp mRNA in parallel with Na+/taurocholate co-transport activity. Images Figure 2 PMID:7945260

  18. What factors drive prolactin and corticosterone responses to stress in a long-lived bird species (snow petrel Pagodroma nivea)?

    Angelier, Frédéric; Moe, Børge; Blanc, Samuel; Chastel, Olivier


    Life-history theory predicts that individuals should adapt their parental investment to the costs and benefits of the current reproductive effort. This could be achieved by modulating the hormonal stress response, which may shift energy investment away from reproduction and redirect it toward survival. In birds, this stress response consists of a release of corticosterone that may be accompanied by a decrease in circulating prolactin, a hormone involved in the regulation of parental care. We lack data on the modulation of the prolactin stress response. In this study, we tested the hypothesis that individuals should modulate their prolactin stress response according to the fitness value of the current reproductive effort relative to the fitness value of future reproduction. Specifically, we examined the influence of breeding status (failed breeders vs. incubating birds) and body condition on prolactin and corticosterone stress responses in a long-lived species, the snow petrel Pagodroma nivea. When facing stressors, incubating birds had higher prolactin levels than failed breeders. However, we found no effect of body condition on the prolactin stress response. The corticosterone stress response was modulated according to body condition but was not affected by breeding status. We also performed an experiment using injections of adrenocorticotropic hormone (ACTH) and found that the modulation of the corticosterone stress response was probably associated with a reduction in ACTH release by the pituitary and a decrease in adrenal sensitivity to ACTH. In addition, we examined whether prolactin and corticosterone secretion were functionally linked. We found that these two hormonal stress responses were not correlated. Moreover, injection of ACTH did not affect prolactin levels, demonstrating that short-term variations in prolactin levels are not governed directly or indirectly by ACTH release. Thus, we suggest that the corticosterone and prolactin responses to short

  19. Characterization of ductal and lobular breast carcinomas using novel prolactin receptor isoform specific antibodies

    Heger Christopher D


    Full Text Available Abstract Background Prolactin is a polypeptide hormone responsible for proliferation and differentiation of the mammary gland. More recently, prolactin's role in mammary carcinogenesis has been studied with greater interest. Studies from our laboratory and from others have demonstrated that three specific isoforms of the prolactin receptor (PRLR are expressed in both normal and cancerous breast cells and tissues. Until now, reliable isoform specific antibodies have been lacking. We have prepared and characterized polyclonal antibodies against each of the human PRLR isoforms that can effectively be used to characterize human breast cancers. Methods Rabbits were immunized with synthetic peptides of isoform unique regions and immune sera affinity purified prior to validation by Western blot and immunohistochemical analyses. Sections of ductal and lobular carcinomas were stained with each affinity purified isoform specific antibody to determine expression patterns in breast cancer subclasses. Results We show that the rabbit antibodies have high titer and could specifically recognize each isoform of PRLR. Differences in PRLR isoform expression levels were observed and quantified using histosections from xenografts of established human breast cancer cells lines, and ductal and lobular carcinoma human biopsy specimens. In addition, these results were verified by real-time PCR with isoform specific primers. While nearly all tumors contained LF and SF1b, the majority (76% of ductal carcinoma biopsies expressed SF1a while the majority of lobular carcinomas lacked SF1a staining (72% and 27% had only low levels of expression. Conclusions Differences in the receptor isoform expression profiles may be critical to understanding the role of PRL in mammary tumorigenesis. Since these antibodies are specifically directed against each PRLR isoform, they are valuable tools for the evaluation of breast cancer PRLR content and have potential clinical importance in

  20. 狮头鹅PRL基因的克隆及原核表达%Cloning and Prokaryotic Expression of PRL Gene in Shitou Goose

    贾汝敏; 吴慧英; 刘铀; 张丽


    To further study the physiological regulatory mechanisms of PRL on the reproductive performance of Shitou goose. The cDNA of goose prolactin (PRL) gene was amplified from anterior pituitary gland of Shitou goose by RT-PCR. Then the PCR product was cloned into the pMD18-T vector to construct the pMD18-PRL for sequencing. And then the cDNA was subcloned into the prokaryotic expressing vector pET32a (+). Subsequently, the recombinant plasmid pET32-PRL was transformed into the E. coli BL21 (DE3) expression bacteria, then the recombinant PRL was induced by IPTG. The purified recombinant PRL was detected by SDSPAGE and Western Blot. The results showed that coding region of PRL gene was comprised of 600 nucleotides(GenBank No. GQ856665) and encoded 199 amino acids putative protein which shared highly conservation with that of other birds. It was found that PRL protein was comprised of several α-Helixes, β-Sheets and Coils. It was inferred that the superiority region of antigenic epitope were in the N' 70-76,95-102,150-155 and 207-213 sections. A high proportion of soluble PRL fusion protein about 53. 6% of total bacterial protein was obtained in E. coli BL21 (DE3).The molecular weight of the fusion protein was about 41 ku. The Western Blot result showed that the recombinant protein was recognized by antiserum specifically. The result of this study will provide basis for further study of the biological function of prolactin protein and the effects of PRL on the broodiness and production traits of Shitou goose.%为了进一步研究PRL对狮头鹅繁殖性能的生理调节机制,采用RT-PCR方法从狮头鹅脑垂体组织扩增获得PRL基因的cDNA序列,克隆至pMD18-T载体获得重组质粒pMD18-PRI,并进行序列测定和分析.将测序正确的cDNA序列定向克隆到pET32a(+),构建表达载体pET32a-PRI,并转化至BL21(DE3)大肠杆菌表达目的蛋白,经IPTG诱导后进行SDS-PAGE检测和Western Blot分析.狮头鹅PRL基因编码区含有600

  1. PRL-3促进子宫内膜腺癌细胞侵袭能力%PRL-3 inhibits migration and invasion of endometrial adenocarcinoma cell lines

    姜国成; 明健; 姜彦多


    目的 探讨肝再生磷酸酶(PRL-3)在子宫内膜腺癌细胞中的表达及其与子宫内膜腺癌细胞迁移和侵袭的关系.方法 应用逆转录- 聚合酶链式反应(RT-PCR)和Western方法检测了PRL-3 在2 种子宫内膜腺癌细胞系中的表达情况,并在两种细胞中转染PRL-3siRNA 24、36、48、60 和72 h 后检测PRL-3 的表达情况.同时应用transwell 小室观察抑制PRL-3 后,两种细胞侵袭能力的变化.采用独立t 检验比较实验组与对照组间PRL-3 的结果的差异.结果 PRL-3 在2 种子宫内膜腺癌细胞系中均高表达.在两种细胞中,转染PRL-3 siRNA 36 h 后,PRL-3 表达最低(P < 0.01),并进一步发现,转染后HEC-1-B 和AN3CA 细胞迁移[ 细胞数为(18.67 ± 7.49) 个、(15.96 ± 8.42) 个,与各对照组比较,t 值分别为5.23 ~ 6.45、3.32 ~ 5.33 间,P 均= 0.000];转染后HEC-1-B 和AN3 CA 细胞侵袭[ 细胞数为(4.67 ± 0.98)个、(3.89 ± 1.09)个,与各对照组比较,t 值分别为4.86 ~ 6.98、4.36 ~ 5.64 间,P 均= 0.000].结论 PRL-3 在子宫内膜腺癌细胞中高表达,且下调PRL-3 能够抑制细胞迁移和侵袭能力.

  2. Correlation analysis of prolactin with breast fibroadenoma%垂体泌乳素与乳腺纤维腺瘤的相关性分析

    张丽媛; 谷元廷; 吕鹏威; 王芳; 李林


    目的 探究垂体泌乳素水平与乳腺纤维腺瘤发病的相关性.方法 选取2012年6月至2013年2月就诊于郑州大学第一附属医院乳腺外二科的249例患者,术前采血查雌二醇(E2)及垂体泌乳素(PRL),并对数值进行统计;根据术后病理分为纤维腺瘤组和腺病组.54例门诊体检者采用相同方法查E2及PRL,定为正常乳腺组.用SAS 9.1统计软件对数据进行分析,分析三组间E2水平比较及PRL水平是否存在差异.结果 三组间的E2水平及PRL水平均不符合正态分布,纤维腺瘤组的PRL水平明显高于腺病组和正常乳腺组,差异有统计学意义(P<0.05);而三组的E2水平差异未见统计学意义(P>0.05).结论 垂体泌乳素水平升高与纤维腺瘤的发生有相关性,但是否可通过控制垂体泌乳素水平来降低乳腺纤维腺瘤的发病尚需进一步研究.%Objective To investigate the correlation of prolactin level with morbidity of fibroadenoma of breast.Methods From June 2012 to February 2013,249 patients diagnosed in the second department of breast surgery in the first affiliated hospital of Zhengzhou university were selected,before operation,blood was collected to examine estradiol (E2) and prolactin (PRL) and the numerical values were counted.According to the post-operation pathology,the patients were divided into fibroadenoma group and adenopathy group.Fifty-four cases of clinic examination,were given the same method to check E2 and PRL,and were "normal breast group".SAS 9.1 statistical software was used for rank sum test and the inter-group E2 level and PRL level were analyzed to see whether there was difference.Results The E2 level and PRL level of the three groups were not conformed to normal distribution,the PRL level of fibroadenoma group was obviously higher than that of the other two groups,the differences were significant(P <0.05),while the E2 level of the three groups had no difference(P > 0.05).Conclusions The rising of

  3. Protein Tyrosine Phosphatase PRL2 Mediates Notch and Kit Signals in Early T Cell Progenitors.

    Kobayashi, Michihiro; Nabinger, Sarah C; Bai, Yunpeng; Yoshimoto, Momoko; Gao, Rui; Chen, Sisi; Yao, Chonghua; Dong, Yuanshu; Zhang, Lujuan; Rodriguez, Sonia; Yashiro-Ohtani, Yumi; Pear, Warren S; Carlesso, Nadia; Yoder, Mervin C; Kapur, Reuben; Kaplan, Mark H; Daniel Lacorazza, Hugo; Zhang, Zhong-Yin; Liu, Yan


    The molecular pathways regulating lymphoid priming, fate, and development of multipotent bone marrow hematopoietic stem and progenitor cells (HSPCs) that continuously feed thymic progenitors remain largely unknown. While Notch signal is indispensable for T cell specification and differentiation, the downstream effectors are not well understood. PRL2, a protein tyrosine phosphatase that regulates hematopoietic stem cell proliferation and self-renewal, is highly expressed in murine thymocyte progenitors. Here we demonstrate that protein tyrosine phosphatase PRL2 and receptor tyrosine kinase c-Kit are critical downstream targets and effectors of the canonical Notch/RBPJ pathway in early T cell progenitors. While PRL2 deficiency resulted in moderate defects of thymopoiesis in the steady state, de novo generation of T cells from Prl2 null hematopoietic stem cells was significantly reduced following transplantation. Prl2 null HSPCs also showed impaired T cell differentiation in vitro. We found that Notch/RBPJ signaling upregulated PRL2 as well as c-Kit expression in T cell progenitors. Further, PRL2 sustains Notch-mediated c-Kit expression and enhances stem cell factor/c-Kit signaling in T cell progenitors, promoting effective DN1-DN2 transition. Thus, we have identified a critical role for PRL2 phosphatase in mediating Notch and c-Kit signals in early T cell progenitors. Stem Cells 2017;35:1053-1064.

  4. Aryl‐hydrocarbon receptor activity modulates prolactin expression in the pituitary

    Moran, Tyler B.; Brannick, Katherine E.; Raetzman, Lori T., E-mail:


    Pituitary tumors account for 15% of intracranial neoplasms, however the extent to which environmental toxicants contribute to the proliferation and hormone expression of pituitary cells is unknown. Aryl-hydrocarbon receptor (AhR) interacting protein (AIP) loss of function mutations cause somatotrope and lactotrope adenomas in humans. AIP sequesters AhR and inhibits its transcriptional function. Because of the link between AIP and pituitary tumors, we hypothesize that exposure to dioxins, potent exogenous ligands for AhR that are persistent in the environment, may predispose to pituitary dysfunction through activation of AhR. In the present study, we examined the effect of AhR activation on proliferation and endogenous pituitary hormone expression in the GH3 rat somatolactotrope tumor cell line and the effect of loss of AhR action in knockout mice. GH3 cells respond to nM doses of the reversible AhR agonist β-naphthoflavone with a robust induction of Cyp1a1. Although mRNA levels of the anti-proliferative signaling cytokine TGFbeta1 are suppressed upon β-naphthoflavone treatment, we did not observe an alteration in cell proliferation. AhR activation with β-naphthoflavone suppresses Ahr expression and impairs expression of prolactin (PRL), but not growth hormone (GH) mRNA in GH3 cells. In mice, loss of Ahr similarly leads to a reduction in Prl mRNA at P3, while Gh is unaffected. Additionally, there is a significant reduction in pituitary hormones Lhb and Fshb in the absence of Ahr. Overall, these results demonstrate that AhR is important for pituitary hormone expression and suggest that environmental dioxins can exert endocrine disrupting effects at the pituitary. -- Highlights: ► AhR signaling suppresses Prl mRNA expression. ► AhR signaling does not influence pituitary proliferation in culture. ► AhR is necessary for Prl, Lhb and Fshb expression at postnatal day 3.

  5. Prolactin regulation of kisspeptin neurones in the mouse brain and its role in the lactation-induced suppression of kisspeptin expression.

    Brown, R S E; Herbison, A E; Grattan, D R


    Hyperprolactinaemia is a major cause of infertility in both males and females, although the mechanism by which prolactin inhibits the reproductive axis is not clear. The aim of the present study was to test the hypothesis that elevated prolactin causes suppression of kisspeptin expression in the hypothalamus, resulting in reduced release of gonadotrophin-releasing hormone (GnRH) and consequent infertility. In oestrogen-treated ovariectomised mice, chronic prolactin-treatment prevented the rise in luteinising hormone (LH) seen in vehicle-treated mice. Kiss1 mRNA was significantly suppressed in both the rostral periventricular region of the third ventricle (RP3V) and arcuate nucleus after prolactin treatment. Exogenous prolactin treatment induced phosphorylated signal transducer and activator of transcription 5 (pSTAT5) in kisspeptin neurones, and suppression of endogenous prolactin using bromocriptine reduced levels of pSTAT5 in kisspeptin neurones, suggesting that prolactin acts directly on kisspeptin neurones. By contrast, fewer than 1% of GnRH neurones expressed pSTAT5 in either dioestrous or lactating mice. As reported previously, there was significant suppression of kisspeptin mRNA and protein in the RP3V on day 7 of lactation, although not in the arcuate nucleus. Bromocriptine treatment significantly increased Kiss1 mRNA expression in the RP3V, although not to dioestrous levels. Unilateral thelectomy, aiming to eliminate sensory inputs from nipples on one side of the body, failed to alter the reduction in the number of kisspeptin neurones observed in the RP3V. These data demonstrate that chronic prolactin administration suppressed serum LH, and reduced Kiss1 mRNA levels in both the RP3V and arcuate nucleus, consistent with the hypothesis that prolactin-induced suppression of kisspeptin secretion might mediate the inhibitory effects of prolactin on GnRH secretion. During lactation, however, the suppression of Kiss1 mRNA in the RP3V was only partially reversed

  6. Developmental aspects of adipose tissue in GH receptor and prolactin receptor gene disrupted mice: site-specific effects upon proliferation, differentiation and hormone sensitivity.

    Flint, David J; Binart, Nadine; Boumard, Stephanie; Kopchick, John J; Kelly, Paul


    Direct metabolic effects of GH on adipose tissue are well established, but effects of prolactin (PRL) have been more controversial. Recent studies have demonstrated PRL receptors on adipocytes and effects of PRL on adipose tissue in vitro. The role of GH in adipocyte proliferation and differentiation is also controversial, since GH stimulates adipocyte differentiation in cell lines, whereas it stimulates proliferation but inhibits differentiation of adipocytes in primary cell culture. Using female gene disrupted (ko) mice, we showed that absence of PRL receptors (PRLRko) impaired development of both internal and s.c. adipose tissue, due to reduced numbers of adipocytes, an effect differing from that of reduced food intake, where cell volume is decreased. In contrast, GHRko mice exhibited major decreases in the number of internal adipocytes, whereas s.c. adipocyte numbers were increased, even though body weight was decreased by 40-50%. The changes in adipose tissue in PRLRko mice appeared to be entirely due to extrinsic factors since preadipocytes proliferated and differentiated in similar fashion to wild-type animals in vitro and their response to insulin and isoproterenol was similar to wild-type animals. This contrasted with GHRko mice, where s.c. adipocytes proliferated, differentiated, and responded to hormones in identical fashion to controls, whereas parametrial adipocytes exhibited markedly depressed proliferation and differentiation potential and failed to respond to insulin or noradrenaline. Our results provide in vivo evidence that both GH and PRL stimulate differentiation of adipocytes but that the effects of GH are site specific and induce intrinsic changes in the precursor population, which are retained in vitro.

  7. Role of Mammary Prolactin in Carcinogenesis


    pcDNA3 moderate rise in plasma PRL levels and does not readily form neomycin expression vector (Invitrogen, San Diego, CA). Positive cloneswere... poultry polycarbonate (60%) and epoxy resins BPA can be facilitated when canned and livestock in the USA (Marselos (30%), with the remaining 10% being

  8. PRL-3, an emerging marker of carcinogenesis, is strongly associated with poor prognosis.

    Guzińska-Ustymowicz, Katarzyna; Pryczynicz, Anna


    PRL-3 protein belongs to the family of protein tyrosine phosphatases with unique COOH-terminal prenylation motif, which determines the functions of this protein and its location in the cell. Numerous research studies revealed that apart from performing the poorly investigated physiological role, PRL-3 takes part in the process of carcinogenesis. Specifically, it is involved in reconstructing of the cytoskeleton, regulating adhesion and cell cycle of the cancer cells, and in epithelial-mesenchymal transition. Through these mechanisms PRL-3 protein participates in invasion, migration, metastasis and angiogenesis. Numerous studies indicate that PRL-3 expression is particularly important in colorectal, as well as in gastric, ovarian and breast carcinomas. Recently, several studies on PRL-3 protein in other types of cancer have been published. They reveal a significant role of this protein in the process of angiogenesis and metastasis. It has been proven that a higher expression of PRL-3 correlates with tumor progression and its severity. While the degree of overexpression of PRL-3 varies in different types of tumors, most research shows that in the metastases of these tumors, whether to the lymph nodes or to other organs, the level of expression is extremely high. Overexpression of PRL-3 protein was repeatedly confirmed in metastases, but not with primary tumors. PRL-3 seems to be an adequate marker in diagnosing the stage of tumor advancement for various types of carcinomas, especially for colorectal carcinoma investigated thoroughly in this study. PRL-3 overexpression predicts poor prognosis in patients with various carcinomas and is a promising target in the cancer treatment.

  9. 正常早期妊娠妇女以β-hCG为参照的催乳素曲线研究%Study on the Curve of PRL as A Reference of β-hCG for Normal Early Pregnant Women



    目的:探讨正常早期妊娠妇女催乳素(PRL)随不同水平血清人绒毛膜促性腺激素β亚单位(β-hCG)的变化规律.方法:采用化学发光免疫测定法检测正常早期妊娠妇女不同孕龄血清β-hCG、PRL水平.结果:当β-hCG≤80 000 IU/L时,PRL随着β-hCG上升同样呈直线上升趋势,其中当β-hCG为70 000~80 000 IU/L时PRL达到高峰,为76.04±38.97 μg/L,提示妊娠早期血清PRL水平随血清β-hCG浓度增高而增加;当β-hCG>80 000 IU/L之后,PRL的变化趋于平稳,无明显的直线上升趋势.结论:建立了正常早期妊娠妇女以β-hCG为参照的PRL变化曲线,为正常早期妊娠妇女的PRL水平提供了合适参考范围.%Objective: To discuss the changing law of prolactin (PRL) with different levels of beta-subunit of human chorionic gonadotropin (P-hCG) of normal early pregnant women. Methods: The levels of serum β-hCG and PRL of normal pregnant women in different gestational age ( 80 000 IU/L, the changing tend of PRL was smooth, no obvious linear upward trend was observed. Conclusion: The curve of PRL as a reference of p-hCG for normal early pregnant women is established, which provides an appropriate range of PRL for normal women during early pregnancy.

  10. Stimulatory effect of PGF2α on PRL based on experimental inhibition of each hormone in mares.

    Ginther, O J; Pinaffi, F L V; Rodriguez, M B; Duarte, L F; Beg, M A


    During the luteolytic period in mares, the peak of 65% of pulses of a PGF2α metabolite (PGFM) and the peak of a pulse of PRL have been reported to occur at the same hour. It is unknown whether the synchrony reflects an effect of PGF2α on PRL or vice versa. Controls, a flunixin meglumine (FM)-treated group (to inhibit PGF2α), and a bromocriptine-treated group (to inhibit PRL), were used at 14 days postovulation in June and in September (n = 6 mares/group/mo). Blood samples were collected hourly from just before treatment (Hour 0) to Hour 10. Concentrations of PGFM in the FM group were lower (P PRL in June were lower (P PRL averaged over groups was lower (P PRL concentrations in mares represents an effect of PGF2α on PRL rather than an effect of PRL on PGF2α.

  11. Hypergravity induced prolactin surge in female rats

    Megory, E.; Oyama, J.


    Acute initial exposure to hypergravity (HG) was previously found to induce prolonged diestrous in rats, which was followed by return to normal estrous cycling upon more prolonged exposure to continuous HG. Bromergocryptine was found to prevent this prolonged diestrous. In this study it is found that in female rats 20 h of 3.14 G exposure (D-1 1200 h until D-2 0800 h) can induce prolactin surge at D-2 1600 h. Shorter exposure time (8 h), or exposure during a different part of the estrous cycle (19 h: from D-1 0700 h until D-2 0200 h) could not elicit this prolactin surge. Similar exposure of male rats of HG did not alter significantly their prolactin levels. It is possible that the hypothalamus of male and female rats responds differently to stimulation by HG.

  12. Prolactin response to low dose sulpiride.


    1 Prolactin levels in response to sulpiride were studied in healthy volunteers. 2 Oral doses of 1 mg-50 mg sulpiride or placebo were given. 3 A 3 mg sulpiride dose produced similar levels to those achieved with both 10 mg and 50 mg. 4 Circadian effects were studied showing no significant differences in the prolactin response to sulpiride. 5 Acute or chronic responses showed an attenuation with chronic sulpiride treatment to 50% of the peak levels attained with acute treatment. 6 These results...

  13. Characterization of growth hormone and prolactin produced by human pituitary in culture.

    Skyler, J S; Rogol, A D; Lovenberg, W; Knazek, R A


    Fragments of a pituitary tumor from a patient with acromegaly were grown in tissue culture. The tumor secreted both growth hormone and prolactin,which were recovered in high concentrations. The nonpurified hormones were characterized and compared to their respective counterparts obtained by extraction from normal pituitaries obtained at autopsy. The tissue culture and pituitary extracted hormones were eluted from Sephadex G-100 with the same partition coefficients. Growth hormone from both sources showed parallel dose-response displacement curves, by logit-log transformation, in both specific immunoassay and in a specific lymphocyte binding assay. Prolactin from both sources was compared in specific immunoassay using three different antisera. Parallel logit-log displacement curves were seen with one antiserum, while the other two antisera yielded non-parallel curves, indicating structural differences between prolactin from the two sources. Quantitative polyacrylamide gel electrophoresis was performed using multiphasic buffer systems previously developed for characterization of each hormone. By the criteria of joint 95% confidence envelopes of retardation co-efficient and relative free mobility, tissue culture growth hormone and prolactin were indistinguishable from their pituitary-extracted counterparts. This study demonstrates that, prior to purification, tissue culture derived hormone can be characterized by multiple criteria and compared to a standard preparation. Structural differences can be detected, as in the case of prolactin. When the hormones are indistinguishable, as in the case of growth hormone, it becomes worthwhile to increase the scale of tissue cultured production, with the prospect that tissue culture may serve as a source of hormone for both experimental and therapeutic use.

  14. Prolactin-induced Subcellular Targeting of GLUT1 Glucose Transporter in Living Mammary Epithelial Cells

    Arieh Riskin


    Full Text Available Background: Studying the biological pathways involved in mammalian milk production during lactation could have many clinical implications. The mammary gland is unique in its requirement for transport of free glucose into the cell for the synthesis of lactose, the primary carbohydrate in milk. Objective: To study GLUT1 trafficking and subcellular targeting in living mammary epithelial cells (MEC in culture. Methods: Immunocytochemistry was used to study GLUT1 hormonally regulated subcellular targeting in human MEC (HMEC. To study GLUT1 targeting and recycling in living mouse MEC (MMEC in culture, we constructed fusion proteins of GLUT1 and green fluorescent protein (GFP and expressed them in CIT3 MMEC. Cells were maintained in growth medium (GM, or exposed to secretion medium (SM, containing prolactin. Results: GLUT1 in HMEC localized primarily to the plasma membrane in GM. After exposure to prolactin for 4 days, GLUT1 was targeted intracellularly and demonstrated a perinuclear distribution, co-localizing with lactose synthetase. The dynamic trafficking of GFP-GLUT1 fusion proteins in CIT3 MMEC suggested a basal constitutive GLUT1 recycling pathway between an intracellular pool and the cell surface that targets most GLUT1 to the plasma membrane in GM. Upon exposure to prolactin in SM, GLUT1 was specifically targeted intracellularly within 90–110 minutes. Conclusions: Our studies suggest intracellular targeting of GLUT1 to the central vesicular transport system upon exposure to prolactin. The existence of a dynamic prolactin-induced sorting machinery for GLUT1 could be important for transport of free glucose into the Golgi for lactose synthesis during lactation.

  15. Prepregnant overweight and obesity diminish the prolactin response to suckling in the first week postpartum.

    Rasmussen, Kathleen M; Kjolhede, Chris L


    The population subgroups with the highest proportion of overweight and obese women often are characterized by the lowest rates of initiation and shortest durations of breastfeeding. We previously documented that these 2 population-level trends may be related. In a population of white women who lived in a rural area, we observed that prepregnant overweight and obesity were associated with failure to initiate and also to sustain lactation. The means by which being overweight or obese negatively affect lactational performance is unknown and likely to be multifactorial in origin, including the simple mechanical difficulties of latching on and proper positioning of the infant. In addition, we have shown that prepregnant body mass index (BMI) is negatively associated with the timing of lactogenesis II, the onset of copious milk secretion. Although the effects of obesity on the prolactin response to infant suckling have never been studied, we postulated that maternal obesity could compromise this important response. We proposed that this might occur because obesity alters the 24-hour spontaneous release of prolactin and also because prolactin secretion is blunted in response to various stimuli among obese subjects. The fall in progesterone concentration that occurs immediately postpartum is the trigger for the onset of copious milk secretion, but maintenance of prolactin and cortisol concentrations is necessary for this trigger to be effective. Adipose tissue concentrates progesterone. We proposed that this additional source of progesterone would lead to consistently higher progesterone concentrations among obese compared with normal-weight women. This, in turn, would lead to a delay in reaching the appropriate concentration to trigger the onset of lactogenesis II. We tested the hypotheses that a reduced prolactin response to suckling and higher-than-normal progesterone concentration in the first week after delivery might be among the means by which maternal overweight

  16. 剖宫产术后两种镇痛方法对产妇泌乳及产后恢复的影响%Effects of Two Kinds of Analgesia Methods on Plasma Prolactin and Colostrum Time in Parturi-ents After Cesarean Section

    仇海滨; 李会来; 高志伟


    【目的】探讨剖宫产术后两种阵痛方法对产妇泌乳及产后恢复的影响。【方法】分析2008年1月至2010年12月本院收治的120例健康足月产妇择期在联合椎管内麻醉下施行剖宫产术的临床资料。术后在知情同意的原则下,按镇痛方式的不同,随机分为行0.2%罗比卡因(5 mL/h)的硬膜外自控镇痛(PCEA)组(A组)和曲马多10 mg/kg +氟哌利多5 mg 的静脉自控镇痛(PCIA )组(B组),每组60例。两组均持续48 h镇痛。观察产妇血浆泌乳素(PRL )水平、初乳时间、肠蠕动恢复时间及并发症发生情况。【结果】两组术后PRL 水平均较术前明显升高( P <0.01),A组PRL高于B组,术后24 h有显著性差异( P <0.05),48 h有极显著性差异(P <0.01)。A组初乳时间、肠蠕动恢复时间较B组均提前(P <0.05),A组术后生命体征平稳,无恶心呕吐、头痛、肢体麻木发生,B组术后有5例出现恶心呕吐、头痛、盗汗现象,无其他不适。【结论】剖宫产术后罗比卡因PCEA镇痛效果确切安全,更能促进PRL分泌,有利于产妇泌乳,哺乳。%[Objective] To explore the effects of two kinds of analgesia methods on plasma prolactin(PRL) and colostrum time in parturients after Cesarean section .[Methods]Totally 120 healthy full‐term parturients in our hospital from Jan .2008 to Dec .2010 underwent elective Cesarean section under the combined intraspinal anesthesia .Under the informed consent after operation ,all patients were randomly divided into patient‐con‐trolled epidural analgesia(PCEA) with 0 .2% ropivacaine(5mL/h) group(group A ,n=60) and self‐controlled intravenous analgesia(PCIA) with tramadol 10mg/kg and droperidol 5mg group(group B ,n=60) .The anal‐gesia lasted for continuous 48h .Plasma prolactin(PRL) ,colostrum time ,enterocinesia recovery time and com‐plications of parturients were observed .[Results

  17. Cloning of human PRL-3 gene and construction of its prokaryotic expression vector%PRL-3基因的克隆及其原核表达载体的构建表达

    周军; 李建明; 柳玉红; 丁彦青


    目的 克隆人PRL-3基因并构建其原核表达载体.方法 设计PRL-3特异性引物,提取人大肠癌细胞系SW480总RNA,用RT-PCR方法获取人PRL-3 cDNA.经T-A克隆,通过双酶切鉴定及测序确认后,构建人PRL-3基因的原核表达载体pGEX-4T-1-PRL-3.结果 成功扩增出人PRL-3全长cDNA,并构建pGEX-4T-1-PRL-3原核表达载体,测序结果表明PRL-3全长cDNA与GenBank中PRL-3序列完全一致,SDS-PAGE胶分析表明,在大肠杆菌BL21(DE3)中成功表达了重组蛋白.结论 获得人PRL-3基因全长cDNA并构建其原核表达载体,使其在大肠杆菌中获得了高效表达,为深入研究PRL-3基因在大肠癌发生发展中的作用奠定了基础.

  18. Prolactin genomics and biology in herbivores

    Circulating prolactin concentrations are typically reduced in animals suffering from tall fescue toxicosis, and have become a standard biological marker for tall fescue toxicosis. Wild-type endophyte infestations of tall fescue pastures result in forage containing ergot alkaloids. Ergot alkaloids ...

  19. Binding of a 100-kDa ubiquitous factor to the human prolactin promoter is required for its basal and hormone-regulated activity.

    Peers, B; Nalda, A M; Monget, P; Voz, M L; Belayew, A; Martial, J A


    cAMP strongly stimulates the activity of the human prolactin (hPRL) promoter. We have previously shown that two types of cis-element are required for this cAMP regulation; binding sites for the pituitary-specific factor Pit-1, and the sequence spanning nucleotides -115 to -85 (named sequence A). Sequence A contains the TGACG motif found in the consensus sequence of the cAMP-responsive element (CRE). In this study, we show that a mutation in the TGACG motif of sequence A strongly reduces not only the cAMP regulation but also the Ca2+ regulation and basal activity of the hPRL promoter. Furthermore, gel-shift assays indicate that the mutation prevents binding of a ubiquitous factor which is not the CRE-binding protein. Southwestern experiments suggest that this ubiquitous factor's molecular mass is approximately 100 kDa. We conclude that binding of a 100-kDa ubiquitous factor to sequence A is required for full basal and hormonal regulation of hPRL-promoter activity.

  20. Transcriptional induction of the human prolactin gene by cAMP requires two cis-acting elements and at least the pituitary-specific factor Pit-1.

    Peers, B; Monget, P; Nalda, M A; Voz, M L; Berwaer, M; Belayew, A; Martial, J A


    To identify the cis-acting elements responsible for cAMP stimulation of human prolactin (hPRL) promoter activity, pituitary GC cells were transfected with 5'-deleted hPRL promoters fused to the chloramphenicol acetyltransferase reporter gene. The proximal regulatory region (coordinates -250 to -42) was sufficient to confer strong cAMP stimulation (+/- 25 fold). Further 5' and 3' deletions performed within this proximal region demonstrated that two types of cis-acting elements are involved in the cAMP regulation: (i) the binding sites of the pituitary-specific factor Pit-1, and (ii) the sequence between coordinates -115 and -85 (named fragment A), which contains a TGACG motif. We show by gel-shift and Southwestern experiments that fragment A binds Pit-1 monomer and also a ubiquitous factor that is neither cAMP-responsive element-binding protein nor activator protein-1. Strong cAMP induction was observed when fragment A was juxtaposed to a Pit-1 binding site. That Pit-1 plays an important role was supported further by the finding that the hPRL proximal region conferred cAMP regulation when linked to the herpes simplex virus thymidine kinase promoter only in pituitary GC cells and not in other heterologous cells, which do not express Pit-1. Furthermore, we observed that concatenated Pit-1 binding sites were able to confer cAMP responsiveness to the thymidine kinase promoter in GC cells.

  1. Two Independent Histidines One in Human Prolactin and One in Its Receptor Are Critical for pH-dependent Receptor Recognition and Activation

    M Kulkarni; M Tettamanzi; J Murphy; C Keeler; D Myszka; N Chayen; E Lolis; M Hodsdon


    Human prolactin (hPRL), a member of the family of hematopoietic cytokines, functions as both an endocrine hormone and autocrine/paracrine growth factor. We have previously demonstrated that recognition of the hPRL-receptor depends strongly on solution acidity over the physiologic range from pH 6 to pH 8. The hPRL-receptor binding interface contains four histidines whose protonation is hypothesized to regulate pH-dependent receptor recognition. Here, we systematically dissect its molecular origin by characterizing the consequences of His to Ala mutations on pH-dependent receptor binding kinetics, site-specific histidine protonation, and high resolution structures of the intermolecular interface. Thermodynamic modeling of the pH dependence to receptor binding affinity reveals large changes in site-specific protonation constants for a majority of interface histidines upon complexation. Removal of individual His imidazoles reduces these perturbations in protonation constants, which is most likely explained by the introduction of solvent-filled, buried cavities in the crystallographic structures without inducing significant conformational rearrangements.

  2. First Light results from PARAS: The PRL Echelle Spectrograph

    Chakraborty, Abhijit; Roy, Arpita; Pathan, Fazalahmed M; Shah, Vishal; Richardson, Eric H; Ubale, Girish; Shah, Rajesh


    We present the first light commissioning results from the Physical Research Laboratory (PRL) optical fiber-fed high resolution cross-dispersed Echelle Spectrograph. It is capable of a single- shot spectral coverage of 3700A to 8600A at R ~ 63,000 and is under very stable conditions of temperature (0.04{\\deg}C at 23{\\deg}C). In the very near future pressure control will also be achieved by enclosing the entire spectrograph in a low-pressure vacuum chamber (~0.01mbar). It is attached to a 1.2m telescope using two 50micron core optical fibers (one for the star and another for simultaneous Th-Ar spectral calibration). The 1.2m telescope is located at Mt. Abu, India, and we are guaranteed about 80 to 100 nights a year for observations with the spectrograph. The instrument will be ultimately used for radial-velocity searches of exoplanets around 1000 dwarf stars, brighter than 10th magnitude, for the next 5 years with a precision of 3 to 5m/s using the simultaneous Th-Ar spectral lamp reference technique. The spect...

  3. VEGF promotes the transcription of the human PRL-3 gene in HUVEC through transcription factor MEF2C.

    Jianliang Xu

    Full Text Available Phosphatase of regenerating liver 3 (PRL-3 is known to be overexpressed in many tumors, and its transcript level is high in the vasculature and endothelial cells of malignant tumor tissue. However, the mechanism(s underlying its enhanced expression and its function in endothelial cells remain unknown. Here, we report that vascular endothelial growth factor (VEGF can induce PRL-3 transcription in human umbilical vein endothelial cells (HUVEC. An analysis of its 5'UTR revealed that PRL-3 transcription is initiated from two distinct sites, which results in the formation of the two transcripts, PRL-3-iso1 and PRL-3-iso2, but only the latter is up-regulated in HUVEC by VEGF. The PRL-3-iso2 promoter region includes two functional MEF2 (myocyte enhancer factor2 binding sites. The over-expression of the constitutively active form of MEF2C promotes the abundance of the PRL-3-iso2 transcript in a number of human cell lines. The siRNA-induced knockdown of MEF2C abolished the stimulative effect of VEGF on PRL-3 transcript in HUVEC, indicating that the VEGF-induced promotion of PRL-3 expression requires the presence of MEF2C. Finally, blocking PRL-3 activity or expression suppresses tube formation by HUVEC. We suggest that PRL-3 functions downstream of the VEGF/MEF2C pathway in endothelial cells and may play an important role in tumor angiogenesis.

  4. VEGF promotes the transcription of the human PRL-3 gene in HUVEC through transcription factor MEF2C.

    Xu, Jianliang; Cao, Shaoxian; Wang, Lu; Xu, Rui; Chen, Gong; Xu, Qiang


    Phosphatase of regenerating liver 3 (PRL-3) is known to be overexpressed in many tumors, and its transcript level is high in the vasculature and endothelial cells of malignant tumor tissue. However, the mechanism(s) underlying its enhanced expression and its function in endothelial cells remain unknown. Here, we report that vascular endothelial growth factor (VEGF) can induce PRL-3 transcription in human umbilical vein endothelial cells (HUVEC). An analysis of its 5'UTR revealed that PRL-3 transcription is initiated from two distinct sites, which results in the formation of the two transcripts, PRL-3-iso1 and PRL-3-iso2, but only the latter is up-regulated in HUVEC by VEGF. The PRL-3-iso2 promoter region includes two functional MEF2 (myocyte enhancer factor2) binding sites. The over-expression of the constitutively active form of MEF2C promotes the abundance of the PRL-3-iso2 transcript in a number of human cell lines. The siRNA-induced knockdown of MEF2C abolished the stimulative effect of VEGF on PRL-3 transcript in HUVEC, indicating that the VEGF-induced promotion of PRL-3 expression requires the presence of MEF2C. Finally, blocking PRL-3 activity or expression suppresses tube formation by HUVEC. We suggest that PRL-3 functions downstream of the VEGF/MEF2C pathway in endothelial cells and may play an important role in tumor angiogenesis.

  5. The essential role of FKBP38 in regulating phosphatase of regenerating liver 3 (PRL-3) protein stability.

    Choi, Myung-Suk; Min, Sang-Hyun; Jung, Haiyoung; Lee, Ju Dong; Lee, Tae Ho; Lee, Heung Kyu; Yoo, Ook-Joon


    The phosphatase of regenerating liver-3 (PRL-3) is a member of protein tyrosine phosphatases and whose deregulation is implicated in tumorigenesis and metastasis of many cancers. However, the underlying mechanism by which PRL-3 is regulated is not known. In this study, we identified the peptidyl prolyl cis/trans isomerase FK506-binding protein 38 (FKBP38) as an interacting protein of PRL-3 using a yeast two-hybrid system. FKBP38 specifically binds to PRL-3 in vivo, and that the N-terminal region of FKBP38 is crucial for binding with PRL-3. FKBP38 overexpression reduces endogenous PRL-3 expression levels, whereas the depletion of FKBP38 by siRNA increases the level of PRL-3 protein. Moreover, FKBP38 promotes degradation of endogenous PRL-3 protein via protein-proteasome pathway. Furthermore, FKBP38 suppresses PRL-3-mediated p53 activity and cell proliferation. These results demonstrate that FKBP38 is a novel regulator of the oncogenic protein PRL-3 abundance and that alteration in the stability of PRL-3 can have a dramatic impact on cell proliferation. Thus, FKBP38 may play a critical role in tumorigenesis.

  6. TRH (thyrotropin-releasing hormone) and BAY K 8644 synergistically stimulate prolactin release but not sup 45 Ca sup 2+ uptake

    Pachter, J.A.; Law, G.J.; Dannies, P.S. (Yale Univ. School of Medicine, New Haven, CT (USA))


    Thyrotropin-releasing hormone (TRH) and the Ca{sup 2+}-channel agonist BAY K 8644 each induced transient increases in prolactin secretion from primary cultures of rat anterior pituitary cells in perfusion. When BAY K 8644 was added after a TRH-induced secretory peak, the additional effect of BAY K 8644 on prolactin release was approximately twofold greater over a 30-min period than the effect of BAY K 8644 on previously untreated cells. TRH and BAY K 8644 were also synergistic when added in the opposite order or simultaneously. Substitution of other agents for BAY K 8644 revealed that only high K{sup +} was at least additive with TRH in stimulating prolactin secretion; treatment with TRH inhibited, rather than facilitated, subsequent stimulation of prolactin secretion by angiotensin II or the ionophore A23187. The cooperative effect was not specific for TRH because BAY K 8644 also acted synergistically with angiotensin II or 40 mM K{sup +}. In GH{sub 4}C{sub 1} cells, in which TRH and BAY K 8644 were also synergistic in releasing prolactin, measurements with the fluorescent indicator indo-1 showed that TRH and BAY K 8644 could each elevate cytosolic Ca{sup 2+} above the level stimulated by the other. Unexpectedly, TRH was found to inhibit BAY K 8644-stimulated {sup 45}Ca{sup 2+} uptake in both GH{sub 4}C{sub 1} and primary cultured cells. These results indicate that BAY K 8644 and TRH synergistically stimulate prolactin secretion by a mechanism other than a cooperative effect on the activity of dihydropyridine-sensitive Ca{sup 2+} channels.

  7. Profiles of circulating steroid hormones, gonadotropins, immunoreactive inhibin and prolactin during pregnancy in goats and immunolocalization of inhibin subunits, steroidogenic enzymes and prolactin in the corpus luteum and placenta.

    Kandiel, Mohamed M M; Watanabe, Gen; Sosa, Gamal A; Abou El-Roos, Mahmoud E A; Abdel-Ghaffar, Alaa E; Li, Jun Y; Manabe, Noboru; El Azab, Abd El Salam I; Taya, Kazuyoshi


    The current study was performed to follow up the circulating hormonal changes and to correlate the findings with the physiological activity of the corpus luteum (CL) and placenta during pregnancy in goats. Blood samples were collected weekly from five goats during pregnancy for measuring steroid and protein hormones. A gradual increase was observed in immunoreactive (ir-) inhibin, with maximal levels at the 17th week. The plasma concentrations of estradiol and prolactin (PRL) showed nearly similar patterns during pregnancy, where they declined to basal levels during the first 4 weeks post-breeding and then increased significantly, with the maximal concentration during late pregnancy. The plasma FSH and LH concentrations were maintained at basal levels throughout the gestation period. The plasma progesterone concentration abruptly increased in the first week post-breeding and remained at high values throughout the pregnancy period. Immunohistochemical localization of inhibin alpha, beta(A), beta(B) and steroidogenic enzymes cytochrome P450 aromatase, 3alpha-hydroxysteroid dehydrogenase (3betaHSD), cytochrome 17alpha-hydroxylase P450 and cholesterol side-chain cleavage cytochrome P450 in the cyclic and pregnant goat CL revealed positive immunoreactivity without affinity differences between the luteal and pregnancy stages. The placental syncytiotrophoblasts also showed positive staining, except for inhibin beta(A) and 3betaHSD. The giant binucleate cells of the placenta showed positive immunoreactions to PRL. These results suggest that the high concentrations of ir-inhibin, estradiol and PRL during late pregnancy are of placental origin and that the placenta may have a vital role in the maintenance of pregnancy, regulation of mammary growth and preparation for kidding and lactation in goats.

  8. Vasoinhibin, an N-terminal Prolactin Fragment, Directly Inhibits Cardiac Angiogenesis in Three-dimensional Heart Culture

    Nakajima, Ryojun; Nakamura, Eri; Harigaya, Toshio


    Vasoinhibins (Vi) are fragments of the growth hormone/prolactin (PRL) family and have antiangiogenic functions in many species. It is considered that Vi derived from PRL are involved in the pathogenesis of peripartum cardiomyopathy (PPCM). However, the pathogenic mechanism of PPCM, as well as heart angiogenesis, is not yet clear. Therefore, the aim of the present study is to clarify whether Vi act directly on angiogenesis inhibition in heart blood vessels. Endothelial cell viability was decreased by Vi treatment in a culture experiment. Furthermore, expression of proangiogenic genes, such as vascular endothelial growth factor, endothelial nitric oxide synthase, and VE-cadherin, were decreased. On the other hand, apoptotic factor gene, caspase 3, and inflammatory factor genes, tumor necrosis factor α and interleukin 6, were increased by Vi treatment. In three-dimensional left ventricular wall angiogenesis assay in mice, Vi treatment also inhibited cell migration, neovessel sprouting, and growth toward collagen gel. These data demonstrate that Vi treatment directly suppresses angiogenesis of the heart and support the hypothesis that Vi induce PPCM. PMID:28163696

  9. Kinetics of Phosphatase of Regenerating Liver-3 (PRL-3) Inhibition by Small-molecular Inhibitors


    Phosphatase of Regenerating Liver-3 (PRL-3) is a newly identified colorectal cancer metastasis-related protein,which isa 22 kDa non-classical protein tyrosine phosphatase with a C-terminal prenylation motif. In this study, the inhibition kinetics of protein tyrosine phosphatases (PTPs) by a fluorescent substrate, 6,8-difluoro-4-methylumbelliferyl phosphate (DiFMUP) was evaluated. PRL-3 exhibits classical Michaelis-Menten kinetics with a vmax value of the inhibitor magnolol can cause Km to increase, but does not alter the vmax value, which suggests the competitive inhibition of PRL-3. At the same time, it was found that DiFMUP is a more sensitive substrate for PRL-3 than para-nitrophenyl phosphate(pNPP) that is more frequently used at present. Furthermore, the method of screening for PTPs by the use of DiFMUP was developed, which studied the acceptance of DiFMUP by other PTPs.

  10. Individual variation in baseline and stress-induced corticosterone and prolactin levels predicts parental effort by nesting mourning doves

    Miller, David A.; Vleck, Carol M.; Otis, David L.


    Endocrine systems have an important mechanistic role in structuring life-history trade-offs. During breeding, individual variation in prolactin (PRL) and corticosterone (CORT) levels affects behavioral and physiological processes that drive trade-offs between reproduction and self-maintenance. We examined patterns in baseline (BL) and stress induced (SI; level following a standard capture-restraint protocol) levels of PRL and CORT for breeding mourning doves (Zenaida macroura). We determined whether the relationship of adult condition and parental effort to hormone levels in wild birds was consistent with life-history predictions. Both BL PRL and BL CORT level in adults were positively related to nestling weight at early nestling ages, consistent with the prediction of a positive relationship of hormone levels to current parental effort of adults and associated increased energy demand. Results are consistent with the two hormones acting together at baseline levels to limit negative effects of CORT on reproduction while maintaining beneficial effects such as increased foraging for nestling feeding. Our data did not support predictions that SI responses would vary in response to nestling or adult condition. The magnitude of CORT response in the parents to our capture-restraint protocol was negatively correlated with subsequent parental effort. Average nestling weights for adults with the highest SI CORT response were on average 10–15% lighter than expected for their age in follow-up visits after the stress event. Our results demonstrated a relationship between individual hormone levels and within population variation in parental effort and suggested that hormonal control plays an important role in structuring reproductive decisions for mourning doves.

  11. Individual variation in baseline and stress-induced corticosterone and prolactin levels predicts parental effort by nesting mourning doves.

    Miller, David A; Vleck, Carol M; Otis, David L


    Endocrine systems have an important mechanistic role in structuring life-history trade-offs. During breeding, individual variation in prolactin (PRL) and corticosterone (CORT) levels affects behavioral and physiological processes that drive trade-offs between reproduction and self-maintenance. We examined patterns in baseline (BL) and stress induced (SI; level following a standard capture-restraint protocol) levels of PRL and CORT for breeding mourning doves (Zenaida macroura). We determined whether the relationship of adult condition and parental effort to hormone levels in wild birds was consistent with life-history predictions. Both BL PRL and BL CORT level in adults were positively related to nestling weight at early nestling ages, consistent with the prediction of a positive relationship of hormone levels to current parental effort of adults and associated increased energy demand. Results are consistent with the two hormones acting together at baseline levels to limit negative effects of CORT on reproduction while maintaining beneficial effects such as increased foraging for nestling feeding. Our data did not support predictions that SI responses would vary in response to nestling or adult condition. The magnitude of CORT response in the parents to our capture-restraint protocol was negatively correlated with subsequent parental effort. Average nestling weights for adults with the highest SI CORT response were on average 10-15% lighter than expected for their age in follow-up visits after the stress event. Our results demonstrated a relationship between individual hormone levels and within population variation in parental effort and suggested that hormonal control plays an important role in structuring reproductive decisions for mourning doves.

  12. PRL S-030A Verification Survey at Former McClellan AFB, Sacramento, CA


    Consultative Letter 3. DATES COVERED (From – To) Oct 2012 – Feb 2013 4. TITLE AND SUBTITLE PRL S-030A Verification Survey at Former McClellan AFB ...verification survey from 23-25 Oct 12 at site PRL S-030A on former McClellan AFB , CA. This verification survey was conducted at the site after the...of Aerospace Medicine (USAFSAM), former McClellan AFB , radium-226, verification survey, final status survey, independent radiological assessment 16

  13. KCNN4 channels participate in the EMT induced by PRL-3 in colorectal cancer.

    Lai, Wei; Liu, Lu; Zeng, Yujie; Wu, Heng; Xu, Heyang; Chen, Shuang; Chu, Zhonghua


    Studies have shown that phosphatase of regenerating liver-3 (PRL-3) promotes the invasion, migration, and metastasis of human tumor cells by facilitating an epithelial-mesenchymal transition (EMT). However, the mechanism by which PRL-3 induces tumor cell EMT is unknown. Our previous research revealed that PRL-3 promotes LoVo cell proliferation by up-regulating KCNN4 channels. In the current study, we explored the mechanism by which PRL-3 mediates EMT. We demonstrated that PRL-3 induced the expression of KCNN4 channels, leading to EMT and the down-regulation of E-cadherin. Further studies revealed that KCNN4 channels increased intracellular calcium levels and activated components of cell signaling downstream of calcium, including CaM-kinase II and glycogen synthase kinase-3 beta (GSK-3 beta), which increased Snail expression. Inhibiting KCNN4 with siRNA and TRAM-34, a specific inhibitor, restored E-cadherin expression and inhibited Snail expression. These results implicated the up-regulation of KCNN4 channels in the PRL-3-mediated induction of EMT and promotion of cancer metastasis.

  14. PRL-3 disrupts epithelial architecture by altering the post-mitotic midbody position.

    Luján, Pablo; Varsano, Giulia; Rubio, Teresa; Hennrich, Marco L; Sachsenheimer, Timo; Gálvez-Santisteban, Manuel; Martín-Belmonte, Fernando; Gavin, Anne-Claude; Brügger, Britta; Köhn, Maja


    Disruption of epithelial architecture is a fundamental event during epithelial tumorigenesis. We show that the expression of the cancer-promoting phosphatase PRL-3 (PTP4A3), which is overexpressed in several epithelial cancers, in polarized epithelial MDCK and Caco2 cells leads to invasion and the formation of multiple ectopic, fully polarized lumens in cysts. Both processes disrupt epithelial architecture and are hallmarks of cancer. The pathological relevance of these findings is supported by the knockdown of endogenous PRL-3 in MCF-7 breast cancer cells grown in three-dimensional branched structures, showing the rescue from multiple-lumen- to single-lumen-containing branch ends. Mechanistically, it has been previously shown that ectopic lumens can arise from midbodies that have been mislocalized through the loss of mitotic spindle orientation or through the loss of asymmetric abscission. Here, we show that PRL-3 triggers ectopic lumen formation through midbody mispositioning without altering the spindle orientation or asymmetric abscission, instead, PRL-3 accelerates cytokinesis, suggesting that this process is an alternative new mechanism for ectopic lumen formation in MDCK cysts. The disruption of epithelial architecture by PRL-3 revealed here is a newly recognized mechanism for PRL-3-promoted cancer progression.

  15. Aggressive and malignant prolactin pituitary tumors: pathological diagnosis and patient management.

    Zemmoura, Ilyess; Wierinckx, Anne; Vasiljevic, Alexandre; Jan, Michel; Trouillas, Jacqueline; François, Patrick


    According to the World Health Organization classification of pituitary tumors, only tumors with systemic metastasis must be considered as carcinomas. Invasive tumors with multiple recurrences are only classified as aggressive tumors or "atypical adenomas". To illustrate the problems encountered in the pathological diagnosis of pituitary carcinoma and in patient management, we present two male patients operated on for an aggressive prolactin pituitary adenoma with and without metastasis. In case 1, 5 surgeries, 3 irradiations, increased doses of dopamine agonists, and trials of temozolomide and carboplatine-VP16 failed to control tumor progression and the appearance of metastases which lead to death 16 years after onset. In case 2, based on the initial diagnosis of an aggressive-invasive adenoma that was resistant to dopamine agonists, gamma-Knife irradiation was initially performed on the intra-cavernous remnant. Eight years after onset, the remnant remained stabilized and the plasma PRL normalized under dopamine agonist. From these 2 cases alongside other cases found in the literature, we propose that the association of certain clinical signs (male sex, dopamine-resistant hyperprolactinemia), radiological signs (invasive macro or giant tumor on MRI) and histological signs (angiogenesis, Ki-67 > 3%, p53 positive, mitoses >2 per high power field, vascular invasion, up-regulation of genes related to invasion and proliferation, and allelic loss of chromosome 11) might suggest aggressiveness and be suspicious of malignancy before the appearance of metastasis. The early detection of an aggressive phenotype of a prolactin pituitary tumor should permit the earlier establishment of the optimum therapeutic strategy associating surgery and radiotherapy to delay or inhibit metastasis.

  16. Hypothyroidism advances mammary involution in lactating rats through inhibition of PRL signaling and induction of LIF/STAT3 mRNAs.

    Campo Verde Arboccó, Fiorella; Sasso, Corina V; Actis, Esteban A; Carón, Rubén W; Hapon, María Belén; Jahn, Graciela A


    Thyroid diseases have deleterious effects on lactation, litter growth and survival, and hinder the suckling-induced hormone release, leading in the case of hyperthyroidism, to premature mammary involution. To determine the effects of hypothyroidism (HypoT) on late lactation, we analyzed the effect of chronic 6-propyl-2-thiouracil (PTU)-induced HypoT on mammary histology and the expression of members of the JAK/STAT/SOCS signaling pathway, milk proteins, prolactin (PRLR), estrogen (ER), progesterone (PR) and thyroid hormone (TR) receptors, markers of involution (such as stat3, lif, bcl2, BAX and PARP) on lactation (L) day 21. HypoT mothers showed increased histological markers of involution compared with control rats, such as adipose/epithelial ratio, inactive alveoli, picnotic nuclei and numerous detached apoptotic cells within the alveolar lumina. We also found decreased PRLR, β-casein and α-lactoalbumin mRNAs, but increased SOCS1, SOCS3, STAT3 and LIF mRNAs, suggesting a decrease in PRL signaling and induction of involution markers. Furthermore, Caspase-3 and 8 and PARP labeled cells and the expression of structural proteins such as β-Actin, α-Tubulin and Lamin B were increased, indicating the activation of apoptotic pathways and tissue remodelation. HypoT also increased PRA (mRNA and protein) and erβ and decreased erα mRNAs, and increased strongly TRα1, TRβ1, PRA and ERα protein levels. These results show that lactating HypoT rats have premature mammary involution, most probably induced by the inhibition of prolactin signaling along with the activation of the LIF-STAT3 pathway.

  17. Decreased prolactin levels reduce parental commitment, egg temperatures, and breeding success of incubating male Adélie penguins.

    Thierry, Anne-Mathilde; Brajon, Sophie; Massemin, Sylvie; Handrich, Yves; Chastel, Olivier; Raclot, Thierry


    Hormones regulate many aspects of an individual's phenotype, including various physiological and behavioral traits. Two hormones have been described as important players in the regulation of parental investment in birds: the glucocorticoid hormone corticosterone and prolactin, a pituitary hormone, widely involved in mediating parental behavior. In comparison with corticosterone, the role of prolactin on parental investment remains poorly documented, and most studies so far have been correlative. In this study, the effects of an experimental decrease of prolactin levels on the incubation behavior of a long-lived seabird species were assessed. Male Adélie penguins were treated with self-degradable bromocriptine pellets, inhibiting prolactin secretion. Filming and subsequent video analysis allowed the determination of a behavioral time budget for birds and their position on the nest, while dummy eggs recorded incubation parameters. Incubation duration and breeding success at hatching were also monitored. As expected, bromocriptine-treatment significantly decreased plasma prolactin levels, but did not affect corticosterone levels. The behavioral time budget of penguins was not affected by the treatment. However, treated birds spent significantly more time in an upright position on the nest. These birds also incubated their eggs at lower temperatures and turned their eggs more frequently than controls, resulting in a lengthened incubation period. Despite this, the treatment was insufficient to trigger nest desertion and eggs of treated birds still hatched, indicating that several endocrine signals are required for the induction of nest abandonment. We suggest that the decreased prolactin levels in treated birds offset their timeline of breeding, so that birds displayed behavior typical of early incubation.

  18. Involvement of phospholipase C and intracellular calcium signaling in the gonadotropin-releasing hormone regulation of prolactin release from lactotrophs of tilapia (Oreochromis mossambicus)

    Tipsmark, Christian Kølbæk; Weber, G M; Strom, C N


    pituitary gland from which a nearly pure population of PRL cells can be isolated, we examined whether GnRH might stimulate PRL release through an increase in phospholipase C (PLC), inositol triphosphate (IP3), and intracellular calcium (Ca(i)2+) signaling. Using Ca(i)2+ imaging and the calcium-sensitive dye...... fura-2, we found that chicken GnRH-II (cGnRH-II) induced a rapid dose-dependent increase in Ca(i)2+ in dispersed tilapia lactotrophs. The Ca(i)2+ signal was abolished by U-73122, an inhibitor of PLC-dependent phosphoinositide hydrolysis. Correspondingly, cGnRH-II-induced tPRL188 secretion was inhibited...... by U-73122, suggesting that activation of PLC mediates cGnRH-II's stimulatory effect on PRL secretion. Pretreatment with 8-(N,N-diethylamino)octyl-3,4,5-trimethoxybenzoate hydrochloride (TMB-8), an inhibitor of Ca2+ release from intracellular stores, impeded the effect of cGnRH-II on Ca(i)2...

  19. Prolactin in the Afrotheria: characterization of genes encoding prolactin in elephant (Loxodonta africana), hyrax (Procavia capensis) and tenrec (Echinops telfairi).

    Wallis, Michael


    Pituitary prolactin shows an episodic pattern of molecular evolution, with occasional short bursts of rapid change imposed on a generally rather slow evolutionary rate. In mammals, episodes of rapid change occurred in the evolution of primates, cetartiodactyls, rodents and the elephant. The bursts of rapid evolution in cetartiodactyls and rodents were followed by duplications of the prolactin gene that gave rise to large families of prolactin-related proteins including placental lactogens, while in primates the burst was followed by corresponding duplications of the related GH gene. The position in elephant is less clear. Extensive data relating to the genomic sequences of elephant and two additional members of the group Afrotheria are now available, and have been used here to characterize the prolactin genes in these species and explore whether additional prolactin-related genes are present. The results confirm the rapid evolution of elephant (Loxodonta africana) prolactin - the sequence of elephant prolactin is substantially different from that predicted for the ancestral placental mammal. Hyrax (Procavia capensis) prolactin is even more divergent but tenrec (Echinops telfairi) prolactin is strongly conserved. No evidence was obtained from searches of public databases for additional genes encoding prolactin-like proteins in any of these species. Detailed analysis of evolutionary rates, and other factors, indicates that the episode of rapid change in hyrax, and probably elephant, was adaptive, though the nature of the associated biological change(s) is not clear.

  20. Hypergravity effects on litter size, nursing activity, prolactin, TSH, T3, and T4 in the rat

    Megory, E.; Oyama, J.


    In a recent study of the effects of hypergravity (HG) on the reproductive system of the rat, it was found that the estrous cycle is perturbed in a pseudopregnancy-like pattern upon first exposure of animals to HG. This can be prevented by previous exposure to HG or by administration of bromergo cryptin. Adapted rats can mate and deliver in HG. However, little is known of the condition of the individual pregnant rat, fetuses, and newborn pups in this environment. There are also questions regarding the effects of HG on the number of fetuses, the mortality rate in different HG levels, and the effects on production and secretion of PRL and TSH. The present investigation is concerned with such questions, taking into account possible approaches to avoid or minimize the lethal effects of HG. The obtained results suggest that peripartum plasma PRL levels and thyroid hormone levels are critical for the survival of the litter.

  1. Genomic gain of the PRL-3 gene may represent poor prognosis of primary colorectal cancer, and associate with liver metastasis.

    Nakayama, N; Yamashita, K; Tanaka, T; Kawamata, H; Ooki, A; Sato, T; Nakamura, T; Watanabe, M


    PRL-3 genomic copy number is increased in colorectal cancer (CRC), and PRL-3 expression is closely associated with lymph node and liver metastasis of CRC. However, the clinical significance of PRL-3 genomic gain for CRC remains obscure. Here, PRL-3 genomic status in 109 primary CRC tumors and in 44 CRC tumors that had metastasized to the liver, was quantified using real time PCR. Association of PRL-3 genomic status with clinicopathological factors and prognosis was assessed in detail. PRL-3 genomic gain was identified in 31 primary CRC (27.4 %) and was more frequently seen in stage III than in stage II (p = 0.025). Among the clinicopathological factors assessed, PRL-3 genomic gain was significantly associated with poorly differentiated histology (p = 0.0039). Moreover, CRC patients with PRL-3 genomic gain exhibited poorer prognosis than those with no gain in stage II-IV CRC (p = 0.017). PRL-3 genomic gain was identified in 18 (41 %) of the liver metastasis tumors, and this frequency of gain was significantly increased as compared to that of the corresponding primary CRCs (11 %) (p = 0.001). Our findings suggested that PRL-3 genomic gain may represent an aggressive phenotype of primary CRC, and may associate with liver metastasis.

  2. The metastasis-promoting phosphatase PRL-3 shows activity toward phosphoinositides.

    McParland, Victoria; Varsano, Giulia; Li, Xun; Thornton, Janet; Baby, Jancy; Aravind, Ajay; Meyer, Christoph; Pavic, Karolina; Rios, Pablo; Köhn, Maja


    Phosphatase of regenerating liver 3 (PRL-3) is suggested as a biomarker and therapeutic target in several cancers. It has a well-established causative role in cancer metastasis. However, little is known about its natural substrates, pathways, and biological functions, and only a few protein substrates have been suggested so far. To improve our understanding of the substrate specificity and molecular determinants of PRL-3 activity, the wild-type (WT) protein, two supposedly catalytically inactive mutants D72A and C104S, and the reported hyperactive mutant A111S were tested in vitro for substrate specificity and activity toward phosphopeptides and phosphoinositides (PIPs), their structural stability, and their ability to promote cell migration using stable HEK293 cell lines. We discovered that WT PRL-3 does not dephosphorylate the tested phosphopeptides in vitro. However, as shown by two complementary biochemical assays, PRL-3 is active toward the phosphoinositide PI(4,5)P(2). Our experimental results substantiated by molecular docking studies suggest that PRL-3 is a phosphatidylinositol 5-phosphatase. The C104S variant was shown to be not only catalytically inactive but also structurally destabilized and unable to promote cell migration, whereas WT PRL-3 promotes cell migration. The D72A mutant is structurally stable and does not dephosphorylate the unnatural substrate 3-O-methylfluorescein phosphate (OMFP). However, we observed residual in vitro activity of D72A against PI(4,5)P(2), and in accordance with this, it exhibits the same cellular phenotype as WT PRL-3. Our analysis of the A111S variant shows that the hyperactivity toward the unnatural OMFP substrate is not apparent in dephosphorylation assays with phosphoinositides: the mutant is completely inactive against PIPs. We observed significant structural destabilization of this variant. The cellular phenotype of this mutant equals that of the catalytically inactive C104S mutant. These results provide a possible

  3. Epidermal growth factor receptor cross-talks with ligand-occupied estrogen receptor-α to modulate both lactotroph proliferation and prolactin gene expression

    Chen, Shenglin; Bangaru, Madhavi Latha Yadav; Sneade, Leighton; Dunckley, Joseph A.; Ben-Jonathan, Nira; Kansra, Sanjay


    Both estrogen (E2) and EGF regulate lactotrophs, and we recently demonstrated that EGF phosphorylates S118 on estrogen receptor-α (ERα) and requires ERα to stimulate prolactin (PRL) release. However, the interactions between ligand-occupied ERα and activated ErbB1 and its impact on lactotroph function are unknown. Using rat GH3 lactotrophs, we found that both E2 and EGF independently stimulated proliferation and PRL gene expression. Furthermore, their combination resulted in an enhanced stimulatory effect on both cell proliferation and PRL gene expression. Inhibitors of ER as well as ErbB1 blocked the combined effects of E2 and EGF. Pretreatment with UO126 abolished the combined effects, demonstrating Erk1/2 requirement. Although bidirectionality in ER-ErbB1 cross-talk is a well-accepted paradigm, interestingly in lactotrophs, ErbB1 kinase inhibitor failed to block the effect of E2 on proliferation and stimulation of PRL gene expression, suggesting that ER does not require ErbB1 to mediate its effects. Furthermore, E2 did not affect the ability of EGF to induce c-Fos expression or modulate AP-1 activity. However, both E2 and EGF combine to enhance S118 phosphorylation of ERα, leading to enhanced E2-mediated estrogen response element transactivation. Taken together, our results suggest that, in lactotrophs, activated ErbB1 phosphorylates ERα to enhance the stimulatory effect of E2, thereby providing the molecular basis by which EGF amplifies the response of E2. PMID:19470835

  4. Insulin-like growth factor 1 (IGF-1) regulates prolactin, growth hormone, and IGF-1 receptor expression in the pituitary gland of the gilthead sea bream Sparus aurata.

    Mohammed-Geba, Khaled; Martos-Sitcha, J A; Galal-Khallaf, A; Mancera, J M; Martínez-Rodríguez, G


    The role of insulin-like growth factor 1 (IGF-1) on regulation of growth hormone (GH) and prolactin (PRL) as well as the possible involvement of IGF-1 receptor subtype a (IGF-1Ra) mRNA was assessed in juvenile specimens of Sparus aurata. IGF-1Ra was successfully cloned, and active receptor domains were localized in its mRNA precursor. Also, phylogenetic analysis of the protein sequence indicated a closer proximity to IGF-1Ra isoform found in zebrafish and other teleosts, than to the isoform IGF-1Rb. The most abundant presence of IGF-1Ra mRNA was detected in white muscle, whereas head kidney showed the lowest gene expression among 24 different studied tissues. Pituitaries of juvenile specimens of S. aurata were incubated in vitro with different doses of IGF-1 (0, 1, 100, and 1000 ng mL(-1)) during a period of 10 h. Total RNA with a high quality could be obtained from these pituitaries. PRL mRNA expression significantly increased with increasing IGF-1 doses. Similarly, IGF-1Ra mRNA increased its expression in response to IGF-1. However, GH mRNA levels decreased in a dose-dependent manner after IGF-1 treatment. The contradictory responses of GH and PRL expressions to IGF-1 in our experiment are possibly mediated by IGF-1Ra presence on the somatotrophs and prolactotrophs. The increase in IGF-1Ra mRNA levels may be related to the proper activation of the PI3-K/Akt signal transduction pathways which are normally involved in GH and PRL regulation.

  5. Prolactin and aggression in women with fertility problems.

    Barry, J A; Moran, E; Parekh, H S; Morewood, T; Thomas, M; Hardiman, P J


    This study tested the hypothesis that women with higher prolactin feel more hostility, anger and aggression. A total of 66 women with moderate fertility problems were grouped into the 50% who had the highest and the 50% who had the lowest levels of prolactin. Levels of hostility, aggression and anger were compared. Women with higher prolactin levels did not report significantly increased hostility. After Bonferroni correction, women with lower prolactin showed non-significantly increased scores on two measures of state anger, and on a measure of trait temper. When comparing those with the highest and lowest 20% of prolactin levels, those with lower prolactin had non-significantly higher scores on trait temper and outward expression of anger, and non-significantly lower scores for control of anger. Although non-significant, these findings run counter to those of earlier studies on this topic. Implications for future research and patient care are discussed.

  6. Cysteamine depletes prolactin in young and old hyperprolactinemic rats

    Simpkins, J.W.; Estes, K.S.; Millard, W.J.; Sagar, S.M.; Martin, J.B.


    Studies were undertaken to evaluate the effects of cysteamine on serum and anterior pituitary concentrations of prolactin in hyperprolactinemic female rats. Serum prolactin was elevated in young (4 to 5 months old) rats by implantation of 17 beta-estradiol while 26- to 28-month-old rats were in constant estrus and exhibited an age-related hyperprolactinemia. At 4 h after treatment with cysteamine (90 mg/kg body wt) serum and anterior pituitary prolactin concentrations were reduced in young animals by 98 and 85%, respectively. In old constant-estrous rats, cysteamine reduced serum prolactin by 92% and anterior pituitary prolactin by 82%. In young pseudopregnant rats, cysteamine induced a prompt resumption of estrous cycles. These studies indicate that cysteamine is an effective depletor of serum and pituitary prolactin in hyperprolactinemic rats.

  7. Rankl Impairs Lactogenic Differentiation Through Inhibition of the Prolactin/Stat5 Pathway at Midgestation.

    Cordero, Alex; Pellegrini, Pasquale; Sanz-Moreno, Adrián; Trinidad, Eva M; Serra-Musach, Jordi; Deshpande, Chetan; Dougall, William C; Pujana, Miguel Angel; González-Suárez, Eva


    Prolactin and progesterone both orchestrate the proliferation and differentiation of the mammary gland during gestation. Differentiation of milk secreting alveoli depends on the presence of prolactin receptor, the downstream Jak2-Stat5 pathway and the transcription factor Elf5. A strict regulation of Rank signaling is essential for the differentiation of the mammary gland and in particular for alveolar commitment. Impaired alveologenesis and lactation failure are observed in both, knockout and Rank overexpressing mice; however, the underlying molecular mechanism responsible for these phenotypes remains largely unknown. Using genome-wide expression analyses and functional studies, we show here that Rankl (RL) exposure leads to impaired secretory differentiation of alveolar cells not only in MMTV-RANK but also in wild-type (WT) mammary acini. Conversely, pharmacological blockage of Rank signaling at midgestation in WT mice leads to precocious and exacerbated lactogenesis. Mechanistically, RL negatively regulates Stat5 phosphorylation and Elf5 expression at the onset of lactogenesis. Continuous RL exposure leads to the expansion of basal and bipotent cells in WT and MMTV-RANK acini. Overall, we demonstrate that enhanced Rank signaling impairs secretory differentiation during pregnancy by inhibition of the prolactin/p-Stat5 pathway.

  8. Decreased prolactin response to hypoglycaemia in patients with rheumatoid arthritis: correlation with disease activity.

    Eijsbouts, A.M.M.; Hoogen, F.H.J. van den; Laan, R.F.J.M.; Sweep, C.G.J.; Hermus, A.R.M.M.; Putte, L.B.A. van de


    OBJECTIVE: To compare basal and stimulated prolactin levels between patients with rheumatoid arthritis and healthy controls, and to assess the effects of antirheumatic treatment on prolactin concentrations. METHODS: Serum prolactin was assessed under basal conditions and during an insulin tolerance

  9. Reproduction and energy balance: the integrative role of prolactin

    T I Romantsova


    The physiological mechanisms controlling reproduction are closely linked to energy balance. In the recent years, accumulating evidence suggests that prolactin regulates metabolic functions, besides regulating breast development and stimulating milk formation. Hyperprolactinemia is associated with obesity and treatment with dopamine agonists results in weight loss. We discuss the integrated effects of prolactin in the metabolic control and reproductive function, the role of prolactin in the pa...

  10. Symptoms of hyperprolactinemia with normal serum prolactin: is treatment required?

    Deepti Verma


    Full Text Available Galactorrhea with menstrual abnormalities like oligomenorrhea or amenorrhea point towards a provisional diagnosis of increased serum prolactin levels or hyperprolactinemia. However, as the prolactin hormone is heterogeneous with two forms- the bioactive and the immunoactive forms, patients can have all the features of hyperprolactinemia with normal serum prolactin levels. [Int J Reprod Contracept Obstet Gynecol 2016; 5(6.000: 2041-2042

  11. The effects of immersion and exercise on prolactin during pregnancy.

    Katz, V L; McMurray, R; Turnbull, C D; Berry, M; Bowman, C; Cefalo, R C


    Prolactin is an important hormone during pregnancy, affecting mother, fetus, and amniotic fluid volume. Immersion is known to affect prolactin levels significantly. To determine the effect of immersion and exercise on the prolactin response during pregnancy, we examined serum prolactin levels at 15, 25, and 35 weeks' gestation and 10 weeks post partum. Twelve women completed 20 min land rest, 20 min immersion in 30 degrees C water to the xiphoid, and 20 min exercise in the water at 60% VO2max. Resting prolactin levels were 1.91 +/- 0.32, 4.55 +/- 0.5, and 5.85 +/- 0.27 nmol.l-1 +/- standard error of the mean at 15, 25, and 35 weeks' gestation, respectively. Postpartum lactating women had a resting mean prolactin level of 3.95 +/- 1.6 versus 0.22 +/- 0.4 nmol.l-1 in non-lactating women. Prolactin levels declined significantly during immersion even after correction for dilution by plasma volume shifts. The immersion response was inversely related to the duration of pregnancy with 29%, 22%, and 12% drops during 15-, 25- and 35-week trials, respectively. Compared to rest, exercise prolactin levels remained depressed during the 15th and 25th week trials. We hypothesize that immersion in water caused prolactin levels to decline.

  12. Study of Prolactin Level Changes of Patients with Hyperprolactinemia in Different Time Period%高泌乳素患者不同时间段泌乳素水平研究

    秦辛玲; 石青峰


    目的:探讨高泌乳素血症患者泌乳素水平在不同时间段的变化。方法使用电化学发光法、罗氏 E170全自动免疫分析仪测定124例高泌乳素(PRL>880 uIU/ml),女性患者在7:30AM,10:00AM及4:00PM不同时间段血浆泌乳素(PRL)水平,并根据经聚乙二醇(PEG)6000沉淀巨泌乳素后的 PRL回收率分成巨泌乳素组(回收率≤40%)、单泌乳素组(回收率>60%)、可疑泌乳素组(40%<回收率≤60%),同时检测45例正常对照组的PRL水平。结果高泌乳素组巨泌乳素阳性率(33.1%)与正常对照组中巨泌乳素阳性率(0.0%)比较,差异有统计学意义(χ2=17.8867,P<0.05),巨泌乳素组及单体泌乳素组经PEG处理前在10:00AM时间段的泌乳素浓度(1160±714 uIU/ml,885±801 uIU/ml)与7:30AM时间段的泌乳素浓度(1521±914 uIU/ml,1497±845 uIU/ml)差异均有统计学意义(t=1.993,4.46,P<0.05),巨泌乳素组及单体泌乳素组经PEG处理后在10:00AM时间段的泌乳素浓度(316±231 uIU/ml,766±611 uIU/ml)与7:30AM时间段的泌乳素浓度(488±394 uIU/ml,1235±912 uIU/ml)差异均有统计学意义(t=2.4114,3.6252,P<0.05),单泌乳素组4:00PM时间段处理前的泌乳素浓度(1033±911 uIU/ml)与7:30AM时间段处理前的泌乳素浓度(1497±845 uIU/ml)差异也有统计学意义(t=3.1686,P<0.05)。结论不同时间段泌乳素水平有变化,确定正确的采血时间,有助于临床对高泌乳素血症的诊断。%Objective To investigate prolactin(PRL)levels in patient with hyperprolactinemia in different period of time. Methods Used electrochemical luminescence method,Roche E170 automatic immune analyzer determination of detect 124 cases female patients of hyperprolactinemia (PRL>880 uIU/ml)at 7:30AM,10:00AM and 4:00PM respectivelye of plas-ma PRL level,and in accordance

  13. Effects of Prolactin and Lactation on A15 Dopamine Neurones in the Rostral Preoptic Area of Female Mice.

    Brown, R S E; Herbison, A E; Grattan, D R


    There are several distinct populations of dopamine neurones in the hypothalamus. Some of these, such as the A12 tuberoinfundibular dopamine neurones and the A14 periventricular dopamine neurones, are known to be regulated by the anterior pituitary hormone prolactin, whereas others, such as the A13 zona incerta dopaminergic neurones, are not. The present study aimed to investigate the role of prolactin in the regulation of a fourth population of hypothalamic dopamine neurones: the A15 dopamine population in the rostral hypothalamus. These neurones may play a role in the regulation of gonadotrophin-releasing hormone (GnRH) secretion, and we hypothesised that they might contribute to the suppression of GnRH release and infertility caused by hyperprolactinaemia. Under basal (low prolactin) conditions, only 8% of A15 dopamine neurones in the anteroventral periventricular nucleus (AVPV) of vehicle-treated dioestrous mice expressed phosphorylated signal transducer and activator of transcription 5 (pSTAT5), as labelled by immunohistochemistry. We have previously shown that this transcription factor can be used as an index of prolactin-receptor activation. Following acute prolactin administration, 35% of AVPV dopamine neurones co-expressed pSTAT5, whereas, during lactation, when endogenous prolactin levels are chronically elevated, 55% of AVPV dopamine neurones expressed pSTAT5. There was also a significant increase in dopamine turnover in the rostral hypothalamus, both in the diagonal band of Broca at the level of the organum vasculosum of the lamina terminalis and in the rostral preoptic area during lactation, with the 3,4-dihydroxyphenylacetic acid/dopamine ratio increasing from 0.28 ± 0.04 and 0.14 ± 0.01 in dioestrous mice to 0.82 ± 0.06 and 0.38 ± 0.03, respectively, in day 7 lactating mice. It is not yet known whether this change is driven by the hyperprolactinaemia of lactation, or another lactation-specific signal. These data demonstrate that the A15

  14. Prostate response to prolactin in sexually active male rats

    Garcia Luis I


    Full Text Available Abstract Background The prostate is a key gland in the sexual physiology of male mammals. Its sensitivity to steroid hormones is widely known, but its response to prolactin is still poorly known. Previous studies have shown a correlation between sexual behaviour, prolactin release and prostate physiology. Thus, here we used the sexual behaviour of male rats as a model for studying this correlation. Hence, we developed experimental paradigms to determine the influence of prolactin on sexual behaviour and prostate organization of male rats. Methods In addition to sexual behaviour recordings, we developed the ELISA procedure to quantify the serum level of prolactin, and the hematoxilin-eosin technique for analysis of the histological organization of the prostate. Also, different experimental manipulations were carried out; they included pituitary grafts, and haloperidol and ovine prolactin treatments. Data were analyzed with a One way ANOVA followed by post hoc Dunnet test if required. Results Data showed that male prolactin has a basal level with two peaks at the light-dark-light transitions. Consecutive ejaculations increased serum prolactin after the first ejaculation, which reached the highest level after the second, and started to decrease after the third ejaculation. These normal levels of prolactin did not induce any change at the prostate tissue. However, treatments for constant elevations of serum prolactin decreased sexual potency and increased the weight of the gland, the alveoli area and the epithelial cell height. Treatments for transient elevation of serum prolactin did not affect the sexual behaviour of males, but triggered these significant effects mainly at the ventral prostate. Conclusion The prostate is a sexual gland that responds to prolactin. Mating-induced prolactin release is required during sexual encounters to activate the epithelial cells in the gland. Here we saw a precise mechanism controlling the release of prolactin

  15. The tyrosine phosphatase PRL-1 localizes to the endoplasmic reticulum and the mitotic spindle and is required for normal mitosis.

    Wang, Jing; Kirby, Celeste E; Herbst, Ronald


    PRL-1 is one of three closely related protein-tyrosine phosphatases, which are characterized by C-terminal farnesylation. Recent reports suggest that they are involved in the regulation of cell proliferation and transformation. However, their biological function has not yet been determined. Here we show that PRL-1 mRNA is overexpressed in a number of human tumor cell lines, including HeLa cells. Using immunofluorescence we studied the subcellular localization of endogenous PRL-1, and our results demonstrate that PRL-1 exhibits cell cycle-dependent localization; in non-mitotic HeLa cells, PRL-1 is localized to the endoplasmic reticulum in a farnesylation-dependent manner. In mitotic cells PRL-1 relocalizes to the centrosomes and the spindle apparatus, proximal to the centrosomes, in a farnesylation-independent manner. Conditional expression of a catalytic domain mutant in HeLa cells results in a delay in the progression of cells through mitosis but has no effect on other phases of the cell cycle. Further, expression of a farnesylation site PRL-1 mutant results in mitotic defects, characterized by chromosomal bridges in anaphase and lagging chromosomes, without affecting spindle checkpoint function. Together, these results suggest that PRL-1 function is regulated in a cell cycle-dependent manner and implicate PRL-1 in regulating progression through mitosis, possibly by modulating spindle dynamics.

  16. Integrated analysis of global mRNA and protein expression data in HEK293 cells overexpressing PRL-1.

    Carmen M Dumaual

    Full Text Available BACKGROUND: The protein tyrosine phosphatase PRL-1 represents a putative oncogene with wide-ranging cellular effects. Overexpression of PRL-1 can promote cell proliferation, survival, migration, invasion, and metastasis, but the underlying mechanisms by which it influences these processes remain poorly understood. METHODOLOGY: To increase our comprehension of PRL-1 mediated signaling events, we employed transcriptional profiling (DNA microarray and proteomics (mass spectrometry to perform a thorough characterization of the global molecular changes in gene expression that occur in response to stable PRL-1 overexpression in a relevant model system (HEK293. PRINCIPAL FINDINGS: Overexpression of PRL-1 led to several significant changes in the mRNA and protein expression profiles of HEK293 cells. The differentially expressed gene set was highly enriched in genes involved in cytoskeletal remodeling, integrin-mediated cell-matrix adhesion, and RNA recognition and splicing. In particular, members of the Rho signaling pathway and molecules that converge on this pathway were heavily influenced by PRL-1 overexpression, supporting observations from previous studies that link PRL-1 to the Rho GTPase signaling network. In addition, several genes not previously associated with PRL-1 were found to be significantly altered by its expression. Most notable among these were Filamin A, RhoGDIα, SPARC, hnRNPH2, and PRDX2. CONCLUSIONS AND SIGNIFICANCE: This systems-level approach sheds new light on the molecular networks underlying PRL-1 action and presents several novel directions for future, hypothesis-based studies.

  17. Peripartal progesterone and prolactin have little effect on the rapid transport of immunoglobulin G into colostrum of dairy cows.

    Gross, J J; Kessler, E C; Bjerre-Harpoth, V; Dechow, C; Baumrucker, C R; Bruckmaier, R M


    Colostrum formation and lactogenesis in the mammary gland and the timing of parturition are regulated by endocrine signals. Changes in progesterone (P4) and prolactin (PRL) are considered key events that inhibit colostrum formation, trigger parturition, and signal the onset of lactation. The goal of our study was to determine if colostrum yield and composition and immunoglobulin transfer are affected by prepartum milking relative to the decrease in P4, peak of PRL, or occurrence of parturition. Twenty-three multiparous cows were randomly assigned to 1 of 2 groups: (1) control with first milking at 4h postcalving (CON, n=11), and (2) treatment group with first milking approximately 1d before calving and second milking at 4h after parturition (APM, n=12). Colostrum yields were recorded and proportional samples were analyzed for immunoglobulin G (IgG) concentration. Blood plasma samples for the analyses of P4 and PRL were collected 3 times daily at 8-h intervals for 4d prepartum and again taken at 4h after parturition. Total colostrum mass of APM cows was higher than that of CON cows. Immunoglobulin G concentration and protein content did not differ between antepartum milking in APM cows and postpartum milking in CON cows. Colostrum IgG concentration and protein content in APM cows at the postpartum milking were lower compared with the IgG concentration established at the prepartum (APM) and postpartum milkings of CON cows. Immunoglobulin G mass did not differ in first and second colostrum collection in APM cows but was lower compared with that of CON cows. The sum of IgG mass in APM cows (prepartum + postpartum collections) did not differ from that of CON cows. Lactose and fat in milk (concentration and mass) increased from first to second milking in APM cows. Total mass of lactose and fat in APM cows (prepartum + postpartum collections) was greater compared with that of CON cows. The finding that the time of milking relative to parturition, P4 decrease, and PRL peak

  18. Heat stress abatement during the dry period influences prolactin signaling in lymphocytes Heat stress abatement during the dry period influences prolactin signaling in lymphocytes

    Heat stress perturbs PRL release and affects dairy cow lactational performance and immune cell function. We hypothesized that greater PRL concentration in plasma of heat-stressed cows would decrease expression of PRL-R mRNA and increase mRNA expression of suppressors of cytokine signaling (SOCS) in ...

  19. 蛋白酪氨酸磷酸酶PRL-3在乳腺癌中表达及意义%Expression and significance of protein tyrosine phosphatase PRL-3 in breast cancer

    班振英; 曾宪旭; 焦艳; 党秋红; 楚天骄; 雷冬梅; 王玉萍


    Objective To study the expression of protein tyrosine phosphatase PRL-3 in breast cancer and in adjacent mammary gland tissue. Methods The expression of PRL-3 was detected in 60 paraffin-embedded specimens of breast cancer and 50 copies of atypical hyperplasia mammary tissue with immunohistochemcal stain and RT-PCR. The relationship between PRL-3 expression and clinicopathological features was analyzed. Results The positive expression rate of PRL-3 p