Induction of mammary tumors in rat by intraperitoneal injection of NMU: histopathology and estral cycle influence.

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Rivera, E S; Andrade, N; Martin, G; Melito, G; Cricco, G; Mohamad, N; Davio, C; Caro, R; Bergoc, R M

1994-11-11

In order to obtain an experimental model we induced mammary tumors in female Sprague-Dawley rats. The carcinogen N-nitroso-N-methylurea (NMU) was injected intraperitoneally (i.p.) at doses of 50 mg/kg body weight when animals were 50, 80 and 110 days old. Tumor sizes were measured with a caliper and their growth parameters and histopathological properties were tested. For 100 rats, 88.4% of developed lesions were ductal carcinomas, histologically classified as 52.8% cribiform variety, 30.6% solid carcinoma. Metastases in liver, spleen and lung were present. Other primary tumors were detected with low incidence. The influence of the rat estrous cycle during the first exposure to intraperitoneal NMU injection was studied. The latency period in estrus, proestrus and diestrus was 82 +/- 15, 77 +/- 18 and 79 +/- 18 days, respectively. Tumor incidence was significantly higher in estrus (95.2%) than proestrus (71.4%) or diestrus (77.4), (P rats.

Plasticity of Signaling by Spinal Estrogen Receptor α, κ-Opioid Receptor, and Metabotropic Glutamate Receptors over the Rat Reproductive Cycle Regulates Spinal Endomorphin 2 Antinociception: Relevance of Endogenous-Biased Agonism.

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Liu, Nai-Jiang; Murugaiyan, Vijaya; Storman, Emiliya M; Schnell, Stephen A; Kumar, Arjun; Wessendorf, Martin W; Gintzler, Alan R

2017-11-15

We previously showed that intrathecal application of endomorphin 2 [EM2; the highly specific endogenous μ-opioid receptor (MOR) ligand] induces antinociception that varies with stage of the rat estrous cycle: minimal during diestrus and prominent during proestrus. Earlier studies, however, did not identify proestrus-activated signaling strategies that enable spinal EM2 antinociception. We now report that in female rats, increased spinal dynorphin release and κ-opioid receptor (KOR) signaling, as well as the emergence of glutamate-activated metabotropic glutamate receptor 1 (mGluR 1 ) signaling, are critical to the transition from an EM2 nonresponsive state (during diestrus) to an analgesically responsive state (during proestrus). Differential signaling by mGluR 1 , depending on its activation by membrane estrogen receptor α (mERα; during diestrus) versus glutamate (during proestrus), concomitant with the ebb and flow of spinal dynorphin/KOR signaling, functions as a switch, preventing or promoting, respectively, spinal EM2 antinociception. Importantly, EM2 and glutamate-containing varicosities appose spinal neurons that express MOR along with mGluRs and mERα, suggesting that signaling mechanisms regulating analgesic effectiveness of intrathecally applied EM2 also pertain to endogenous EM2. Regulation of spinal EM2 antinociception by both the nature of the endogenous mGluR 1 activator (i.e., endogenous biased agonism at mGluR 1 ) and changes in spinal dynorphin/KOR signaling represent a novel mechanism for modulating analgesic responsiveness to endogenous EM2 (and perhaps other opioids). This points the way for developing noncanonical pharmacological approaches to pain management by harnessing endogenous opioids for pain relief. SIGNIFICANCE STATEMENT The current prescription opioid abuse epidemic underscores the urgency to develop alternative pharmacotherapies for managing pain. We find that the magnitude of spinal endomorphin 2 (EM2) antinociception not only

Insulin binding characteristics in canine muscle tissue: effects of the estrous cycle phases

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Álan G. Pöppl

Full Text Available Abstract: Hormonal fluctuations during the different estrous cycle are a well-recognized cause of insulin resistance in bitches, and little is known about insulin receptor binding or post-binding defects associated with insulin resistance in dogs. To evaluate insulin binding characteristics in muscle tissue of bitches during the estrous cycle, 17 owned bitches were used in the study (six in anestrus, five in estrus, and six in diestrus. An intravenous glucose tolerance test (IVGTT was performed in all patients by means of injection of 1mL/kg of a glucose 50% solution (500mg/kg, with blood sample collection for glucose determination at 0, 3, 5, 7, 15, 30, 45 and 60 minutes after glucose infusion. Muscle samples, taken after spaying surgery, were immediately frozen in liquid nitrogen and then stored at -80 ºC until the membranes were prepared by sequential centrifugation after being homogenized. For binding studies, membranes were incubated in the presence of 20,000cpm of human 125I-insulin and in increasing concentrations of unlabeled human regular insulin for cold saturation. The IVGTT showed no differences among bitches during the estrous cycle regarding baseline glycemia or glycemic response after glucose infusion. Two insulin binding sites - high-affinity and low-affinity ones - were detected by Scatchard analysis, and significant statistical differences were observed in the dissociation constant (Kd1 and maximum binding capacity (Bmax1 of the high-affinity binding sites. The Kd1 for the anestrus group (6.54±2.77nM/mg of protein was smaller (P<0.001 than for the estrus (28.54±6.94nM/mg of protein and diestrus (15.56±3.88nM/mg of protein groups. Bmax1 in the estrus (0.83±0.42nM/mg of protein and diestrus (1.24±0.24nM/mg of protein groups were also higher (P<0.001 than the values observed in anestrus (0.35±0.06nM/mg of protein. These results indicate modulation of insulin binding characteristics during different phases of the estrous

[Activity of the hypophyseal-thyroid gland system in relation to the funcitonal state of the sex glands. Report I].

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Babichev, V N; Samsonova, V M

1975-01-01

Experiments were conducted on intact female rats; it was revealed that the content of protein-bound iodine (PBI) in the blood depended on the stage of the estral cycle. It was decreased at the metestrus and diestrus stages. Castration produced an even greater reduction in the blood PBI content. The blood PBI content proved to elevate in administration of estradiol dipropionate (EDP) to castrated rats. The TSH content in the hypophysis increased at the metestrus and diestrus stages and decreased at the proestrus and estrus stages. The relationship was reverse in the case with the blood TTH content. Castration was followed by a marked increase in the TSH content in the hypophysis accompanied by a reduction in the blood hormone level. The TSH concentration in the hypophysis decreased and in the blood increased under the effect of EDP in castrated animals. The data obtained indicated that the interrelationship between the thyroid gland and the sex glands was realized at the level of the hypophysis, and possibly, of the hypothalamus.

Induction of canine deciduoma in some reproductive stages with the different condition of corpora lutea.

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Nomura, K

1997-03-01

Bitches were examined to see whether canine deciduoma could be induced at some reproductive stages with the different conditions of corpora lutea by inserting a silk suture into the uterine lumen. The bitches stimulated in the early and middle stages of diestrus or in unilateral pregnancy corresponding to these diestrous stages formed deciduoma at a high induction rate, however, no difference in the strength of decidual reaction between the pregnant and diestrous stages was recognized. On the other hand, no reaction could be seen in bitches in late diestrus, the late stage of unilateral pregnancy or the post partum repair phase in which stromal decidual cells similar to those of the rodentia can be seen. In already implanted uteri, however, no deciduoma was formed in the interplacental areas. Even though the corpora lutea were functional, new additional stimulations were not accepted at the interplacental area in which the uterine horn had already been influenced by fertilized ova. From these results, it was suggested that in the dog as well as the rodentia, the endometrium has to be under the influence of functional corpora lutea in order to form deciduoma.

Immuno-histochemical localization of LH-RH during different phases of estrus cycle of rat, with reference to the preoptic and arcuate neurons, and the ependymal cells.

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Naik, D V

1976-10-06

Immunohistochemical localization of luteinizing hormone-releasing hormone (LH-RH), during different phases of the estrus cycle, in the preoptic, suprachiasmatic and arcuate nuclei, and in the OVLT of rats, with special emphasis on the ependymal cells, was studied by light, fluorescent and electron microscopy, by using rabbit anti serum to synthetic LH-RH. The LH-RH neurons in the above mentioned areas, were very active during late diestrus and early proestrus phases. Specialized ependymal cells bordering the 3rd ventricle also showed varied LH-RH positive reaction during different phases of the estrus cycle. Immunofluorescent studies showed cyclic variations in the LH-RH material in the CSF of the preoptic and infundibular recesses, as well as in the 3rd ventricle near OVLT, in that, it was maximum during late diestrus and early proestrus phases. Immediately after this, the LH-RH late proestrus was reached. We have also observed that during the proestrus phase, as the LH-RH material started declining in the CSF, it had started building up in the specialized ependyma. Estrus, metaestrus and early diestrus phases showed very weak immunofluorescent LH-RH material in the lumen of the infundibular recess and in the specialized ependyma. Our immuno-electron microscopic observations showed pleomorphic LH-RH granules in the specialized ependyma during late kiestrus and proestrus phases. All these observations lead us to believe that LH-RH is not synthesized in the ependymal cells,but is phagocytosed from the CSF of the 3rd ventricle by the specialized ependyma, which transports it to the ME portal system. In males, the fluorescent LH-RH material did not show any noticeable changes. With the present and previous work,it is concluded that the neurons in differentnuclei synthesize LH-RH and transport it to the ME portal system,primarily through the nerve fibers and secondarily by the ventricular route. It is also suggested that the ependymal transport of LH-RH to the ME

Comparative occurrence of diabetes in canine, feline, and few wild animals and their association with pancreatic diseases and ketoacidosis with therapeutic approach

OpenAIRE

Kamal Niaz; Faheem Maqbool; Fazlullah Khan; Fatima Ismail Hassan; Saeideh Momtaz; Mohammad Abdollahi

2018-01-01

Diabetes mellitus (DM) is a chronic metabolic disorder in which blood glucose level raises that can result in severe complications. However, the incidence increased mostly by obesity, pregnancy, persistent corpus luteum, and diestrus phase in humans and animals. This review has focused on addressing the possible understanding and pathogenesis of spontaneous DM in canine, feline, and few wild animals. Furthermore, pancreatic associated disorders, diabetic ketoacidosis, hormonal and drug intera...

Light, electron microscopic and immunohistochemical study of the effect of low-dose aspirin during the proestrus phase on rat endometrium in the preimplantation period.

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Ateş, Utku; Baka, Meral; Turgut, Mehmet; Uyanikgil, Yiğit; Ulker, Sibel; Yilmaz, Ozlem; Tavmergen, Erol; Yurtseven, Mine

2007-04-01

To evaluate structural alterations in rat endometrium at preimplantation following treatment with aspirin beginning from proestrus by light microscopy, electron microscopy and immunohistochemical techniques. Twenty rats were divided into control (n = 10) and experimental (n = 10) groups. Experimental rats were treated with low-dose aspirin daily (2 mg/kg/day) during estrus, beginning from the proestrus phase, mated at end of cycle and treated with aspirin. Untreated pregnant rats were the control group. Rats in both groups were sacrificed at the 84th pregnancy hour; the uterus was rapidly removed and dissected free of surrounding adipose tissue. Uteri specimens from nonpregnant rats were transferred into fixative solution and processed for light, electron microscopic and immunohistochemical study. Light and electron microscopy of endometrium from control rats conformed to mid-diestrus phase; endometrial histology of the aspirin-treated group conformed to late diestrus phase. The endometrial layer was significantly thicker in the aspirin-treated group compared to the untreated control group (p <0.001). No significant difference was found in vessel number between groups. Staining with alphaV integrin was more dense in the aspirin-treated group. Based on histologic findings, we suggest low-dose aspirin has positive effects on preparing endometrium before implantation.

Ovarian matrix metalloproteinases are differentially regulated during the estrous cycle but not during short photoperiod induced regression in Siberian hamsters (Phodopus sungorus

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Vrooman Lisa A

2010-06-01

Full Text Available Abstract Background Matrix metalloproteinases (MMPs are implicated as mediators for ovarian remodeling events, and are involved with ovarian recrudescence during seasonal breeding cycles in Siberian hamsters. However, involvement of these proteases as the photoinhibited ovary undergoes atrophy and regression had not been assessed. We hypothesized that 1 MMPs and their tissue inhibitors, the TIMPs would be present and differentially regulated during the normal estrous cycle in Siberian hamsters, and that 2 MMP/TIMP mRNA and protein levels would increase as inhibitory photoperiod induced ovarian degeneration. Methods MMP-2, -9, -14 and TIMP-1 and -2 mRNA and protein were examined in the stages of estrous (proestrus [P], estrus [E], diestrus I [DI], and diestrus II [DII] in Siberian hamsters, as well as after exposure to 3, 6, 9, and 12 weeks of inhibitory short photoperiod (SD. Results MMP-9 exhibited a 1.6-1.8 fold decrease in mRNA expression in DII (p Conclusions Although MMPs appear to be involved in the normal ovarian estrus cycle at the protein level in hamsters, those examined in the present study are unlikely to be key players in the slow atrophy of tissue as seen in Siberian hamster ovarian regression.

The use of infrared thermography to detect the stages of estrus cycle and ovulation time in anatolian shepherd dogs

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Kemal Tuna Olğaç; Ergun Akçay; Beste Çil; Burak Mehmet Uçar; Ali Daşkın

2017-01-01

Abstract Background The aim of the study is to evaluate the effectiveness of thermographic monitoring, using the temperature changes of perianal and perivulvar areas for the determination of estrus in Anatolian Shepherd bitches. Fifteen bitches were used in the study. Blood and vaginal smear samples were collected and thermographic monitoring of perianal and perivulvar areas were carried out starting from proestrus to early diestrus. Also, external signs of estrus were investigated. Smear sam...

Gonadal Steroids: Effects on Excitability of Hippocampal Pyramidal Cells

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Teyler, Timothy J.; Vardaris, Richard M.; Lewis, Deborah; Rawitch, Allen B.

1980-08-01

Electrophysiological field potentials from hippocampal slices of rat brain show sex-linked differences in response to 1 × 10-10M concentrations of estradiol and testosterone added to the incubation medium. Slices from male rats show increased excitability to estradiol and not to testosterone. Slices from female rats are not affected by estradiol, but slices from female rats in diestrus show increased excitability in response to testosterone whereas slices from females in proestrus show decreased excitability.

C/EBPβ Isoforms Expression in the Rat Brain during the Estrous Cycle

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Valeria Hansberg-Pastor

2015-01-01

Full Text Available The CCAAT/enhancer-binding protein beta (C/EBPβ is a transcription factor expressed in different areas of the brain that regulates the expression of several genes involved in cell differentiation and proliferation. This protein has three isoforms (LAP1, LAP2, and LIP with different transcription activation potential. The role of female sex hormones in the expression pattern of C/EBPβ isoforms in the rat brain has not yet been described. In this study we demonstrate by western blot that the expression of the three C/EBPβ isoforms changes in different brain areas during the estrous cycle. In the cerebellum, LAP2 content diminished on diestrus and proestrus and LIP content diminished on proestrus and estrus days. In the prefrontal cortex, LIP content was higher on proestrus and estrus days. In the hippocampus, LAP isoforms presented a switch on diestrus day, since LAP1 content was the highest while that of LAP2 was the lowest. The LAP2 isoform was the most abundant one in all the three brain areas. The LAP/LIP ratio changed throughout the cycle and was tissue specific. These results suggest that C/EBPβ isoforms expression changes in a tissue-specific manner in the rat brain due to the changes in sex steroid hormone levels presented during the estrous cycle.

Voluntary Exercise Improves Estrous Cyclicity in Prenatally Androgenized Female Mice Despite Programming Decreased Voluntary Exercise: Implications for Polycystic Ovary Syndrome (PCOS).

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Homa, Lori D; Burger, Laura L; Cuttitta, Ashley J; Michele, Daniel E; Moenter, Suzanne M

2015-12-01

Prenatal androgen (PNA) exposure in mice produces a phenotype resembling lean polycystic ovary syndrome. We studied effects of voluntary exercise on metabolic and reproductive parameters in PNA vs vehicle (VEH)-treated mice. Mice (8 wk of age) were housed individually and estrous cycles monitored. At 10 weeks of age, mice were divided into groups (PNA, PNA-run, VEH, VEH-run, n = 8-9/group); those in the running groups received wheels allowing voluntary running. Unexpectedly, PNA mice ran less distance than VEH mice; ovariectomy eliminated this difference. In ovary-intact mice, there was no difference in glucose tolerance, lower limb muscle fiber types, weight, or body composition among groups after 16 weeks of running, although some mitochondrial proteins were mildly up-regulated by exercise in PNA mice. Before running, estrous cycles in PNA mice were disrupted with most days in diestrus. There was no change in cycles during weeks 1-6 of running (10-15 wk of age). In contrast, from weeks 11 to 16 of running, cycles in PNA mice improved with more days in proestrus and estrus and fewer in diestrus. PNA programs reduced voluntary exercise, perhaps mediated in part by ovarian secretions. Exercise without weight loss improved estrous cycles, which if translated could be important for fertility in and counseling of lean women with polycystic ovary syndrome.

Histomorfometria e função tireoidiana no ciclo estral da rata

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Serakides, R.; Nunes, V.A; Nascimento, E.F.; Serra, G.V.

2002-01-01

The influence of the estrous cycle on the thyroid gland was studied. Twenty one five-to-seven-month-old Wistar female rats were divided according to the stage of the estrous cycle in two groups: metaestrus-diestrus and proestrus-estrus. After gross inspection, the thyroids were weighed, sampled, and processed for staining with hematoxilyn-eosin. Seric concentrations of total T4, free T4, total T3, TSH, progesterone, and estradiol were measured. The values of estradiol were significantly highe...

Determinação das fases do ciclo estral em ratas: considerações úteis

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MARCONDES, F. K.; BIANCHI, F. J.; TANNO, A. P.

2002-01-01

The short length of the estrous cycle of rats makes them ideal for investigation of changes occurring during the reproductive cycle. The estrous cycle lasts four days and is characterized as: proestrus, estrus, metestrus and diestrus, which may be determined according to the cell types observed in the vaginal smear. Since the collection of vaginal secretion and the use of stained material generally takes some time, the aim of the present work was to provide researchers with some helpful consi...

Sensorimotor-correlated discharge recorded from ensembles of cerebellar Purkinje cells varies across the estrous cycle of the rat.

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Smith, S S

1995-09-01

1. In the present study, locomotor-correlated activity of cerebellar Purkinje cells, recorded using arrays of microwires chronically implanted in adult female rats, was examined across estrous-cycle-associated fluctuations in endogenous sex steroids. Ongoing studies from this laboratory have shown that systemic and local administration of the sex steroid 17 beta-estradiol (E2) augments excitatory responses of cerebellar Purkinje cells to iontophoretically applied glutamate, recorded in vivo from anesthetized female rats. In addition, this steroid potentiated discharge correlated with limb movement. For the present study, extracellular single-unit activity was recorded from as many as 5-11 Purkinje cells simultaneously during treadmill locomotion paradigms. Motor modulation of activity was recorded across three to five consecutive estrous cycles from behaviorally identified cohorts of neurons to test the hypothesis that fluctuations in endogenous sex steroids alter motor modulation of Purkinje cell discharge. 2. Locomotor-associated discharge correlated with treadmill locomotion was increased by a mean of 47% on proestrus, when E2 levels are elevated, relative to diestrus 1. These changes in discharge rate during treadmill locomotion were of significantly greater magnitude than corresponding cyclic alterations in discharge during stationary periods. 3. Correlations with the circadian cycle were also significant, because peak levels of locomotor-associated discharge on the night of behavioral estrus, following elevations in circulating E2, were on average 67% greater than corresponding discharge recorded during the light (proestrus). 4. Alterations in the step cycle were also observed across the estrous cycle: significant decreases in the duration of the flexion phase (by 265 ms, P estrus compared with diestrus. 5. When recorded on estrus, Purkinje cell discharge correlated with the stance or flexion phase of the step cycle was greater in magnitude and preceded the

Stable Density and Dynamics of Dendritic Spines of Cortical Neurons Across the Estrous Cycle While Expressing Differential Levels of Sensory-Evoked Plasticity

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Bailin H. Alexander

2018-03-01

Full Text Available Periodic oscillations of gonadal hormone levels during the estrous cycle exert effects on the female brain, impacting cognition and behavior. While previous research suggests that changes in hormone levels across the cycle affect dendritic spine dynamics in the hippocampus, little is known about the effects on cortical dendritic spines and previous studies showed contradictory results. In this in vivo imaging study, we investigated the impact of the estrous cycle on the density and dynamics of dendritic spines of pyramidal neurons in the primary somatosensory cortex of mice. We also examined if the induction of synaptic plasticity during proestrus, estrus, and metestrus/diestrus had differential effects on the degree of remodeling of synapses in this brain area. We used chronic two-photon excitation (2PE microscopy during steady-state conditions and after evoking synaptic plasticity by whisker stimulation at the different stages of the cycle. We imaged apical dendritic tufts of layer 5 pyramidal neurons of naturally cycling virgin young female mice. Spine density, turnover rate (TOR, survival fraction, morphology, and volume of mushroom spines remained unaltered across the estrous cycle, and the values of these parameters were comparable with those of young male mice. However, while whisker stimulation of female mice during proestrus and estrus resulted in increases in the TOR of spines (74.2 ± 14.9% and 75.1 ± 12.7% vs. baseline, respectively, sensory-evoked plasticity was significantly lower during metestrus/diestrus (32.3 ± 12.8%. In males, whisker stimulation produced 46.5 ± 20% increase in TOR compared with baseline—not significantly different from female mice at any stage of the cycle. These results indicate that, while steady-state density and dynamics of dendritic spines of layer 5 pyramidal neurons in the primary somatosensory cortex of female mice are constant during the estrous cycle, the susceptibility of these neurons to

Neonatal handling induces anovulatory estrous cycles in rats

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Gomes C.M.

1999-01-01

Full Text Available Since previous work has shown that stimulation early in life decreases sexual receptiveness as measured by the female lordosis quotient, we suggested that neonatal handling could affect the function of the hypothalamus-pituitary-gonadal axis. The effects of neonatal handling on the estrous cycle and ovulation were analyzed in adult rats. Two groups of animals were studied: intact (no manipulation, N = 10 and handled (N = 11. Pups were either handled daily for 1 min during the first 10 days of life or left undisturbed. At the age of 90 days, a vaginal smear was collected daily at 9:00 a.m. and analyzed for 29 days; at 9:00 a.m. on the day of estrus, animals were anesthetized with thiopental (40 mg/kg, ip, the ovaries were removed and the oviduct was dissected and squashed between 2 glass slides. The number of oocytes of both oviductal ampullae was counted under the microscope. The average numbers for each phase of the cycle (diestrus I, diestrus II, proestrus and estrus during the period analyzed were compared between the two groups. There were no significant differences between intact and handled females during any of the phases. However, the number of handled females that showed anovulatory cycles (8 out of 11 was significantly higher than in the intact group (none out of 10. Neonatal stimulation may affect not only the hypothalamus-pituitary-adrenal axis, as previously demonstrated, but also the hypothalamus-pituitary-gonadal axis in female rats.

A fase estrogênica altera a resposta do osso e do metabolismo mineral de ratas com hipertireoidismo? Does the estrogenic phase modify the bone and mineral metabolism response in rats under hyperthyroidism?

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N.M. Ocarino

2003-08-01

Full Text Available The effect of the estrogenic phase in the bone and in the mineral metabolism was studied in Wistar adult female rats kept under euthyroidism or hyperthyroidism for 60 days. The rats were divided, according to the stage of the estrous cycle, into four groups: 1 euthyroid (proestrus-estrus, 2 euthyroid (metaestrus-diestrus, 3 hyperthyroid (proestrus-estrus, and 4 hyperthyroid (metaestrus-diestrus. After 60 days the blood plasma was collected and the concentrations of free T4, estradiol, progesterone, calcium, phosphorus, and of alkaline phosphatase were determined. The bones (femur and tibia were analysed microscopically. Despite of the functional state of the thyroid, the levels of estrogen were significantly higher in the proestrus-estrus. The estrogenic phase increased the plasmatic concentration of calcium significantly in the euthyroid rats but it did not alter the levels of phosphorus and alkaline phosphatase. In the hyperthyroid state no significant differences in the plasmatic concentrations of calcium, phosphorus and alkaline phosphatase throughout the cycle were found. The phases of the cycle did not also influence the bone morphology in the euthyroid and hyperthyroid states. It was concluded that the estrogenic phase increases the plasmatic concentration of calcium, even without altering the bone morphology of the euthyroid rats. In addition the estrogenic phase does not increase the plasmatic calcium and it does not modify the response of the bone as well as of the mineral metabolism under effect of the hyperthyroidism.

Perfil de glicosaminoglicanos sulfatados no útero de camundongas durante o ciclo estral Profile of sulphated glycosaminoglycans content in the murine uterus during the different phases of the estrous cycle

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Regina Célia Teixeira Gomes

2007-06-01

Full Text Available OBJETIVOS: Quantificar glicosaminoglicanos sulfatados (GAGs no útero de camundongas durante o ciclo estral. MÉTODOS: Utilizaram-se quatro grupos de camundongas virgens com 100 dias de idade (n= 10 cada conforme a fase ciclo estral: proestro, estro, metaestro e diestro. Amostras da porção média dos cornos uterinos foram preparadas para observação em microscopia de luz (H/E e Alcian blue + PAS. Os GAGs foram extraídos e caracterizados por eletroforese em gel de agarose. Os dados foram analisados pelo teste t de Student não pareado. RESULTADOS: À microscopia de luz, os GAGs sulfatados apresentam-se em todas as camadas do útero, em especial no endométrio, entre as fibras colágenas, na membrana basal e ao redor dos fibroblastos. A análise bioquímica mostrou haver dermatam sulfato (DS, condroitim sulfato (CS e heparam sulfato (HS durante todas as fases do ciclo estral. Não houve separação eletroforética clara entre DS e CS, de modo que estes dois GAGs foram considerados em conjunto (DS+CS (proestro = 0,854 ± 0,192; estro = 1,073 ± 0,254; metaestro = 1,003 ± 0,255; e diestro = 0,632 ± 0,443 µg/mg. Os resultados de HS foram: proestro = 0,092 ± 0,097; estro = 0,180 ± 0,141; metaestro = 0,091 ± 0,046; e diestro = 0,233 ± 0,147 µg/mg. A concentração DS+CS apresentou-se maior no estro (ação estrogênica e a do HS no diestro (ação progestagênica. CONCLUSÃO: Os GAGs no útero de camundongas sofrem alterações durante as fases do ciclo estral, refletindo o constante processo de renovação, sendo modulados pelos hormônios sexuais.OBJECTIVE: Identification and quantitation of sulphated glycosaminoglycans (GAGs in the uterus of female mice during the estrous cycle. METHODS: Four groups (n = 10 each of virgin, 100-day old female mice were assembled according to the estrous cycle phase: proestrus, estrus, metaestrus and diestrus. Samples of the median portion of uterine horns were processed for light microscopy examination (H

Estrogen levels regulate the subcellular distribution of phosphorylated Akt in hippocampal CA1 dendrites.

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Znamensky, Vladimir; Akama, Keith T; McEwen, Bruce S; Milner, Teresa A

2003-03-15

In addition to genomic pathways, estrogens may regulate gene expression by activating specific signal transduction pathways, such as that involving phosphatidylinositol 3-kinase (PI3-K) and the subsequent phosphorylation of Akt (protein kinase B). The Akt pathway regulates various cellular events, including the initiation of protein synthesis. Our previous studies showed that synaptogenesis in hippocampal CA1 pyramidal cell dendritic spines is highest when brain estrogen levels are highest. To address the role of Akt in this process, the subcellular distribution of phosphorylated Akt immunoreactivity (pAkt-I) in the hippocampus of female rats across the estrous cycle and male rats was analyzed by light microscopy (LM) and electron microscopy (EM). By LM, the density of pAkt-I in stratum radiatum of CA1 was significantly higher in proestrus rats (or in estrogen-supplemented ovariectomized females) compared with diestrus, estrus, or male rats. By EM, pAkt-I was found throughout the shafts and in select spines of stratum radiatum dendrites. Quantitative ultrastructural analysis identifying pAkt-I with immunogold particles revealed that proestrus rats compared with diestrus, estrus, and male rats contained significantly higher pAkt-I associated with (1) dendritic spines (both cytoplasm and plasmalemma), (2) spine apparati located within 0.1 microm of dendritic spine bases, (3) endoplasmic reticula and polyribosomes in the cytoplasm of dendritic shafts, and (4) the plasmalemma of dendritic shafts. These findings suggest that estrogens may regulate spine formation in CA1 pyramidal neurons via Akt-mediated signaling events.

Factors affecting gestation duration in the bitch.

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Eilts, Bruce E; Davidson, Autumn P; Hosgood, Giselle; Paccamonti, Dale L; Baker, David G

2005-07-15

A retrospective analysis was performed to determine the effects of age, breed, parity, and litter size on the duration of gestation in the bitch. Bitches at two locations were monitored from breeding to whelping. A total of 764 litters whelped from 308 bitches (36 large hounds, 34 Golden Retrievers, 23 German Shepherd Dogs (GSD), and 215 Labrador Retrievers). By breed, the number of whelpings was 152, 72, 58, and 482 for the hounds, Golden Retrievers, German Shepherd Dogs, and Labrador Retrievers, respectively. Whelping was predicted to be 57 d from the first day of cytologic diestrus in the hounds or 65 d from the initial progesterone rise in the other breeds. The average gestation duration (calculated as 8 d prior to Day 1 of cytologic diestrus in hounds or measured from the initial progesterone rise in other breeds) by breed (days +/- S.D.) was 66.0 +/- 2.8, 64.7 +/- 1.5, 63.6 +/- 2.1, and 62.9 +/- 1.3 for the hounds, Golden Retrievers, German Shepherd Dogs, and Labrador Retrievers, respectively. The relationship of age, breed, parity, and litter size with the difference in gestation duration was evaluated using log linear modeling. Age or parity had no effect on gestation duration. Compared to Labrador Retrievers, the German Shepherd Dogs, Golden Retrievers and hounds were more likely to have a longer gestation duration; three, four and nearly eight times as likely, respectively. Bitches whelping four or fewer pups were significantly more likely to have a longer gestation duration than those whelping five or more pups; the prolongation averaging 1 d.

Sex and age differences in the antidepressant-like effect of fluoxetine in the forced swim test.

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Fernández-Guasti, Alonso; Olivares-Nazario, Maribel; Reyes, Rebeca; Martínez-Mota, Lucía

2017-01-01

This study compared in males and females of three representative ages: young adults (3-5months old), middle-aged (12-15months old) and senescent (23-25months old) the antidepressant-like effect of fluoxetine (FLX, 5.0 and 10mg/kg) in the forced swim test (FST). Intact (non gonadectomized) rats were evaluated. Young adult females were chosen in proestrus/estrus or in metestrus/diestrus, while middle-aged and senescent females were selected in metestrus/diestrus. Locomotion and motor coordination were also recorded. Under basal conditions (without FLX), young adult and middle-aged females showed less immobility than males. This sex difference disappeared at senescence because males diminished their levels of immobility. Thus, senescent males showed lower immobility than middle-aged and young males. FLX (5 and 10mg/kg) produced similar actions in young females irrespective of their estrous cycle phase, therefore, these subgroups were pooled in a single one. Young adult and middle aged females clearly responded to 5 and 10mg/kg of FLX with a reduction in immobility, while young adult and middle-aged males only did to 10mg/kg. In senescent females 10mg/kg FLX reduced immobility. Remarkably, in senescent males this FLX dose did not produce an antidepressant-like effect. FLX marginally affected locomotion; however, at its highest dose (10mg/kg), and only in senescent males, interfered with motor coordination tested in the rotarod. These data show that sex and aging influence behavioral despair without treatment and after FLX. Copyright © 2016 Elsevier Inc. All rights reserved.

The effects of estrus cycle on drug metabolism in the rat.

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Brandstetter, Y; Kaplanski, J; Leibson, V; Ben-Zvi, Z

1986-01-01

The effect of the female rat estral cycle on microsomal drug metabolism in-vivo and in-vitro has been studied. Two microsomal enzymes, aminopyrine-N-demethylase and aniline hydroxylase showed a greater specific activity (p less than 0.01) in the diestrus phase of the estral cycle while the oxidative enzyme aryl hydrocarbon hydroxylase and the conjugative enzyme, glucuronyl transferase, were not affected. In vivo studies which included theophylline and antipyrine metabolism, and hexobarbital sleeping times showed no difference between the different phases of the estral cycle. Conflicting evidence about the effect of steroid sex hormones on hepatic drug metabolism is discussed.

Plasma concentration of progesterone and 17β-estradiol of black-rumped agouti (Dasyprocta prymnolopha) during the estrous cycle

International Nuclear Information System (INIS)

Guimaraes, Diva Anelie; Ramos, Rosemar Luz; Ohashi, Otavio Mitio; Garcia, Gary Wayne; Gomes Vale, William

2011-01-01

The hormonal profile of progesterone and 17 β-estradiol has been evaluated during the estrous cycle of the agouti (Dasyprocta prymnolopha). The hormones were analyzed by radioimmunoassay. Blood samples were collected without sedation twice a week. The concentrations of progesterone were as follows: proestrus 0.78±0.39 ng/ml, estrus 2.83±2.34 ng/ml, metestrus 1.49±1.24 ng/ml, diestrus 3.71±1.48 ng/ml. An increase in the progesterone level was observed during a period of 24 h in the estrous phase. The average 17 β-estradiol levels were as follows: proestrus 2 030.98±961.00 pg/ml, estrus 1 910.56±650.54 pg/ml, metestrus 1 724.83±767.28 pg/ml, diestrus 1 939.94±725.29 pg/ml. The current results have suggested that the progesterone plasma concentration during the estrous cycle in the agouti has a similar increasing, stabilizing and decreasing pattern, as in domestic mammals. Agoutis have two phases of follicular development, as two periods of 17β-estradiol peaks were observed, the first one in the metestrus and the second during the proestrus. Spontaneous ovulation seems to occur after the progesterone peak, indicating that this hormone has been associated with the ovulatory process. A more detailed investigation is needed for better understanding of how progesterone influenced ovulation. Studies on the involvement of progesterone in follicular rupture can be carried out, using steroid biosynthesis inhibitors and observing the effect of this hormone on ovarian activity of proteolytic enzymes in the follicular wall. (author)

Estradiol increases the Bax/Bcl-2 ratio and induces apoptosis in the anterior pituitary gland.

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Zaldivar, Verónica; Magri, María Laura; Zárate, Sandra; Jaita, Gabriela; Eijo, Guadalupe; Radl, Daniela; Ferraris, Jimena; Pisera, Daniel; Seilicovich, Adriana

2009-01-01

Estrogens are recognized as acting as modulators of pituitary cell renewal, sensitizing cells to mitogenic and apoptotic signals, thus participating in anterior pituitary homeostasis during the estrous cycle. The balance of pro- and antiapoptotic proteins of the Bcl-2 family is known to regulate cell survival and apoptosis. In order to understand the mechanisms underlying apoptosis during the estrous cycle, we evaluated the expression of the proapoptotic protein Bax and the antiapoptotic proteins Bcl-2 and Bcl-xL in the anterior pituitary gland in cycling female rats as well as the influence of estradiol on the expression of these proteins in anterior pituitary cells of ovariectomized rats. As determined by Western blot, the expression of Bax was higher in anterior pituitary glands from rats at proestrus than at diestrus I, Bcl-2 protein levels showed no difference and Bcl-xL expression was lower, thus increasing the Bax/Bcl-2 ratio at proestrus. Assessed by annexin V binding and flow cytometry, the percentage of apoptotic anterior pituitary cells was higher in rats at proestrus than at diestrus I. Chronic estrogen treatment in ovariectomized rats enhanced the Bax/Bcl-2 ratio and induced apoptosis. Moreover, incubation of cultured anterior pituitary cells from ovariectomized rats with 17beta-estradiol for 24 h increased the Bax/Bcl-2 ratio, decreased Bcl-xL expression and induced apoptosis. Our results demonstrate that estradiol increases the ratio between proapoptotic and antiapoptotic proteins of the Bcl-2 family. This effect could participate in the sensitizing action of estrogens to proapoptotic stimuli and therefore be involved in the high apoptotic rate observed at proestrus in the anterior pituitary gland.

High-fat diet with stress impaired islets' insulin secretion by reducing plasma estradiol and pancreatic GLUT2 protein levels in rats' proestrus phase.

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Salimi, M; Zardooz, H; Khodagholi, F; Rostamkhani, F; Shaerzadeh, F

2016-10-01

This study was conducted to determine whether two estrus phases (proestrus and diestrus) in female rats may influence the metabolic response to a high-fat diet and/or stress, focusing on pancreatic insulin secretion and content. Animals were divided into high-fat and normal diet groups, then each group was subdivided into stress and non-stress groups, and finally, each one of these was divided into proestrus and diestrus subgroups. At the end of high-fat diet treatment, foot-shock stress was applied to the animals. Then, blood samples were taken to measure plasma factors. Finally, the pancreas was removed for determination of glucose transporter 2 (GLUT2) protein levels and assessment of insulin content and secretion of the isolated islets. In the normal and high-fat diet groups, stress increased plasma corticosterone concentration in both phases. In both study phases, high-fat diet consumption decreased estradiol and increased leptin plasma levels. In the high-fat diet group in response to high glucose concentration, a reduction in insulin secretion was observed in the proestrus phase compared with the same phase in the normal diet group in the presence and absence of stress. Also, high-fat diet decreased the insulin content of islets in the proestrus phase compared with the normal diet. High-fat diet and/or stress caused a reduction in islet GLUT2 protein levels in both phases. In conclusion, it seems possible that high-fat diet alone or combined with foot-shock, predispose female rats to impaired insulin secretion, at least in part, by interfering with estradiol levels in the proestrus phase and decreasing pancreatic GLUT2 protein levels.

Collagen and Glycosaminoglycan Profiles in the Canine Cervix during Different Stages of the Estrous Cycle and in Open- and Closed-Cervix Pyometra

Science.gov (United States)

LINHARATTANARUKSA, Pichanun; SRISUWATANASAGUL, Sayamon; PONGLOWHAPAN, Suppawiwat; KHALID, Muhammad; CHATDARONG, Kaywalee

2013-01-01

ABSTRACT The extracellular matrix of the cervix that comprises collagen, elastin, proteoglycans and glycosaminoglycans (GAGs) is thought to have an essential role in cervical relaxation. This study investigated the proportion of collagen and smooth muscle as well as the GAGs in cervices obtained from healthy bitches at different stages of the estrous cycle and bitches with open- and closed-cervix pyometra. Cervices were collected after ovariohysterectomy. The proportion of collagen to smooth muscle was determined using Masson’s trichrome staining. Alcian blue staining was used to evaluate the relative distribution of cervical GAGs. The proportion of cervical collagen relative to smooth muscle was higher at estrus compared to anestrus (P≤0.05). It was also higher (P≤0.05) in bitches with open- compared to those with closed-cervix pyometra. Overall, hyaluronan (HA) was the predominant GAG in the canine cervix. In the luminal epithelium, the staining intensity for HA was stronger in estrus than in anestrus (P≤0.05), but not in diestrus (P>0.05). On the contrary, the intensity for the combined keratan sulfate (KS) and heparan sulfate (HS) was stronger in anestrus than in estrus and diestrus (P≤0.05). In bitches with pyometra, the staining intensity of the stroma for KS and HS was weaker in open- compared to closed-cervix pyometra (P≤0.05). Collectively, the different profiles of collagen and GAG suggest that the metabolism of both collagen and GAGs in the canine cervix is associated with hormonal statuses during the estrous cycle and cervical patency of bitches with pathological uterine conditions, such as pyometra. PMID:24152876

Evaluation of von Willebrand factor during pregnancy, lactation and oestrous cycle in bitches affected and unaffected by von Willebrand disease.

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Mattoso, C R S; Takahira, R K; Beier, S L; Araujo, J P; Corrente, J E

2013-06-01

Plasmatic concentrations of von Willebrand Factor (vWF) increase during pregnancy in humans and dogs; however the mechanism of such increase is still not well defined. The aims of this study were: (i) to evaluate changes in vWF concentration during pregnancy and during the subsequent oestrous cycle in bitches affected and unaffected by von Willebrand Disease (vWD); (ii) to correlate the vWF levels and cortisol levels in both groups. Seven vWD affected (GI) and nine unaffected (GII) bitches were used. The animals were assessed during pregnancy, parturition, lactation and non-gestational oestrous cycle in 11 moments (Pregnancy 1, Pregnancy 2, Parturition, Lactation 1, Lactation 2, Lactation 3, Anestrus, Proestrus, Oestrus, Diestrus 1, and Diestrus 2). The following tests were performed; measurement of von Willebrand factor antigen (vWF:Ag), albumin and cortisol. In both groups, vWF concentration remained stable during the non-gestational oestrous cycle, but increased during pregnancy, with the highest value observed at parturition. Increases of 70% and 124% in vWF were seen in GI and GII, respectively, compared to anestrus. No correlation was found between vWF and cortisol. Values of vWF:Ag changed during pregnancy, with a peak at parturition, both in vWD affected and unaffected animals. Values of vWF were not altered in the different phases of the oestrous cycle following pregnancy in both groups. Evaluation of vWF during pregnancy can cause false negative results for vWD, but assessment can be performed at any point in the oestrous cycle of non-pregnant bitches. © 2012 Blackwell Verlag GmbH.

Kappa opioid receptors in rat spinal cord vary across the estrous cycle.

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Chang, P C; Aicher, S A; Drake, C T

2000-04-07

Kappa opioid receptors (KORs) were immunocytochemically localized in the lumbosacral spinal cord of female rats in different stages of the estrous cycle to examine the influence of hormonal status on receptor density. KOR labeling was primarily in fine processes and a few neuronal cell bodies in the superficial dorsal horn and the dorsolateral funiculus. Quantitative light microscopic densitometry of the superficial dorsal horn revealed that rats in diestrus had significantly lower KOR densities than those in proestrus or estrus. This suggests that female reproductive hormones regulate spinal KOR levels, which may contribute to variations in analgesic effectiveness of KOR agonists across the estrous cycle.

A study on the effects of the estrous cycle on uterine fluid and blood serum immunoglobulin G (IgG content in the cow

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Sayed Mortaza Alavi-Shoushtari

2014-06-01

Full Text Available To investigate the IgG content and its variations in uterine fluid (UF during the estrous cycle of the cow and to compare them with those of the blood serum (S, six pairs of serum and UF samples for each phase of the cycle selected out of 240 bovine genital tracts and blood samples were collected from Urmia abattoir. The UF samples were collected by gentle scraping of the endometrium using a curette after uterine incision and their IgG content and those of the serum were measured by single radial immuno-diffusion (SRID assay. Serum IgG values (Mean ± SEM were generally higher than the UF values throughout the cycle except for di-estrus (S: 38.50 ± 0.90, UF: 51.60 ± 2.10 mg mL-1, in which the highest values were observed in UF samples. In met-estrus the difference was not significant (S: 34.80 ± 1.80mg mL-1, UF: 30.80 ± 5.20 mg mL-1, however, in estrus the mean UF IgG value (12.50 ± 1.10 mg mL-1 was lower than that of the serum (31.30 ± 1.20 mg mL-1. In pro-estrus, the lowest values (S: 27.80 ± 1.30 mg mL-1, UF: 9.10 ± 1.50 mg mL-1 were obtained. The results showed a lower IgG values in the bovine UF than those of the serum in the follicular phase of the cycle, while in di-estrus the UF IgG content was the highest, suggesting some IgG production in the uterus at this phase.

Crybb2 deficiency impairs fertility in female mice

International Nuclear Information System (INIS)

Gao, Qian; Sun, Li-Li; Xiang, Fen-Fen; Gao, Li; Jia, Yin; Zhang, Jian-Rong; Tao, Hai-Bo; Zhang, Jun-Jie; Li, Wen-Jie

2014-01-01

Highlights: • Crybb2 deletion impaired female fertility. • Crybb2 deletion dramatically affected the production of reproduction-related hormones and hormone response. • Crybb2 deletion impaired follicular development and inhibited the proliferation of granulosa cells. • Crybb2 deletion promoted follicular atresia and apoptosis in granulosa cells. - Abstract: Beta-B2-crystallin (CRYBB2), encoded by Crybb2 gene, is a major protein in the mammalian eye lens that plays an important role in maintaining the transparency of the ocular lens. However, CRYBB2 also plays important roles in many extra-lenticular tissues and organs such as the retina, brain and testis. Our previous studies demonstrated that male Crybb2 deficient (Crybb2 −/− ) mice have reduced fertility compared with wild-type (WT) mice, while female Crybb2 −/− mice exhibited reduced ovary weights and shorter estrous cycle percentages. Here we specifically investigated the role of CRYBB2 in the female reproductive system. Our studies revealed that ovaries from female Crybb2 −/− mice exhibited significantly reduced numbers of primordial, secondary and pre-ovulatory follicles when compared with WT mice, while the rate of atretic follicles was also increased. Additionally, fewer eggs were collected from the oviduct of Crybb2 −/− female mice after superovulation. Estrogen levels were higher in the metestrus and diestrus cycles of female Crybb2 −/− mice, while progesterone levels were lower in diestrus cycles. Furthermore, the expression of survival and cell cycle genes, Bcl-2, Cdk4 and Ccnd2, were significantly decreased in granulosa cells isolated from female Crybb2 −/− mice, consistent with the predominant expression of CRYBB2 in ovarian granulosa cells. Our results reveal a critical role for CRYBB2 in female fertility and specific effects on the proliferation and survival status of ovarian granulosa cells

Sex differences in hippocampal estradiol-induced N-methyl-D-aspartic acid binding and ultrastructural localization of estrogen receptor-alpha.

Science.gov (United States)

Romeo, Russell D; McCarthy, J Brian; Wang, Athena; Milner, Teresa A; McEwen, Bruce S

2005-01-01

Estradiol increases dendritic spine density and synaptogenesis in the CA1 region of the female hippocampus. This effect is specific to females, as estradiol-treated males fail to show increases in hippocampal spine density. Estradiol-induced spinogenesis in the female is dependent upon upregulation of the N-methyl-D-aspartic acid (NMDA) receptor as well as on non-nuclear estrogen receptors (ER), including those found in dendrites. Thus, in the male, the inability of estradiol to induce spinogenesis may be related to a failure of estradiol to increase hippocampal NMDA receptors as well as a paucity of dendritic ER. In the first experiment, we sought to investigate this possibility by assessing NMDA receptor binding, using [(3)H]-glutamate autoradiography, in estradiol-treated males and females. We found that while estradiol increases NMDA binding in gonadectomized females, estradiol fails to modulate NMDA binding in gonadectomized males. To further investigate sex differences in the hippocampus, we conducted a second separate, but related, ultrastructural study in which we quantified ERalpha-immunoreactivity (ERalpha-ir) in neuronal profiles in the CA1 region of the hippocampus in intact males and females in diestrus and proestrus. Consistent with previous reports in the female, we found ERalpha-ir in several extranuclear sites including dendrites, spines, terminals and axons. Statistical analyses revealed that females in proestrus had a 114.3% increase in ERalpha-labeled dendritic spines compared to females in diestrus and intact males. Taken together, these studies suggest that both the ability of estrogen to increase NMDA binding in the hippocampus and the presence of ERalpha in dendritic spines may contribute to the observed sex difference in estradiol-induced hippocampal spinogenesis. Copyright (c) 2005 S. Karger AG, Basel.

Crybb2 deficiency impairs fertility in female mice

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Gao, Qian [Department of Laboratory Diagnosis, Changhai Hospital, Second Military Medical University, Shanghai 200433 (China); Sun, Li-Li [Aviation Medical Evaluation and Training Center of Airforce in Dalian, Dalian, Liaoning Province 116013 (China); Department of Laboratory Diagnosis, Changhai Hospital, Second Military Medical University, Shanghai 200433 (China); Xiang, Fen-Fen [Department of Laboratory Medicine, Putuo Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai 200062 (China); Gao, Li [Department of Pathology, Changhai Hospital, Second Military Medical University, Shanghai 200433 (China); Jia, Yin; Zhang, Jian-Rong; Tao, Hai-Bo [Department of Laboratory Diagnosis, Changhai Hospital, Second Military Medical University, Shanghai 200433 (China); Zhang, Jun-Jie, E-mail: zhangjj910@163.com [Department of Obstetrics and Gynecology, Changhai Hospital, Second Military Medical University, Shanghai 200433 (China); Li, Wen-Jie, E-mail: wenjieli@pku.org.cn [Department of Laboratory Diagnosis, Changhai Hospital, Second Military Medical University, Shanghai 200433 (China)

2014-10-10

Highlights: • Crybb2 deletion impaired female fertility. • Crybb2 deletion dramatically affected the production of reproduction-related hormones and hormone response. • Crybb2 deletion impaired follicular development and inhibited the proliferation of granulosa cells. • Crybb2 deletion promoted follicular atresia and apoptosis in granulosa cells. - Abstract: Beta-B2-crystallin (CRYBB2), encoded by Crybb2 gene, is a major protein in the mammalian eye lens that plays an important role in maintaining the transparency of the ocular lens. However, CRYBB2 also plays important roles in many extra-lenticular tissues and organs such as the retina, brain and testis. Our previous studies demonstrated that male Crybb2 deficient (Crybb2{sup −/−}) mice have reduced fertility compared with wild-type (WT) mice, while female Crybb2{sup −/−} mice exhibited reduced ovary weights and shorter estrous cycle percentages. Here we specifically investigated the role of CRYBB2 in the female reproductive system. Our studies revealed that ovaries from female Crybb2{sup −/−} mice exhibited significantly reduced numbers of primordial, secondary and pre-ovulatory follicles when compared with WT mice, while the rate of atretic follicles was also increased. Additionally, fewer eggs were collected from the oviduct of Crybb2{sup −/−} female mice after superovulation. Estrogen levels were higher in the metestrus and diestrus cycles of female Crybb2{sup −/−} mice, while progesterone levels were lower in diestrus cycles. Furthermore, the expression of survival and cell cycle genes, Bcl-2, Cdk4 and Ccnd2, were significantly decreased in granulosa cells isolated from female Crybb2{sup −/−} mice, consistent with the predominant expression of CRYBB2 in ovarian granulosa cells. Our results reveal a critical role for CRYBB2 in female fertility and specific effects on the proliferation and survival status of ovarian granulosa cells.

Ovarian cycle-linked plasticity of δ-GABAA receptor subunits in hippocampal interneurons affects γ oscillations in vivo

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Albert Miklos Barth

2014-08-01

Full Text Available GABAA receptors containing δ subunits (δ-GABAARs are GABA-gated ion channels with extra- and perisynaptic localization, strong sensitivity to neurosteroids (NS, and a high degree of plasticity. In selective brain regions they are expressed on specific principal cells and interneurons (INs, and generate a tonic conductance that controls neuronal excitability and oscillations. Plasticity of δ-GABAARs in principal cells has been described during states of altered NS synthesis including acute stress, puberty, ovarian cycle, pregnancy and the postpartum period, with direct consequences on neuronal excitability and network dynamics. The defining network events implicated in cognitive function, memory formation and encoding are γ oscillations (30-120 Hz, a well-timed loop of excitation and inhibition between principal cells and PV-expressing INs (PV+INs. The δ-GABAARs of INs can modify γ oscillations, and a lower expression of δ-GABAARs on INs during pregnancy alters γ frequency recorded in vitro. The ovarian cycle is another physiological event with large fluctuations in NS levels and δ-GABAARs. Stages of the cycle are paralleled by swings in memory performance, cognitive function, and mood in both humans and rodents. Here we show δ-GABAARs changes during the mouse ovarian cycle in hippocampal cell types, with enhanced expression during diestrus in principal cells and specific INs. The plasticity of δ-GABAARs on PV-INs decreases the magnitude of γ oscillations continuously recorded in area CA1 throughout several days in vivo during diestrus and increases it during estrus. Such recurring changes in γ magnitude were not observed in non-cycling wild-type (WT females, cycling females lacking δ-GABAARs only on PV-INs (PV-Gabrd-/-, and in male mice during a time course equivalent to the ovarian cycle. Our findings may explain the impaired memory and cognitive performance experienced by women with premenstrual syndrome (PMS or premenstrual

Estrous cycle affects the neurochemical and neurobehavioral profile of carvacrol-treated female rats

International Nuclear Information System (INIS)

Trabace, L.; Zotti, M.; Morgese, M.G.; Tucci, P.; Colaianna, M.; Schiavone, S.; Avato, P.; Cuomo, V.

2011-01-01

Carvacrol is the major constituent of essential oils from aromatic plants. It showed antimicrobial, anticancer and antioxidant properties. Although it was approved for food use and included in the chemical flavorings list, no indication on its safety has been estimated. Since the use of plant extracts is relatively high among women, aim of this study was to evaluate carvacrol effects on female physiology and endocrine profiles by using female rats in proestrus and diestrus phases. Serotonin and metabolite tissue content in prefrontal cortex and nucleus accumbens, after carvacrol administration (0.15 and 0.45 g/kg p.o.), was measured. Drug effects in behavioral tests for alterations in motor activity, depression, anxiety-related behaviors and endocrine alterations were also investigated. While in proestrus carvacrol reduced serotonin and metabolite levels in both brain areas, no effects were observed in diestrus phase. Only in proestrus phase, carvacrol induced a depressive-like behavior in forced swimming test, without accompanying changes in ambulation. The improvement of performance in FST after subchronic treatment with fluoxetine (20 mg/kg) suggested a specific involvement of serotonergic system. No differences were found across the groups with regard to self-grooming behavior. Moreover, in proestrus phase, carvacrol reduced only estradiol levels without binding hypothalamic estradiol receptors. Our study showed an estrous-stage specific effect of carvacrol on depressive behaviors and endocrine parameters, involving serotonergic system. Given the wide carvacrol use not only as feed additive, but also as cosmetic essence and herbal remedy, our results suggest that an accurate investigation on the effects of its chronic exposure is warranted. - Highlights: → Carvacrol induced a depressive-like phenotype in rats, depending on ovarian cyclicity. → Carvacrol selectively reduced serotonin content in female rats in proestrus phase. → Carvacrol reduced serotonin

The Effect of a GnRH Agonist Injection or Progesterone Implant at Diestrus in Cryopreserved Embryo Transferred Cows

OpenAIRE

KIRBAŞ, Mesut; BÜLBÜL, Bülent; KÖSE, Mehmet; DURSUN, Şükrü; ÇOLAK, Mehmet

2014-01-01

In this study, the effect of a single dose of GnRH on d 13 or progesterone implant for 7 days between d 13 and 20 on plasma progesterone levels and pregnancy rates on cryopreserved embryo transferred cows were investigated. Synchronized 48 Brown Swiss recipient cows were used as animal material. Seven days after estrus detection, cryopreserved cattle embryos were transferred into recipients and cows were assigned randomly into three groups. In GnRH group (n=16), cows were intramuscularly inje...

Relationship between release of LH and incorporation of tritiated thymidine in the anterior pituitary gland of the castrated female rat.

Science.gov (United States)

Machiavelli, G A; Romano, M I; Burdman, J A

1985-06-01

Castration of female rats during diestrus increases the concentration of circulating LH from days 3 and the incorporation of 3H thymidine into pituitary DNA from day 5. Both effects are completely abolished by the administration of dihydrotestosterone. Although the i.v. injection of LHRH markedly enhances the concentration of LH in serum, it does not modify the incorporation of 3H thymidine into pituitary DNA. Castration might produce a maximal stimulation in 3H thymidine incorporation and a further stimulation of LH release with LHRH is unable to enhance the incorporation of the radioactive precursor. The results suggest a relationship between LH secretion and DNA synthesis in the pituitary gland of the rat.

Mast cell dynamics in the house rat (Rattus rattus) ovary during estrus cycle, pregnancy and lactation.

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Batth, B K; Parshad, R K

2000-02-01

The distribution of mast cells in various ovarian compartments was studied during different stages of the reproductive cycles in Rattus rattus. Two types of mast cell populations were recognized with light microscopy i.e., light purple and deep purple, the latter also includes deeply stained cells with extruded granules. Mast cells identified by electron microscopy showed the ultrastructural features during granule formation and release of their content. Significantly higher numbers of mast cells per unit area of ovary were seen at estrus and diestrus. Numbers of mast cells also remained high during pregnancy with possible involvement of mast cell products in vascularization of corpora lutea. A positive correlation existed between mast cell counts and embryo number during pregnancy. However, numbers of mast cells declined significantly after parturition.

Hypothalamic expression of KiSS-1 system and gonadotropin-releasing effects of kisspeptin in different reproductive states of the female Rat.

Science.gov (United States)

Roa, J; Vigo, E; Castellano, J M; Navarro, V M; Fernández-Fernández, R; Casanueva, F F; Dieguez, C; Aguilar, E; Pinilla, L; Tena-Sempere, M

2006-06-01

Kisspeptins, products of the KiSS-1 gene with ability to bind G protein-coupled receptor 54 (GPR54), have been recently identified as major gatekeepers of reproductive function with ability to potently activate the GnRH/LH axis. Yet, despite the diversity of functional states of the female gonadotropic axis, pharmacological characterization of this effect has been mostly conducted in pubertal animals or adult male rodents, whereas similar studies have not been thoroughly conducted in the adult female. In this work, we evaluated maximal LH and FSH secretory responses to kisspeptin-10, as well as changes in sensitivity and hypothalamic expression of KiSS-1 and GPR54 genes, in different physiological and experimental models in the adult female rat. Kisspeptin-10 (1 nmol, intracerebroventricular) was able to elicit robust LH bursts at all phases of the estrous cycle, with maximal responses at estrus; yet, in diestrus LH, responses to kisspeptin were detected at doses as low as 0.1 pmol. In contrast, high doses of kisspeptin only stimulated FSH secretion at diestrus. Removal of ovarian sex steroids did not blunt the ability of kisspeptin to further elicit stimulated LH and FSH secretion, but restoration of maximal responses required replacement with estradiol and progesterone. Finally, despite suppressed basal levels, LH and FSH secretory responses to kisspeptin were preserved in pregnant and lactating females, although the magnitude of LH bursts and the sensitivity to kisspeptin were much higher in pregnant dams. Interestingly, hypothalamic KiSS-1 gene expression significantly increased during pregnancy, whereas GPR54 mRNA levels remained unaltered. In summary, our current data document for the first time the changes in hypothalamic expression of KiSS-1 system and the gonadotropic effects (maximal responses and sensitivity) of kisspeptin in different functional states of the female reproductive axis. The present data may pose interesting implications in light of the

COMPLEXO HIPERPLASIA ENDOMETRIAL CÍSTICA (PIOMETRA EM CADELAS – DIAGNÓSTICO E TERAPÊUTICA

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Augusto Schweigert

2009-06-01

Full Text Available Cystic endometrial hyperplasia-pyometra complex is a disease that affects a large number of bitches. It has high morbity and mortality routes, and it occurs particularly in middle-aged bitches during diestrus phase. The bitches with pyometra exhibit apathy, anorexia and possible signs of acute renal failure due to renal parenchyma injuries. There are two types of pyometra: open and closed. The most common sign of open pyometra is the purulent vaginal discharge. In closed pyometra, diagnostic is facilitated by abdominal palpation, laboratory test, ultrasound and X-ray. If untreated, pyometra can cause renal failure, sepsis, septic shock and death. Treatment of pyometra is based on medical or surgical procedures. The treatment choice may vary according to the clinical signs and the state of the patient.

[Effect of estradiol on the prolactin content in the adenohypophysis of sexually mature and immature rats].

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Arse, Kh A

1979-01-01

Gel electrophoresis was used in a comparative study of prolactin content in the hypophysis of rats of different age and sex, and at various stages of the estral cycle. The hormone level in the pubertal rats was twice or thrice greater than in the immature ones; it was by 16% less at the diestrus than at the estrus stage. There was no change in the hypophysis prolactin content in male rats at puberty. Ovariectomy was accompained by a sharp reduction of prolactin in the hypophysis. Replacing estradiol therapy increased the amount of prolactin in the hypophysis, without bringing it, however, to the level characteristic of intact rats. Estrogens are responsible for the maintenance of prolactin level, but apparently other factors influencing its content in the hypophysis also exist.

Implante Autólogo Ovariano no Omento Maior: Estudo Experimental Ovarian Autotransplantation to the Greater Omentum: Experimental Model

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Luiz Ronaldo Alberti

2002-01-01

autotransplantation to the greater omentum; and Group IV (n = 10, sliced ovarian autotransplantation, both to the greater omentum. The estrous cycle was investigated in the third and sixth postoperative months and histological studies of the ovarian implants were carried out considering: degeneration, fibrosis, inflammatory reaction, angiogenesis, follicular cysts, follicular development and corpora lutea. Results: the animals of Group I preserved the cycling sequence. The rats of Group II remained in diestrus. In Group III, 11 rats remained in diestrus, three presented incomplete cycles and one showed normal cycle. In Group IV, three animals remained in diestrus, eight showed incomplete cycles and four showed normal cycles. The histology of the ovaries of Group III was normal in ten female rats; however, the ovaries of the other five animals presented degeneration. In Group IV, 14 female rats had ovaries with preserved morphological aspect, and signs of degeneration occurred in one. Conclusions: the ovarian autotransplantation to the greater omentum is viable and the sliced form presented better morphofunctional aspects than the intact implants.

Histomorfometria e histoquímica da tuba uterina e do útero de ratas púberes e pré-púberes induzidas ao hipertireoidismo Histomorphometry and histochemistry of the uterine tubes and uterus of puberal and prepuberal rats induced for hyperthyroidism

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T.S. Oliveira

2005-08-01

Full Text Available Foram estudadas a histomorfometria e a atividade secretória das tubas uterinas e do útero de 38 ratas Wistar púberes, distribuídas em quatro grupos: (1 eutireóideo em proestro-estro, (2 hipertireóideo em proestro-estro, (3 eutireóideo em metaestro-diestro e (4 hipertireóideo em metaestro-diestro. Posteriormente, foram utilizadas outras 24 ratas Wistar pré-púberes, com 12 dias de idade, distribuídas em dois grupos: (1 hipertireóideo (n=12 e (2 eutireóideo (n=12. O útero e as tubas uterinas foram colhidos para avaliação histomorfométrica e histoquímica. A altura do epitélio da ampola, tanto no proestro-estro quanto no metaestro-diestro, elevou-se com a administração de tiroxina, tornando-se semelhante à do istmo. O hipertireoidismo aumentou a secreção PAS positiva e de mucossubstâncias ácidas do infundíbulo na fase estrogênica, igualando-a à do istmo. A parede uterina apresentou-se mais espessa na fase estrogênica, resultado da ação conjunta da tiroxina no endométrio e no miométrio. A atividade secretória e a composição do colágeno uterino não diferiram entre tratamentos. Nas ratas pré-púberes, o hipertireoidismo aumentou a espessura do miométrio e da parede uterina, mas não alterou a tuba uterina. O hipertireoidismo em ratas pré-púberes induz modificações significativas somente no útero; após a maturidade sexual, as modificações ocorrem no útero e na tuba uterina em intensidade variável e dependentes da fase do ciclo estral.The histomorphometry and the secretory activity of the uterine tubes and uterus of 38 puberal Wistar rats were studied. Rats were divided in four groups: (1 euthyroid in proestrus-estrus, (2 hyperthyroid in proestrus-estrus, (3 euthyroid in metestrus-diestrus and, (4 hyperthyroid in metestrus-diestrus. In other experiment, 24 prepuberal 12-day-old Wistar rats were divided in two groups: (1 hyperthyroid and (2 euthyroid. The uterus and the uterine tubes were collected for

Intrauterine inoculation of minipigs with Chlamydia trachomatis during diestrus establishes a longer lasting infection compared to vaginal inoculation during estrus

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Lorenzen, Emma; Follmann, Frank; Secher, Jan O

2017-01-01

Advanced animal models, such as minipigs, are needed for the development of a globally requested human Chlamydia vaccine. Previous studies have shown that vaginal inoculation of sexually mature Göttingen minipigs with Chlamydia trachomatis resulted in an infection lasting only 3-5 days. The aim...... resulted in a longer lasting infection (at least 10 days) compared to estrus (3-5 days). Furthermore, we found a significant C. trachomatis specific IFN-γ response in pigs inoculated during estrus correlating with the accelerated clearance of infection in these pigs. These findings suggest...

Histomorphometric and functional studies of the rat thyroid throughout the estrous cycle Histomorfometria e função tireoidiana no ciclo estral da rata

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R. Serakides

2002-02-01

Full Text Available The influence of the estrous cycle on the thyroid gland was studied. Twenty one five-to-seven-month-old Wistar female rats were divided according to the stage of the estrous cycle in two groups: metaestrus-diestrus and proestrus-estrus. After gross inspection, the thyroids were weighed, sampled, and processed for staining with hematoxilyn-eosin. Seric concentrations of total T4, free T4, total T3, TSH, progesterone, and estradiol were measured. The values of estradiol were significantly higher in the proestrus-estrus stage. However, no significant differences in the plasmatic concentrations of progesterone, free T4, total T4 and TSH throughout the cycle were found. The results of the morphometric study of the thyroid did not indicate any significant differences between the groups. These findings suggest that there is no thyreotrophic effect of estrogen during the estrous cycle in rats.

[Changes in the monoamine content in different parts of hypothalamus depending on the stages of the estrous cycle].

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Babichev, V N; Adamskaia, E I

1976-01-01

Fluorimetric determination of monoamines in various regions of the hypothalamus and at different stages of the estral cycle in rats showed that the serotonin, noradrenaline, and particularly dophamine content changed both in the course of the cycle and at different time (10, 15 and 18 hours) of the same stage of the cycle. Dophamine concentration in the arcuate area--the centre of the tonic activity--reached its maximum at 18 hours of the diestrus-2 (D2) and fell to the minimum at 10 hours of the proestrus (P). Noradrenaline level in the preoptic area increased at 18 hours of the D2 and fell at 10 hours of the P. It is supposed that in the hypothalamic regulation of the estral cycle at least two monoamines (dopamine and noradrenaline) took part; the trigger role belongs to noradrenaline of the preoptic area (the cyclic centre).

Differential effects of unilateral lesions in the medial amygdala on spontaneous and induced ovulation.

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Sanchez, M A; Dominguez, R

1995-01-01

The possible existence of asymmetry in the control of ovulation by the medial amygdala was explored. Unilateral lesions of the medial amygdala were performed on each day of the estrous cycle. The estral index diminished in almost all animals with a lesion in the right side of medial amygdala. Lesions of the right medial amygdala, when performed on diestrus-1, resulted in a significant decrease in the number of rats ovulating compared to controls (4/8 vs. 8/8, p rats with lesions of the right medial amygdala. However, sequential injections of PMSG-hCG did result in ovulation by all members of a group of lesioned animals. In this last condition a significant decrease in the number of ova shed by the right ovary was found compared to animals in the lesion-only condition (1.5 +/- 0.5 vs. 6.0 +/- 1.5, p cycle.

Early life seizures in female rats lead to anxiety-related behavior and abnormal social behavior characterized by reduced motivation to novelty and deficit in social discrimination.

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Castelhano, Adelisandra Silva Santos; Ramos, Fabiane Ochai; Scorza, Fulvio Alexandre; Cysneiros, Roberta Monterazzo

2015-03-01

Previously, we demonstrated that male Wistar rats submitted to neonatal status epilepticus showed abnormal social behavior characterized by deficit in social discrimination and enhanced emotionality. Taking into account that early insult can produce different biological manifestations in a gender-dependent manner, we aimed to investigate the social behavior and anxiety-like behavior in female Wistar rats following early life seizures. Neonate female Wistar rats at 9 days postnatal were subject to pilocarpine-induced status epilepticus and the control received saline. Behavioral tests started from 60 days postnatal and were carried out only during the diestrus phase of the reproductive cycle. In sociability test experimental animals exhibited reduced motivation for social encounter and deficit in social discrimination. In open field and the elevated plus maze, experimental animals showed enhanced emotionality with no changes in basal locomotor activity. The results showed that female rats submitted to neonatal status epipepticus showed impaired social behavior, characterized by reduced motivation to novelty and deficit in social discrimination in addition to enhanced emotionality.

Antifertility effect of betal leaf stalk (Tambul patrabrint): a preliminary experimental study.

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Tewari, P V; Chaturvedi, C; Dixit, S N

1970-01-01

This study was undertaken to determine possible antifertility properties of the stalk of the betel plant, Piper betle, which is extensively cultivated in warm moist parts of India for its leaves. The thin stalks were dried, powdered, and extracted with alcohol; the residue was used in the study and named betel leaf stalk extract (BLSE). It was macerated with gum acacia, suspended in distilled water, and diluted to 25 mg/ml. The drug was fed by oral intubation. Initially 20 rats were used in 2 groups, one receiving BLSE 50 mg/kg body weight for 10 days and the other vehicle only. Both were caged with males for 15 days. Only 2 of 10 rats receiving BLSE gave birth to litters while 9 of 10 controls delivered. Number of pups was also reduced. In another experiment using 60 female rats to 30 while BLSE at 50 mg/100 gm body weight was fed for 3 days during diestrus to 30 while 30 controls received vehicle only. Successful mating was confirmed by sperm in vaginal smears. 8 of 30 treated rats delivered 3.5 pups each while 29 of 30 controls delivered 7 pups per rat. In a third experiment 10 female rats were given BLSE 50mg/100 gm body weight, 10 vehicle only, and 10 neoclinesterol 150 mcg/100 gm body weight for 4 consecutive days. On Day 5 the animals were sacrificed and weights of uterus and ovaries recorded. Antiestrogenic properties were studied in oophorectomized rats given stilbestrol 150 mcg/100 gm body weight by injection, then fed 150 mcg/100 gm body weight of neoclinesterol or BLSE, 50 mg/100 gm, but the neoclinesterol. Vaginal smears were examined for cornification on Days 2, 3, and 4. Progestational activity was studied in 12 immature female rabbits injected with stilbestrol then treated with BLSE or leutocycline. Tests for estrogenic and antiestrogenic activity of BLSE were negative. A mild progestational activity was found in immature estrogen-primed rabbits but some follicle depressant type action was noted as several graffian follicles were seen in their

Female Offspring From Chronic Hyperandrogenemic Dams Exhibit Delayed Puberty and Impaired Ovarian Reserve.

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Wang, Zhiqiang; Shen, Mingjie; Xue, Ping; DiVall, Sara A; Segars, James; Wu, Sheng

2018-02-01

Female offspring of many species exposed to high doses of androgens in utero experience endocrine dysfunction during adulthood. The phenotype of offspring from females with prepregnancy hyperandrogenemia and impaired ovulation, however, has not been examined. We developed a mouse model of hyperandrogenemia by implanting a low-dose dihydrotestosterone (DHT) pellet 15 days before conception. Female offspring born to dams with hyperandrogenemia (DHT daughters) had delayed puberty (P DHT (non-DHT daughters, PND37.5). Serum follicle-stimulating hormone (FSH) levels in the DHT daughters were fourfold higher (P DHT daughters (controls). DHT daughters showed an extended time in metestrus/diestrus and a shorter time in the proestrus/estrus phase compared with non-DHT daughters (P DHT daughters compared with non-DHT daughters (P DHT daughters compared with non-DHT daughters. Daughters from hyperandrogenemic females exhibited elevated prepubertal FSH levels, diminished ovarian response to superovulation, impaired estrous cyclicity, delayed onset of puberty, and reduced ovarian reserve, suggesting that fetal androgen exposure had lasting effects on female reproductive function. Copyright © 2018 Endocrine Society.

Progesterone Prevents High-Grade Serous Ovarian Cancer by Inducing Necroptosis of p53-Defective Fallopian Tube Epithelial Cells

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Na-Yiyuan Wu

2017-03-01

Full Text Available High-grade serous ovarian carcinoma (HGSOC originates mainly from the fallopian tube (FT epithelium and always carries early TP53 mutations. We previously reported that tumors initiate in the FT fimbria epithelium because of apoptotic failure and the expansion of cells with DNA double-strand breaks (DSB caused by bathing of the FT epithelial cells in reactive oxygen species (ROSs and hemoglobin-rich follicular fluid (FF after ovulation. Because ovulation is frequent and HGSOC is rare, we hypothesized that luteal-phase progesterone (P4 could eliminate p53-defective FT cells. Here we show that P4, via P4 receptors (PRs, induces necroptosis in Trp53−/− mouse oviduct epithelium and in immortalized human p53-defective fimbrial epithelium through the TNF-α/RIPK1/RIPK3/MLKL pathway. Necroptosis occurs specifically at diestrus, recovers at the proestrus phase of the estrus cycle, and can be augmented with P4 supplementation. These results reveal the mechanism of the well-known ability of progesterone to prevent ovarian cancer.

[Concentration of monoamines and activity of several enzymes in the arcuate nucleus of the hypothalamus in young and aging rats during the estrous cycle].

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Grantyn', V A

1976-07-01

The arcuate nucleus (AN) and the median eminence (ME) of the hypothalamus were investigated in young and ageing female rats. During the estral cycle (EC) the monoamine (MA) content, the monoaminoxidase (MAO), NADP and NAD-diaphorase activities were determined in the AN, and the MA content and the activity of alkaline phosphatase (AP) -- in the ME. In young rats in the proestrus-estrus there was an increase in the activity of the NADP and NAD-diaphorase and of the MA content, but a decrease of the MAO activity. This indicated an intensified function of the nucleus at these stages of the EC. Accumulation of the MA in the ME was noted in the diestrus, while in the proestrus their concentration sharply fell; on the other hand, the activity of the AP was considerably increased. In the ageing rats the dynamics of the indices under study during the EC were largely unchanged. However, the functional activity of the AN proved to increase, and in the ME and elevation of the MA concentration and disturbance of its release from the nerve terminals was seen.

[Morphological changes in the thyroid gland of rats during various phases of the estral cycle].

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Pliner, L I; Ledovskaia, S M

1975-08-01

The functional state of the thyroid gland and the concentration of thyroid hormones in the peripheral blood were studied in 20 mature female albino rats during their estral cycle. Evaluation of the thyroid functional state was made according to data of histological, morphological (the diameter of folliculi, the height of the thyroid epithelium) and histochemical analysis (determination of NAD and NADP-dehydrogenase, succinatedehydrogenase, lactate dehydrogenase, peroxydase, acid and alkaline phosphatase) as well as biochemical determination of iodine bound with protein (IBP) in the blood plasma and investigation of the ratio of the parameters in question under conditions of the sex cycle. The cyclic changes of the morphological state of the thyroid gland attended by the phases of the estral cycle were revealed. The activation of the organ was observed in proestrus and estrus which was evidenced by high levels of activity of the enzymes under study, high concentration of IBP in the blood and increased height of thyreocytes. A decreased function of the thyroid parenchyma was observed at the period of metaestrus-diestrus.

The use of infrared thermography to detect the stages of estrus cycle and ovulation time in anatolian shepherd dogs.

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Olğaç, Kemal Tuna; Akçay, Ergun; Çil, Beste; Uçar, Burak Mehmet; Daşkın, Ali

2017-01-01

The aim of the study is to evaluate the effectiveness of thermographic monitoring, using the temperature changes of perianal and perivulvar areas for the determination of estrus in Anatolian Shepherd bitches. Fifteen bitches were used in the study. Blood and vaginal smear samples were collected and thermographic monitoring of perianal and perivulvar areas were carried out starting from proestrus to early diestrus. Also, external signs of estrus were investigated. Smear samples were evaluated by light microscopy after Diff-Quik staining method and superficial and keratinized superficial cells were determined as percentage (S + KS%). Progesterone and luteinizing hormone measurements were done by radioimmunoassay. The difference in temperature between perianal and perivulvar areas was evaluated through thermographic images by FLIR ResearchIR Software. According to the results obtained from the study, differences between progesterone and S + KS% were statistically significant ( P   0,05). Serum luteinizing hormone levels did not sign any difference ( P  > 0,05). As a result, thermographic monitoring alone is not enough for estrus detection in Anatolian Shepherd bitches. However, it can be used to assist the actual estrus detection technique in terms of providing some foreknowledge by evaluating the differences in temperature.

Mouse estrous cycle identification tool and images.

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Shannon L Byers

Full Text Available The efficiency of producing timed pregnant or pseudopregnant mice can be increased by identifying those in proestrus or estrus. Visual observation of the vagina is the quickest method, requires no special equipment, and is best used when only proestrus or estrus stages need to be identified. Strain to strain differences, especially in coat color can make it difficult to determine the stage of the estrous cycle accurately by visual observation. Presented here are a series of images of the vaginal opening at each stage of the estrous cycle for 3 mouse strains of different coat colors: black (C57BL/6J, agouti (CByB6F1/J and albino (BALB/cByJ. When all 4 stages (proestrus, estrus, metestrus, and diestrus need to be identified, vaginal cytology is regarded as the most accurate method. An identification tool is presented to aid the user in determining the stage of estrous when using vaginal cytology. These images and descriptions are an excellent resource for learning how to determine the stage of the estrous cycle by visual observation or vaginal cytology.

Flehmen response in bull: role of vaginal mucus and other body fluids of bovine with special reference to estrus.

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Sankar, R; Archunan, G

2004-07-30

The present investigation was carried out with a view to evaluate the frequency of Flehmen behaviour in bull in response to body fluids of cows in various stages of the estrous cycle, in the context of estrus detection. The study was performed on free moving bulls under natural conditions. Samples of vaginal mucus, saliva, faeces and milk of pro-estrus, estrus and di-estrus stages collected from donor cows were rubbed individually onto the genital regions of non-estrus animals (dummy cows) and the bulls were observed for 30 min for assessment of Flehmen behaviour. The duration of Flehmen behaviour shown by bulls was maximum towards the dummy cows receiving estrus sample. Such Flehmen behaviour, however, did not occur in bulls in response to the cows receiving samples of other stages. The statistical significance was higher (P mucus may act as an additional/secondary source along with urine in eliciting copulatary behaviour and executing coitus in bulls during estrus. The results further suggest that in addition to vaginal mucus, other body fluids like saliva, faeces and milk have estrus-related odours and are probably involved in bovine bio-communication.

Age-Associated Changes in Estrogen Receptor Ratios Correlate with Increased Female Susceptibility to Coxsackievirus B3-Induced Myocarditis

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Andreas Koenig

2017-11-01

Full Text Available Sexual bias is a hallmark in various diseases. This review evaluates sexual dimorphism in clinical and experimental coxsackievirus B3 (CVB3 myocarditis, and how sex bias in the experimental disease changes with increased age. Coxsackieviruses are major causes of viral myocarditis, an inflammation of the heart muscle, which is more frequent and severe in men than women. Young male mice infected with CVB3 develop heart-specific autoimmunity and severe myocarditis. Females infected during estrus (high estradiol develop T-regulatory cells and when infected during diestrus (low estradiol develop autoimmunity similar to males. During estrus, protection depends on estrogen receptor alpha (ERα, which promotes type I interferon, activation of natural killer/natural killer T cells and suppressor cell responses. Estrogen receptor beta has opposing effects to ERα and supports pro-inflammatory immunity. However, the sexual dimorphism of the disease is significantly ameliorated in aged animals when old females become as susceptible as males. This correlates to a selective loss of the ERα that is required for immunosuppression. Therefore, sex-associated hormones control susceptibility in the virus-mediated disease, but their impact can alter with the age and physiological stage of the individual.

Elevated expression of steroidogenesis pathway genes; CYP17, GATA6 and StAR in prenatally androgenized rats.

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Jahromi, Marziyeh Salehi; Tehrani, Fahimeh Ramezani; Noroozzadeh, Mahsa; Zarkesh, Maryam; Ghasemi, Asghar; Zadeh-Vakili, Azita

2016-11-15

It is believed that excess androgen exposure of the fetus, via altered gene expression, causes hyperandrogenism a key feature of polycystic ovary syndrome (PCOS). The aim of this study was to evaluate expression of Cytochrome P450-17 (CYP17), GATA-binding protein (GAGT6) and Steroidogenic acute regulatory protein (StAR), genes of adult female rats prenatally exposed to androgen excess, closely reflect endocrine and ovarian disturbances of PCOS in women, by comparing them during different phases of estrus cycle with those of non-treated rats. Both the adult prenatally testosterone exposed and control rats (n=23, each) were divided into four groups based on their observed vaginal smear (proestrus, estrus, metestrus and diestrus) and the relative expression of CYP17, GATA6 and StAR genes was measured in ovarian theca cells using Cyber-green Real-Time PCR. Serum sex steroid hormones and gonadotropins levels were measured using the ELISA method; a comparison of these two groups showed that there was an overall increase in the studied genes (CYP17; 2.39 fold change, 95% CI: 1.23-3.55; PPCOS. Copyright © 2016 Elsevier B.V. All rights reserved.

Are endogenous sex hormones related to DNA damage in paradoxically sleep-deprived female rats?

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Andersen, Monica L; Ribeiro, Daniel A; Alvarenga, Tathiana A; Silva, Andressa; Araujo, Paula; Zager, Adriano; Tenorio, Neuli M; Tufik, Sergio

2010-02-01

The aim of this investigation was to evaluate overall DNA damage induced by experimental paradoxical sleep deprivation (PSD) in estrous-cycling and ovariectomized female rats to examine possible hormonal involvement during DNA damage. Intact rats in different phases of the estrous cycle (proestrus, estrus, and diestrus) or ovariectomized female Wistar rats were subjected to PSD by the single platform technique for 96 h or were maintained for the equivalent period as controls in home-cages. After this period, peripheral blood and tissues (brain, liver, and heart) were collected to evaluate genetic damage using the single cell gel (comet) assay. The results showed that PSD caused extensive genotoxic effects in brain cells, as evident by increased DNA migration rates in rats exposed to PSD for 96 h when compared to negative control. This was observed for all phases of the estrous cycle indistinctly. In ovariectomized rats, PSD also led to DNA damage in brain cells. No significant statistically differences were detected in peripheral blood, the liver or heart for all groups analyzed. In conclusion, our data are consistent with the notion that genetic damage in the form of DNA breakage in brain cells induced by sleep deprivation overrides the effects related to endogenous female sex hormones. Copyright 2009 Elsevier Inc. All rights reserved.

Selecting Female Mice in Estrus and Checking Plugs.

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Behringer, Richard; Gertsenstein, Marina; Nagy, Kristina Vintersten; Nagy, Andras

2016-08-01

The female mouse estrous cycle is divided into four phases: proestrus (development of ovarian follicles), estrus (ovulation), metestrus (formation of corpora lutea), and diestrus (beginning of follicle development for next ovulation and elimination of previous oocytes). The appearance of the epithelium of the external genitalia is used to identify the stage of the estrous cycle of a female mouse. This is usually easier to see in strains with either no or only light skin pigmentation. By examining the color, moistness, and degree of swelling of the vagina, females in estrus can readily be identified. To set up the matings, females are examined in the afternoon, and those in estrus are placed into the cages with males (one or two females in each cage with one male). Usually, 50% or more of the selected females will mate. The presence of a vaginal copulation plug next morning indicates that mating has occurred, but it does not mean that a pregnancy will result even if proven breeder fertile males were used. It is important to check vaginal plugs early in the morning because they fall out or are no longer detectable ~12 h after mating or sometimes earlier. © 2016 Cold Spring Harbor Laboratory Press.

The use of infrared thermography to detect the stages of estrus cycle and ovulation time in anatolian shepherd dogs

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Kemal Tuna Olğaç

2017-10-01

Full Text Available Abstract Background The aim of the study is to evaluate the effectiveness of thermographic monitoring, using the temperature changes of perianal and perivulvar areas for the determination of estrus in Anatolian Shepherd bitches. Fifteen bitches were used in the study. Blood and vaginal smear samples were collected and thermographic monitoring of perianal and perivulvar areas were carried out starting from proestrus to early diestrus. Also, external signs of estrus were investigated. Smear samples were evaluated by light microscopy after Diff-Quik staining method and superficial and keratinized superficial cells were determined as percentage (S + KS%. Progesterone and luteinizing hormone measurements were done by radioimmunoassay. The difference in temperature between perianal and perivulvar areas was evaluated through thermographic images by FLIR ResearchIR Software. Results According to the results obtained from the study, differences between progesterone and S + KS% were statistically significant (P  0,05. Serum luteinizing hormone levels did not sign any difference (P > 0,05. Conclusions As a result, thermographic monitoring alone is not enough for estrus detection in Anatolian Shepherd bitches. However, it can be used to assist the actual estrus detection technique in terms of providing some foreknowledge by evaluating the differences in temperature.

Beta-endorphin in genetically hypoprolactinemic rat: IPL nude rat

International Nuclear Information System (INIS)

Cohen, H.; Sabbagh, I.; Abou-Samra, A.B.; Bertrand, J.

1986-01-01

Beta-endorphin has been reported to regulate not only stress- and suckling-induced but also basal prolactin secretion. In the aim to better evaluate the endogenous beta-endorphin-prolactin interrelation, the authors measured beta-endorphin levels in a new rat strain, genetically hypoprolactinemic and characterized by a total lack of lactation: IPL nude rat. Beta-endorphin was measured using a specific anti-h-β endorphin in plasma and extracts of anterior and neurointermediate lobes of the pituitary, hypothalamus and brain. Pituitary extracts were also chromatographed on Sephadex G50 column. Results obtained showed that in IPL nude females on diestrus and males, the beta-endorphin contents of the neurointermediate lobe was significantly lower than in normal rats, while the values found in the other organs and plasma were similar. However, elution pattern of the anterior pituitary extracts from male rats showed greater immunoactivity eluting as I 125 h-beta-endorphin than in normal rat; this was not the case for the female rat. These results are consistent with a differential regulation of beta-endorphin levels of anterior and neurointermediate lobe by catecholamines. Moreover they suggest that PRL secretion was more related to neurointermediate beta-endorphin. 40 references, 2 figures, 4 tables

Canine diabetes mellitus risk factors: A matched case-control study.

Science.gov (United States)

Pöppl, Alan Gomes; de Carvalho, Guilherme Luiz Carvalho; Vivian, Itatiele Farias; Corbellini, Luis Gustavo; González, Félix Hilário Díaz

2017-10-01

Different subtypes of canine diabetes mellitus (CDM) have been described based on their aetiopathogenesis. Therefore, manifold risk factors may be involved in CDM development. This study aims to investigate canine diabetes mellitus risk factors. Owners of 110 diabetic dogs and 136 healthy controls matched by breed, sex, and age were interviewed concerning aspects related to diet, weight, physical activity, oral health, reproductive history, pancreatitis, and exposure to exogenous glucocorticoids. Two multivariate multivariable statistical models were created: The UMod included males and females without variables related to oestrous cycle, while the FMod included only females with all analysed variables. In the UMod, "Not exclusively commercial diet" (OR 4.86, 95%CI 2.2-10.7, Pdiet" (OR 4.14, 95%CI 1.3-12.7, P=0.01), "Table scraps abuse" (OR 3.62, 95%CI 1.1-12.2, P=0.03), "Overweight" (OR 3.91, 95%CI 1.2-12.6, P=0.02), and "Dioestrus" (OR 5.53, 95%CI 1.9-16.3, P=0.002) were statistically significant. The findings in this study support feeding not exclusively balanced commercial dog food, overweight, treats abuse, and diestrus, as main CDM risk factors. Moreover, those results give subside for preventive care studies against CDM development. Copyright © 2017 Elsevier Ltd. All rights reserved.

Beta-endorphin in genetically hypoprolactinemic rat: IPL nude rat

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Cohen, H.; Sabbagh, I.; Abou-Samra, A.B.; Bertrand, J.

1986-01-20

Beta-endorphin has been reported to regulate not only stress- and suckling-induced but also basal prolactin secretion. In the aim to better evaluate the endogenous beta-endorphin-prolactin interrelation, the authors measured beta-endorphin levels in a new rat strain, genetically hypoprolactinemic and characterized by a total lack of lactation: IPL nude rat. Beta-endorphin was measured using a specific anti-h-..beta.. endorphin in plasma and extracts of anterior and neurointermediate lobes of the pituitary, hypothalamus and brain. Pituitary extracts were also chromatographed on Sephadex G50 column. Results obtained showed that in IPL nude females on diestrus and males, the beta-endorphin contents of the neurointermediate lobe was significantly lower than in normal rats, while the values found in the other organs and plasma were similar. However, elution pattern of the anterior pituitary extracts from male rats showed greater immunoactivity eluting as I/sup 125/ h-beta-endorphin than in normal rat; this was not the case for the female rat. These results are consistent with a differential regulation of beta-endorphin levels of anterior and neurointermediate lobe by catecholamines. Moreover they suggest that PRL secretion was more related to neurointermediate beta-endorphin. 40 references, 2 figures, 4 tables.

Cellular organization of pre-mRNA splicing factors in several tissues. Changes in the uterus by hormone action.

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George-Téllez, R; Segura-Valdez, M L; González-Santos, L; Jiménez-García, L F

2002-05-01

In the mammalian cell nucleus, splicing factors are distributed in nuclear domains known as speckles or splicing factor compartments (SFCs). In cultured cells, these domains are dynamic and reflect transcriptional and splicing activities. We used immunofluorescence and confocal microscopy to monitor whether splicing factors in differentiated cells display similar features. Speckled patterns are observed in rat hepatocytes, beta-cells, bronchial and intestine epithelia and also in three cell types of the uterus. Moreover, the number, distribution and sizes of the speckles vary among them. In addition, we studied variations in the circular form (shape) of speckles in uterine cells that are transcriptionally modified by a hormone action. During proestrus of the estral cycle, speckles are irregular in shape while in diestrus I they are circular. Experimentally, in castrated rats luminal epithelial cells show a pattern where speckles are dramatically rounded, but they recover their irregular shape rapidly after an injection of estradiol. The same results were observed in muscle and gland epithelial cells of the uterus. We concluded that different speckled patterns are present in various cells types in differentiated tissues and that these patterns change in the uterus depending upon the presence or absence of hormones such as estradiol.

Effect of ethanolic seed extract of Caesalpinia bonducella on female reproductive system of albino rat: a focus on antifertility efficacy

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Lilaram

2012-10-01

Full Text Available Objective: To evaluate the effect of oral administration of the ethanolic seed extract of Caesalpinia bonducella on the reproductive system in Wistar female albino rat. Methods: The study was divided into four groups. The group I received distilled water and served as vehicle treated control. Groups II, III and IV were orally administered 100, 200 and 300 mg/kg body weight dose of seed extract respectively, for 10 consecutive days and subsequently euthanized twenty four hours after the last dose. Results: The treatment prolonged the length of estrous cycle with significant increase in the duration of diestrus stage. The analysis of the principal hormones viz. LH, FSH, estradiol and progesterone showed significantly decreased levels in dose-dependant manner. Ovarian and uterine weight was significantly reduced as compared to that of the control group. Histoarchitectural observations revealed follicular atresia and degeneration of corpora lutea in ovary. Oviduct showed degeneration of mucosal folds and epithelium cells. Uterus showed evidence of degeneration of endometrial epithelium and endometrial glands. Lamina propria and muscularis layer of vagina were found slightly disorganized. Conclusions: It can be concluded that significant decrease in the hormone levels, reproductive organs weight and alterations in histoarchitecture of reproductive organs might be due to antiestrogenic nature of seed extract.

Expression of aquaporin-7 and aquaporin-9 in tanycyte cells and choroid plexus during mouse estrus cycle.

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Yaba, A; Sozen, B; Suzen, B; Demir, N

2017-03-01

Tanycytes are special ependymal cells located in the ventrolateral wall and floor of the third ventricle having processes extending nuclei that regulate reproductive functions and around of vessels in median eminance. The aquaporins (AQPs) are a family of transmembrane proteins that transport water and glycerol. AQP-7 and -9 are permeable to other small molecules as glycerol and therefore called aquaglyceroporins. In this study, we aimed to show localization of AQP-7 and -9 in epithelial cells of choroid plexus and tanycytes during female mouse estrus cycle. AQP-7 and -9 proteins were detected in α2 and β1 tanycytes in prœstrus stage. Interestingly, there is no staining in estrus stage in any type of tanycytes. We observed weak immunoreactivity in α1, α2 and β1 tanycyte cells in metestrus stage for AQP-7 and α1 for AQP-9 protein. AQP-7 and -9 showed intense immunoreactivity in α2, β1 and β2 tanycyte cells during diestrus stage. Consequently, AQP-7 and -9 showed differential staining pattern in different stages of mouse estrus cycle. In the light of our findings and other recent publications, we suggest that AQP-7 and -9-mediated glycerol transport in tanycyte cells might be under hormonal control to use glycerol as a potential energy substrate during mouse estrus cycle. Copyright © 2016. Published by Elsevier Masson SAS.

Sex differences in paradoxical sleep: influences of estrus cycle and ovariectomy.

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Fang, J; Fishbein, W

1996-09-23

Previously, we reported that paradoxical sleep (PS) is sexually dimorphic in mice and rats. Since some early studies indicate that PS is suppressed during proestrus night, it is important to know whether the estrus cycle and accompanying circulating ovarian hormones could explain the sexual dimorphism of PS. To examine this, sleep patterns of male rats were compared with those of normal cycling female rats and ovariectomized females in a 12:12 h light/dark cycle. Slow wave sleep and total sleep time are indistinguishable between the males, cycling females and ovariectomized females. However, normal males display significantly more PS than cycling females during both daytime and nighttime (average of all estrus stages). On the other hand, while ovariectomy has no visible effect on daytime sleep--the sexual dimorphism of PS is unchanged by ovariectomy--during nighttime, ovariectomy produces a selective increase of PS, eliminating the sex difference during the night. In sum, normal cycling females show no change in daytime sleep patterns across the estrus cycle, but have significantly less PS during proestrus nights than during metestrus and diestrus nights. The results indicate that the sex difference in nighttime PS is due to the suppression of PS by ovarian hormones during proestrus and, to a less extent, estrus nights. The sex difference in daytime PS, on the other hand, appears to be independent of circulating ovarian hormones.

Oxytocin promotes bone formation during the alveolar healing process in old acyclic female rats.

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Colli, Vilma Clemi; Okamoto, Roberta; Spritzer, Poli Mara; Dornelles, Rita Cássia Menegati

2012-09-01

OT was reported to be a direct regulator of bone mass in young rodents, and this anabolic effect on bone is a peripheral action of OT. The goal of this study was to investigate the peripheral action of oxytocin (OT) in the alveolar healing process in old female rats. Females Wistar rats (24-month-old) in permanent diestrus phase, received two ip (12h apart) injections of saline (NaCl 0.15M - control group) or OT (45μg/rat - treated group). Seven days later, the right maxillary incisor was extracted and analyses were performed up to 28 days of the alveolar healing process (35 days after saline or OT administration). Calcium and phosphorus plasma concentrations did not differ between the groups. The plasma biochemical bone formations markers, alkaline phosphatase (ALP) and osteocalcin were significantly higher in the treated group. Histomorphometric analyses confirmed bone formation as the treated group presented the highest mean value of post-extraction bone formation. Tartrate-resistant acid phosphatase (TRAP) was significantly reduced in the treated group indicating an anti-resorptive effect of OT. Immunohistochemistry reactions performed in order to identify the presence of osteocalcin and TRAP in the bone cells of the dental socket confirmed these outcomes. OT was found to promote bone formation and to inhibit bone resorption in old acyclic female rats during the alveolar healing process. Published by Elsevier Ltd.

Responses of the mouse to microwave radiation during estrous cycle and pregnancy

International Nuclear Information System (INIS)

Rugh, R.; Ginns, E.I.; Ho, H.S.; Leach, W.M.

1975-01-01

A new facility for microwave irradiation of mice that will provide reproducible dosimetry is described. The waveguide used provided the integral dose rate to experimental animals under stable and controlled environmental conditions of relative humidity and temperature, variables which have been found to be critical in microwave studies. In terms of average absorbed lethal dose, the female mouse was found to be more sensitive to microwave irradiation during estrus than during diestrus. Teratogenesis (e.g., exencephalies) after sublethal irradiation of pregnant mice at 8 gestation days resulted from absorbed doses within the range of 3 to 5 calories per gram of body weight, and was never an all-or-none response. The incidence and variety of effects produced (hemorrhage, resorption, stunting, and fetal death) indicate that the cause and effect relationships are neither linear nor well enough established and understood to permit prediction of the biological effects either in the mouse of other species. As the absorbed dose of radiant energy is increased to the 8-day pregnant mouse, the probability of it producing at least one exencephaly is likewise increased. Nevertheless, the determination of the absorbed dose of microwave energy in each mouse is one step closer to determining the precise absorbed-dose-effect relationship for microwave exposures. A total of 1096 mice were exposed to microwave radiation and separately monitored to gather the related data. (U.S.)

Colonic transit in rats: effect of ovariectomy, sex steroid hormones, and pregnancy

International Nuclear Information System (INIS)

Ryan, J.P.; Bhojwani, A.

1986-01-01

In vitro studies suggest that the female sex steroid hormones [estrogen (E) and progesterone (P)] can affect the myoelectric and mechanical activity of colonic smooth muscle. The present study was designed to examine the influence of the hormones on colonic transit in vivo. Transit was assessed by quantifying the distribution within the colon of a radiolabeled marker (0.5 μCi Na 2 51 CrO 4 ), using the geometric center method of analysis. Studies were performed with adult male rats and the following groups of female rats: nonpregnant, ovariectomized, ovariectomy plus hormone pretreatment, and pregnant (day 18). Hormone-pretreated animals were studied 24 h following the fourth injection. The data can be summarized as follows. 1) Colonic transit was affected by the timing of the estrus cycle. 2) Ovariectomy eliminated the biphasic transit pattern observed in estruscycling females and resulted in a geometric center value comparable with that of the metestrus-diestrus animals. 3) E + P pretreatment of ovariectomized rats resulted in a significant decrease in the geometric center compared with the untreated ovariectomized rats. 4) The geometric center value in pregnant anials and hormone-pretreated animals. 5) Adult male rats had a geometric center value of 4.12 +/- 0.29. The results suggest that a relation exists between colonic transit and the circulating levels of the steroid hormones

Effects of Simulated Hypogravity and Diet on Estrous Cycling in Rats

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Tou, Janet C.; Grindeland, Richard E.; Baer, Lisa A.; Wade, Charles E.

2003-01-01

Environmental factors can disrupt ovulatory cycles. The study objective was to determine the effect of diet and simulated hypogravity on rat estrous cycles. Age 50 d Sprague-Dawley rats were randomly assigned to he fed either a purified or chow diet. Only normal cycling rats were used. Experimental rats (n=9-10/group) were kept as ambulatory controls (AC) or subjected to 40 d simulated hypogravity using a disuse atrophy hindlimb suspension (HLS) model. There was no effect on estrous cycles of AC fed either diet. At day 18, HLS rats fed either diet, had lengthened estrous cycles due to prolonged diestrus. HLS rats fed purified diet also had reduced time in estrus. Plasma estradiol was reduced in HLS rats fed purified diet but there was no effect on progesterone. This may have occurred because blood was collected from rats in estrus. Urinary progesterone collected during initial HLS was elevated in rats fed purified diet. In AC, corticosterone was elevated in chow vs purified diet fed rats. Differences were particularly striking following the application of a stressor with HLS/chow-fed rats displaying an enhanced stress response. Results emphasize the importance of diet selection when measuring endocrine-sensitive endpoints. HLS is a useful model for investigating the effects of environment on reproduction and providing insight about the impact extreme environment such as spaceflight on female reproductive health.

Cyclic estrogenic fluctuation influences synaptic transmission of the medial vestibular nuclei in female rats.

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Pettorossi, Vito E; Frondaroli, Adele; Grassi, Silvarosa

2011-04-01

The estrous cycle in female rats influences the basal synaptic responsiveness and plasticity of the medial vestibular nucleus (MVN) neurons through different levels of circulating 17β-estradiol (cE(2)). The aim of this study was to verify, in the female rat, whether cyclic fluctuations of cE(2) influence long-term synaptic effects induced by high frequency afferent stimulation (HFS) in the MVN, since we found that HFS in the male rat induces fast long-term potentiation (fLTP), which depends on the neural synthesis of E(2) (nE(2)) from testosterone (T). We analyzed the field potential (FP) evoked in the MVN by vestibular afferent stimulation, under basal conditions, and after HFS, in brainstem slices of female rats during high levels (proestrus, PE) and low levels (diestrus, DE) of cE(2). Selective blocking agents of converting T enzymes were used. Unlike in the male rat, HFS induced three effects: fLTP through T conversion into E(2), and slow LTP (sLTP) and long-term depression (LTD), through T conversion into DHT. The occurrence of these effects depended on the estrous cycle phase: the frequency of fLTP was higher in DE, and those of sLTP and LTD were higher in PE. Conversely, the basal FP was also higher in PE than in DE.

Hormonal fluctuations during the estrous cycle modulate Heme Oxygenase-1 expression in the uterus

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Maria Laura Zenclussen

2014-03-01

Full Text Available Deletion of the Heme Oxygenase-1 (Hmox1 locus in mice results in intrauterine lethality. The expression of the heme catabolyzing enzyme encoded by this gene, namely HO 1, is required to successfully support reproductive events. We have previously observed that HO-1 acts at several key events in reproduction ensuring pregnancy. HO-1 defines ovulation, positively influences implantation and placentation and ensures fetal growth and survival. Here, we embarked on a study aimed to determine whether hormonal changes during the estrous cycle in the mouse define HO-1 expression, thus influencing receptivity. We analyzed the serum levels of progesterone and estrogen by ELISA and HO-1 mRNA expression in uterus by real time RT-PCR at the metestrus, proestrus, estrus and diestrus phases of the estrous cycle. Further, we studied the HO-1 protein expression by Western Blot upon hormone addition to cultured uterine AN3 cells. We observed that HO-1 variations in uterine tissue correlated to changes in hormonal levels at different phases of the estrus cycle. In vitro, HO-1 protein levels in AN3 cells augmented after the addition of physiological concentrations of progesterone and estradiol, which confirmed our in vivo observations. Our data suggest an important role for hormones in HO-1 regulation in uterus that has a significant impact in receptivity and later on blastocyst implantation.

Sex differences in the stress response in SD rats.

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Lu, Jing; Wu, Xue-Yan; Zhu, Qiong-Bin; Li, Jia; Shi, Li-Gen; Wu, Juan-Li; Zhang, Qi-Jun; Huang, Man-Li; Bao, Ai-Min

2015-05-01

Sex differences play an important role in depression, the basis of which is an excessive stress response. We aimed at revealing the neurobiological sex differences in the same study in acute- and chronically-stressed rats. Female Sprague-Dawley (SD) rats were randomly divided into 6 groups: chronic unpredictable mild stress (CUMS), acute foot shock (FS) and controls, animals in all 3 groups were sacrificed in proestrus or diestrus. Male SD rats were randomly divided into 3 groups: CUMS, FS and controls. Comparisons were made of behavioral changes in CUMS and control rats, plasma levels of corticosterone (CORT), testosterone (T) and estradiol (E2), and of the hypothalamic mRNA-expression of stress-related molecules, i.e. estrogen receptor α and β, androgen receptor, aromatase, mineralocorticoid receptor, glucocorticoid receptor, corticotropin-releasing hormone, arginine vasopressin and oxytocin. CUMS resulted in disordered estrus cycles, more behavioral and hypothalamic stress-related molecules changes and a stronger CORT response in female rats compared with male rats. Female rats also showed decreased E2 and T levels after FS and CUMS, while male FS rats showed increased E2 and male CUMS rats showed decreased T levels. Stress affects the behavioral, endocrine and the molecular response of the stress systems in the hypothalamus of SD rats in a clear sexual dimorphic way, which has parallels in human data on stress and depression. Copyright © 2015 Elsevier B.V. All rights reserved.

Ovarian hormones modify anxiety behavior and glucocorticoid receptors after chronic social isolation stress.

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Ramos-Ortolaza, Dinah L; Doreste-Mendez, Raura J; Alvarado-Torres, John K; Torres-Reveron, Annelyn

2017-06-15

Chronic social isolation could lead to a disruption in the Hypothalamic-Pituitary-Adrenal (HPA) axis, resulting in anxiety and depressive-like behaviors but cycling estrogens could modify these behaviors. The aim of this study was to determine if changes in ovarian hormones during the normal cycle could interact with social isolation to alter anxiety and depressive-like behaviors. In parallel, we examined the expression of glucocorticoid receptor (GR) and synaptic vesicle protein synaptophysin in the hippocampus and hypothalamus of Sprague Dawley normal cycling female rats. We assigned rats to either isolated or paired housing for 8 weeks. To assess anxiety and depressive-like behaviors, we used the open field test and forced swim test, respectively. Female rats were tested at either diestrus, estrus, or proestrus stage of the estrous cycle. After behaviors, rats were perfused and brains collected. Brain sections containing hippocampus and hypothalamus were analyzed using immunohistochemistry for synaptophysin and glucocorticoid receptor (GR) levels. We found an increase in depressive-like behaviors for isolated animals compared to paired housed rats, regardless of the estrous cycle stage. Interestingly, we found a decrease in anxiety behaviors in females in the estrus stage accompanied by a decrease in GR expression in hippocampal DG and CA3. However, no changes in synaptophysin were observed in any of the areas of studied. Our results support the beneficial effects of circulating ovarian hormones in anxiety, possibly by decreasing GR expression. Copyright © 2017 Elsevier B.V. All rights reserved.

In Utero and Lactational Effects of Aqueous Foeniculum Vulgare (Fennel Seed Extract on Puberty Timing, Estrus Cycle and Sexual Behavior in Mice

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Rahmatollah Parandin

2018-02-01

Full Text Available Abstract Background: Several studies have shown that developmental exposure to phytoestrogens causes adverse effects on the reproductive functions. Fennel as a phytoestrogen plant has a rich history in household use and traditional medicine.So, the current study was designed to investigate the effects of in utero and neonatal exposure with fennel on the puberty onset, estrus cycle, reproductive organs and sexual behavior of their offspring. Materials and Methods: BALB/c mice were injected intraperitoneally with 0 (control, 100, 200 and 400 (mg/kg bw aqueous fennel seed extract (AFSE, daily from day 7 of gestation to postnatal day (PND 7. Results: Vaginal opening (sign of puberty onset was advanced in 200 (p<0.01 and 400 AFSE (p<0.001 treated females. A 30 days vaginal smear check indicated that 200 or 400 AFSE treated mice showed a prolonged estrus with decreased proestrus, estrus and metestrus stages and increased and diestrus stage and index. The ovary weight, number of corpora lutea and LH concentration decreased and uterus weight and estradiol concentration increased in the 200 or 400 treated mice in PND 70. 400 AFSE (p<0.01 treated females showed lordosis with a low lordosis quotient (LQ when compared to the control group. Conclusion: These results suggest that developmental exposure to AFSE, due to its estrogenic compounds, it may cause the precocious puberty, disrupted estrus cycle, altered weight of reproductive organs, hormonal imbalance and low lordosis behavior.

Sites of production of sex steroids: secretion of steroids from x-irradiated and polycystic ovaries of rats

International Nuclear Information System (INIS)

Sawada, T.; Ichikawa, S.

1978-01-01

Ovaries of immature rats and PMS-induced pregnant rats were unilaterally x-irradiated. Ten days later, the concentrations of pregnane compounds in the ovarian venous plasma were measured. LH (2 μg) was injected iv 30 min before bleeding. A comparison of steroid levels in the ovarian venous effluent of rats with and without destruction of selected tissue components by irradiation of the ovaries suggests that the follicles contribute to the secretion of 5α-pregnane-3,20-dione and 3α-hydroxy-5α-pregnan-20-one in the presence of interstitial gland tissue. Because it is known that follicular tissue is involved in the production of estrogens, we studied the interrelationship between the secretion of the two progesterone metabolites and estrogens in follicular polycystic ovaries of androgen-sterilized rats. Normal ovaries of diestrus-2 rats were used as controls for the polycystic ovaries. The injection of LH greatly increased the secretion of 5α-pregnane-3,20-dione and 3α-hydroxy-5α-pregnan-20-one within 1 h in normal ovaries, but the response of polycystic ovaries was low, suggesting low 5α-reductase activity in the cystic ovary. The polycystic ovaries exhibited a marked increase in the secretion of estrogens in response to LH, whereas normal ovaries showed no significant change. These results suggest that low 5α-reductase activity may be causally related to the high level of estrogen secretion in polycystic ovaries of androgen-sterilized rats

Kisspeptin system in ovariectomized mice: Estradiol and progesterone regulation.

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Marraudino, Marilena; Martini, Mariangela; Trova, Sara; Farinetti, Alice; Ponti, Giovanna; Gotti, Stefano; Panzica, GianCarlo

2018-06-01

The kisspeptin system is clustered in two main groups of cell bodies (the periventricular region, RP3V and the arcuate nucleus, ARC) that send fibers mainly to the GnRH neurons and in a few other locations, including the paraventricular nucleus, PVN. In physiological conditions, gonadal hormones modulate the kisspeptin system with expression changes according to different phases of the estrous cycle: the highest being in estrus phase in RP3V and PVN (positive feedback), and in ARC during the diestrus phase (negative feedback). In this work we wanted to study these hormonal fluctuations during the estrous cycle, investigating the role played by progesterone (P) or estradiol (E 2 ), alone or together, on the kisspeptin system. Gonadectomized CD1 female mice were treated with P, E 2 or both (E 2  + P), following a timing of administration that emulates the different phases of estrous cycle, for two cycles of 4 days. As expected, the two cell groups were differentially affected by E 2 ; the RP3V group was positively influenced by E 2 (alone or with the P), whereas in the ARC the administration of E 2 did not affect the system. However P (alone) induced a rise in the kisspeptin immunoreactivity. All the treatments significantly affected the kisspeptin innervation of the PVN, with regional differences, suggesting that these fibers arrive from both RP3V and ARC nuclei. Copyright © 2018 Elsevier B.V. All rights reserved.

Prenatal zinc reduces stress response in adult rat offspring exposed to lipopolysaccharide during gestation.

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Galvão, Marcella C; Chaves-Kirsten, Gabriela P; Queiroz-Hazarbassanov, Nicolle; Carvalho, Virgínia M; Bernardi, Maria M; Kirsten, Thiago B

2015-01-01

Previous investigations by our group have shown that prenatal treatment with lipopolysaccharide (LPS; 100 μg/kg, intraperitoneally) on gestation day (GD) 9.5 in rats, which mimics infections by Gram-negative bacteria, induces short- and long-term behavioral and neuroimmune changes in the offspring. Because LPS induces hypozincemia, dams were treated with zinc after LPS in an attempt to prevent or ameliorate the impairments induced by prenatal LPS exposure. LPS can also interfere with hypothalamic-pituitary-adrenal (HPA) axis development; thus, behavioral and neuroendocrine parameters linked to HPA axis were evaluated in adult offspring after a restraint stress session. We prenatally exposed Wistar rats to LPS (100 μg/kg, intraperitoneally, on GD 9.5). One hour later they received zinc (ZnSO4, 2 mg/kg, subcutaneously). Adult female offspring that were in metestrus/diestrus were submitted to a 2 h restraint stress session. Immediately after the stressor, 22 kHz ultrasonic vocalizations, open field behavior, serum corticosterone and brain-derived neurotrophic factor (BDNF) levels, and striatal and hypothalamic neurotransmitter and metabolite levels were assessed. Offspring that received prenatal zinc after LPS presented longer periods in silence, increased locomotion, and reduced serum corticosterone and striatal norepinephrine turnover compared with rats treated with LPS and saline. Prenatal zinc reduced acute restraint stress response in adult rats prenatally exposed to LPS. Our findings suggest a potential beneficial effect of prenatal zinc, in which the stress response was reduced in offspring that were stricken with infectious/inflammatory processes during gestation. Copyright © 2014 Elsevier Inc. All rights reserved.

Tributyltin impairs the reproductive cycle in female rats.

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Lang Podratz, Priscila; Delgado Filho, Vicente Sathler; Lopes, Pedro Francisco Iguatemy; Cavati Sena, Gabriela; Matsumoto, Silvia Tamie; Samoto, Vivian Yochiko; Takiya, Christina Maeda; de Castro Miguel, Emilio; Silva, Ian Victor; Graceli, Jones Bernardes

2012-01-01

Triorganotins are environmental contaminants, commonly used in antifouling agents for boats, that bioaccumulate and thus are found in mammals and humans due to ingestion of contaminated seafood diets. The importance of triorganotins as environmental endocrine disruptors and consequent reproductive toxicity in different animal models is well known; however, the adverse effects on reproductive cycle are less well understood. The potential reproductive toxicity of tributyltin (TBT) on regular reproductive cycling of female rats was examined. Wistar female rats (12 wk old, weighing approximately 230 g) were divided into two groups: control (vehicle, ethanol 0.4%) and tributyltin (100 ng/kg/d, 7 d/wk, for 16 d by gavage). Tributyltin significantly decreased the cycle regularity (%), duration of the reproductive cycle, the proestrus and diestrus phases, and number of epithelial cell in proestrus phase. TBT also increased the duration of metestrus and the number of cornified cells in this phase. Ovary weight and serum 17β-estradiol levels decreased markedly, accompanied by a significant increase in progesterone levels. Histological analysis showed apoptotic cells in corpus luteum and granulosa cells layer, with cystic follicles after TBT exposure. Tributyltin also elevated number of atretic follicles and corpoa lutea. The micronucleus (MN) test, using Chinese hamster ovary cells, demonstrated a concentration-dependent mutagenic effect of TBT, and at 2.0 × 10(-2)ng/ml most of the cells were nonviable. The toxic potential of TBT over the reproductive cycle may be attributed to changes found in the ovarian weight, unbalanced levels of sexual female hormones, and number of ovarian follicles and corpora lutea.

Vaginocervical stimulation enhances social recognition memory in rats via oxytocin release in the olfactory bulb.

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Larrazolo-López, A; Kendrick, K M; Aburto-Arciniega, M; Arriaga-Avila, V; Morimoto, S; Frias, M; Guevara-Guzmán, R

2008-03-27

The ability of vaginocervical stimulation (VCS) to promote olfactory social recognition memory at different stages of the ovarian cycle was investigated in female rats. A juvenile social recognition paradigm was used and memory retention tested at 30 and 300 min after an adult was exposed to a juvenile during three 4-min trials. Results showed that an intact social recognition memory was present at 30 min in animals with or without VCS and at all stages of the estrus cycle. However, whereas no animals in any stage of the estrus cycle showed retention of the specific recognition memory at 300 min, those in the proestrus/estrus phase that received VCS 10 min before the trial started did. In vivo microdialysis studies showed that there was a significant release of oxytocin after VCS in the olfactory bulb during proestrus. There was also increased oxytocin immunoreactivity within the olfactory bulb after VCS in proestrus animals compared with diestrus ones. Furthermore, when animals received an infusion of an oxytocin antagonist directly into the olfactory bulb, or a systemic administration of alpha or beta noradrenaline-antagonists, they failed to show evidence for maintenance of a selective olfactory recognition memory at 300 min. Animals with vagus or pelvic nerve section also showed no memory retention when tested after 300 min. These results suggest that VCS releases oxytocin in the olfactory bulb to enhance the social recognition memory and that this may be due to modulatory actions on noradrenaline release. The vagus and pelvic nerves are responsible for carrying the information from the pelvic area to the CNS.

Sensitive radioimmunoassay of total thyroxine (T4) in horses using a simple extraction method.

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Tangyuenyong, Siriwan; Nambo, Yasuo; Nagaoka, Kentaro; Tanaka, Tomomi; Watanabe, Gen

2017-07-28

Most thyroid hormone determinations in animals are based on immunoassays adapted from those used to test human samples, which may not reflect the actual values of thyroid hormone in horses because of the presence of binding proteins. The aims of the present study were i) to establish a novel radioimmunoassay (RIA) using a more simple and convenient method to separate binding proteins for the measurement of total thyroxine (T4) in horses and ii) to validate the assay by comparing total T4 concentrations in yearling horses raised in different climates. Blood samples were collected from trained yearlings in Hokkaido (temperate climate) and Miyazaki (subtropical climate) in Japan and from adult horses in estrus and diestrus. T4 was extracted from both serum and plasma using modified acid ethanol cryo-precipitation and sodium acetate ethanol methods. Circulating total T4 concentrations were determined by RIA. T4 concentration by sodium acetate ethanol was appropriately detectable rather than sodium salicylate method and was the same as for acid ethanol method. Furthermore, this sodium acetate ethanol method required fewer extraction steps than the other methods. Circulating T4 concentrations in yearlings were 225.98 ± 20.89 ng/ml, which was higher than the previous reference values. With respect to climate, T4 levels in Hokkaido yearlings tended to be higher than those in Miyazaki yearlings throughout the study period. These results indicated that this RIA protocol using a modified sodium acetate ethanol separation technique might be an appropriate tool for specific measurement of total T4 in horses.

The fate of autologous endometrial mesenchymal stromal cells after application in the healthy equine uterus.

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Rink, Elisabeth; Beyer, Teresa; French, Hilari; Watson, Elaine; Aurich, Christine; Donadeu, Xavier

2018-05-23

Because of their distinct differentiation, immunomodulatory and migratory capacities, endometrial mesenchymal stromal cells (MSCs) may provide an optimum source of therapeutic cells not only in relation to the uterus but also for regeneration of other tissues. This study reports the fate of endometrial MSCs following intrauterine application in mares. Stromal cell fractions were isolated from endometrial biopsies taken from seven reproductively healthy mares, expanded and fluorescence-labeled in culture. MSCs (15 x 106) or PBS were autologously infused into each uterine horn during early diestrus and subsequently tracked by fluorescence microscopy and flow cytometry of endometrial biopsies and blood samples taken periodically after infusion. The inflammatory response to cell infusion was monitored in endometrial cytology samples. MSCs were detected in endometrial sections at 6, 12 and 24 hours but not later (7 or 14 days) after cell infusion. Cells were in all cases located in the uterine lumen, never within endometrial tissue. No fluorescence signal was detected in blood samples at any time point after infusion. Cytology analyses showed an increase in %PMN between 1 and 3 hours after uterine infusion with either MSCs or PBS, and a further increase by 6 hours only in mares infused with PBS. In summary, endometrial MSCs were detected in the uterine lumen for up to 24 h after infusion but did not migrate into healthy endometrium. Moreover, MSCs effectively attenuated the inflammatory response to uterine infusion. We conclude that endometrial MSCs obtained from routine uterine biopsies could provide a safe and effective cell source for treatment of inflammatory conditions of the uterus and potentially other tissues.

A Novel Letrozole Model Recapitulates Both the Reproductive and Metabolic Phenotypes of Polycystic Ovary Syndrome in Female Mice1

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Kauffman, Alexander S.; Thackray, Varykina G.; Ryan, Genevieve E.; Tolson, Kristen P.; Glidewell-Kenney, Christine A.; Semaan, Sheila J.; Poling, Matthew C.; Iwata, Nahoko; Breen, Kellie M.; Duleba, Antoni J.; Stener-Victorin, Elisabet; Shimasaki, Shunichi; Webster, Nicholas J.; Mellon, Pamela L.

2015-01-01

Polycystic ovary syndrome (PCOS) pathophysiology is poorly understood, due partly to lack of PCOS animal models fully recapitulating this complex disorder. Recently, a PCOS rat model using letrozole (LET), a nonsteroidal aromatase inhibitor, mimicked multiple PCOS phenotypes, including metabolic features absent in other models. Given the advantages of using genetic and transgenic mouse models, we investigated whether LET produces a similar PCOS phenotype in mice. Pubertal female C57BL/6N mice were treated for 5 wk with LET, which resulted in increased serum testosterone and normal diestrus levels of estradiol, similar to the hyperandrogenemia and follicular phase estrogen levels of PCOS women. As in PCOS, ovaries from LET mice were larger, polycystic, and lacked corpora lutea versus controls. Most LET females were acyclic, and all were infertile. LET females displayed elevated serum LH levels and higher Lhb mRNA in the pituitary. In contrast, serum FSH and Fshb were significantly reduced in LET females, demonstrating differential effects on gonadotropins, as in PCOS. Within the ovary, LET females had higher Cyp17, Cyp19, and Fsh receptor mRNA expression. In the hypothalamus, LET females had higher kisspeptin receptor mRNA expression but lower progesterone receptor mRNA levels. LET females also gained more weight than controls, had increased abdominal adiposity and adipocyte size, elevated adipose inflammatory mRNA levels, and impaired glucose tolerance, mirroring the metabolic phenotype in PCOS women. This is the first report of a LET paradigm in mice that recapitulates both reproductive and metabolic PCOS phenotypes and will be useful to genetically probe the PCOS condition. PMID:26203175

Electron-microscopic characteristics of neuroendocrine neurons in the amygdaloid body of the brain in male rats and female rats at different stages of the estral cycle.

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Akhmadeev, A V; Kalimullina, L B

2008-01-01

The ultrastructural features of neuroendocrine neurons in the dorsomedial nucleus (DMN) of the amygdaloid body of the brain - one of the major zones of sexual dimorphism - in 12 Wistar rats weighing 250-300 g were studied in three males and nine females at different stages of the estral cycle. On the basis of ultrastructural characteristics, analysis of the functional states of an average of 50 DMN neurons were studied in each animal. A morphofunctional classification reflecting hormone-dependent variations in neuron activity is proposed. DMN neurons were found to be in different structural-functional states, which could be classified as the states of rest, moderate activity, elevated activity, tension (maximal activity), decreased activity (types 1 and 2, depending on prior history), return to the initial state, and apoptosis. At the estrus stage, there was a predominance of neurons in the states of elevated activity (40% of all cells) and maximal activity (26%). At the metestrus stage, neurons in the state of decreased activity type 1 (with increased nuclear heterochromatin content) predominated (30% of cells), while 25% and 20% of cells were in the states of maximal activity and elevated activity respectively. In diestrus, neurons in the resting state, in moderate and elevated activity, in maximal activity, and in decreased activity type 1 were present in essentially identical proportions (18%, 21%, 18%, 20%, and 16% respectively). In males, 35% and 22% of neurons were in the states of elevated and maximal activity respectively. Neuron death was seen only in males.

Estrus, ovulation, and serum progesterone, estradiol, and LH concentrations in mares after an increased photoperiod during winter.

Science.gov (United States)

Oxender, W D; Noden, P A; Hafs, H D

1977-02-01

On December 11, 1974, 15 seasonally anestrous mares were assigned at random to 1 of 3 experimental groups: outdoor-control, indoor-control, or indoor light-treated (a 16-hour photo-period). This experiment was terminated on April 21, 1975. The five mares in the indoor light-treated group ovulated 59.0+/-6.9 days later, which was 74 days earlier (P less than 0.01) than 2 of the 5 outdoor-controls (the other 3 ovulated after April 21 during a subsequent experiment) and 50 days earlier (P less than 0.05) than the indoor-controls. Durations of the 1st estrus for the 3 groups of mares were 13.3+/-3.6, 8.4+/-2.0, and 6.0+/-1.0 days for the indoor light-treated, indoor-control, and outdoor-control groups, respectively. The indoor light-treated mares averaged 4.2 estrous cycles before April 21, the indoor-control mares averaged 1.4 estrous cycles, and 2 of 5 outdoor-control mares ovulated 1 time during the experiment. The peripheral blood luteinizing hormone (LH), estradiol, and progesterone concentrations were minimal during winter anestrous. The hormone changes normally associated with estrous cycle activity in mares--maximal estradiol and luteinizing hormone concentrations near ovulation and maximal progesterone concentration during diestrus--were observed in all mares beginning at the 1st estrus. Hair loss was observed earlier in the light-treated mares, than in either of the other groups. In conclusion, a 16-hour photo-period initiated in early December for anestrous brood mares caused endocrinologically normal estrous cycles to begin within 2 months. This may allow breeding and foaling considerably earlier than normally expected.

Estradiol increases the expression of TNF-α and TNF receptor 1 in lactotropes.

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Zaldivar, Verónica; Magri, María Laura; Zárate, Sandra; Jaita, Gabriela; Eijo, Guadalupe; Radl, Daniela; Ferraris, Jimena; Pisera, Daniel; Seilicovich, Adriana

2011-01-01

Estrogens are recognized modulators of pituitary cell renewal, sensitizing cells to mitogenic and apoptotic signals. Tumor necrosis factor-α (TNF-α) is a proinflammatory cytokine that plays an important role in tissue homeostasis modulating cell proliferation, differentiation and death. We previously demonstrated that TNF-α-induced apoptosis of anterior pituitary cells from female rats is estrogen-dependent and predominant in cells from rats at proestrus when estradiol levels are the highest. Considering that one of the mechanisms involved in the apoptotic action of estrogens can result from increased expression of cytokines and/or their receptors, the aim of the present study was to evaluate the effect of estrogens on the expression of TNF-α and its receptor, TNF receptor 1 (TNFR1), in anterior pituitary cells. TNFR1 expression, determined by Western blot, was higher in anterior pituitary glands from rats at proestrus than at diestrus. Incubation of anterior pituitary cells from ovariectomized rats with 17β-estradiol enhanced TNFR1 protein expression. As determined by double immunocytochemistry, the expression of TNF-α and TNFR1 was detected in prolactin-, GH-, LH- and ACTH-bearing cells. 17β-estradiol increased the percentage of TNF-α and TNFR1-immunoreactive lactotropes but did not modify the number of GH-bearing cells expressing TNF-α or TNFR1. Our results demonstrate that estradiol increases the expression of TNF-α and TNFR1 in anterior pituitary cells, especially in lactotropes. The sensitizing action of estrogens to proapoptotic stimuli at proestrus in the anterior pituitary gland may involve changes in the expression of the TNF-α/TNFR1 system. Copyright © 2011 S. Karger AG, Basel.

Developmental changes in FSH secretion induced by 5-hydroxytryptophan, naloxone and haloperidol in male and female rats.

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Becú-Villalobos, D; Lacau-Mengido, I M; Libertun, C

1989-06-01

Follicle-stimulating hormone (FSH) secretion is increased in the immature female rat from day 5 to days 17-18 of life, and decreases steadily thereafter until puberty. It has been reported that estradiol negative feedback and inhibin-like peptides are low during this period, while luteinizing hormone (LH) and FSH sensitivity to LH-releasing hormone (LHRH) are maximal. It was therefore of interest to study the effects of some neurotropic drugs on FSH release at 12 days of age, and to compare their effects at 1 and 20 days. Besides, as developmental patterns and regulation of FSH are different in male and female rats, the experiments were carried out using male and female littermates. The drugs chosen were haloperidol, 5-hydroxytryptophan and naloxone. These drugs release LH in the infantile female rat, the effect decreasing or disappearing as the animal matures; no effects of these drugs have been reported on FSH release in infantile rats to the present time. It was found that haloperidol (0.25 mg/kg), naloxone (2 mg/kg) and 5-hydroxytryptophan (50 mg/kg) markedly increased the already high titers of FSH in the 12-day-old female rat. This effect could not be discerned in newborn rats, and had disappeared at 20 days of age. Male littermates failed to respond at any age. When adult male and female rats in diestrus were tested, all drugs at the chosen doses were ineffective in altering FSH release. These data suggest that the infantile female rat represents an interesting physiological model to evaluate the neural regulation of FSH in a situation in which inhibitory signals provided by inhibin and estrogen in later life are diminished.

Effects of thyroid status on NEI concentration in specific brain areas related to reproduction during the estrous cycle.

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Ayala, Carolina; Pennacchio, Gisela Erika; Soaje, Marta; Carreño, Norma Beatriz; Bittencourt, Jakson Cioni; Jahn, Graciela Alma; Celis, María Ester; Valdez, Susana Ruth

2013-11-01

We previously showed that short-term hypo- and hyperthyroidism induce changes in neuropeptide glutamic-acid-isoleucine-amide (NEI) concentrations in discrete brain areas in male rats. To investigate the possible effects of hypo- and hyperthyroidism on NEI concentrations mainly in hypothalamic areas related to reproduction and behavior, female rats were sacrificed at different days of the estrous cycle. Circulating luteinizing hormone (LH), estradiol and progesterone concentrations were measured in control, hypothyroid (hypoT, treated with PTU during 7-9 days) and hyperthyroid (hyperT, l-T4 during 4-7 days) animals. Both treatments blunted the LH surge. Hypo- and hyperthyroidism increased estradiol concentrations during proestrus afternoon (P-PM), although hypoT rats showed lower values compared to control during proestrus morning (P-AM). Progesterone levels were higher in all groups at P-PM and in the hyperT during diestrus morning (D2). NEI concentrations were lower in hypoT rats during the estrous cycle except in estrus (E) in the peduncular part of the lateral hypothalamus (PLH). They were also reduced by both treatments in the perifornical part of the lateral hypothalamus (PeFLH) during P-PM. Hypothyroidism led to higher NEI concentrations during P-PM in the organum vasculosum of the lamina terminalis and anteroventral periventricular nucleus (OVLT+AVPV). The present results indicate that NEI concentration is regulated in a complex manner by hypo- and hyperthyroidism in the different areas studied, suggesting a correlation between NEI values and the variations of gonadal steroid levels during estrous cycle. These changes could be, in part, responsible for the alterations observed in the hypothalamic-pituitary-gonadal axis in these pathologies. Copyright © 2013 Elsevier Inc. All rights reserved.

Steroid influences on GABAergic neurotransmission: A behavioral and biochemical approach

International Nuclear Information System (INIS)

McCarthy, M.M.

1989-01-01

Steroid influences on GABAergic neurotransmission are varied and complex. However, there has been little investigation into the behavioral relevance of steroid effects on GABA. GABA had been implicated in the control of lordosis, a steroid dependent posture exhibited by sexually receptive female rats, but with conflicting results. This data demonstrated that GABA plays a dual role in the regulation of lordosis; stimulation of GABAergic transmission in the medial hypothalamus enhances lordosis whereas stimulation of GABA in the preoptic area inhibits lordosis. In separate experiments it was determined that progesterone enhances binding of the GABA A agonist, muscimol, in an in vitro exchange assay utilizing synaptic membranes prepared from the hypothalamus of ovariectomized rats. Scatchard analysis revealed a difference in affinity of the GABA A receptor between ovariectomized, receptive and post receptive females. In the preoptic area there was a significant decrease in the binding of 3 H-muscimol in receptive females versus post-receptive and ovariectomized rats. In other behavioral experiments, the influence of estrogen and progesterone on GABA-induced analgesia was assessed. Intrathecal infusion of a low dose of muscimol at the lumbar level of the spinal cord did not alter nociceptive thresholds in ovariectomized rats. However, when intact females were administered the same dose of muscimol, they exhibited differential responses over the estrous cycle. Females in estrus were analgesic after muscimol, whereas diestrus females did not differ from ovariectomized controls. Ovariectomized rats injected s.c. with progesterone (2mg) exhibited a pronounced analgesia after intrathecal muscimol beginning 15 minutes after steroid treatment, whereas similar treatment with estrogen (10ug) was without effect

Efficiency of different hormonal treatments for estrus synchronization in tropical Santa Inês sheep.

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Texeira, Tarcísio Alves; da Fonseca, Jeferson Ferreira; de Souza-Fabjan, Joanna Maria Gonçalves; de Rezende Carvalheira, Luciano; de Moura Fernandes, Daniel Andrews; Brandão, Felipe Zandonadi

2016-03-01

The aim of this study was to evaluate the effect of (i) the duration of hormone treatment with progestogen sponges during the seasonal anestrus and (ii) the administration of two doses of prostaglandin at 7 days apart during the breeding season on reproductive parameters of Santa Inês ewes. In experiment 1, 32 ewes received intravaginal MAP sponges for 6 (G6 days), 9 (G9 days), or 12 (G12days) days and 75 μg D-cloprostenol i.m. and 300 IU eCG i.m. 1 day before sponge removal. In experiment 2, 23 ewes received two doses of 0.48-mg sodium cloprostenol i.m. 7 days apart. Ovarian follicular dynamic was assessed through transrectal ultrasonography. Blood samples were collected daily to determine progesterone concentrations. In experiment 1, estrus and ovulation rates did not differ (P > 0.05) among protocols and between cyclic and acyclic ewes at the beginning of the experiment. The G9 days treatment showed a lower dispersion of ovulations in relation to onset of estrus when compared to G6 days and G12 days. In experiment 2, all ewes exhibit estrus and ovulated after the second dose of prostaglandin, although ewes that were in diestrus at D0 showed subluteal concentrations of progesterone during the follicle development stage of the treatment. In conclusion, the use of progestogen device during 9 days promotes lower dispersion of ovulation when compared to its use for 6 or 12 days, and the protocol of two doses of prostaglandin 7 days apart synchronizes estrus efficiently but results in follicular development under low progesterone concentrations.

Analysis of activity and motor coordination in rats undergoing stereotactic surgery and implantation of a cannula into the dorsal hippocampus.

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Hernández-López, F; Rodríguez-Landa, J F; Puga-Olguín, A; Germán-Ponciano, L J; Rivadeneyra-Domínguez, E; Bernal-Morales, B

Stereotactic surgery is used to place electrodes or cannulas in the brain in order to study the function of several brain structures in preclinical research. The hippocampus has been extensively studied with this methodology due to its involvement in a wide range of neurological, cognitive, emotional, and affective disorders. However, the effects of stereotactic surgery on coordination and motor activity should be evaluated in order to determine whether this surgical procedure causes any neurological alterations that may bias the results of studies incorporating this technique. We evaluated the effects of stereotactic surgery and implantation of a cannula into the hippocampus of female Wistar rats on the motor activity, forced swim, and rotarod tests. The stage of the oestrous cycle was included in the statistical analysis. Stereotactic surgery had no impact on any of the motor activity variables assessed in the open field (squares crossed, time spent in grooming, and rearing), forced swim (turning behaviour, lateral swimming, latency to first immobility, and time spent immobile), and rotarod (latency to fall) tests, compared with intact rats. Regardless of surgical manipulation, rats in the metestrus and diestrus stages crossed a greater number of squares and displayed longer immobility times than those in the proestrus and estrus stages. Stereotactic surgery for cannula placement in the dorsal hippocampus does not affect coordination and motor activity in rats. We can therefore conclude that this procedure has no neurological complications that may interfere in the interpretation of results of studies applying this technique. Copyright © 2016 Sociedad Española de Neurología. Publicado por Elsevier España, S.L.U. All rights reserved.

Functional hypothalamic amenorrhea due to increased CRH tone in melanocortin receptor 2-deficient mice.

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Matsuwaki, Takashi; Nishihara, Masugi; Sato, Tsuyoshi; Yoda, Tetsuya; Iwakura, Yoichiro; Chida, Dai

2010-11-01

Exposure to chronic stressors results in dysregulation of the hypothalamic-pituitary-adrenal axis and a disruption in reproduction. CRH, the principal regulator of the hypothalamic-pituitary-adrenal axis induces the secretion of ACTH from the pituitary, which stimulates adrenal steroidogenesis via the specific cell-surface melanocortin 2 receptor (MC2R). Previously, we demonstrated that MC2R(-/-) mice had undetectable levels of corticosterone despite high ACTH levels. Here, we evaluated the reproductive functions of female MC2R(-/-) mice and analyzed the mechanism of the disrupted cyclicity of these mice. The expression of CRH in the paraventricular nucleus was significantly increased in MC2R(-/-) mice under nonstressed conditions. Although MC2R(-/-) females were fertile, they showed a prolonged estrous cycle. After hormonal stimulation, MC2R(-/-) females produced nearly-normal numbers of eggs, but slightly less than MC2R(+/-) females, and showed near-normal ovarian histology. During diestrus, the number of GnRH-positive cells in the medial preoptic area was significantly reduced in MC2R(-/-) females. CRH type 1 receptor antagonist restored estrous cyclicity in MC2R(-/-) females. Kisspeptin-positive areas in the arcuate nucleus were comparable, whereas kisspeptin-positive areas in the anteroventral periventricular nucleus in MC2R(-/-) females were significantly reduced compared with MC2R(+/-) females, suggesting that arcuate nucleus kisspeptin is not involved, but anteroventral periventricular nucleus kisspeptin may be involved, in the maintenance of estrous cyclicity. Our findings show that high levels of hypothalamic CRH disturb estrous cyclicity in the female animals and that the MC2R(-/-) female is a unique animal model of functional hypothalamic amenorrhea.

RHOG-DOCK1-RAC1 Signaling Axis Is Perturbed in DHEA-Induced Polycystic Ovary in Rat Model.

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Ubba, Vaibhave; Soni, Upendra Kumar; Chadchan, Sangappa; Maurya, Vineet Kumar; Kumar, Vijay; Maurya, Ruchika; Chaturvedi, Himanshu; Singh, Rajender; Dwivedi, Anila; Jha, Rajesh Kumar

2017-05-01

The function of RHOG, a RAC1 activator, was explored in the ovary during ovarian follicular development and pathological conditions. With the help of immunoblotting and immunolocalization, we determined the expression and localization of RHOG in normal (estrous cycle) and polycystic ovaries using Sprague Dawley (SD) rat model. Employing polymerase chain reaction and flow cytometry, we analyzed the transcript and expression levels of downstream molecules of RHOG, DOCK1, and RAC1 in the polycystic ovarian syndrome (PCOS) ovary along with normal antral follicular theca and granulosa cells after dehydroepiandrosterone (DHEA) supplementation. The effect of RHOG knockdown on DOCK1, VAV, and RAC1 expression was evaluated in the human ovarian cells (SKOV3), theca cells, and granulosa cells from SD rats with the help of flow cytometry. Oocyte at secondary follicles along with stromal cells showed optimal expression of RHOG. Immunoblotting of RHOG revealed its maximum expression at diestrus and proestrus, which was downregulated at estrus stage. Mild immunostaining of RHOG was also present in the theca and granulosa cells of the secondary and antral follicles. Polycystic ovary exhibited weak immunostaining for RHOG and that was corroborated by immunoblotting-based investigations. RHOG effectors DOCK1 and ELMO1 were found reduced in the ovary in PCOS condition/DHEA. RHOG silencing reduced the expression of DOCK1 and RAC1 in the theca and granulosa cells from SD rat antral follicles and that was mirrored in the human ovarian cells. Collectively, RHOG can mediate signaling through downstream effectors DOCK1 and RAC1 during ovarian follicular development (theca and granulosa cells and oocyte), but DHEA downregulated them in the PCOS ovary.

Genomic priming of the antisecretory response to estrogen in rat distal colon throughout the estrous cycle.

LENUS (Irish Health Repository)

O'Mahony, Fiona

2009-11-01

The secretion of Cl(-) across distal colonic crypt cells provides the driving force for the movement of fluid into the luminal space. 17beta-Estradiol (E2) produces a rapid and sustained reduction in secretion in females, which is dependent on the novel protein kinase C delta (PKC delta) isozyme and PKA isoform I targeting of KCNQ1 channels. This sexual dimorphism in the E2 response is associated with a higher expression level of PKC delta in female compared with the male tissue. The present study revealed the antisecretory response is regulated throughout the female reproductive (estrous) cycle and is primed by genomic regulation of the kinases. E2 (1-10 nm) decreased cAMP-dependent secretion in colonic epithelia during the estrus, metestrus, and diestrus stages. A weak inhibition of secretion was demonstrated in the proestrus stage. The expression levels of PKC delta and PKA fluctuated throughout the estrous cycle and correlated with the potency of the antisecretory effect of E2. The expression of PKC delta and PKA were up-regulated by estrogen at a transcriptional level via a PKC delta-MAPK-cAMP response element-binding protein-regulated pathway indicating a genomic priming of the antisecretory response. PK Cdelta was activated by the membrane-impermeant E2-BSA, and this response was inhibited by the estrogen receptor antagonist ICI 182,780. The 66-kDa estrogen receptor-alpha isoform was present at the plasma membrane of female colonic crypt cells with a lower abundance found in male colonic crypts. The study demonstrates estrogen regulation of intestinal secretion both at a rapid and transcriptional level, demonstrating an interdependent relationship between both nongenomic and genomic hormone responses.

Blood periovulatory progesterone quantification using different techniques in the dog.

Science.gov (United States)

Gloria, Alessia; Contri, Alberto; Carluccio, Augusto; Robbe, Domenico

2018-05-01

Blood progesterone concentration is used in several procedures related to the reproduction in the bitch, such as ovulation monitoring, estimating time of parturition, or hypo-luteoidism management. Several techniques are available to evaluate blood progesterone concentration, such as the radioimmunoassay (RIA), the chemiluminescent immunoassay (CLIA), and the enzyme-linked immunosorbent assay (ELISA). The aim of this study was to compare the blood progesterone concentration using these three methods during the periovulatory period of 23 bitches. Vaginal cytology was used to classify cytologic estrus (CE) and cytologic diestrus (CD), and blood samples were collected once during proestrus and every other day between CE and CD. The samples were retrospectively classified in the different phases of the estrus based on CD. Pregnancy rate and gestational length were also recorded. A significant increase of the circulating progesterone during the progression of the estrus was recorded, and there were significant differences in the values when using the different methods, with lesser, intermediate, and greatest values with use of the RIA, CLIA, and ELISA, respectively. There was a high correlation (Pearson's correlation coefficient = 0.978) and substantial strength-of-agreement (Lin's concordance correlation coefficient = 0.966) between values obtained when using CLIA and RIA, while there was a high correlation (Pearson's correlation coefficient = 0.955) but poor strength-of-agreement (Lin's concordance correlation coefficient = 0.866) with use of the ELISA and RIA. The data reported in this study provide evidence that the method used for measuring the blood progesterone concentration during the periovulatory phase of the bitch significantly affected the progesterone values. Copyright © 2018 Elsevier B.V. All rights reserved.

Neuromedin s as novel putative regulator of luteinizing hormone secretion.

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Vigo, E; Roa, J; López, M; Castellano, J M; Fernandez-Fernandez, R; Navarro, V M; Pineda, R; Aguilar, E; Diéguez, C; Pinilla, L; Tena-Sempere, M

2007-02-01

Neuromedin S (NMS), a 36 amino acid peptide structurally related to neuromedin U, was recently identified in rat brain as ligand for the G protein-coupled receptor FM4/TGR-1, also termed neuromedin U receptor type-2 (NMU2R). Central expression of NMS appears restricted to the suprachiasmatic nucleus, and NMS has been involved in the regulation of dark-light rhythms and suppression of food intake. Reproduction is known to be tightly regulated by metabolic and photoperiodic cues. Yet the potential contribution of NMS to the control of reproductive axis remains unexplored. We report herein analyses of hypothalamic expression of NMS and NMU2R genes, as well as LH responses to NMS, in different developmental and functional states of the female rat. Expression of NMS and NMU2R genes was detected at the hypothalamus along postnatal development, with significant fluctuations of their relative levels (maximum at prepubertal stage and adulthood). In adult females, hypothalamic expression of NMS (which was confined to suprachiasmatic nucleus) and NMU2R significantly varied during the estrous cycle (maximum at proestrus) and was lowered after ovariectomy and enhanced after progesterone supplementation. Central administration of NMS evoked modest LH secretory responses in pubertal and cyclic females at diestrus, whereas exaggerated LH secretory bursts were elicited by NMS at estrus and after short-term fasting. Conversely, NMS significantly decreased elevated LH concentrations of ovariectomized rats. In summary, we provide herein novel evidence for the ability of NMS to modulate LH secretion in the female rat. Moreover, hypothalamic expression of NMS and NMU2R genes appeared dependent on the functional state of the female reproductive axis. Our data are the first to disclose the potential implication of NMS in the regulation of gonadotropic axis, a function that may contribute to the integration of circadian rhythms, energy balance, and reproduction.

Differential expression of secretogranin II and chromogranin A genes in the female rat pituitary through sexual maturation and estrous cycle

International Nuclear Information System (INIS)

Anouar, Y.; Duval, J.

1991-01-01

Secretogranin II (SgII) is a protein of pituitary secretory granules released by LHRH-stimulated gonadotrope cells. Estrogens and androgens are modulators of SgII release. Experiments were performed to determine the regulation of expression of the SgII gene in the female rat pituitary, during sexual maturation and according to the estrous cycle. Age- and cycle-related changes in SgII mRNA content were estimated through cytoplasmic slot blot; SgII content was determined by western blotting; maturation of the protein was controlled through [35S]sulfate labeling. Variations in chromogranin A (CgA), another protein of secretory granules, were analyzed in the same experimental conditions to assess the specificity of SgII regulation. The pituitary SgII concentration increased between days 7 and 21 (2.2-fold) and then declined to the initial 7-day-old value. Simultaneously, the CgA concentration went through a maximum between days 14 and 21 and then strongly dropped to barely detectable levels in the adult pituitary. The SgII mRNA concentration followed roughly the same pattern as the protein. Moreover, the sulfation level remained constant between days 14 and 60. These results demonstrated a regulatory mechanism operating, during sexual maturation, on the SgII gene and not on the protein processing or on storage/release steps. In the 4-day cycling females, the pituitary SgII mRNA and protein contents were the lowest during estrus. They then increased to their highest values in diestrus II. Moreover, the sulfation level of SgII was significantly higher during estrus than during any other stage. Due to its low content level, variations in pituitary CgA could not be demonstrated during the cycle

Modulation of sodium-bicarbonate co-transporter (SLC4A4/NBCe1) protein and mRNA expression in rat's uteri by sex-steroids and at different phases of the oestrous cycle.

Science.gov (United States)

Gholami, Khadijeh; Muniandy, Sekaran; Salleh, Naguib

2014-02-01

Oestrogen-induced uterine fluid sodium (Na(+)) and bicarbonate (HCO3(-)) secretion may involve SLC4A4. We hypothesized that uterine SLC4A4 expression changes under different sex-steroid influence, therefore may account for the fluctuation in uterine fluid Na(+) and HCO3(-) content throughout the oestrous cycle. The aim of this study is to investigate the differential effects of sex-steroids and oestrous cycle phases on uterine SLC4A4 expression. Adult female WKY rats were ovariectomised and treated with different doses of 17β-oestradiol (E2) (0.2, 2, 20 and 50 μg/ml/day) or progesterone (P4) (4 mg/ml/day) for three consecutive days and 3 days treatment with 0.2 μg/ml/day E2 followed by another 3 days with P4 to mimic the hormonal changes in early pregnancy. Oestrous cycle phases in intact, non-ovariectomised rats were determined by vaginal smear. The animals were then sacrificed and uteri were removed for protein and mRNA expression analyses by Western blotting and Real Time PCR, respectively. SLC4A4 distribution was observed by immunohistochemistry. Treatment with increasing E2 doses resulted in a dose-dependent increase in SLC4A4 protein expression. High SLC4A4 protein and mRNA expression can be seen at estrus. SLC4A4 is distributed mainly at the apical as well as basolateral membranes of the luminal and glandular epithelia following E2 treatment and at Es. Meanwhile, SLC4A4 expression was reduced following P4 treatment and was low at diestrus. High SLC4A4 expression under estrogen dominance may contribute to the increase in uterine fluid Na(+) and HCO3(-) content, while its low expression under P4 dominance may result in vice versa. Copyright © 2013 Elsevier Ltd. All rights reserved.

Vaginal disorders.

Science.gov (United States)

Soderberg, S F

1986-05-01

Chronic vaginitis is the most common vaginal disorder. Dogs with vaginitis show no signs of systemic illness but often lick at the vulva and have purulent or hemorrhagic vaginal discharges. Vaginitis is most commonly secondary to a noninfectious inciting factor such as congenital vaginal anomalies, clitoral hypertrophy, foreign bodies, trauma to the vaginal mucosa, or vaginal tumors. Inspection of the caudal vagina and vestibule both visually and digitally will often reveal the source of vaginal irritation. Vaginal cytology is used to establish the stage of the estrous cycle as well as distinguish uterine from vaginal sources of discharge. Vaginal cultures are used to establish the predominant offending organism associated with vaginal discharges and may be used as a guide for selection of a therapeutic agent. Vaginitis is best managed by removing the inciting cause and treating the area locally with antiseptic douches. Congenital malformations at the vestibulovaginal or vestibulovulvar junction may prevent normal intromission. Affected bitches may be reluctant to breed naturally because of pain. Such defects are detected best by digital examination. Congenital vaginal defects may be corrected by digital or surgical means. Prolapse of tissue through the lips of the vulva may be caused by clitoral hypertrophy, vaginal hyperplasia, or vaginal tumors. Enlargement of clitoral tissue is the result of endogenous or exogenous sources of androgens. Treatment of this condition includes removal of the androgen source and/or surgical removal of clitoral tissue. Vaginal hyperplasia is detected during proestrus or estrus of young bitches. Hyperplastic tissue will regress during diestrus. Tissue that is excessively traumatized and/or prolapse of the entire vaginal circumference may be removed surgically. Ovariohysterectomy may be used to prevent recurrence. Vaginal tumors are detected most often in older intact bitches. Such tumors are generally of smooth muscle or fibrous

Parabens Accelerate Ovarian Dysfunction in a 4-Vinylcyclohexene Diepoxide-Induced Ovarian Failure Model

Directory of Open Access Journals (Sweden)

Jae-Hwan Lee

2017-02-01

Full Text Available Parabens are widely used preservatives in basic necessities such as cosmetic and pharmaceutical products. In previous studies, xenoestrogenic actions of parabens were reported in an immature rat model and a rat pituitary cell line (GH3 cells. The relationship between parabens and ovarian failure has not been described. In the present study, the influence of parabens on ovarian folliculogenesis and steroidogenesis was investigated. A disruptor of ovarian small pre-antral follicles, 4-vinylcyclohexene diepoxide (VCD, 40 mg/kg, was used to induce premature ovarian failure (POF. Methylparaben (MP, 100 mg/kg, propylparaben (PP, 100 mg/kg, and butylparaben (BP, 100 mg/kg dissolved in corn oil were treated in female 8-week-old Sprague-Dawley rat for 5 weeks. Estrus cycle status was checked daily by vaginal smear test. Ovarian follicle development and steroid synthesis were investigated through real-time PCR and histological analyses. Diestrus phases in the VCD, PP, and BP groups were longer than that in the vehicle group. VCD significantly decreased mRNA level of folliculogenesis-related genes (Foxl2, Kitl and Amh. All parabens significantly increased the Amh mRNA level but unchanged Foxl2 and Kitlg acting in primordial follicles. VCD and MP slightly increased Star and Cyp11a1 levels, which are related to an initial step in steroidogenesis. VCD and parabens induced an increase in FSH levels in serum and significantly decreased the total number of follicles. Increased FSH implies impairment in ovarian function due to VCD or parabens. These results suggest that VCD may suppress both formation and development of follicles. In particular, combined administration of VCD and parabens accelerated inhibition of the follicle-developmental process through elevated AMH level in small antral follicles.

Comparative occurrence of diabetes in canine, feline, and few wild animals and their association with pancreatic diseases and ketoacidosis with therapeutic approach.

Science.gov (United States)

Niaz, Kamal; Maqbool, Faheem; Khan, Fazlullah; Hassan, Fatima Ismail; Momtaz, Saeideh; Abdollahi, Mohammad

2018-04-01

Diabetes mellitus (DM) is a chronic metabolic disorder in which blood glucose level raises that can result in severe complications. However, the incidence increased mostly by obesity, pregnancy, persistent corpus luteum, and diestrus phase in humans and animals. This review has focused on addressing the possible understanding and pathogenesis of spontaneous DM in canine, feline, and few wild animals. Furthermore, pancreatic associated disorders, diabetic ketoacidosis, hormonal and drug interaction with diabetes, and herbal remedies associated with DM are elucidated. Bibliographic search for the present review was done using PubMed, Scopus, and Google Scholar for articles on concurrent DM in small and wild animals. Persistent corpus luteal and pseudopregnancy in female dogs generate gestational DM (GDM). GDM can also be caused by extensive use of drugs/hormones such as glucocorticosteroids. Although many similarities are present between diabetic cats and diabetic humans which present islet amyloidosis, there was a progressive loss of β- and α-cells and the normal number of δ-cells. The most prominent similarity is the occurrence of islet amyloidosis in all cases of diabetic cat and over 90% of human non-insulin dependent DM Type-2. Acute pancreatic necrosis (APN) occurs due to predisposing factors such as insulin antagonism, insulin resistance, alteration in glucose tolerance, obesity, hyperadrenocorticism, and persistent usage of glucocorticoids, as these play a vital role in the progression of APN. To manage such conditions, it is important to deal with the etiological agent, risk factors, diagnosis of diabetes, and hormonal and drug interaction along with its termination with suitable therapy (herbal) protocols. It should be noted that the protocols used for the diagnosis and treatment of human DM are not appropriate for animals. Further investigations regarding diabetic conditions of pets and wild animals are required, which will benefit the health status of

Comparative occurrence of diabetes in canine, feline, and few wild animals and their association with pancreatic diseases and ketoacidosis with therapeutic approach

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Kamal Niaz

2018-04-01

Full Text Available Diabetes mellitus (DM is a chronic metabolic disorder in which blood glucose level raises that can result in severe complications. However, the incidence increased mostly by obesity, pregnancy, persistent corpus luteum, and diestrus phase in humans and animals. This review has focused on addressing the possible understanding and pathogenesis of spontaneous DM in canine, feline, and few wild animals. Furthermore, pancreatic associated disorders, diabetic ketoacidosis, hormonal and drug interaction with diabetes, and herbal remedies associated with DM are elucidated. Bibliographic search for the present review was done using PubMed, Scopus, and Google Scholar for articles on concurrent DM in small and wild animals. Persistent corpus luteal and pseudopregnancy in female dogs generate gestational DM (GDM. GDM can also be caused by extensive use of drugs/hormones such as glucocorticosteroids. Although many similarities are present between diabetic cats and diabetic humans which present islet amyloidosis, there was a progressive loss of β- and α-cells and the normal number of δ-cells. The most prominent similarity is the occurrence of islet amyloidosis in all cases of diabetic cat and over 90% of human non-insulin dependent DM Type-2. Acute pancreatic necrosis (APN occurs due to predisposing factors such as insulin antagonism, insulin resistance, alteration in glucose tolerance, obesity, hyperadrenocorticism, and persistent usage of glucocorticoids, as these play a vital role in the progression of APN. To manage such conditions, it is important to deal with the etiological agent, risk factors, diagnosis of diabetes, and hormonal and drug interaction along with its termination with suitable therapy (herbal protocols. It should be noted that the protocols used for the diagnosis and treatment of human DM are not appropriate for animals. Further investigations regarding diabetic conditions of pets and wild animals are required, which will benefit the

Fear extinction in an obsessive-compulsive disorder animal model: Influence of sex and estrous cycle.

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Reimer, Adriano Edgar; de Oliveira, Amanda Ribeiro; Diniz, Juliana Belo; Hoexter, Marcelo Queiroz; Miguel, Euripedes Constantino; Milad, Mohammed Ragib; Brandão, Marcus Lira

2018-03-15

Obsessive-compulsive disorder (OCD) is a neuropsychiatric condition that affects men and women equally, but with a sexually dimorphic pattern of development. Reproductive cycle events can influence symptom severity of OCD in females, indicating that ovarian hormones or their interaction with distinct neurotransmitter systems may play a role in OCD pathophysiology. Clinical studies and animal models have confirmed the importance of the serotonergic (5-HT) system in the neurobiology and treatment of OCD. Accordingly, the non-selective 5-HT2c agonist, meta-chlorophenylpiperazine (mCPP), exacerbates symptoms in untreated OCD patients. In rodents, it evokes repetitive behaviors that engage brain areas that are homologous with those found to be dysfunctional in OCD patients. These regions, including the medial prefrontal and anterior cingulate cortices, are also involved in fear inhibition, which is impaired in OCD. Here, we treated rats with mCPP (0.5 and 3.0 mg/kg) to evaluate its influence on self-grooming behavior and assess potential fear extinction retention deficits, taking into account sex differences and females' estrous cycle. We found that mCPP exacerbated grooming in male and female rats, irrespective of the estrous cycle phase. Fear extinction retention, however, was impaired only in females. Moreover, females undergoing fear extinction training during the metestrus/diestrus phases of the estrous cycle were more sensitive to the impairments induced by mCPP. Our results indicate that mCPP can induce OCD-like symptoms, exacerbating self-grooming and impairing fear extinction. It suggests that changes in 5-HT signaling through 5-HT2c receptors may have an important role in the OCD pathophysiology and that the influence of gonadal hormones in OCD should be further investigated. Copyright © 2017 Elsevier Ltd. All rights reserved.

Dietary Deficiency of Essential Amino Acids Rapidly Induces Cessation of the Rat Estrous Cycle

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Bannai, Makoto; Ichimaru, Toru; Nakano, Sayako; Murata, Takuya; Higuchi, Takashi; Takahashi, Michio

2011-01-01

Reproductive functions are regulated by the sophisticated coordination between the neuronal and endocrine systems and are sustained by a proper nutritional environment. Female reproductive function is vulnerable to effects from dietary restrictions, suggesting a transient adaptation that prioritizes individual survival over reproduction until a possible future opportunity for satiation. This adaptation could also partially explain the existence of amenorrhea in women with anorexia nervosa. Because amino acid nutritional conditions other than caloric restriction uniquely alters amino acid metabolism and affect the hormonal levels of organisms, we hypothesized that the supply of essential amino acids in the diet plays a pivotal role in the maintenance of the female reproductive system. To test this hypothesis, we examined ovulatory cyclicity in female rats under diets that were deficient in threonine, lysine, tryptophan, methionine or valine. Ovulatory cyclicity was monitored by daily cytological evaluations of vaginal smears. After continuous feeding of the deficient diet, a persistent diestrus or anovulatory state was induced most quickly by the valine-deficient diet and most slowly by the lysine-deficient diet. A decline in the systemic insulin-like growth factor 1 level was associated with a dietary amino acid deficiency. Furthermore, a paired group of rats that were fed an isocaloric diet with balanced amino acids maintained normal estrous cyclicity. These disturbances of the estrous cycle by amino acid deficiency were quickly reversed by the consumption of a normal diet. The continuous anovulatory state in this study is not attributable to a decrease in caloric intake but to an imbalance in the dietary amino acid composition. With a shortage of well-balanced amino acid sources, reproduction becomes risky for both the mother and the fetus. It could be viewed as an adaptation to the diet, diverting resources away from reproduction and reallocating them to

Long-term melatonin treatment reduces ovarian mass and enhances tissue antioxidant defenses during ovulation in the rat

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L.G.A. Chuffa

2011-03-01

Full Text Available Melatonin regulates the reproductive cycle, energy metabolism and may also act as a potential antioxidant indoleamine. The present study was undertaken to investigate whether long-term melatonin treatment can induce reproductive alterations and if it can protect ovarian tissue against lipid peroxidation during ovulation. Twenty-four adult female Wistar rats, 60 days old (± 250-260 g, were randomly divided into two equal groups. The control group received 0.3 mL 0.9% NaCl + 0.04 mL 95% ethanol as vehicle, and the melatonin-treated group received vehicle + melatonin (100 µg·100 g body weight-1·day-1 both intraperitoneally daily for 60 days. All animals were killed by decapitation during the morning estrus at 4:00 am. Body weight gain and body mass index were reduced by melatonin after 10 days of treatment (P < 0.05. Also, a marked loss of appetite was observed with a fall in food intake, energy intake (melatonin 51.41 ± 1.28 vs control 57.35 ± 1.34 kcal/day and glucose levels (melatonin 80.3 ± 4.49 vs control 103.5 ± 5.47 mg/dL towards the end of treatment. Melatonin itself and changes in energy balance promoted reductions in ovarian mass (20.2% and estrous cycle remained extensive (26.7%, arresting at diestrus. Regarding the oxidative profile, lipid hydroperoxide levels decreased after melatonin treatment (6.9% and total antioxidant substances were enhanced within the ovaries (23.9%. Additionally, melatonin increased superoxide dismutase (21.3%, catalase (23.6% and glutathione-reductase (14.8% activities and the reducing power (10.2% GSH/GSSG ratio. We suggest that melatonin alters ovarian mass and estrous cyclicity and protects the ovaries by increasing superoxide dismutase, catalase and glutathione-reductase activities.

Radioimmunologic assessment of the level of circulating LH antibodies after passive immunization in the rat: relation to the level of LH secretion

International Nuclear Information System (INIS)

Morishige, W.K.; Billiar, R.B.; Rothchild, I.

1975-01-01

A double antibody radioimmunologic technique was used to estimate circulating levels of free LH antibodies (Ab) (i.e., Ab available for binding to radioiodinated rat LH in vitro) after a single injection of an equine antiserum to bovine LH (LH--AS) into cyclic (diestrus-l), early pregnant (d 6 or d 8), short-term (1 d) or long-term (12 d) ovariectomized, or 8-d hyopophysectomized female rats. In both cyclic and pregnant rats given 0.5 ml LH--AS SC the blood Ab levels peaked 1 to 2 days after injection and then decreased exponentially (half-time: 14.6 to 17.0 h) and equally; vaginal estrus also appeared in the cyclic and in the aborting pregnant rats on the 6th day, and ovulation on the 7th day after LH--AS treatment, when the blood levels had fallen to very low values. The rate of exponential decrease in blood Ab levels was not affected by other routes of administration (iv or ip) of LH--AS, or by SC doses of 1.0 or 0.25 ml, although the peak levels and their duration were related to dose and route of administration. Ovariectomy significantly increased the rate of exponential Ab decrease (half-time: 9.8 h in rats tested 12 days after operation) and hypophysectomy markedly diminished it (half-time: 63.0 h in rats tested 8 days after operation). Daily treatment of hypophysectomized rats with 20 μg/day of ovine LH from the time of LH-AS injection increased the rate of exponential Ab decrease to one approaching that of the intact rats (half-time: 20.5 h). Free LH antibodies thus seem to disappear from the circulation at a rate proportional to the amount of LH in the circulation. (U.S.)

Influence of sex and estrous cycle on synaptic responses of the medial vestibular nuclei in rats: role of circulating 17β-estradiol.

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Grassi, Silvarosa; Frondaroli, Adele; Scarduzio, Mariangela; Dieni, Cristina V; Brecchia, Gabriele; Boiti, Cristiano; Pettorossi, Vito E

2012-02-10

We investigated the possible influence of sex and estrous cycle on the synaptic responses of neurons in the medial vestibular nucleus (MVN) and their long-term modifications. In brain stem slices of male and female rats during proestrus (PE) and diestrus (DE), we evaluated the field potential evoked in the MVN by vestibular afferent stimulation. Here we find that in PE females the field potential had a lower threshold and higher amplitude than in DE females and in males and also that the stimulus-response curve was shifted to the left. Such difference is related to the level and cyclic fluctuation of circulating 17β-estradiol (E(2)). This is supported by the exogenous administration of E(2) in DE females and males, with low levels of circulating E(2) that enhanced the field potential amplitude to values close to those of PE females. Sex and estrous cycle also influence the MVN synaptic plasticity. This has been shown by investigating the effect of testosterone (T) on the induction of long-term effects, since T is the precursor for the neural synthesis of E(2) (estrogenic pathway), which is involved in the induction of fast long-term potentiation (LTP), or of 5α-dihydrotestosterone (DHT, androgenic pathway) which mediates slow LTP and long-term depression (LTD). We found that T mostly induced LTD in PE females and no effect in DE females, while it only provoked fast LTP in males. We suggest that high level of circulating E(2) may interfere with the conversion of T, by inhibiting the neural estrogenic pathway and facilitating the androgenic one. On the whole these results demonstrate an influence of circulating E(2) on vestibular synaptic transmission and plasticity that in some cases may contribute to the sex and menstrual cycle dependence of symptoms in human vestibular pathology. Copyright © 2011 Elsevier Inc. All rights reserved.

Impact of Triclosan on Female Reproduction through Reducing Thyroid Hormones to Suppress Hypothalamic Kisspeptin Neurons in Mice

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Xin-Yuan Cao

2018-01-01

Full Text Available Triclosan (TCS, a broad-spectrum antimicrobial agent, is widely used in clinical settings and various personal care products. The aim of this study was to evaluate the influence of TCS on reproductive endocrine and function. Here, we show that the exposure of adult female mice to 10 or 100 mg/kg/day TCS caused prolongation of diestrus, and decreases in antral follicles and corpora lutea within 2 weeks. TCS mice showed decreases in the levels of serum luteinizing hormone (LH, follicle-stimulating hormone (FSH and progesterone, and gonadotrophin-releasing hormone (GnRH mRNA with the lack of LH surge and elevation of prolactin (PRL. TCS mice had lower kisspeptin immunoreactivity and kiss1 mRNA in anteroventral periventricular nucleus (AVPV and arcuate nucleus (ARC. Moreover, the estrogen (E2-enhanced AVPV-kisspeptin expression was reduced in TCS mice. In addition, the serum thyroid hormones (triiodothyronine (T3 and thyroxine (T4 in TCS mice were reduced with increases in levels of thyroid stimulating hormone (TSH and thyroid releasing hormone (TRH. In TCS mice, the treatment with Levothyroxine (L-T4 corrected the increases in PRL, TSH and TRH; the administration of L-T4 or type-2 dopamine receptors agonist quinpirole inhibiting PRL release could rescue the decline of kisspeptin expression in AVPV and ARC; the treatment with L-T4, quinpirole or the GPR45 agonist kisspeptin-10 recovered the levels of serum LH and FSH and progesterone, and GnRH mRNA. Furthermore, TCS mice treated with L-T4 or quinpirole resumed regular estrous cycling, follicular development and ovulation. Together, these results indicate that exposing adult female mice to TCS (≥10 mg/kg reduces thyroid hormones causing hyperprolactinemia that then suppresses hypothalamic kisspeptin expression, leading to deficits in reproductive endocrine and function.

GnRH Neuron Activity and Pituitary Response in Estradiol-Induced vs Proestrous Luteinizing Hormone Surges in Female Mice.

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Silveira, Marina A; Burger, Laura L; DeFazio, R Anthony; Wagenmaker, Elizabeth R; Moenter, Suzanne M

2017-02-01

During the female reproductive cycle, estradiol exerts negative and positive feedback at both the central level to alter gonadotropin-releasing hormone (GnRH) release and at the pituitary to affect response to GnRH. Many studies of the neurobiologic mechanisms underlying estradiol feedback have been done on ovariectomized, estradiol-replaced (OVX+E) mice. In this model, GnRH neuron activity depends on estradiol and time of day, increasing in estradiol-treated mice in the late afternoon, coincident with a daily luteinizing hormone (LH) surge. Amplitude of this surge appears lower than in proestrous mice, perhaps because other ovarian factors are not replaced. We hypothesized GnRH neuron activity is greater during the proestrous-preovulatory surge than the estradiol-induced surge. GnRH neuron activity was monitored by extracellular recordings from fluorescently tagged GnRH neurons in brain slices in the late afternoon from diestrous, proestrous, and OVX+E mice. Mean GnRH neuron firing rate was low on diestrus; firing rate was similarly increased in proestrous and OVX+E mice. Bursts of action potentials have been associated with hormone release in neuroendocrine systems. Examination of the patterning of action potentials revealed a shift toward longer burst duration in proestrous mice, whereas intervals between spikes were shorter in OVX+E mice. LH response to an early afternoon injection of GnRH was greater in proestrous than diestrous or OVX+E mice. These observations suggest the lower LH surge amplitude observed in the OVX+E model is likely not attributable to altered mean GnRH neuron activity, but because of reduced pituitary sensitivity, subtle shifts in action potential pattern, and/or excitation-secretion coupling in GnRH neurons. Copyright © 2017 by the Endocrine Society.

Ethanol preference is impacted by estrus stage but not housing or stress in female C57BL/6J mice

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Kimberly N. Williams

2018-01-01

Full Text Available Vulnerability to maladaptive patterns of alcohol use, including dependence and relapse, is influenced by a combination of biological and environmental factors. A better understanding of how individual factors influence alcohol use is needed to help reduce alcohol dependence and relapse rates in the general population. This study explored how environmental enrichment (EE, stress and estrus cycle stage affect ethanol (ETOH preference in female mice. Mice were housed in enriched or standard environments and exposed chronically to ETOH for two hours a day for twelve days, before entering a brief ETOH-free abstinence period. At the end of this abstinence period, mice were exposed to a series of mild stressors (forced swim tests and anxiety was assessed via an elevated plus-maze. Preference was measured using a two-bottle choice test prior to ETOH exposure (baseline, after chronic ETOH exposure, and immediately following the abstinence period and stressor. Results revealed that mice preferred ETOH more strongly after chronic ETOH exposure, but that this increase was not affected by environment. ETOH preference was further increased after a brief abstinence period, but preference was not affected by environment or mild stress. However, mice in the proestrus/estrus stage of the estrus cycle preferred ETOH more strongly after a brief abstinence period than did mice in the metestrus/diestrus stage, suggesting that circulating levels of gonadal hormones may contribute to the incubation of drug preference. Anxiety- and despair-like behaviors were not impacted by estrus cycle stage. These findings suggest that estrus stage may affect ETOH preference, even after relatively short drug-free periods. Further research is needed to rectify the role of EE and stress in individual vulnerability or resilience to substance abuse. These findings also highlight a need for increased research into how gonadal hormones may influence ETOH preference in both mice and humans.

Central estrogenic pathways protect against the depressant action of acute nicotine on reflex tachycardia in female rats

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El-Mas, Mahmoud M.; Fouda, Mohamed A.; El-gowilly, Sahar M.; Saad, Evan I.

2012-01-01

We have previously shown that acute exposure of male rats to nicotine preferentially attenuates baroreceptor-mediated control of reflex tachycardia in contrast to no effect on reflex bradycardia. Here, we investigated whether female rats are as sensitive as their male counterparts to the baroreflex depressant effect of nicotine and whether this interaction is modulated by estrogen. Baroreflex curves relating reflex chronotropic responses evoked by i.v. doses (1–16 μg/kg) of phenylephrine (PE) or sodium nitroprusside (SNP), were constructed in conscious freely moving proestrus, ovariectomized (OVX), and estrogen (50 μg/kg/day s.c., 5 days)-replaced OVX (OVXE 2 ) rats. Slopes of the curves were taken as a measure of baroreflex sensitivity (BRS PE and BRS SNP ). Nicotine (100 μg/kg i.v.) reduced BRS SNP in OVX rats but not in proestrus or OVXE 2 rats. The attenuation of reflex tachycardia by nicotine was also evident in diestrus rats, which exhibited plasma estrogen levels similar to those of OVX rats. BRS PE was not affected by nicotine in all rat preparations. Experiments were then extended to determine whether central estrogenic receptors modulate the nicotine–BRS SNP interaction. Intracisteral (i.c.) treatment of OVX rats with estrogen sulfate (0.2 μg/rat) abolished the BRS SNP attenuating effect of i.v. nicotine. This protective effect of estrogen disappeared when OVX rats were pretreated with i.c. ICI 182,780 (50 μg/rat, selective estrogen receptor antagonist). Together, these findings suggest that central neural pools of estrogen receptors underlie the protection offered by E 2 against nicotine-induced baroreceptor dysfunction in female rats. -- Highlights: ► Estrogen protects against the depressant effect of nicotine on reflex tachycardia. ► The baroreflex response and estrogen status affect the nicotine–BRS interaction. ► The protection offered by estrogen is mediated via central estrogen receptors.

Clinical doses of citalopram or reboxetine differentially modulate passive and active behaviors of female Wistar rats with high or low immobility time in the forced swimming test.

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Flores-Serrano, Ana Gisela; Vila-Luna, María Leonor; Álvarez-Cervera, Fernando José; Heredia-López, Francisco José; Góngora-Alfaro, José Luis; Pineda, Juan Carlos

2013-09-01

The sensitivity of immobility time (IT) to antidepressant-drugs differs in rats expressing high or low motor activity during the forced swimming test (FST). However, whether this heterogeneity is expressed after the administration of the most selective serotonin and norepinephrine reuptake inhibitors (SSRIs and SNRIs, respectively) is unknown. We compared the influence of either the SSRI citalopram or the SNRI reboxetine with the tricyclic antidepressant amitriptyline on two subgroups of female Wistar rats expressing high IT (HI; at or above the mean value) or low IT (LI; below the mean) during the initial 5 min of the first session of the FST. None of the tested drugs increased motor activity in the open field test. When vehicle was applied to either HI or LI rats, IT increased in the second session of the FST. This increment concurred with a simultaneous climbing time (CT) decrement. When amitriptyline (15 mg/kg) was tested the CT increased for both HI and LI rats. This increment was accompanied by an IT decrement in HI and LI rats. Reboxetine (0.16 or 1 mg/kg) precluded IT and CT changes in both HI and LI rats and produced a swimming time reduction. Citalopram (0.4, 1, and 3 mg/kg) essentially mimicked the influence of reboxetine on the IT and CT in LI rats, as well as in HI rats, but in the latter case only at 3 mg/kg. Yet, at the dose of 10 mg/kg citalopram lacked this effect in both subgroups. No differences were detected when the IT of LI rats was evaluated with citalopram (3 mg/kg) during estrus or diestrus stage. These results show that clinical doses of citalopram produced an antidepressant-like effect selectively in LI rats, while amitriptyline or reboxetine produced this effect in both LI and HI animals. Copyright © 2013 Elsevier Inc. All rights reserved.

Distinct cardiac transcriptional profiles defining pregnancy and exercise.

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Eunhee Chung

Full Text Available BACKGROUND: Although the hypertrophic responses of the heart to pregnancy and exercise are both considered to be physiological processes, they occur in quite different hormonal and temporal settings. In this study, we have compared the global transcriptional profiles of left ventricular tissues at various time points during the progression of hypertrophy in exercise and pregnancy. METHODOLOGY/PRINCIPAL FINDINGS: The following groups of female mice were analyzed: non-pregnant diestrus cycle sedentary control, mid-pregnant, late-pregnant, and immediate-postpartum, and animals subjected to 7 and 21 days of voluntary wheel running. Hierarchical clustering analysis shows that while mid-pregnancy and both exercise groups share the closest relationship and similar gene ontology categories, late pregnancy and immediate post-partum are quite different with high representation of secreted/extracellular matrix-related genes. Moreover, pathway-oriented ontological analysis shows that metabolism regulated by cytochrome P450 and chemokine pathways are the most significant signaling pathways regulated in late pregnancy and immediate-postpartum, respectively. Finally, increases in expression of components of the proteasome observed in both mid-pregnancy and immediate-postpartum also result in enhanced proteasome activity. Interestingly, the gene expression profiles did not correlate with the degree of cardiac hypertrophy observed in the animal groups, suggesting that distinct pathways are employed to achieve similar amounts of cardiac hypertrophy. CONCLUSIONS/SIGNIFICANCE: Our results demonstrate that cardiac adaptation to the later stages of pregnancy is quite distinct from both mid-pregnancy and exercise. Furthermore, it is very dynamic since, by 12 hours post-partum, the heart has already initiated regression of cardiac growth, and 50 genes have changed expression significantly in the immediate-postpartum compared to late-pregnancy. Thus, pregnancy

Short communication: Ability of dogs to detect cows in estrus from sniffing saliva samples.

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Fischer-Tenhagen, C; Tenhagen, B-A; Heuwieser, W

2013-02-01

Efficient estrus detection in high-producing dairy cows is a permanent challenge for successful reproductive performance. In former studies, dogs have been trained to identify estrus-specific odor in vaginal fluid, milk, urine, and blood samples under laboratory conditions with an accuracy of more than 80%. For on-farm utilization of estrus-detection dogs it would be beneficial in terms of hygiene and safety if dogs could identify cows from the feed alley. The objective of this proof of concept study was to test if dogs can be trained to detect estrus-specific scent in saliva of cows. Saliva samples were collected from cows in estrus and diestrus. Thirteen dogs of various breeds and both sexes were trained in this study. Five dogs had no experience in scent detection, whereas 8 dogs had been formerly trained for detection of narcotics or cancer. In the training and test situation, dogs had to detect 1 positive out of 4 samples. Dog training was based on positive reinforcement and dogs were rewarded with a clicker and food for indicating saliva samples of cows in estrus. A false indication was ignored and documented in the test situation. Dogs with and without prior training were trained for 1 and 5 d, respectively. For determining the accuracy of detection, the position of the positive sample was unknown to the dog handler, to avoid hidden cues to the dog. The overall percentage of correct positive indications was 57.6% (175/304), with a range from 40 (1 dog) to 75% (3 dogs). To our knowledge, this is the first indication that dogs are able to detect estrus-specific scent in saliva of cows. Copyright © 2013 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Efeito dos fixadores formalina e Bouin na preservação de biópsias do endométrio de éguas após inclusão em resina plástica Effect of formalin and Bouin fixation upon the mare's endometrial biopsies embedded in plastic resin

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D. Amaral

2004-02-01

Full Text Available Biópsias do endométrio de 16 éguas sexualmente maduras, em estro e diestro, foram processadas para microscopia de luz utilizando-se fixação em formalina ou Bouin e inclusão em resina plástica à base de glicol metacrilato. Análises morfológicas de 46 biópsias demonstraram que o epitélio de revestimento do endométrio, o epitélio glandular, as fibras do tecido conjuntivo e os diferentes tipos celulares presentes na lâmina própria, tais como fibroblastos, plasmócitos, mastócitos e macrófagos, apresentaram-se melhor preservados quando os fragmentos de tecidos foram fixados em formalina. O epitélio de revestimento mostrou grau mais acentuado de retração tecidual nas biópsias fixadas em Bouin, independente da fase do ciclo estral. A fixação em formalina aliada à inclusão em resina plástica resultou em melhor resolução das células ao microscópio de luz, permitindo um estudo citológico mais acurado do endométrio eqüino.Endometrial biopsies were performed in 16 mares at estrus and diestrus and tissues were processed for light microscopy using formalin or Bouin fixatives and plastic resin glycol methacrylate for embedding. Results of the tissue processing demonstrated that the luminal and glandular epithelium, connective tissue fibers and many cell types present in the lamina propria such as fibroblasts, plasmocytes, mast cells and macrophages were best preserved in formalin fixed samples. The luminal epithelium showed increased shrinkage in Bouin fixed specimens when compared to formalin fixed ones. Those morphological findings were present throughout the estral cycle. The formalin fixation procedure associated with plastic resin embedding yielded increased tissue resolution as seen by light microscopy, and allowed a more accurate cytological study of the endometrium of the mare.

Estrous cycle modulation of extracellular serotonin in mediobasal hypothalamus: role of the serotonin transporter and terminal autoreceptors.

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Maswood, S; Truitt, W; Hotema, M; Caldarola-Pastuszka, M; Uphouse, L

1999-06-12

In vivo microdialysis was used to examine extracellular serotonin (5-HT) in the mediobasal hypothalamus (MBH) of male and female Fischer (CDF-344) rats. Females from the stages of diestrus, proestrus, and estrus were used. Additionally, ovariectomized rats, primed subcutaneously (s.c.) with estradiol benzoate or estradiol benzoate plus progesterone were examined. Extracellular 5-HT in the MBH varied with stage of the estrous cycle and with the light/dark cycle. Proestrous females had the highest microdialysate concentrations of 5-HT during the light portion of the light/dark cycle and lowest concentrations during the dark portion of the cycle. Diestrous females had the highest levels during the dark portion of the cycle, while males and estrous females showed little change between light and dark portions of the cycle. In ovariectomized rats, there was no effect of 2.5 microg or 25 microg estradiol benzoate (s.c.) on extracellular 5-HT; but the addition of 500 microg progesterone, 48 h after estrogen priming, reduced microdialysate 5-HT near the threshold for detection. In intact females and in males, reverse perfusion with 3 microM fluoxetine, a selective serotonin reuptake inhibitor (SSRI), or 2 microM methiothepin, a 5-HT receptor antagonist, increased microdialysate concentrations of 5-HT. Estrous females and males showed nearly a 4-fold increase in microdialysate 5-HT in response to fluoxetine while smaller responses were seen in diestrous and proestrous rats. In contrast, proestrous rats showed the largest response to methiothepin. Estrous females showed a delayed response to methiothepin, but there was no methiothepin-induced increase in extracellular 5-HT in males. These findings are discussed in reference to the suggestion that extracellular 5-HT in the MBH is regulated in a manner that is gender and estrous cycle dependent. The 5-HT terminal autoreceptor may exert a greater role in proestrous females; the serotonin transporter appears to play a more active

N-terminal prolactin-derived fragments, vasoinhibins, are proapoptoptic and antiproliferative in the anterior pituitary.

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Ferraris, Jimena; Radl, Daniela Betiana; Zárate, Sandra; Jaita, Gabriela; Eijo, Guadalupe; Zaldivar, Verónica; Clapp, Carmen; Seilicovich, Adriana; Pisera, Daniel

2011-01-01

The anterior pituitary is under a constant cell turnover modulated by gonadal steroids. In the rat, an increase in the rate of apoptosis occurs at proestrus whereas a peak of proliferation takes place at estrus. At proestrus, concomitant with the maximum rate of apoptosis, a peak in circulating levels of prolactin is observed. Prolactin can be cleaved to different N-terminal fragments, vasoinhibins, which are proapoptotic and antiproliferative factors for endothelial cells. It was reported that a 16 kDa vasoinhibin is produced in the rat anterior pituitary by cathepsin D. In the present study we investigated the anterior pituitary production of N-terminal prolactin-derived fragments along the estrous cycle and the involvement of estrogens in this process. In addition, we studied the effects of a recombinant vasoinhibin, 16 kDa prolactin, on anterior pituitary apoptosis and proliferation. We observed by Western Blot that N-terminal prolactin-derived fragments production in the anterior pituitary was higher at proestrus with respect to diestrus and that the content and release of these prolactin forms from anterior pituitary cells in culture were increased by estradiol. A recombinant preparation of 16 kDa prolactin induced apoptosis (determined by TUNEL assay and flow cytometry) of cultured anterior pituitary cells and lactotropes from ovariectomized rats only in the presence of estradiol, as previously reported for other proapoptotic factors in the anterior pituitary. In addition, 16 kDa prolactin decreased forskolin-induced proliferation (evaluated by BrdU incorporation) of rat total anterior pituitary cells and lactotropes in culture and decreased the proportion of cells in S-phase of the cell cycle (determined by flow cytometry). In conclusion, our study indicates that the anterior pituitary production of 16 kDa prolactin is variable along the estrous cycle and increased by estrogens. The antiproliferative and estradiol-dependent proapoptotic actions of this

N-terminal prolactin-derived fragments, vasoinhibins, are proapoptoptic and antiproliferative in the anterior pituitary.

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Jimena Ferraris

Full Text Available The anterior pituitary is under a constant cell turnover modulated by gonadal steroids. In the rat, an increase in the rate of apoptosis occurs at proestrus whereas a peak of proliferation takes place at estrus. At proestrus, concomitant with the maximum rate of apoptosis, a peak in circulating levels of prolactin is observed. Prolactin can be cleaved to different N-terminal fragments, vasoinhibins, which are proapoptotic and antiproliferative factors for endothelial cells. It was reported that a 16 kDa vasoinhibin is produced in the rat anterior pituitary by cathepsin D. In the present study we investigated the anterior pituitary production of N-terminal prolactin-derived fragments along the estrous cycle and the involvement of estrogens in this process. In addition, we studied the effects of a recombinant vasoinhibin, 16 kDa prolactin, on anterior pituitary apoptosis and proliferation. We observed by Western Blot that N-terminal prolactin-derived fragments production in the anterior pituitary was higher at proestrus with respect to diestrus and that the content and release of these prolactin forms from anterior pituitary cells in culture were increased by estradiol. A recombinant preparation of 16 kDa prolactin induced apoptosis (determined by TUNEL assay and flow cytometry of cultured anterior pituitary cells and lactotropes from ovariectomized rats only in the presence of estradiol, as previously reported for other proapoptotic factors in the anterior pituitary. In addition, 16 kDa prolactin decreased forskolin-induced proliferation (evaluated by BrdU incorporation of rat total anterior pituitary cells and lactotropes in culture and decreased the proportion of cells in S-phase of the cell cycle (determined by flow cytometry. In conclusion, our study indicates that the anterior pituitary production of 16 kDa prolactin is variable along the estrous cycle and increased by estrogens. The antiproliferative and estradiol-dependent proapoptotic

Prenatal IV Cocaine: Alterations in Auditory Information Processing

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Charles F. Mactutus

2011-06-01

Full Text Available One clue regarding the basis of cocaine-induced deficits in attentional processing is provided by the clinical findings of changes in the infants’ startle response; observations buttressed by neurophysiological evidence of alterations in brainstem transmission time. Using the IV route of administration and doses that mimic the peak arterial levels of cocaine use in humans, the present study examined the effects of prenatal cocaine on auditory information processing via tests of the acoustic startle response (ASR, habituation, and prepulse inhibition (PPI in the offspring. Nulliparous Long-Evans female rats, implanted with an IV access port prior to breeding, were administered saline, 0.5, 1.0, or 3.0 mg/kg/injection of cocaine HCL (COC from gestation day (GD8-20 (1x/day-GD8-14, 2x/day-GD15-20. COC had no significant effects on maternal/litter parameters or growth of the offspring. At 18-20 days of age, one male and one female, randomly selected from each litter displayed an increased ASR (>30% for males at 1.0 mg/kg and >30% for females at 3.0 mg/kg. When reassessed in adulthood (D90-100, a linear dose-response increase was noted on response amplitude. At both test ages, within-session habituation was retarded by prenatal cocaine treatment. Testing the females in diestrus vs. estrus did not alter the results. Prenatal cocaine altered the PPI response function across interstimulus interval (ISI and induced significant sex-dependent changes in response latency. Idazoxan, an alpha2-adrenergic receptor antagonist, significantly enhanced the ASR, but less enhancement was noted with increasing doses of prenatal cocaine. Thus, in utero exposure to cocaine, when delivered via a protocol designed to capture prominent features of recreational usage, causes persistent, if not permanent, alterations in auditory information processing, and suggests dysfunction of the central noradrenergic circuitry modulating, if not mediating, these responses.

Preliminary study on plasma proteins in pregnant and non-pregnant female dogs.

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Szczubiał, Marek; Wawrzykowski, Jacek; Dąbrowski, Roman; Krawczyk, Magdalena; Kankofer, Marta

2017-07-15

In this study, we used a combined approach based on 2-dimensional electrophoresis (2-DE), difference in gel electrophoresis (DIGE), and mass spectrometry (MS) to identify the plasma protein composition in pregnant female dogs and compared it with non-pregnant female dogs. We used the plasma samples obtained from four female dogs during I, II, and III thirds of pregnancy, three days after parturition, as well as from four non-pregnant female dogs in diestrus phase. Analysis of 2-DE gel image exhibited of 249 protein spots. The intensity of staining of 35 spots differed significantly (P dogs. We used matrix-assisted laser desorption/ionization-time of flight-mass spectrometry (MALDI TOF MS) to identify 47 spots corresponding to 52 different proteins. Five identified protein spots, including zinc finger BED domain-containing protein 5, hemoglobin subunit beta-2, integrator complex subunit 7, apolipoprotein A-I, and glutamyl aminopeptidase were differentially presented in the plasma of pregnant and non-pregnant female dogs. To the best of our knowledge, this is the first report on the plasma protein profile of pregnant and non-pregnant female dogs. In this study, we identified proteins that have not been previously identified in dogs. Our findings showed that numerous protein spots were differentially presented in the plasma of female dogs during normal pregnancy. Although we identified only a limited number of differentially presented proteins, our study demonstrated that the plasma protein profile changed during pregnancy in female dogs, which suggests its importance in maintaining pregnancy. Further studies are necessary to define complete plasma protein profile of pregnant female dogs and to identify all proteins that are differentially presented in the pregnant animals compared with the non-pregnant ones. In addition, studies are warranted to explain the role of those proteins in maintaining the pregnancy and their usefulness in detection of early pregnancy

In utero bisphenol A exposure disrupts germ cell nest breakdown and reduces fertility with age in the mouse

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Wang, Wei, E-mail: weiwang2@illinois.edu; Hafner, Katlyn S., E-mail: katlynhafner@gmail.com; Flaws, Jodi A., E-mail: jflaws@illinois.edu

2014-04-15

Bisphenol A (BPA) is a known reproductive toxicant in rodents. However, the effects of in utero BPA exposure on early ovarian development and the consequences of such exposure on female reproduction in later reproductive life are unclear. Thus, we determined the effects of in utero BPA exposure during a critical developmental window on germ cell nest breakdown, a process required for establishment of the finite primordial follicle pool, and on female reproduction. Pregnant FVB mice (F0) were orally dosed daily with tocopherol-striped corn oil (vehicle), diethylstilbestrol (DES; 0.05 μg/kg, positive control), or BPA (0.5, 20, and 50 μg/kg) from gestational day 11 until birth. Ovarian morphology and gene expression profiles then were examined in F1 female offspring on postnatal day (PND) 4 and estrous cyclicity was examined daily after weaning for 30 days. F1 females were also subjected to breeding studies with untreated males at three to nine months. The results indicate that BPA inhibits germ cell nest breakdown via altering expression of selected apoptotic factors. BPA also significantly advances the age of first estrus, shortens the time that the females remain in estrus, and increases the time that the females remain in metestrus and diestrus compared to controls. Further, F1 females exposed to low doses of BPA exhibit various fertility problems and have a significantly higher percentage of dead pups compared to controls. These results indicate that in utero exposure to low doses of BPA during a critical ovarian developmental window interferes with early ovarian development and reduces fertility with age. - Highlights: • In utero BPA exposure inhibits germ cell nest breakdown in female mouse offspring. • In utero BPA exposure alters expression of apoptosis regulators in the ovaries of mouse offspring. • In utero BPA exposure advances first estrus age and alters cyclicity in mouse offspring. • In utero BPA exposure causes various fertility problems in

Central estrogenic pathways protect against the depressant action of acute nicotine on reflex tachycardia in female rats

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El-Mas, Mahmoud M., E-mail: mahelm@hotmail.com; Fouda, Mohamed A.; El-gowilly, Sahar M.; Saad, Evan I.

2012-02-01

We have previously shown that acute exposure of male rats to nicotine preferentially attenuates baroreceptor-mediated control of reflex tachycardia in contrast to no effect on reflex bradycardia. Here, we investigated whether female rats are as sensitive as their male counterparts to the baroreflex depressant effect of nicotine and whether this interaction is modulated by estrogen. Baroreflex curves relating reflex chronotropic responses evoked by i.v. doses (1–16 μg/kg) of phenylephrine (PE) or sodium nitroprusside (SNP), were constructed in conscious freely moving proestrus, ovariectomized (OVX), and estrogen (50 μg/kg/day s.c., 5 days)-replaced OVX (OVXE{sub 2}) rats. Slopes of the curves were taken as a measure of baroreflex sensitivity (BRS{sub PE} and BRS{sub SNP}). Nicotine (100 μg/kg i.v.) reduced BRS{sub SNP} in OVX rats but not in proestrus or OVXE{sub 2} rats. The attenuation of reflex tachycardia by nicotine was also evident in diestrus rats, which exhibited plasma estrogen levels similar to those of OVX rats. BRS{sub PE} was not affected by nicotine in all rat preparations. Experiments were then extended to determine whether central estrogenic receptors modulate the nicotine–BRS{sub SNP} interaction. Intracisteral (i.c.) treatment of OVX rats with estrogen sulfate (0.2 μg/rat) abolished the BRS{sub SNP} attenuating effect of i.v. nicotine. This protective effect of estrogen disappeared when OVX rats were pretreated with i.c. ICI 182,780 (50 μg/rat, selective estrogen receptor antagonist). Together, these findings suggest that central neural pools of estrogen receptors underlie the protection offered by E{sub 2} against nicotine-induced baroreceptor dysfunction in female rats. -- Highlights: ► Estrogen protects against the depressant effect of nicotine on reflex tachycardia. ► The baroreflex response and estrogen status affect the nicotine–BRS interaction. ► The protection offered by estrogen is mediated via central estrogen receptors.

Estrous cycle dependent fluctuations of regulatory neuropeptides in the lower urinary tract of female rats upon colon-bladder cross-sensitization.

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Xiao-Qing Pan

Full Text Available Co-morbidity of bladder, bowel, and non-specific pelvic pain symptoms is highly prevalent in women. Little evidence is present on modulation of pelvic pain syndromes by sex hormones, therefore, the objective of this study was to clarify the effects of hormonal fluctuations within the estrous cycle on regulatory neuropeptides in female rats using a model of neurogenic bladder dysfunction. The estrous cycle in female rats (Sprague-Dawley, 230-250 g was assessed by vaginal smears and weight of uterine horns. Neurogenic bladder dysfunction was induced by a single inflammatory insult to the distal colon. Protein expression of calcitonin gene related peptide (CGRP, substance P (SP, nerve growth factor (NGF, and brain derived neurotrophic factor (BDNF in the pelvic organs, sensory ganglia and lumbosacral spinal cord was compared in rats in proestrus (high estrogen vs diestrus (low estrogen. Under normal physiological conditions, concentration of SP and CGRP was similar in the distal colon and urinary bladder during all phases of the estrous cycle, however, acute colitis induced a significant up-regulation of CGRP content in the colon (by 63% and urinary bladder (by 54%, p≤0.05 to control of rats in proestrus. These changes were accompanied by a significant diminution of CGRP content in L6-S2 DRG after colonic treatment, likely associated with its release in the periphery. In rats with high estrogen at the time of testing (proestrus, experimental colitis caused a significant up-regulation of BDNF colonic content from 26.1±8.5 pg/ml to 83.4±32.5 pg/ml (N = 7, p≤0.05 to control and also induced similar effects on BDNF in the urinary bladder which was also up-regulated by 5-fold in rats in proestrus (p≤0.05 to respective control. Our results demonstrate estrous cycle dependent fluctuations of regulatory neuropeptides in the lower urinary tract upon colon-bladder cross-sensitization, which may contribute to pain fluctuations in female patients

Gender, exercise training, and eNOS expression in porcine skeletal muscle arteries.

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Laughlin, M Harold; Welshons, Wade V; Sturek, Michael; Rush, James W E; Turk, James R; Taylor, Julia A; Judy, Barbara M; Henderson, Kyle K; Ganjam, V K

2003-07-01

Our purpose was to determine the effects of gender and exercise training on endothelial nitric oxide synthase (eNOS) and superoxide dismutase (SOD) protein content of porcine skeletal muscle arteries and to evaluate the role of 17beta-estradiol (E2) in these effects. We measured eNOS and SOD content with immunoblots and immunohistochemistry in femoral and brachial arteries of trained and sedentary male and female pigs and measured estrogen receptor (ER) mRNA and alpha-ER and beta-ER protein in aortas of male and female pigs. Results indicate that female arteries contain more eNOS than male arteries and that exercise training increases eNOS content independent of gender. Male and female pigs expressed similar levels of alpha-ER mRNA and protein and similar amounts beta-ER protein in their arteries. E2 concentrations as measured by RIA were 180 +/- 34 pg/ml in male sera and approximately 5 pg/ml in female sera, and neither was changed by training. However, bioassay indicated that biologically active estrogen equivalent to only 35 +/- 5 pg/ml was present in male sera. E2 in female pigs, whether measured by RIA or bioassay, was approximately 24 pg/ml at peak estrous and 2 pg/ml on day 5 diestrus. The free fraction of E2 in sera did not explain the low measurements, relative to RIA, of E2. We conclude that 1). gender has significant influence on eNOS and SOD content of porcine skeletal muscle arteries; 2). the effects of gender and exercise training vary among arteries of different anatomic origin; 3). male sera contains compounds that cause RIA to overestimate circulating estrogenic activity; and 4). relative to human men, the male pig is not biologically estrogenized by high levels of E2 reported by RIA, whereas in female pigs E2 levels are lower than in the blood of human women.

Interleukin 6 deficiency modulates the hypothalamic expression of energy balance regulating peptides during pregnancy in mice.

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Pazos, Patricia; Lima, Luis; Casanueva, Felipe F; Diéguez, Carlos; García, María C

2013-01-01

Pregnancy is associated with hyperphagia, increased adiposity and multiple neuroendocrine adaptations. Maternal adipose tissue secretes rising amounts of interleukin 6 (IL6), which acts peripherally modulating metabolic function and centrally increasing energy expenditure and reducing body fat. To explore the role of IL6 in the central mechanisms governing dam's energy homeostasis, early, mid and late pregnant (gestational days 7, 13 and 18) wild-type (WT) and Il6 knockout mice (Il6-KO) were compared with virgin controls at diestrus. Food intake, body weight and composition as well as indirect calorimetry measurements were performed in vivo. Anabolic and orexigenic peptides: neuropeptide Y (Npy) and agouti-related peptide (Agrp); and catabolic and anorectic neuropeptides: proopiomelanocortin (Pomc), corticotrophin and thyrotropin-releasing hormone (Crh and Trh) mRNA levels were determined by in situ hybridization. Real time-PCR and western-blot were used for additional tissue gene expression and protein studies. Non-pregnant Il6-KO mice were leaner than WT mice due to a decrease in fat but not in lean body mass. Pregnant Il6-KO mice had higher fat accretion despite similar body weight gain than WT controls. A decreased fat utilization in absence of Il6 might explain this effect, as shown by increased respiratory exchange ratio (RER) in virgin Il6-KO mice. Il6 mRNA levels were markedly enhanced in adipose tissue but reduced in hypothalamus of mid and late pregnant WT mice. Trh expression was also stimulated at gestational day 13 and lack of Il6 blunted this effect. Conversely, in late pregnant mice lessened hypothalamic Il6 receptor alpha (Il6ra), Pomc and Crh mRNA were observed. Il6 deficiency during this stage up-regulated Npy and Agrp expression, while restoring Pomc mRNA levels to virgin values. Together these results demonstrate that IL6/IL6Ra system modulates Npy/Agrp, Pomc and Trh expression during mouse pregnancy, supporting a role of IL6 in the central

In utero bisphenol A exposure disrupts germ cell nest breakdown and reduces fertility with age in the mouse

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Wang, Wei; Hafner, Katlyn S.; Flaws, Jodi A.

2014-01-01

Bisphenol A (BPA) is a known reproductive toxicant in rodents. However, the effects of in utero BPA exposure on early ovarian development and the consequences of such exposure on female reproduction in later reproductive life are unclear. Thus, we determined the effects of in utero BPA exposure during a critical developmental window on germ cell nest breakdown, a process required for establishment of the finite primordial follicle pool, and on female reproduction. Pregnant FVB mice (F0) were orally dosed daily with tocopherol-striped corn oil (vehicle), diethylstilbestrol (DES; 0.05 μg/kg, positive control), or BPA (0.5, 20, and 50 μg/kg) from gestational day 11 until birth. Ovarian morphology and gene expression profiles then were examined in F1 female offspring on postnatal day (PND) 4 and estrous cyclicity was examined daily after weaning for 30 days. F1 females were also subjected to breeding studies with untreated males at three to nine months. The results indicate that BPA inhibits germ cell nest breakdown via altering expression of selected apoptotic factors. BPA also significantly advances the age of first estrus, shortens the time that the females remain in estrus, and increases the time that the females remain in metestrus and diestrus compared to controls. Further, F1 females exposed to low doses of BPA exhibit various fertility problems and have a significantly higher percentage of dead pups compared to controls. These results indicate that in utero exposure to low doses of BPA during a critical ovarian developmental window interferes with early ovarian development and reduces fertility with age. - Highlights: • In utero BPA exposure inhibits germ cell nest breakdown in female mouse offspring. • In utero BPA exposure alters expression of apoptosis regulators in the ovaries of mouse offspring. • In utero BPA exposure advances first estrus age and alters cyclicity in mouse offspring. • In utero BPA exposure causes various fertility problems in

Hormone-dependence of sarin lethality in rats: Sex differences and stage of the estrous cycle

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Smith, Carl D., E-mail: carl.d.smith179.mil@mail.mil; Wright, Linnzi K.M.; Garcia, Gregory E.; Lee, Robyn B.; Lumley, Lucille A.

2015-09-15

Chemical warfare nerve agents (CWNAs) are highly toxic compounds that cause a cascade of symptoms and death, if exposed casualties are left untreated. Numerous rodent models have investigated the toxicity and mechanisms of toxicity of CWNAs, but most are limited to male subjects. Given the profound physiological effects of circulating gonadal hormones in female rodents, it is possible that the daily cyclical fluctuations of these hormones affect females' sensitivity to the lethal effects of CWNAs, and previous reports that included female subjects did not control for the stage of the hormonal cycle. The aim of the current study was to determine the 24-hour median lethal dose (LD{sub 50}) of the CWNA sarin in male, ovariectomized (OVEX) female, and female rats during different stages of the estrous cycle (diestrus, proestrus, and estrus). Additionally, baseline activity levels of plasma acetylcholinesterase, butyrylcholinesterase, and carboxylesterase were measured to determine differences among the groups. Results indicated that females in proestrus had a significantly higher LD{sub 50} of sarin compared to OVEX and estrous females. Although some sex differences were observed in the activity levels of plasma esterases, they were not consistent and likely not large enough to significantly affect the LD{sub 50}s. These results suggest that hormonal cyclicity can influence the outcome of CWNA-related studies using female rodents, and that this variability can be minimized by controlling for the stage of the cycle. Additional research is necessary to determine the precise mechanism of the observed differences because it is unlikely to be solely explained by plasma esterase activity. - Highlights: • The LD{sub 50} of sarin was determined in female rats throughout the stages of the estrous cycle. • Females in proestrus had a significantly higher LD{sub 50} compared to estrous or ovariectomized females. • No sex differences were observed between male and female

Expression and secretion of plasma membrane Ca2+-ATPase 4a (PMCA4a during murine estrus: association with oviductal exosomes and uptake in sperm.

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Amal A Al-Dossary

Full Text Available PMCA4, a membrane protein, is the major Ca(2+ efflux pump in murine sperm where its deletion leads to a severe loss of hyperactivated motility and to male infertility. We have previously shown that the PMCA4b splice variant interacts with CASK (Ca(2+/CaM-dependent serine kinase in regulating sperm Ca(2+. More recently we detected that PMCA4a isoform, in addition to its presence in testis, is secreted in the epididymal luminal fluid and transferred to sperm. Here we show that Pmca4 mRNA is expressed in both the 4a and 4b variants in the vagina, uterus, and oviduct. Immunofluorescence reveals that PMCA4a is similarly expressed and is elevated during estrus, appearing in the glandular and luminal epithelia. Western analysis detected PMCA4a in all tissues and in the luminal fluids (LF of the vagina (VLF, uterus (ULF, and the oviduct (OLF collected during estrus. It was ~9- and 4-fold higher in OLF than in VLF and ULF, and only marginally present in LF collected at metestrus/diestrus. Fractionation of the LF collected at estrus, via ultracentrifugation, revealed that 100% of the PMCA4a resides in the vesicular fraction of the ULF and OLF. Transmission electron microscopy (TEM revealed that OLF vesicles have an exosomal orientation (with the cytoplasmic-side inward, a size range of 25-100 nm, with the characteristic CD9 biomarker. Thus, we dubbed these vesicles "oviductosomes", to which PMCA4a was immunolocalized. Incubation of caudal sperm in the combined LF or exosomes resulted in up to a ~3-fold increase of sperm PMCA4a, as detected by flow cytometry, indicating in vitro uptake. Our results are consistent with the increased requirement of Ca(2+ efflux in the oviduct. They show for the first time the presence of oviductal exosomes and highlight their role, along with uterosomes and vaginal exosomes, in post-testicular sperm acquisition of PMCA4a which is essential for hyperactivated motility and fertility.

Expression and secretion of plasma membrane Ca2+-ATPase 4a (PMCA4a) during murine estrus: association with oviductal exosomes and uptake in sperm.

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Al-Dossary, Amal A; Strehler, Emanuel E; Martin-Deleon, Patricia A

2013-01-01

PMCA4, a membrane protein, is the major Ca(2+) efflux pump in murine sperm where its deletion leads to a severe loss of hyperactivated motility and to male infertility. We have previously shown that the PMCA4b splice variant interacts with CASK (Ca(2+/)CaM-dependent serine kinase) in regulating sperm Ca(2+). More recently we detected that PMCA4a isoform, in addition to its presence in testis, is secreted in the epididymal luminal fluid and transferred to sperm. Here we show that Pmca4 mRNA is expressed in both the 4a and 4b variants in the vagina, uterus, and oviduct. Immunofluorescence reveals that PMCA4a is similarly expressed and is elevated during estrus, appearing in the glandular and luminal epithelia. Western analysis detected PMCA4a in all tissues and in the luminal fluids (LF) of the vagina (VLF), uterus (ULF), and the oviduct (OLF) collected during estrus. It was ~9- and 4-fold higher in OLF than in VLF and ULF, and only marginally present in LF collected at metestrus/diestrus. Fractionation of the LF collected at estrus, via ultracentrifugation, revealed that 100% of the PMCA4a resides in the vesicular fraction of the ULF and OLF. Transmission electron microscopy (TEM) revealed that OLF vesicles have an exosomal orientation (with the cytoplasmic-side inward), a size range of 25-100 nm, with the characteristic CD9 biomarker. Thus, we dubbed these vesicles "oviductosomes", to which PMCA4a was immunolocalized. Incubation of caudal sperm in the combined LF or exosomes resulted in up to a ~3-fold increase of sperm PMCA4a, as detected by flow cytometry, indicating in vitro uptake. Our results are consistent with the increased requirement of Ca(2+) efflux in the oviduct. They show for the first time the presence of oviductal exosomes and highlight their role, along with uterosomes and vaginal exosomes, in post-testicular sperm acquisition of PMCA4a which is essential for hyperactivated motility and fertility.

Semi-quantitative ultrastructural analysis of the localization and neuropeptide content of gonadotropin releasing hormone nerve terminals in the median eminence throughout the estrous cycle of the rat.

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Prevot, V; Dutoit, S; Croix, D; Tramu, G; Beauvillain, J C

1998-05-01

The ultrastructural appearance of gonadotropin releasing hormone-immunoreactive elements was studied in the external zone of the median eminence of adult female Wistar rats. On the one hand, the purpose of the study was to determine the distribution of gonadotropin releasing hormone terminals towards the parenchymatous basal lamina at the level of hypothalamo-hypophyseal portal vessels, throughout the estrous cycle. On the other hand, we have semi-quantified the gonadotropin releasing hormone content in nerve terminals or preterminals during this physiological condition. A morphometric study was coupled to a colloidal 15 mn gold postembedding immunocytochemistry procedure. Animals were killed at 09.00 on diestrus II, 0.900, 10.00, 13.00, 17.00 and 18.00 on proestrus and 09.00 on estrus (n = 4-8 rats/group). A preliminary light microscopic study was carried out to identify an antero-posterior part of median eminence strongly immunostained by anti-gonadotropin releasing hormone antibodies but which was, in addition, easily spotted. This last condition was necessary to make a good comparison between each animal. Contacts between gonadotropin releasing hormone nerve terminals and the basal lamina were observed only the day of proestrus. Such contacts, however, were rare and in the great majority of cases, gonadotropin releasing hormone terminals are separated from basal lamina by tanycytic end feet. The morphometric analysis showed no significant variation in average distance between gonadotropin releasing hormone terminals and capillaries throughout the estrous cycle. Consequently, it did not appear that a large neuroglial plasticity exists during the estrous cycle. However, the observation of contacts only on proestrus together with some ultrastructural images evoke the possibility of a slight plasticity. The semi-quantitative results show that the content of gonadotropin releasing hormone in the nerve endings presented two peaks on proestrus: one at 09.00 (23 +/- 5

Intra-accumbens Raclopride Administration Prevents Behavioral Changes Induced by Intermittent Access to Sucrose Solution

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Josué O. Suárez-Ortiz

2018-02-01

Full Text Available Overeating is one of the most relevant clinical features in Binge Eating Disorder and in some obesity patients. According to several studies, alterations in the mesolimbic dopaminergic transmission produced by non-homeostatic feeding behavior may be associated with changes in the reward system similar to those produced by drugs of abuse. Although it is known that binge-eating is related with changes in dopaminergic transmission mediated by D2 receptors in the nucleus accumbens shell (NAcS, it has not been determined whether these receptors may be a potential target for the treatment of eating pathology with binge-eating. Accordingly, the aim of the present study was to evaluate whether sugar binging induced by intermittent access to a sucrose solution produced changes in the structure of feeding behavior and whether blocking D2 receptors prevented these changes. We used the intermittent access model to a 10% sucrose solution (2 h/day for 4 weeks to induce sugar binging in Sprague Dawley female rats. Experimental subjects consumed in a 2-h period more than 50% of the caloric intake consumed by the subjects with ad-lib access to the sweetened solution without any increase in body weight or fat accumulation. Furthermore, we evaluated whether sugar binging was associated to the estrous cycle and we did not find differences in caloric intake (estrous vs. diestrus. Subsequently, we characterized the structure of feeding behavior (microstructural analysis and the motivation for palatable food (breakpoints of the subjects with sugar binging and found that feeding episodes had short latencies, high frequencies, as well as short durations and inter-episode intervals. The intermittent access model did not increase breakpoints, as occurred in subjects with ad-lib access to the sucrose. Finally, we evaluated the effects of D2 receptor blockade in the NAcS, and found that raclopride (18 nM prevented the observed changes in the frequency and duration of

Prenatal stress programs neuroendocrine stress responses and affective behaviors in second generation rats in a sex-dependent manner.

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Grundwald, Natalia J; Brunton, Paula J

2015-12-01

An adverse environment in early life is often associated with dysregulation of the hypothalamo-pituitary-adrenal (HPA) axis and higher rates of mood disorders in adulthood. In rats, exposure to social stress during pregnancy results in hyperactive HPA axis responses to stress in the adult offspring and heightened anxiety behavior in the males, but not the females. Here we tested whether, without further intervention, the effects of prenatal stress (PNS) in the first filial generation (F1) are transmitted to the F2 generation via the maternal line. F1 control and PNS female rats were mated with control males and housed under non-stress conditions throughout pregnancy. HPA axis responses to acute stress, anxiety- and depressive-like behavior were assessed in the adult F2 offspring. ACTH and corticosterone responses to an acute stressor were markedly enhanced in F2 PNS females compared with controls. This was associated with greater corticotropin releasing hormone (Crh) mRNA expression in the paraventricular nucleus and reduced hippocampal glucocorticoid (Gr) and mineralocorticoid receptor (Mr) mRNA expression. Conversely, in the F2 PNS males, HPA axis responses to acute stress were attenuated and hippocampal Gr mRNA expression was greater compared with controls. F2 PNS males exhibited heightened anxiety-like behavior (light-dark box and elevated plus maze) compared with F2 control males. Anxiety-like behavior did not differ between F2 control and PNS females during metestrus/diestrus, however at proestrus/estrus, F2 control females displayed a reduction in anxiety-like behavior, but this effect was not observed in the F2 PNS females. Heightened anxiety in the F2 PNS males was associated with greater Crh mRNA expression in the central nucleus of the amygdala compared with controls. Moreover, Crh receptor-1 (Crhr1) mRNA expression was significantly increased, whereas Crhr2 mRNA was significantly decreased in discrete regions of the amygdala in F2 PNS males compared

Vascular endothelial growth factor-D over-expressing tumor cells induce differential effects on uterine vasculature in a mouse model of endometrial cancer

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Stacker Steven A

2010-07-01

Full Text Available Abstract Background It has been hypothesised that increased VEGF-D expression may be an independent prognostic factor for endometrial cancer progression and lymph node metastasis; however, the mechanism by which VEGF-D may promote disease progression in women with endometrial cancer has not been investigated. Our aim was to describe the distribution of lymphatic vessels in mouse uterus and to examine the effect of VEGF-D over-expression on these vessels in a model of endometrial cancer. We hypothesised that VEGF-D over-expression would stimulate growth of new lymphatic vessels into the endometrium, thereby contributing to cancer progression. Methods We initially described the distribution of lymphatic vessels (Lyve-1, podoplanin, VEGFR-3 and VEGF-D expression in the mouse uterus during the estrous cycle, early pregnancy and in response to estradiol-17beta and progesterone using immunohistochemistry. We also examined the effects of VEGF-D over-expression on uterine vasculature by inoculating uterine horns in NOD SCID mice with control or VEGF-D-expressing 293EBNA tumor cells. Results Lymphatic vessels positive for the lymphatic endothelial cell markers Lyve-1, podoplanin and VEGFR-3 profiles were largely restricted to the connective tissue between the myometrial circular and longitudinal muscle layers; very few lymphatic vessel profiles were observed in the endometrium. VEGF-D immunostaining was present in all uterine compartments (epithelium, stroma, myometrium, although expression was generally low. VEGF-D immunoexpression was slightly but significantly higher in estrus relative to diestrus; and in estradiol-17beta treated mice relative to vehicle or progesterone treated mice. The presence of VEGF-D over-expressing tumor cells did not induce endometrial lymphangiogenesis, although changes were observed in existing vessel profiles. For myometrial lymphatic and endometrial blood vessels, the percentage of profiles containing proliferating

Polycystic ovarian disease: animal models.

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Mahajan, D K

1988-12-01

The reproductive systems of human beings and other vertebrates are grossly similar. In the ovary particularly, the biochemical and physiologic processes are identical not only in the formation of germ cells, the development of primordial follicles and their subsequent growth to Graafian follicles, and eventual ovulation but also in anatomic structure. In a noncarcinogenic human ovary, hypersecretion of androgen causes PCOD. Such hypersecretion may result from a nonpulsatile, constant elevated level of circulating LH or a disturbance in the action of neurotransmitters in the hypothalamus. In studying the pathophysiology of PCOD in humans, one must be aware of the limitations for manipulating the hypothalamic-pituitary axis. Although the rat is a polytocous rodent, the female has a regular ovarian cyclicity of 4 or 5 days, with distinct proestrus, estrus, and diestrus phases. Inasmuch as PCOD can be experimentally produced in the rat, that species is a good model for studying the pathophysiology of human PCOD. These PCOD models and their validity have been described: (1) estradiol-valerate, (2) DHA, (3) constant-light (LL), and (4) neonatally androgenized. Among these, the LL model is noninvasive and seems superior to the others for study of the pathophysiology of PCOD. The production of the polycystic ovarian condition in the rat by the injection of estrogens or androgens in neonate animals, or estradiol or DHA in adult rats, or the administration of antigonadotropins to these animals all cause a sudden appearance of the persistent estrus state by disturbing the metabolic and physiologic processes, whereas exposure of the adult rat to LL causes polycystic ovaries gradually, similar to what is seen in human idiopathic PCOD. After about 50 days of LL, the rat becomes anovulatory and the ovaries contain thickened tunica albuginea and many atretic follicles, and the tertiary follicles are considerably distended and cystic. The granulosa and theca cells appear normal

Estrogen receptor beta and 2-arachydonoylglycerol mediate the suppressive effects of estradiol on frequency of postsynaptic currents in gonadotropin-releasing hormone neurons of metestrous mice: an acute slice electrophysiological study

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Flóra eBálint

2016-03-01

Full Text Available Gonadotropin-releasing hormone (GnRH neurons are controlled by 17β-estradiol (E2 contributing to the steroid feedback regulation of the reproductive axis. In rodents, E2 exerts a negative feedback effect upon GnRH neurons throughout the estrus-diestrus phase of the ovarian cycle. The present study was undertaken to reveal the role of estrogen receptor subtypes in the mediation of the E2 signal and elucidate the downstream molecular machinery of suppression. The effect of E2 administration at low physiological concentration (10 pM on GnRH neurons in acute brain slices obtained from metestrous GnRH-GFP mice was studied under paradigms of blocking or activating estrogen receptor subtypes and interfering with retrograde 2-arachydonoylglycerol (2-AG signaling. Whole-cell patch clamp recordings revealed that E2 significantly diminished the frequency of spontaneous postsynaptic currents (sPSCs in GnRH neurons (49. 62±7.6% which effect was abolished by application of the ERα/β blocker Faslodex (1 µM. Pretreatment of the brain slices with cannabinoid receptor type 1 (CB1 inverse agonist AM251 (1 µM and intracellularly applied endocannabinoid synthesis blocker THL (10 µM significantly attenuated the effect of E2 on the sPSCs. E2 remained effective in the presence of TTX indicating a direct action of E2 on GnRH cells. The ERβ specific agonist DPN (10 pM also significantly decreased the frequency of miniature postsynaptic currents (mPSCs in GnRH neurons. In addition, the suppressive effect of E2 was completely blocked by the selective ERβ antagonist PHTPP (1 µM indicating that ERβ is required for the observed rapid effect of the E2. In contrast, the ERα agonist PPT (10 pM or the membrane-associated G protein-coupled estrogen receptor (GPR30 agonist G1 (10 pM had no significant effect on the frequency of mPSCs in these neurons. AM251 and THL significantly abolished the effect of E2 whereas AM251 eliminated the action of DPN on the mPSCs. These

Oviductal extracellular vesicles (oviductosomes, OVS) are conserved in humans: murine OVS play a pivotal role in sperm capacitation and fertility.

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Bathala, Pradeepthi; Fereshteh, Zeinab; Li, Kun; Al-Dossary, Amal A; Galileo, Deni S; Martin-DeLeon, Patricia A

2018-03-01

in sperm and their ability to interact with PMCA1, via co-immunoprecipitation. In vitro uptake of PMCA1 from OVS was analyzed in capacitated and uncapacitated sperm via quantitative western blot analysis, IF localization and flow cytometry. Caudal sperm were also assayed for uptake of tyrosine-phosphorylated proteins which were shown to be present in OVS. Finally, PMCA1 and PMCA4 in OVS and that delivered to sperm were assayed for enzymatic activity. Human fallopian tubes were flushed to recover luminal fluid which was processed for OVS via ultracentrifugation. Human OVS were negatively stained for transmission electron microscopy (TEM) and subjected to immunogold labeling, to detect PMCA4. Western analysis was used to detect HSC70 (an EV biomarker), PMCA1 and endothelial nitric oxide synthase (eNOS) which is a fertility-modulating protein delivered to human sperm by prostasomes. Oviducts of sexually mature female mice were sectioned after perfusion fixation for TEM tomography to obtain 3D information and to distinguish cross-sections of EVs from those of microvilli and cilia. Murine tissues, luminal fluids and EVs were assayed for PMCA1 (IF and western blot) or qRT-PCR. PMCA1 levels from western blots were quantified, using band densities and compared in WT and Pmca4-/- after induced estrus and in proestrus/estrus and metestrus/diestrus in cycling females. In vitro uptake of PMCA1 and tyrosine-phosphorylated proteins was quantified with flow cytometry and/or quantitative western blot. Ca2+-ATPase activity in OVS and sperm before and after PMCA1 and PMCA4 uptake was assayed, via the enzymatic hydrolysis rate of ATP. TEM revealed that human oviducts contain EVs (exosomal and microvesicular). These EVs contain PMCA4 (immunolabeling), eNOS and PMCA1 (western blot) in their cargo. TEM tomography showed the murine oviduct with EV-containing blebs which typify the apocrine pathway for EV biogenesis. Western blots revealed that during proestrus/estrus PMCA1 was

Low-Dose Aspirin Treatment Alleviates Gamma Irradiation Impaired Fertility in Female Albino Rats

International Nuclear Information System (INIS)

Ibrahim, M.F.

2013-01-01

Recent experimental evidence suggests that Aspirin (acetylsalicylic acid), the extensively prescribed analgesic, can improve female fertility by suppressing the prostaglandin (PG) biosynthesis and modulating the uterine circulation. Aspirin has also been found to exhibit a protective ability on the radiation induced oxidative stress. Thus the present work aims to investigate the effect of oral low-dose Aspirin treatment on the radiation induced female reproductive disturbance. Adult female rats were used in the current experiment. All rat group treatments started at the onset of the proestrus phase and terminated at the diestrus encompassing 2 complete estrus cycles. Subsequently, the rats were divided into 4 equal groups: Group 1-Control: female rats receiving distilled water via an oral gavage; Group 2- Irradiation: female rats subjected to 6 Gy gamma rays at the proestrus cycle and receiving distilled water; Group 3-Aspirin: rats orally administered a daily dose of 7mg/kg body weight aspirin dissolved in distilled water via an oral gavage and Group 4- Irradiation + Aspirin: female rats irradiated as group 2 and receiving aspirin treatment. A number of rats from each experimental group were allowed to mate following every treatment to serve as Control mated (Subgroup 1), Irradiated mated (Subgroup 2), Aspirin administered mated (Subgroup 3) and Irradiated + Aspirin treated mated (Subgroup 4). At the assigned day of the second estrus cycle completion, blood was collected from Groups 1-4 for subsequent hormonal assay, lipid peroxides and glutathione (GSH) estimation whereas Subgroups 1-4 were carefully monitored for reproduction and infertility rates. Results have shown that the 6 Gy γ- irradiation of the rats at the proestrus cycle (Group 2) caused a decrease in follicle stimulating hormone (FSH), luteinizing hormone (LH), prolactin (PRL) and estradiol (E2) levels associated with a drastic increase in the progesterone levels in addition to the significant

Liquid-base cytology: a new method for oestral cycle study in wistar's rats Citologia de base líquida: um novo método para o estudo do ciclo estral em ratas Wistar

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Rand Randall Martins

2005-01-01

Full Text Available OBJECTIVES: The objective of this study was the standardization of a collection technique and staining in liquid-base that allies the pratical and cytological wealth, making possible a larger reproductibility and microscopic easiness. METHODS: Female wistar rats (n=20 were submitted to the daily vaginal collection in saline and fastened washed (ether/alcohol and stained in suspension with a solution of Evans Blue 0.025%. The sample was pondered by centrifugation and observed under lens of 40 x. RESULTS: The stained smears allowed clear differentiation of the phases of hormonal cycle (diestrus, proestrus, estrus and metestrus; besides the differentiation of the cellular types in relation to its maturation degree having as parameters the cellular size, nucleus / cytoplasm relationship (NCR and ink reaction. The study demonstrated the existence of three basic cellular patterns: cells with low NCR, accentuated cyanophily and small size; cells with increment in NCR, cyanophilic loss and larger volume cytoplasmatic and without nuclei keratinization cells in squamous aspect. CONCLUSION: The staining of the material allowed, besides the cytological classification, the quantification possibility that would result in a perfected accompaniment of the cycle estrous.OBJETIVOS: O objetivo deste estudo foi à padronização de uma técnica de coleta e coloração em meio líquido que alie a praticidade e a riqueza citológica, possibilitando uma maior reprodutividade e facilidade microscópica. MÉTODOS: Ratas wistar (n=20 foram submetidas à coleta vaginal diária em salina e o lavado fixado (éter/álcool e corado em suspensão com solução de azul de Evans 0,025%. A amostra foi concentrada por centrifugação e observado sob objetiva de 40 x. RESULTADOS: Os esfregaços corados permitiram nítida diferenciação das fases do ciclo hormonal (diestro, proestro, estro e metaestro; além da diferenciação dos tipos celulares em relação ao seu grau de matura

Mechanisms underlying reduced fertility in anovular dairy cows.

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Santos, J E P; Bisinotto, R S; Ribeiro, E S

2016-07-01

downregulated, whereas genes linked to apoptosis and autophagy were upregulated in Day 15 conceptuses collected from anovular cows compared with estrous cyclic counterparts. Similar changes in conceptus transcriptome were not observed in estrous cyclic cows induced to ovulate follicles that grew under low and high concentrations of progesterone, indicating an effect of anovulation on embryonic development that is not mediated solely by progesterone concentrations before ovulation. Finally, risk factors for anovulation have direct effects on embryo development and uterine receptivity to pregnancy that complement those determined by insufficient concentrations of progesterone during follicular growth. One approach to minimize the impact of anovulation on fertility is supplementation with progesterone during recruitment, selection and final stages of development of the preovulatory follicle. It is suggested that a minimum of 2.0 ng/mL of progesterone is needed during growth of the preovulatory follicle to achieve P/AI similar to that of cows growing the preovulatory follicle during diestrus. Copyright © 2016 Elsevier Inc. All rights reserved.

Progesterone levels and days to luteolysis in mares treated with intrauterine fractionated coconut oil.

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Diel de Amorim, Mariana; Nielsen, Kayla; Cruz, Raissa Karolliny Salgueiro; Card, Claire

2016-07-15

difference in DTL between the groups (P = 0.0083), with fewer DTL in Group 1 compared to control (P = 0.011) and to Group 2 (P = 0.034). There was a significant effect of day (P < 0.0001) on P4 levels with Day 11 P4 levels higher than Day 15 and Day 17 and Day 13 P4 levels higher than Day 15 or Day 17 (P < 0.03). There was a significant effect of treatment group (P = 0.0098) on P4 levels with control and Group 2 levels higher than Group 1 mares (P = 0.0012, P = 0.0495, respectively). We concluded that intrauterine administration of 1 mL of fractionated coconut oil lowered P4 levels in diestrus in a dose-dependent fashion and did not prolonged the luteal phase of the mares. Copyright © 2016 Elsevier Inc. All rights reserved.

Ovarian remnant syndrome in small animalsSíndrome do ovário remanescente em pequenos animais

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Gilson Hélio Toniollo

2012-04-01

Full Text Available The ovarian remnant syndrome (ORS is an iatrogenic disorder in bitches and queens, which is characterized by recurrence of estrus following surgical spay, due to the presence of a piece of ovarian tissue within the abdominal cavity. In most cases, the remnant ovary is found in the right ovarian pedicle, due to its topographic position, deeper and more cranial than the left ovary. The main clinical signs of ORS in small animals are the heat behavior and the presence of vaginal swelling/secretion, especially in canines. The diagnosis should be performed by means of vaginal cytology when attraction of males is detected, serum estrogen and progesterone levels and/or by challenging test with GnRH or hCG administration. However, vaginal citology is the most suitable and less expensive diagnostic tool. Nowadays the treatment of choice is a new laparotomy or laparoscopy, followed by removal of the remnant ovarian tissue. The surgical treatment has more chances of success if it is performed in the diestrus (i.e., between 15 and 60 days after the detection of attraction of males. Furthermore, a careful and accurate surgical procedure aided by advanced visualization techniques during ovariohysterectomy or ovariectomy is the best way to prevent ORS in companion animals. A síndrome do ovário remanescente (SOR é um distúrbio iatrogênico em cadelas e gatas caracterizado pelo retorno do estro após contracepção cirúrgica devido à presença de fragmento de tecido ovariano na cavidade abdominal. Frequentemente, o ovário remanescente está situado no pedículo ovariano direito, sobretudo devido a sua posição topográfica mais profunda e cranial em comparação ao ovário esquerdo. Os principais sinais clínicos de SOR em pequenos animais são cio e presença de edemaciamento/secreção vulvar/vaginal, especialmente em caninos. O diagnóstico deve ser realizado por meio de citologia vaginal quando detecta-se o interesse dos machos pela cópula com a f

COLPOCITOLOGY AND SERUM CONCENTRATIONS OF PROGESTERONE IN NULIPAROUS GOATS SUBMMITED TO ARTIFICIAL PHOTOPERIODS COLPOCITOLOGIA E CONCENTRAÇÕES SÉRICAS DE PROGESTERONA EM CABRAS NULÍPARAS SUBMETIDAS AO FOTOPERÍODO ARTIFICIAL

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Caroline Rocha de Oliveira Lima

2008-10-01

Full Text Available The aim of present work was to evaluate the changes of cervico-vaginal epithelial cells and progesterone levels of nuliparous goats submitted to artificial photoperiod, in Middle-West of Brazil. Seventh Alpine and six crossbreed nuliparous goats were used, distributed in two groups: control (GC, maintained at isolated stall and submitted to natural light for the time of the year, and treated (GT, submitted to an alternate regime among natural and artificial light, for 24 hours and 35 uninterrupted days. Cérvico-vaginal content was collected, prepared on glass slides and differential cellular counts were carried out on Papanicolau smears. The progesterone concentration in blood serum was measurement by ELISA. Parabasal were the most frequent cell type present, followed by intermediate cells, mainly in the end of metaestrus and diestrus. Superficial cornified cells were present during proestrus and estrus. The cellular profile and progesterone concentrations oscillated in agreement with estrus cycle phase in control animals, but confuse on the begin of experimental period for treated animals. Cytological evaluation of cervico-vaginal content could be of value for a hormonal bioassay of estrus cycle of goats submitted to artificial photoperiod just after the adaptation period.

KEY WORDS: Artificial photoperiod, caprine, hormone, vaginal cytology.

Ovarian reaction and estrus manifestation in delayed puberty gilts after treatment with equine chorionic gonadotropin

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Stančić Ivan B

2012-08-01

after spontaneous estrus detection. The interval from eCG to induced estrus detection was prolonged (av. 25 days in 95% (19/20 of the sexually mature gilts treated with eCG on day 5 and in 90% (18/20 of gilts treated on day 11 after spontaneous estrus detection (Exp. 1. Forty anestrous gilts reached cyclic pubertal ovarian activity. Estrus manifestation was detected in 56 gilts (93.3% of the total 60 treated prolonged anestrous gilts, av. 259 days of age, after a single 1000 IU eCG injection. Thirty-four gilts (60.7% of the total gilts in estrus with prolonged eCG to estrus interval (av. 24.7 days were considered spontaneously cyclic (sexually mature, but behaviourally anestrous before treatment. The remaining 22 (39.3% of the total gilts in estrus were considered truly sexually immature (acyclic before the treatment or were eCG injected in the late luteal or proestrous phase of spontaneous estrous cycle (Exp. 2. Conclusions In 66.7% of the delayed puberty gilts, pre-ovulatory follicles (PoF, corpora hemorrhagica (CH, corpora lutea (CL, or corpora albicantia (CA were found on the ovaries upon post mortem examination. These gilts were considered as sexually mature before slaughtering. In 60.7% of the delayed puberty gilts, behavioural estrus was detected an average of 24.7 days following eCG injections. These gilts were considered as eCG treated during the luteal phase (diestrus of the spontaneous estrus cycle. Both findings suggest that delayed puberty gilts actually reached cyclic pubertal ovarian activity (sexual maturity before culling from the breeding herd.