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Sample records for waltzing guinea pig

  1. Type I hair cell degeneration in the utricular macula of the waltzing guinea pig

    DEFF Research Database (Denmark)

    Severinsen, Stig A; Raarup, Merete Krog; Ulfendahl, Mats

    2008-01-01

    Waltzing guinea pigs are an inbred guinea pig strain with a congenital and progressive balance and hearing disorder. A unique rod-shaped structure is found in the type I vestibular hair cells, that traverses the cell in an axial direction, extending towards the basement membrane. The present study...... estimates the total number of utricular hair cells and supporting cells in waltzing guinea pigs and age-matched control animals using the optical fractionator method. Animals were divided into four age groups (1, 7, 49 and 343 day-old). The number of type I hair cells decreased by 20% in the 343 day......-old waltzing guinea pigs compared to age-matched controls and younger animals. Two-photon confocal laser scanning microscopy using antibodies against fimbrin and betaIII-tubulin showed that the rods were exclusive to type I hair cells. There was no significant change in the length of the filament rods with age...

  2. THE GENETIC-INDUCED HEARING lOSS CAN BLOCK THE EFFECT OF NOISE TRAUMA IN WAlTZING GUINEA PIG

    Institute of Scientific and Technical Information of China (English)

    Tong Busheng; Duan Maoli

    2013-01-01

    The waltzing guinea pig may be a good model to investigate if genetic factor can change the sensitivity in noise-induced hearing loss. A total of 34 waltzig guinea pigs were studied and we found that there is no any significant increased sensitivity to noise trauma if the age-induced hearing loss was considered in waltz-ing guinea pig.

  3. Reduced noise susceptibility in littermate offspring from heterozygous animals of the German waltzing guinea pig.

    Science.gov (United States)

    Skjönsberg, Åsa; Mannström, Paula

    2015-07-08

    The German waltzing guinea pig is a spontaneously mutated strain with severe auditory and vestibular impairment caused by a so far unknown genetic mutation. The animals are born deaf and show a circling behavior. The heterozygote animals of this guinea pig strain have functionally normal hearing and balance. However, these animals have, in earlier studies, shown an increased resistance to noise compared with normal wild-type guinea pigs. In the present study, we explored the functional hearing with auditory brainstem response thresholds before and at different time points after noise exposure. Symptom-free littermates from heterozygote couples of the German waltzing guinea pigs were exclusively used for the study, which, after the hearing test, were sent back for breeding to confirm their genotype (i.e. heterozygote or normal). The aim of this paper was to ascertain that the previously shown reduced susceptibility to noise trauma in the heterozygote animals of the German waltzing guinea pig was also evident when littermates were used as control animals. The findings are important for further analysis of the heterozygote animals of this strain and for future investigations of the underlying mechanisms behind the diverse susceptibility to exposures of loud sound.

  4. Effect of auditory stress agents on heterozygous German waltzing guinea pigs

    Institute of Scientific and Technical Information of China (English)

    Åsa Skj€onsberg; Maoli Duan; Ann-Christin Johnson; Mats Ulfendahl

    2014-01-01

    The German waltzing guinea pig is a strain of animals expressing deafness and severe balance disorders at birth. The mutation arose spontaneously in a breeding facility in Germany and as the affected animals show a characteristic waltzing behavior, the strain is named the German waltzing guinea pig. The strain is presently bred only at Karolinska Institutet. The hereditary inner ear impairment has a recessive mode of inheritance and the strain thus produces not only affected homozygotes but also symptom-free heterozygotes and fully normal offspring. The outcome depends solely on the genotype of the parents. The heterozygotes, which have obtained the“waltzing”gene from one parent only, have normal hearing and no balance dysfunction. The heterozygous animals appear normal but will, in turn, carry the genetic defect to the next generation. The present thesis is focused on these animals. Noise and ototoxic drugs are well known stress factors that interfere negatively with the hearing organ in both humans and animals, causing hearing impairment. However, the inter-individual variability in susceptibility to auditory stress factors is surprisingly large, most likely due to different genetic predisposition. In this study, heterozygous animals of the German waltzing guinea pig, animals carrying a genetic defect known to cause severe hearing impairment, were used to study how an unexplored gene for deafness interacts with auditory stress agents, i.e. noise exposure and the ototoxic drugs gentamicin and cisplatin. Animals were exposed to both narrowband as well as broadband noise at different ages and hearing thresholds were measured using ABRs. Heterozygotes of the German waltzing guinea pig showed less threshold shifts compared to control strains. Older animals were less affected by the noise trauma than younger animals. To test the hypothesis that the efferent system contributes to protection of the inner ear against noise trauma, measurements using a new method of

  5. The guinea-pig

    DEFF Research Database (Denmark)

    Andersen, Klaus Ejner; Maibach, H I; Anjo, M D

    1980-01-01

    14C ring-labelled hydrocortisone, testosterone and benzoic acid dissolved in acetone were applied to the backs of guinea-pigs (4 microgram/cm2). Percutaneous absorption was quantified by following the excretion of tracer in urine and faeces for 5 days. Absorption of hydrocortisone and benzoic acid...... was 2.4% (s.d. = 0.5; n = 3) and 31.4% (s.d. = 9.1; n = 3) of the applied dose respectively, similar to published human absorption data. Testosterone was absorbed to a greater extent in guinea-pigs (34.9% +/- 5.4; n = 5) than man. A thioglycollate based depilatory cream significantly increased the skin...

  6. Guinea pig maximization test

    DEFF Research Database (Denmark)

    Andersen, Klaus Ejner

    1985-01-01

    Guinea pig maximization tests (GPMT) with chlorocresol were performed to ascertain whether the sensitization rate was affected by minor changes in the Freund's complete adjuvant (FCA) emulsion used. Three types of emulsion were evaluated: the oil phase was mixed with propylene glycol, saline with...... to the saline/oil emulsion. Placing of the challenge patches affected the response, as simultaneous chlorocresol challenge on the flank located 2 cm closer to the abdomen than the usual challenge site gave decreased reactions....

  7. Guinea pig maximization test

    DEFF Research Database (Denmark)

    Andersen, Klaus Ejner

    1985-01-01

    Guinea pig maximization tests (GPMT) with chlorocresol were performed to ascertain whether the sensitization rate was affected by minor changes in the Freund's complete adjuvant (FCA) emulsion used. Three types of emulsion were evaluated: the oil phase was mixed with propylene glycol, saline...... with 30% (v/v) ethanol or saline, respectively. Relative viscosity was used as one measure of physical properties of the emulsion. Higher degrees of sensitization (but not rates) were obtained at the 48 h challenge reading with the oil/propylene glycol and oil/saline + ethanol emulsions compared...... to the saline/oil emulsion. Placing of the challenge patches affected the response, as simultaneous chlorocresol challenge on the flank located 2 cm closer to the abdomen than the usual challenge site gave decreased reactions....

  8. Experimental aerosolized guinea pig-adapted Zaire ebolavirus (variant: Mayinga) causes lethal pneumonia in guinea pigs.

    Science.gov (United States)

    Twenhafel, N A; Shaia, C I; Bunton, T E; Shamblin, J D; Wollen, S E; Pitt, L M; Sizemore, D R; Ogg, M M; Johnston, S C

    2015-01-01

    Eight guinea pigs were aerosolized with guinea pig-adapted Zaire ebolavirus (variant: Mayinga) and developed lethal interstitial pneumonia that was distinct from lesions described in guinea pigs challenged subcutaneously, nonhuman primates challenged by the aerosol route, and natural infection in humans. Guinea pigs succumbed with significant pathologic changes primarily restricted to the lungs. Intracytoplasmic inclusion bodies were observed in many alveolar macrophages. Perivasculitis was noted within the lungs. These changes are unlike those of documented subcutaneously challenged guinea pigs and aerosolized filoviral infections in nonhuman primates and human cases. Similar to findings in subcutaneously challenged guinea pigs, there were only mild lesions in the liver and spleen. To our knowledge, this is the first report of aerosol challenge of guinea pigs with guinea pig-adapted Zaire ebolavirus (variant: Mayinga). Before choosing this model for use in aerosolized ebolavirus studies, scientists and pathologists should be aware that aerosolized guinea pig-adapted Zaire ebolavirus (variant: Mayinga) causes lethal pneumonia in guinea pigs.

  9. Guinea pig model of tuberculosis

    Institute of Scientific and Technical Information of China (English)

    Pushpa Gupta; U.D.Gupta

    2009-01-01

    Animal models are being developed for testing different vaccine candidates as well as testing of new antituber-cular since a long time.Mice,guinea pigs and rabbits are animals which are frequently used.Though each model has got its merits as well as demerits and each of them differ from human tuberculosis in one aspect or the other but none of the model completely mimics the human disease.Out of the different animal species, guinea pig model is one of the better models as it is very sensitive to M.tuberculosis infection but it has certain limitations like paucity of immunological reagents.However,it is the best model for tuberculosis research.

  10. Guinea Pigs: Versatile Animals for the Classroom

    Science.gov (United States)

    Barman, Charles R.

    1977-01-01

    Guinea pigs are presented as versatile classroom animals. Suggestions for animal behavior and genetics studies are given. Also included is information concerning sex determination and the breeding of guinea pigs, and hints on keeping these animals in the classroom. References and illustrations complete the article. (MA)

  11. Endocrine tumours in the guinea pig.

    Science.gov (United States)

    Künzel, Frank; Mayer, Jörg

    2015-12-01

    Functional endocrine tumours have long been thought to be rare in guinea pigs, although conditions such as hyperthyroidism and hyperadrenocorticism have been documented with increasing frequency so the prevalence of hormonal disorders may have been underestimated. Both the clinical signs and diagnosis of hyperthyroidism in guinea pigs appear to be very similar to those described in feline hyperthyroidism, and methimazole has been proven to be a practical therapy option. Hyperadrenocorticism has been confirmed in several guinea pigs with an adrenocorticotropic hormone stimulation test using saliva as a non-invasive sample matrix; trilostane has been successfully used to treat a guinea pig with hyperadrenocorticism. Insulinomas have only rarely been documented in guinea pigs and one animal was effectively treated with diazoxide.

  12. 9 CFR 113.38 - Guinea pig safety test.

    Science.gov (United States)

    2010-01-01

    ... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Guinea pig safety test. 113.38 Section 113.38 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF... Standard Procedures § 113.38 Guinea pig safety test. The guinea pig safety test provided in this section...

  13. Development of a Guinea Pig Lung Deposition Model

    Science.gov (United States)

    2016-01-01

    Development of a Guinea Pig Lung Deposition Model Distribution Statement A. Approved for public release; distribution is unlimited. January...4 Figure 2. Particle deposition in the lung of the guinea pig via endotracheal breathing...Particle deposition in the lungs of guinea pigs via nasal breathing. ......................................... 12 v PREFACE The research work

  14. Malignant transformation of guinea pig cells after exposure to ultraviolet-irradiated guinea pig cytomegalovirus

    Energy Technology Data Exchange (ETDEWEB)

    Isom, H.C.; Mummaw, J.; Kreider, J.W.

    1983-04-30

    Guinea pig cells were malignantly transformed in vitro by ultraviolet (uv)-irradiated guinea pig cytomegalovirus (GPCMV). When guinea pig hepatocyte monolayers were infected with uv-irradiated GPCMV, three continuous epithelioid cell lines which grew in soft agarose were established. Two independently derived GPCMV-transformed liver cells and a cell line derived from a soft agarose clone of one of these lines induced invasive tumors when inoculated subcutaneously or intraperitoneally into nude mice. The tumors were sarcomas possibly derived from hepatic stroma or sinusoid. Transformed cell lines were also established after infection of guinea pig hepatocyte monolayers with human cytomegalovirus (HCMV) or simian virus 40 (SV40). These cell lines also formed colonies in soft agarose and induced sarcomas in nude mice. It is concluded that (i) GPCMV can malignantly transform guinea pig cells; (ii) cloning of GPCMV-transformed cells in soft agarose produced cells that induced tumors with a shorter latency period but with no alteration in growth rate or final tumor size; and (iii) the tumors produced by GPCMV-and HCMV-transformed guinea pig cells were more similar to each other in growth rate than to those induced by SV40-transformed guinea pig cells.

  15. Vitamin C deficiency in weanling guinea pigs

    DEFF Research Database (Denmark)

    Lykkesfeldt, Jens; Trueba, Gilberto Perez; Poulsen, Henrik E.

    2007-01-01

    Neonates are particularly susceptible to malnutrition due to their limited reserves of micronutrients and their rapid growth. In the present study, we examined the effect of vitamin C deficiency on markers of oxidative stress in plasma, liver and brain of weanling guinea pigs. Vitamin C deficiency...... increased, while protein oxidation decreased (P¼0003). The results show that the selective preservation of brain ascorbate and induction of DNA repair in vitamin C-deficient weanling guinea pigs is not sufficient to prevent oxidative damage. Vitamin C deficiency may therefore be particularly adverse during...

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

    Science.gov (United States)

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

    2010-08-01

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

  17. Mesothelium of Reissner's membrane in guinea pigs

    DEFF Research Database (Denmark)

    Qvortrup, K; Rostgaard, Jørgen

    1990-01-01

    The mesothelial cells of Reissner's membrane in guinea pigs were found to be connected by junctional complexes. No cell discontinuities or gaps were observed by scanning or transmission electron microscopy. These results are not in accordance with previous studies. They were achieved by in vivo...

  18. New guinea pig model of Cryptococcal meningitis.

    Science.gov (United States)

    Kirkpatrick, William R; Najvar, Laura K; Bocanegra, Rosie; Patterson, Thomas F; Graybill, John R

    2007-08-01

    We developed a guinea pig model of cryptococcal meningitis to evaluate antifungal agents. Immunosuppressed animals challenged intracranially with Cryptococcus neoformans responded to fluconazole and voriconazole. Disease was monitored by serial cerebrospinal fluid (CSF) cultures and quantitative organ cultures. Our model produces disseminating central nervous system disease and responds to antifungal therapy.

  19. Tibial osteosynthesis in a guinea pig (Cavia porcellus

    Directory of Open Access Journals (Sweden)

    A.S. Macedo

    2015-02-01

    Full Text Available A guinea pig was presented with left pelvic limb lameness after unknown trauma. Radiographs revealed complete oblique diaphyseal fracture of the distal third of the left tibia and fibula. The guinea pig was treated surgically with an intramedullary pin. The day after surgery the guinea pig was using the limb comfortably (grade 1/5 lameness. Callus formation was obtained 21 days after surgery without complications.

  20. Spontaneous reproductive pathology in female guinea pigs.

    Science.gov (United States)

    Veiga-Parga, Tamara; La Perle, Krista M D; Newman, Shelley J

    2016-11-01

    Reproductive pathology of domestic guinea pigs is underreported to date. To provide a comprehensive review of uterine disease in guinea pigs, we performed a retrospective study of the pathology archives of the University of Tennessee, College of Veterinary Medicine. By histology, 13 of 37 uterine lesions in 23 animals were neoplastic; the other 24 nonneoplastic lesions included cystic endometrial hyperplasia (16 of 24), endometrial hemorrhage (3 of 24), pyometra (2 of 24), polyp (2 of 24), and mucometra (1 of 24). The most common guinea pig uterine neoplasms were uterine leiomyomas (6 of 13), followed by adenomas (3 of 13) and leiomyosarcomas (1 of 13). Other neoplasms included anaplastic tumors of unknown origin (2 of 13) and choriocarcinoma (1 of 13). Both anaplastic tumors and the choriocarcinoma were positive for vimentin. The choriocarcinoma was positive for HSD83B1, indicating a trophoblastic origin and its final diagnosis. All were negative for cytokeratin and smooth muscle. In multiple animals, more than 1 tumor or lesion was reported. Estrogen receptor and progesterone receptor expression was nearly 100% in uterine neoplasms. Nearly all animals for which data were available had cystic rete ovarii (18 of 19); the animal with no cystic rete ovarii had paraovarian cysts. In our study, female pet guinea pigs had a tendency to develop cystic endometrial hyperplasia and uterine neoplasia. Factors for the development of these lesions could be cystic rete ovarii, hormone dysregulation, and/or age. Other factors could contribute to the development of uterine lesions. As in other species, early ovariohysterectomy could decrease the prevalence of uterine lesions.

  1. CHARACTERIZATION OF MUSCARINIC RECEPTORS IN GUINEA-PIG UTERUS

    NARCIS (Netherlands)

    DOODS, HN; WILLIM, KD; BODDEKE, HWGM; ENTZEROTH, M

    1993-01-01

    To characterize the muscarinic receptor present in guinea-pig uterus smooth muscle the affinities of a series of 27 muscarinic receptor antagonists for M1 (rat cortex), M2 (rat heart), M3 (rat submandibular gland), m4 (transfected in CHO cells) and muscarinic binding sites in guinea-pig uterus

  2. The Guinea Pigs of a Problem-Based Learning Curriculum

    Science.gov (United States)

    Reddy, Sarasvathie; McKenna, Sioux

    2016-01-01

    Participants in a study on learning the clinical aspects of medicine in a problem-based learning (PBL) curriculum repeatedly referred to themselves as "Guinea pigs" at the mercy of a curriculum experiment. This article interrogates and problematises the "Guinea pig" identity ascribed to and assumed by the first cohort of…

  3. Heterogeneous infectiousness in guinea pigs experimentally infected with Trypanosoma cruzi.

    Science.gov (United States)

    Castillo-Neyra, Ricardo; Borrini Mayorí, Katty; Salazar Sánchez, Renzo; Ancca Suarez, Jenny; Xie, Sherrie; Náquira Velarde, Cesar; Levy, Michael Z

    2016-02-01

    Guinea pigs are important reservoirs of Trypanosoma cruzi, the causative parasite of Chagas disease, and in the Southern Cone of South America, transmission is mediated mainly by the vector Triatoma infestans. Interestingly, colonies of Triatoma infestans captured from guinea pig corrals sporadically have infection prevalence rates above 80%. Such high values are not consistent with the relatively short 7-8 week parasitemic period that has been reported for guinea pigs in the literature. We experimentally measured the infectious periods of a group of T. cruzi-infected guinea pigs by performing xenodiagnosis and direct microscopy each week for one year. Another group of infected guinea pigs received only direct microscopy to control for the effect that inoculation by triatomine saliva may have on parasitemia in the host. We observed infectious periods longer than those previously reported in a number of guinea pigs from both the xenodiagnosis and control groups. While some guinea pigs were infectious for a short time, other "super-shedders" were parasitemic up to 22 weeks after infection, and/or positive by xenodiagnosis for a year after infection. This heterogeneity in infectiousness has strong implications for T. cruzi transmission dynamics and control, as super-shedder guinea pigs may play a disproportionate role in pathogen spread.

  4. A 2-D guinea pig lung proteome map

    Science.gov (United States)

    Guinea pigs represent an important model for a number of infectious and non-infectious pulmonary diseases. The guinea pig genome has recently been sequenced to full coverage, opening up new research avenues using genomics, transcriptomics and proteomics techniques in this species. In order to furth...

  5. Filial attachment and its disruption: insights from the guinea pig.

    Science.gov (United States)

    Hennessy, Michael B

    2014-12-01

    Guinea pigs are precocial rodents that show evidence of a selective attachment to the mother who, in turn, exhibits little active maternal care. Effects of separation in guinea pigs are, therefore, more likely to reflect the disruption of attachment than the removal of, or alterations in, patterns of maternal care. Here, effects in guinea pigs of the presence or absence of the mother on psychobiological endpoints and of maternal separation on depressive-like behavior are reviewed. It is argued that results with guinea pigs often align more closely with those of nonhuman primates than those of laboratory rats and mice, and that the guinea pig offers a valuable translational model for studies of the consequences of attachment and its disruption.

  6. Functional analysis of guinea pig β1-adrenoceptor.

    Science.gov (United States)

    Tanaka, Yoshio; Takahashi, Hiromi; Shibata, Sayuri; Namiki, Kana; Kimura, Sadao; Koike, Katsuo; Kasuya, Yoshitoshi

    2011-12-01

    Although similarity of pharmacological responses to certain stimuli between guinea pigs and humans has been reported, this has been poorly defined by a molecular biological approach. In this study, we cloned the gene of guinea pig ?1-adrenoceptor (ADRB1). The deduced amino acid sequence of guinea pig ADRB1 (467-aa) showed 91% and 92% identity with the human and rat ADRB1 sequences, respectively. Using HEK293T cells expressing guinea pig, human and rat ADRB1s independently, we elucidated the functional characteristics of each ADRB1. The ligand-binding profiles and the concentration-response relationships for isoprenaline-induced cyclic adenosine monophosphate (cAMP) production were similar among the three ADRB1s. Isoprenaline also induced phosphorylation of extracellular-signal related kinases (ERK) through ADRB1s in a concentration-dependent manner. The minimum effective concentration of isoprenaline for phosphorylation of ERK, through guinea pig ADRB1 was the same as through human ADRB1, but markedly lower than that of through rat ADRB1. ERK phosphorylation through guinea pig ADRB1 was sensitive to pertussis toxin, a dominant-negative ras and PD98059, indicating that a G(i)-mediated pathway is involved in the ADRB1/ERK signaling loop. These results suggest that the G(i)-coupling efficacy of guinea pig and human ADRB1s may be higher than that of rat ADRB1.

  7. Immunohistochemical demonstration of airway epithelial cell markers of guinea pig.

    Science.gov (United States)

    Li, Yong; Wang, Jing; He, Hai Yan; Ma, Ling Jie; Zeng, Jin; Deng, Guang Cun; Liu, Xiaoming; Engelhardt, John F; Wang, Yujiong

    2011-10-01

    The guinea pig (Cavea porcellus) is a mammalian non-rodent species in the Caviidae family. The sensitivity of the respiratory system and the susceptibility to infectious diseases allows the guinea pig to be a useful model for both infectious and non-infectious lung diseases such as asthma and tuberculosis. In this report, we demonstrated for the first time, the major cell types and composition in the guinea pig airway epithelium, using cell type-specific markers by immunohistochemical staining using the commercial available immunological reagents that cross-react with guinea pig. Our results revealed the availability of antibodies cross-reacting with airway epithelial cell types of basal, non-ciliated columnar, ciliated, Clara, goblet and alveolar type II cells, as well as those cells expressing Mucin 5AC, Mucin 2, Aquaporin 4 and Calcitonin Gene Related Peptide. The distribution of these various cell types were quantified in the guinea pig airway by immunohistochemical staining and were comparable with morphometric studies using an electron microscopy assay. Moreover, this study also demonstrated that goblet cells are the main secretory cell type in the guinea pig's airway, distinguishing this species from rats and mice. These results provide useful information for the understanding of airway epithelial cell biology and mechanisms of epithelial-immune integration in guinea pig models.

  8. Blood profiles in unanesthetized and anesthetized guinea pigs (Cavia porcellus).

    Science.gov (United States)

    Williams, Wendy R; Johnston, Matthew S; Higgins, Sarah; Izzo, Angelo A; Kendall, Lon V

    2016-01-01

    The guinea pig is a common animal model that is used in biomedical research to study a variety of systems, including hormonal and immunological responses, pulmonary physiology, corticosteroid response and others. However, because guinea pigs are evolutionarily a prey species, they do not readily show behavioral signs of disease, which can make it difficult to detect illness in a laboratory setting. Minimally invasive blood tests, such as complete blood counts and plasma biochemistry assays, are useful in both human and veterinary medicine as an initial diagnostic technique to rule in or rule out systemic illness. In guinea pigs, phlebotomy for such tests often requires that the animals be anesthetized first. The authors evaluated hematological and plasma biochemical effects of two anesthetic agents that are commonly used with guinea pigs in a research setting: isoflurane and a combination of ketamine and xylazine. Hematological and plasma biochemical parameters were significantly different when guinea pigs were under either anesthetic, compared to when they were unanesthetized. Plasma proteins, liver enzymes, white blood cells and red blood cells appeared to be significantly altered by both anesthetics, and hematological and plasma biochemical differences were greater when guinea pigs were anesthetized with the combination of ketamine and xylazine than when they were anesthetized with isoflurane. Overall these results indicate that both anesthetics can significantly influence hematological and plasma biochemical parameters in guinea pigs.

  9. Signal transduction pathways in guinea pig sperm

    Institute of Scientific and Technical Information of China (English)

    李明文; 焦日; 孙青原; 胡国俊; 段崇文; 刘辉; 宋祥芬; 陈大元

    1996-01-01

    Trifluoperazine (TFP), the antagonist of calmodulin (CaM). significantly stimulated the capacitation and acrosome reaction of guinea pig spermatozoa at the concentration of 10-100μmol/L, independent of the external Ca2+. Forskolin, dbcAMP and caffeine evidently promoted the occurrence of acrosome reaction of spermatozoa at early capacitation stage (5 h) in nonsynchronous system but not in synchronous system. If the spermatozoa were capacitated for 15 h in synchronous system, the above three drugs significantly stimulated acrosome reaction in a Ca2+-independent manner. Protein kinase C activators, i.e. phorbol 12-myristate 13-acetate (PMA) and phorbol 12,13-dibutyrate (PDB) did not influence the occurrence of acrosome reaction of spermatozoa at early capacitation stage, but significantly increased the acrosome reaction rate in capacitated spermatozoa in a Ca2+-independent manner. In contrast. PKC inhibitor staurosporine significantly inhibited the occurrence of acrosome reaction.

  10. Radiation-induced micrencephaly in guinea pigs

    Energy Technology Data Exchange (ETDEWEB)

    Wagner, L.K.; Johnston, D.A.; Felleman, D.J.

    1992-01-01

    The effect of x rays on brain weight of guinea pig pups at birth was studied for 21-day old embroys exposed in utero to doses of 75 and 100 mGy. When compared to controls and when corrected for body weight, gestation time, litter size, sex, and examiner differences the brains of irradiated pups weighed approximately 46 mg less than those of controls (p<0.001) for the 75-mGy group and about 55 mg less for the 100-mGy group. Brains of females weighed 51 mg less than those of males of the same body weight. Dam weight and caging conditions had no observed effect on brain weight.

  11. Radiation-induced micrencephaly in guinea pigs

    Energy Technology Data Exchange (ETDEWEB)

    Wagner, L.K.; Johnston, D.A.; Felleman, D.J.

    1992-11-01

    The effect of x rays on brain weight of guinea pig pups at birth was studied for 21-day old embroys exposed in utero to doses of 75 and 100 mGy. When compared to controls and when corrected for body weight, gestation time, litter size, sex, and examiner differences the brains of irradiated pups weighed approximately 46 mg less than those of controls (p<0.001) for the 75-mGy group and about 55 mg less for the 100-mGy group. Brains of females weighed 51 mg less than those of males of the same body weight. Dam weight and caging conditions had no observed effect on brain weight.

  12. Ozone-Induced Hypertussive Responses in Rabbits and Guinea Pigs

    OpenAIRE

    Clay, Emlyn; Patacchini, Riccardo; Trevisani, Marcello; Preti, Delia; Branà, Maria Pia; Spina, Domenico; Page, Clive

    2016-01-01

    Cough remains a major unmet clinical need, and preclinical animal models are not predictive for new antitussive agents. We have investigated the mechanisms and pharmacological sensitivity of ozone-induced hypertussive responses in rabbits and guinea pigs. Ozone induced a significant increase in cough frequency and a decrease in time to first cough to inhaled citric acid in both conscious guinea pigs and rabbits. This response was inhibited by the established antitussive drugs codeine and levo...

  13. Ozone-Induced Hypertussive Responses in Rabbits and Guinea Pigs

    OpenAIRE

    Clay, Emlyn; Patacchini, Riccardo; Trevisani, Marcello; Preti, Delia; Branà, Maria Pia; Spina, Domenico; Page, Clive

    2016-01-01

    Cough remains a major unmet clinical need, and preclinical animal models are not predictive for new antitussive agents. We have investigated the mechanisms and pharmacological sensitivity of ozone-induced hypertussive responses in rabbits and guinea pigs. Ozone induced a significant increase in cough frequency and a decrease in time to first cough to inhaled citric acid in both conscious guinea pigs and rabbits. This response was inhibited by the established antitussive drugs codeine and levo...

  14. Spontaneous cyclic embryonic movements in humans and guinea pigs.

    Science.gov (United States)

    Felt, Renée H M; Mulder, Eduard J H; Lüchinger, Annemarie B; van Kan, Colette M; Taverne, Marcel A M; de Vries, Johanna I P

    2012-08-01

    Motility assessment before birth can be used to evaluate the integrity of the nervous system. Sideways bending (SB) of head and/or rump, the earliest embryonic motility in both humans and guinea pigs, can be visualized sonographically. We know from other species that early embryonic motility is cyclic. This study explores the distribution of SB-to-SB intervals in human and guinea pig embryos before the appearance of more complex movements such as general movements. We hypothesized that the activity in both species is cyclic. We made 15-min sonographic recordings of SBs between 5 weeks and 0 days (5wk0d) and 7wk0d conceptional age (CA) in 18 human embryos of uncomplicated IVF pregnancies (term 38 weeks) and in 20 guinea pig embryos between 3wk4d and 4wk0d CA (term 9 weeks). SB-to-SB interval durations were categorized as long (≥10 s) or short (guinea pigs 38 s (range, 10-288 s) and 5 s (range, 1-9 s), respectively. During development, the duration of long intervals decreased while the number of short intervals increased for both species. The earliest embryonic motility in the human and guinea pig is performed cyclically with distinct developmental milestones. The resemblance of their interval development offers promising possibilities to use the guinea pig as a noninvasive animal model of external influences on motor and neural development.

  15. [Experimental study of infectious hepatitis in guinea pigs].

    Science.gov (United States)

    Asharafova, R A; Tuliaganov, P D; Kasymkhodzhaev, E S

    1976-04-01

    The authors carried out a comparative study of morphological changes in the liver of guinea-pigs in various times following intraperitoneal administration of the serum taken from a patient with infectious hepatitis (1st group), administration of the serum in combination with the urine (2nd group), administration of the serum in combination with the patient's duodenal juice (3rd group), and administration of the serum in combination with a hepatic antigen prepared of the liver of a healthy guinea-pig (4th group). Observations over the behaviour of the animals and morphological investigations showed a high sensitivity of guinea-pigs to virus-containing materials. The reaction was particularly pronounced in animals which were given the serum taken from a patient with infectious hepatitis in combination with a hepatic antigen, and the microscopic picture of the liver almost similar to that of the patient with Botkin's disease. Moreover, in the course of the study it was found possible to re-inoculate the virus obtained from the guinea-pigs subjected to a combined exposure to the serum from a patient with infectious hepatits and hepatic antigen. Comparing the results of the study on guinea-pigs with those obtained previously in the experimental study of viral hepatitis on white rats (1970), the authors have come to the conclusion that guinea-pigs may be used for modelling and experimental investigation of Botkin's disease.

  16. Ototoxicity of vancomycin in guinea pigs

    Institute of Scientific and Technical Information of China (English)

    刘海瑛; 高文元; 刁明芳; 张琰敏; 韩红; 王建文

    2004-01-01

    Objective: To study the effect of vancomycin (V) with multiple intravenous injections on the inner ear of albino guinea pigs. Methods: Three groups of animals were injected with vancomycin hydrochloride (54, 108, 216 mg/kg tively as control groups. Auditory brainstem responses (ABR) and the duration of post-rotatory nystagmus (PRN) were measured before and after administration. Surface preparation and scanning electron microscopy (SEM) of the cochlea were performed for histological examination. Results: In V 54, 108 mg/kg group, similar to saline control, there was 0- 1.1 dB of threshold shift. In V 216 mg/kg group, average hearing loss was 1.0- 5.7 dB immediately after administration and 1.3 -3.8 dB after 14 d, which was significantly lower than those in GM control group. As the saline control, no significant difference was found in PRN in all V groups before and after treatment; while in the GM group, PRN decreased significantly after treatment. Morphological evaluation demonstrated that in all V and saline animals there was no obvious missing of outer and inner hair cells and SEM showed normal surface morphology. In the GM group, there was 10% - 30% of outer and inner hair cells lost in the basal turn. Conclusion: The ototoxicity of vancomycin is absent or minimal after multiple introvenous administration within this dose range.

  17. Radiation induced micrencephaly in guinea pigs

    Energy Technology Data Exchange (ETDEWEB)

    Wagner, L.K.; Johnston, D.A.; Felleman, D.J.

    1991-01-01

    A brain weight deficit of about 70 mg was induced at doses of approximately 75-mGy and a deficit of 60 mg was induced at 100 mGy. This confirms the effects projected and observed by Wanner and Edwards. Although the data do not demonstrate a clear dose-response relationship between the 75-mGy and 100-mGy groups, the data are statistically consistent with a dose-response effect because of the overlapping confidence intervals. The lack of a statistically significant observation is most likely related to the small difference in doses and the limited numbers of animals examined. There are several factors that can influence the brain weight of guinea pig pups, such as caging and housing conditions, the sex of the animal, and litter size. These should be taken into account for accurate analysis. Dam weight did not appear to have a significant effect. The confirmation of a micrencephalic effect induced x rays at doses of 75-mGy during this late embryonic stage of development is consistent with the findings of small head size induced in those exposed prior to the eight week of conception at Hiroshima. This implies a mechanism for micrencephaly different from those previously suggested and lends credence to a causal relation between radiation and small head size in humans at low doses as reported by Miller and Mulvihill. 16 refs., 13 tabs.

  18. A guinea pig model of Zika virus infection.

    Science.gov (United States)

    Kumar, Mukesh; Krause, Keeton K; Azouz, Francine; Nakano, Eileen; Nerurkar, Vivek R

    2017-04-11

    Animal models are critical to understand disease and to develop countermeasures for the ongoing epidemic of Zika virus (ZIKV). Here we report that immunocompetent guinea pigs are susceptible to infection by a contemporary American strain of ZIKV. Dunkin-Hartley guinea pigs were inoculated with 10(6) plaque-forming units of ZIKV via subcutaneous route and clinical signs were observed. Viremia, viral load in the tissues, anti-ZIKV neutralizing antibody titer, and protein levels of multiple cytokine and chemokines were analyzed using qRT-PCR, plaque assay, plaque reduction neutralization test (PRNT) and multiplex immunoassay. Upon subcutaneous inoculation with PRVABC59 strain of ZIKV, guinea pigs demonstrated clinical signs of infection characterized by fever, lethargy, hunched back, ruffled fur, and decrease in mobility. ZIKV was detected in the whole blood and serum using qRT-PCR and plaque assay. Anti-ZIKV neutralizing antibody was detected in the infected animals using PRNT. ZIKV infection resulted in a dramatic increase in protein levels of multiple cytokines, chemokines and growth factors in the serum. ZIKV replication was observed in spleen and brain, with the highest viral load in the brain. This data demonstrate that after subcutaneous inoculation, the contemporary ZIKV strain is neurotropic in guinea pigs. The guinea pig model described here recapitulates various clinical features and viral kinetics observed in ZIKV-infected patients, and therefore may serve as a model to study ZIKV pathogenesis, including pregnancy outcomes and for evaluation of vaccines and therapeutics.

  19. An ecologically relevant guinea pig model of fetal behavior.

    Science.gov (United States)

    Bellinger, S A; Lucas, D; Kleven, G A

    2015-04-15

    The laboratory guinea pig, Cavia porcellus, shares with humans many similarities during pregnancy and prenatal development, including precocial offspring and social dependence. These similarities suggest the guinea pig as a promising model of fetal behavioral development as well. Using innovative methods of behavioral acclimation, fetal offspring of female IAF hairless guinea pigs time mated to NIH multicolored Hartley males were observed longitudinally without restraint using noninvasive ultrasound at weekly intervals across the 10 week gestation. To ensure that the ultrasound procedure did not cause significant stress, salivary cortisol was collected both before and after each observation. Measures of fetal spontaneous movement and behavioral state were quantified from video recordings from week 3 through the last week before birth. Results from prenatal quantification of Interlimb Movement Synchrony and state organization reveal guinea pig fetal development to be strikingly similar to that previously reported for other rodents and preterm human infants. Salivary cortisol readings taken before and after sonography did not differ at any observation time point. These results suggest this model holds translational promise for studying the prenatal mechanisms of neurobehavioral development, including those that may result from adverse events. Because the guinea pig is a highly social mammal with a wide range of socially oriented vocalizations, this model may also have utility for studying the prenatal origins and trajectories of developmental disabilities with social-emotional components, such as autism.

  20. Non-terminal blood sampling techniques in guinea pigs.

    Science.gov (United States)

    Birck, Malene M; Tveden-Nyborg, Pernille; Lindblad, Maiken M; Lykkesfeldt, Jens

    2014-10-11

    Guinea pigs possess several biological similarities to humans and are validated experimental animal models(1-3). However, the use of guinea pigs currently represents a relatively narrow area of research and descriptive data on specific methodology is correspondingly scarce. The anatomical features of guinea pigs are slightly different from other rodent models, hence modulation of sampling techniques to accommodate for species-specific differences, e.g., compared to mice and rats, are necessary to obtain sufficient and high quality samples. As both long and short term in vivo studies often require repeated blood sampling the choice of technique should be well considered in order to reduce stress and discomfort in the animals but also to ensure survival as well as compliance with requirements of sample size and accessibility. Venous blood samples can be obtained at a number of sites in guinea pigs e.g., the saphenous and jugular veins, each technique containing both advantages and disadvantages(4,5). Here, we present four different blood sampling techniques for either conscious or anaesthetized guinea pigs. The procedures are all non-terminal procedures provided that sample volumes and number of samples do not exceed guidelines for blood collection in laboratory animals(6). All the described methods have been thoroughly tested and applied for repeated in vivo blood sampling in studies within our research facility.

  1. [Phototoxicity of Bergamot oil. Comparison between humans and guinea pigs].

    Science.gov (United States)

    Girard, J; Unkovic, J; Delahayes, J; Lafille, C

    1979-01-01

    Phototoxicity of bergamot oil in solar simulating radiation (SSR greater than or equal to 290 nm) and in long ultraviolet radiation (LUV greater than or equal to 320 nm) has been compared by studying photoaugmentation of erythema in the guinea pig after 24 h and pigmentary photoaugmentation in man on the 8th day. The results show that a close relationship exists between guinea pig and human responses, with both radiations used, and that man seems to be slightly more sensitive to phototoxic effects of bergamot oil than the guinea pig. This difference of sensitivity necessarily implies the participation of UVA (320--400 nm) in the phototoxic reaction of bergamot oil with solar radiation. This UVA participation is particularly obvious in the guinea pig; in man, the results are less clear and a certain synergy of UVB rays (290--320 nm) may be involved in the phototoxic UVA-induced reaction of bergamot oil. Despite these slight differences, the erythematous reaction in the guinea pig appears to be a remarkable experimental model to show out potential phototoxic reactions of products containing psoralens in man.

  2. 9 CFR 3.36 - Primary enclosures used to transport live guinea pigs and hamsters.

    Science.gov (United States)

    2010-01-01

    ... live guinea pigs and hamsters. 3.36 Section 3.36 Animals and Animal Products ANIMAL AND PLANT HEALTH..., Care, Treatment, and Transportation of Guinea Pigs and Hamsters Transportation Standards § 3.36 Primary enclosures used to transport live guinea pigs and hamsters. No person subject to the Animal...

  3. Use of a Guinea pig-specific transcriptome array for evaluation of protective immunity against genital chlamydial infection following intranasal vaccination in Guinea pigs.

    Science.gov (United States)

    Wali, Shradha; Gupta, Rishein; Veselenak, Ronald L; Li, Yansong; Yu, Jieh-Juen; Murthy, Ashlesh K; Cap, Andrew P; Guentzel, M Neal; Chambers, James P; Zhong, Guangming; Rank, Roger G; Pyles, Richard B; Arulanandam, Bernard P

    2014-01-01

    Guinea pigs have been used as a second animal model to validate putative anti-chlamydial vaccine candidates tested in mice. However, the lack of guinea pig-specific reagents has limited the utility of this animal model in Chlamydia sp. vaccine studies. Using a novel guinea pig-specific transcriptome array, we determined correlates of protection in guinea pigs vaccinated with Chlamydia caviae (C. caviae) via the intranasal route, previously reported by us and others to provide robust antigen specific immunity against subsequent intravaginal challenge. C. caviae vaccinated guinea pigs resolved genital infection by day 3 post challenge. In contrast, mock vaccinated animals continued to shed viable Chlamydia up to day 18 post challenge. Importantly, at day 80 post challenge, vaccinated guinea pigs experienced significantly reduced genital pathology - a sequelae of genital chlamydial infections, in comparison to mock vaccinated guinea pigs. Sera from vaccinated guinea pigs displayed antigen specific IgG responses and increased IgG1 and IgG2 titers capable of neutralizing GPIC in vitro. Th1-cellular/inflammatory immune genes and Th2-humoral associated genes were also found to be elevated in vaccinated guinea pigs at day 3 post-challenge and correlated with early clearance of the bacterium. Overall, this study provides the first evidence of guinea pig-specific genes involved in anti-chlamydial vaccination and illustrates the enhancement of the utility of this animal model in chlamydial pathogenesis.

  4. Induction and properties of guinea pig serum interferon. Preliminary report.

    Science.gov (United States)

    Nolewajka, E; Mikolajski, K; Kapp-Burzyńska, Z; Trzeciak, J; Wrona, M

    1977-01-01

    Guinea pigs, 250-350 g body weight, both sexes, were injected with 5X10(8.5) EID50 NDV (Radom strain) intracardially and intraperitoneally simultaneously. The animals were bled by cardiac puncture 0, 3, 6, 12, 24 and 48 hours after injection. After virus inactivation, serum interferon titration was performed in cultures of guinea pig embryo kidney cells with 50 percent plaque inhibition test using VSV. The highest interferon titer (64 u./ml) was found after 6 hours of inductor injection. Interferon titer decreased quickly and after 12 hours it was lower than 16 u./ml. Guinea pig serum interferon induced by NDV was resistant to pH 2 and 56 degrees C during 1 hour. Interferon was inactivated by trypsin. The decribed interferon did not protect heterologous species cells (swine) against Teschen Disease Virus infection. Other properties of this interferon are being studied.

  5. Helminths of the guinea pig, Cavia porcellus (Linnaeus, in Brazil

    Directory of Open Access Journals (Sweden)

    Roberto Magalhães Pinto

    2002-07-01

    Full Text Available Worm burdens were evaluated and compared in two groups of the guinea pig, Cavia poreellus (Linnaeus, 1758: animals of the first group were conventionally maintained in an institutional animal house and those of the second group were openly kept in pet shops in Brazil. Animals from both sources were infected only with the nematode Paraspidodera uncinata (Rudolphi, 1819 Travassos, 1914 (10% of prevalence in guinea pigs from lhe institutional facility and 40% in those animals from the pet shop. Other helminth samples recovered from Brazilian guinea pigs during 52 years and that are deposited in the Helminthological Collection of the Oswaldo Cruz Institute (CHIOC were also analyzed. Paraspidodera uncinata and the cestode Monoecocestus parcitesticulatus Rêgo, 1960 were identified in these samples.

  6. INVESTIGATION ON MODEL OF INFLAMMATORY PLEURAL EFFUSION IN GUINEA PIGS

    Institute of Scientific and Technical Information of China (English)

    冯源; 殷凯生; 王祥

    2002-01-01

    Objective To establish an animal model of inflammatory pleural effusion.Methods Forty guinea pigs were divided into two groups: experimental group with 7 subgroups and control group. In the experimental group the right chest cavity of each guinea pig was injected with 0.8~1.0 ml of 1% carrageenan, and guinea pigs of each subgroup were killed and observed respectively on day 1, 2, 3, 5, 7, 10 and day 14 after injection.Results Occurring on day 1(within 24 hours), pleural effusion reached the maximum on day 2~3 after injection, so did the neutrophil count in pleural effusion and inflammation of both pleura and lungs and then gradually decreased. The fibrosis and adhesion of pleura appeared on day 7 and were obvious on day 10. The encysted pleurisy was formed on day 14.Conclusion The carrageenan is an ideal pleural inflammatory inducer. This animal model is useful for studying pleural effusion.

  7. Guinea pig ID-like families of SINEs.

    Science.gov (United States)

    Kass, David H; Schaetz, Brian A; Beitler, Lindsey; Bonney, Kevin M; Jamison, Nicole; Wiesner, Cathy

    2009-05-01

    Previous studies have indicated a paucity of SINEs within the genomes of the guinea pig and nutria, representatives of the Hystricognathi suborder of rodents. More recent work has shown that the guinea pig genome contains a large number of B1 elements, expanding to various levels among different rodents. In this work we utilized A-B PCR and screened GenBank with sequences from isolated clones to identify potentially uncharacterized SINEs within the guinea pig genome, and identified numerous sequences with a high degree of similarity (>92%) specific to the guinea pig. The presence of A-tails and flanking direct repeats associated with these sequences supported the identification of a full-length SINE, with a consensus sequence notably distinct from other rodent SINEs. Although most similar to the ID SINE, it clearly was not derived from the known ID master gene (BC1), hence we refer to this element as guinea pig ID-like (GPIDL). Using the consensus to screen the guinea pig genomic database (Assembly CavPor2) with Ensembl BlastView, we estimated at least 100,000 copies, which contrasts markedly to just over 100 copies of ID elements. Additionally we provided evidence of recent integrations of GPIDL as two of seven analyzed conserved GPIDL-containing loci demonstrated presence/absence variants in Cavia porcellus and C. aperea. Using intra-IDL PCR and sequence analyses we also provide evidence that GPIDL is derived from a hystricognath-specific SINE family. These results demonstrate that this SINE family continues to contribute to the dynamics of genomes of hystricognath rodents.

  8. Parainfluenza 3-Induced Cough Hypersensitivity in the Guinea Pig Airways.

    Directory of Open Access Journals (Sweden)

    Eric J Zaccone

    Full Text Available The effect of respiratory tract viral infection on evoked cough in guinea pigs was evaluated. Guinea pigs were inoculated intranasally with either parainfluenza type 3 (PIV3 and cough was quantified in conscious animals. The guinea pigs infected with PIV3 (day 4 coughed nearly three times more than those treated with the viral growth medium in response to capsaicin, citric acid, and bradykinin. Since capsaicin, citric acid, and bradykinin evoked coughing in guinea pigs can be inhibited by drugs that antagonize the transient receptor potential cation channel, subfamily V, member 1 (TRPV1, it was reasoned that the virally-induced hypertussive state may involve alterations in TPRV1 activity. PIV3 infection caused a phenotypic switch in tracheal nodose Aδ "cough receptors" such that nearly 50% of neurons began to express, de novo, TRPV1 mRNA. There was also an increase TRPV1 expression in jugular C-fiber neurons as determined by qPCR. It has previously been reported that tracheal-specific nodose neurons express the BDNF receptor TrkB and jugular neurons express the NGF receptor TrkA. Jugular neurons also express the artemin receptor GFRα3. All these neurotrophic factors have been associated with increases in TRPV1 expression. In an ex vivo perfused guinea pig tracheal preparation, we demonstrated that within 8 h of PIV3 infusion there was no change in NGF mRNA expression, but there was nearly a 10-fold increase in BDNF mRNA in the tissue, and a small but significant elevation in the expression of artemin mRNA. In summary, PIV3 infection leads to elevations in TRPV1 expression in the two key cough evoking nerve subtypes in the guinea pig trachea, and this is associated with a hypertussive state with respect to various TRPV1 activating stimuli.

  9. Immunoglobulin genomics in the guinea pig (Cavia porcellus.

    Directory of Open Access Journals (Sweden)

    Yongchen Guo

    Full Text Available In science, the guinea pig is known as one of the gold standards for modeling human disease. It is especially important as a molecular and cellular biology model for studying the human immune system, as its immunological genes are more similar to human genes than are those of mice. The utility of the guinea pig as a model organism can be further enhanced by further characterization of the genes encoding components of the immune system. Here, we report the genomic organization of the guinea pig immunoglobulin (Ig heavy and light chain genes. The guinea pig IgH locus is located in genomic scaffolds 54 and 75, and spans approximately 6,480 kb. 507 V(H segments (94 potentially functional genes and 413 pseudogenes, 41 D(H segments, six J(H segments, four constant region genes (μ, γ, ε, and α, and one reverse δ remnant fragment were identified within the two scaffolds. Many V(H pseudogenes were found within the guinea pig, and likely constituted a potential donor pool for gene conversion during evolution. The Igκ locus mapped to a 4,029 kb region of scaffold 37 and 24 is composed of 349 V(κ (111 potentially functional genes and 238 pseudogenes, three J(κ and one C(κ genes. The Igλ locus spans 1,642 kb in scaffold 4 and consists of 142 V(λ (58 potentially functional genes and 84 pseudogenes and 11 J(λ -C(λ clusters. Phylogenetic analysis suggested the guinea pig's large germline V(H gene segments appear to form limited gene families. Therefore, this species may generate antibody diversity via a gene conversion-like mechanism associated with its pseudogene reserves.

  10. Intrinsic innervation of the uterus in guinea pig and rat.

    Science.gov (United States)

    Mustafa, F; Fatani, J A; el-Eishi, H; el-Badawi, M G

    1987-01-01

    The pattern of distribution of cholinergic and adrenergic nerves in the uterus of albino rats and guinea pigs was examined histochemically. In the albino rat, the uterus was found well-innervated by both adrenergic and cholinergic nerves with a clear regional variation. Dense innervation was demonstrated at the tubal and cervical ends of the uterus and in the cervix. Cholinergic nerves supplying the glands were more numerous than the adrenergic nerves which were relatively few. In the guinea-pigs, the uterus was richly innervated by adrenergic nerves with a clear regional variation. No cholinesterase-positive nerves or nerve cells were demonstrated.

  11. DOCA-salts induce heart failure in the guinea pig.

    Science.gov (United States)

    Tiritilli, A

    2001-10-01

    Heart failure (HF) is a common clinical problem confronting physicians and is often the final manifestation of many cardiovascular disorders. Despite recent advances in the pharmacological management of HF, it remains a highly lethal and disabling disorder. A number of animal models have been developed to study both the pathophysiology of HF and new therapeutic approaches to this complex syndrome. Only through an improved understanding of the basic biology of the early stages of the syndrome can HF be prevented or at least anticipated. With this in view, we have developed an easily realisable and inexpensive model in the guinea pig, which presents numerous structural, metabolic and biochemical similarities compared with the human heart. Thirty guinea pigs, aged 5 weeks and weighing 300 g were used. After anaesthesia, left nephrectomy was performed. After 1 week the guinea pigs were divided into: (a) control group (n=15), which received an injection of vehicle as well as tap water for 10 weeks; (b) DOCA-salts group (n=15), where the animals were treated with an IM injection of 10 mg DOCA 5 days a week for 10 weeks and with drinking water containing 9 g/l(-1) NaCl and 2 g/l(-1) KCl. Our results demonstrate that the administration of DOCA-salts to guinea pigs for 10 weeks caused a significant increase in blood pressure (BP+30%) associated with left ventricular hypertrophy (LVH), evaluated by LV weight (+37%), LV wall (+36%), by the ratio LV weight/Body weight (+23%) and by an increase in LV volume (+51%). Concerning HF, the latter was clinically evident through an increase in body weight, heart rate and dyspnoea. Indeed, guinea pigs presented pleural and/or pericardial effusion often associated with ascite. This model, which combines pressure and volume overload, results in a slow evolution towards HF. This allows a better understanding of the mechanisms in early LV remodelling which has the potential to develop into HF. Some recent studies have emphasised the value

  12. Use of a Guinea Pig-Specific Transcriptome Array for Evaluation of Protective Immunity against Genital Chlamydial Infection following Intranasal Vaccination in Guinea Pigs.

    Science.gov (United States)

    2014-12-11

    following Intranasal Vaccination in Guinea Pigs Shradha Wali1., Rishein Gupta1., Ronald L. Veselenak2, Yansong Li3, Jieh-Juen Yu , Ashlesh K. Murthy , Andrew...contributed equally to this work. Abstract Guinea pigs have been used as a second animal model to validate putative anti- chlamydial vaccine candidates...tested in mice. However, the lack of guinea pig- specific reagents has limited the utility of this animal model in Chlamydia sp. vaccine studies. Using

  13. Pig and guinea pig skin as surrogates for human in vitro penetration studies: a quantitative review.

    Science.gov (United States)

    Barbero, Ana M; Frasch, H Frederick

    2009-02-01

    Both human and animal skin in vitro models are used to predict percutaneous penetration in humans. The objective of this review is a quantitative comparison of permeability and lag time measurements between human and animal skin, including an evaluation of the intra and inter species variability. We limit our focus to domestic pig and rodent guinea pig skin as surrogates for human skin, and consider only studies in which both animal and human penetration of a given chemical were measured jointly in the same lab. When the in vitro permeability of pig and human skin were compared, the Pearson product moment correlation coefficient (r) was 0.88 (Pskin permeability of 21% for pig and 35% for human, and an inter species average coefficient of variation of 37% for the set of studied compounds (n=41). The lag times of pig skin and human skin did not correlate (r=0.35, P=0.26). When the in vitro permeability of guinea pig and human skin were compared, r=0.96 (Phuman, and an inter species coefficient of variation of permeability of 41% for the set of studied compounds (n=15). Lag times of guinea pig and human skin correlated (r=0.90, Phuman skin was calculated for pig skin (n=50) and guinea pig skin (n=25). For pig skin, 80% of measurements fell within the range 0.3skin, 65% fell within that range. Both pig and guinea pig are good models for human skin permeability and have less variability than the human skin model. The skin model of choice will depend on the final purpose of the study and the compound under investigation.

  14. Cartilage Degeneration, Subchondral Mineral and Meniscal Mineral Densities in Hartley and Strain 13 Guinea Pigs.

    Science.gov (United States)

    Sun, Yubo; Scannell, Brian P; Honeycutt, Patrick R; Mauerhan, David R; H, James Norton; Hanley, Edward N

    2015-01-01

    Osteoarthritis is a joint disease involved in articular cartilage, subchondral bone, meniscus and synovial membrane. This study sought to examine cartilage degeneration, subchondral bone mineral density (BMD) and meniscal mineral density (MD) in male Hartley, female Hartley and female strain 13 guinea pigs to determine the association of cartilage degeneration with subchondral BMD and meniscal MD. Cartilage degeneration, subchondral BMD and meniscal MD in 12 months old guinea pigs were examined with histochemistry, X-ray densitometry and calcium analysis. We found that male Hartley guinea pigs had more severe cartilage degeneration, subchondral BMD and meniscal MD than female Hartley guinea pigs, but not female strain 13 guinea pigs. Female strain 13 guinea pigs had more severe cartilage degeneration and higher subchondral BMD, but not meniscal MD, than female Hartley guinea pigs. These findings indicate that higher subchondral BMD, not meniscal MD, is associated with more severe cartilage degeneration in the guinea pigs and suggest that abnormal subchondral BMD may be a therapeutic target for OA treatment. These findings also indicate that the pathogenesis of OA in the male guinea pigs and female guinea pigs are different. Female strain 13 guinea pig may be used to study female gender-specific pathogenesis of OA.

  15. Spontaneous cyclic embryonic movements in humans and guinea pigs

    NARCIS (Netherlands)

    Felt, Renee H. M.; Mulder, Eduard J. H.; Luchinger, Annemarie B.; van Kan, Colette M.; Taverne, Marcel A. M.; de Vries, J. I. P.

    2012-01-01

    Motility assessment before birth can be used to evaluate the integrity of the nervous system. Sideways bending (SB) of head and/or rump, the earliest embryonic motility in both humans and guinea pigs, can be visualized sonographically. We know from other species that early embryonic motility is cycl

  16. Ototoxic drugs: difference in sensitivity between mice and guinea pigs.

    Science.gov (United States)

    Poirrier, A L; Van den Ackerveken, P; Kim, T S; Vandenbosch, R; Nguyen, L; Lefebvre, P P; Malgrange, B

    2010-03-01

    The development of experimental animal models has played an invaluable role in understanding the mechanisms of neurosensory deafness and in devising effective treatments. The purpose of this study was to develop an adult mouse model of ototoxic drug-induced hearing loss and to compare the ototoxicity in the adult mouse to that in the well-described guinea pig model. Mice are a powerful model organism, especially due to the large availability of antibodies, probes and genetic mutants. In this study, mice (n=114) and guinea pigs (n=35) underwent systemic treatment with either kanamycin or cisplatin. Auditory brainstem responses showed a significant threshold shift in guinea pigs 2 weeks after the beginning of the ototoxic treatment, while there was no significant hearing impairment recorded in mice. Hair cells and neuronal loss were correlated with hearing function in both guinea pigs and mice. These results indicate that the mouse is not a good model for ototoxicity, which should be taken into consideration in all further investigations concerning ototoxicity-induced hearing loss.

  17. Plague in Guinea pigs and its prevention by subunit vaccines.

    Science.gov (United States)

    Quenee, Lauriane E; Ciletti, Nancy; Berube, Bryan; Krausz, Thomas; Elli, Derek; Hermanas, Timothy; Schneewind, Olaf

    2011-04-01

    Human pneumonic plague is a devastating and transmissible disease for which a Food and Drug Administration-approved vaccine is not available. Suitable animal models may be adopted as a surrogate for human plague to fulfill regulatory requirements for vaccine efficacy testing. To develop an alternative to pneumonic plague in nonhuman primates, we explored guinea pigs as a model system. On intranasal instillation of a fully virulent strain, Yersinia pestis CO92, guinea pigs developed lethal lung infections with hemorrhagic necrosis, massive bacterial replication in the respiratory system, and blood-borne dissemination to other organ systems. Expression of the Y. pestis F1 capsule was not required for the development of pulmonary infection; however, the capsule seemed to be important for the establishment of bubonic plague. The mean lethal dose (MLD) for pneumonic plague in guinea pigs was estimated to be 1000 colony-forming units. Immunization of guinea pigs with the recombinant forms of LcrV, a protein that resides at the tip of Yersinia type III secretion needles, or F1 capsule generated robust humoral immune responses. Whereas LcrV immunization resulted in partial protection against pneumonic plague challenge with 250 MLD Y. pestis CO92, immunization with recombinant F1 did not. rV10, a vaccine variant lacking LcrV residues 271-300, elicited protection against pneumonic plague, which seemed to be based on conformational antibodies directed against LcrV. Copyright © 2011 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.

  18. Antispasmodic effect of 4'-methylepigallocatechin on guinea pig ileum.

    Science.gov (United States)

    da Rocha, Marcelly Barbosa; Souza, Fábia Valéria Menezes; dos Santos Estevam, Charlez; Pizza, Cosimo; Sant'ana, Antônio Euzébio Goulart; Marçal, Rosilene Moretti

    2012-10-01

    The antispasmodic effect of 4'-methylepigallocatechin (MEC), which was isolated from Maytenus rigida Mart (Celestraceae), was investigated in vitro in guinea pig intestinal segments. In the isolated ileum, MEC (1 nM-100 μM) did not modify the ileal spontaneous tonus or the electrically elicited contractions. MEC (8 μM) significantly (prigida stem bark.

  19. EFFECTS OF METHYLNALTREXONE ON GUINEA PIG GASTROINTESTINAL MOTILITY

    Science.gov (United States)

    Anselmi, Laura; Huynh, Jennifer; Vegezzi, Gaia; Sternini, Catia

    2013-01-01

    The purpose of the present study was to compare the effects of methylnaltrexone (MNTX), a peripherally acting μ opioid receptor (μOR) antagonist, on gastrointestinal (GI) motility in naïve vs. opiate-chronically treated guinea pigs in vitro and in vivo. We have used the electrically stimulated muscle twitch contractions of longitudinal muscle-myenteric plexus (LMMP) preparations and total GI transit as measure of GI motility. In LMMP preparations of naïve guinea pigs, MNTX (1–30 μM) induced a significant, dose-response reduction of morphine-induced inhibition of electrically stimulated muscle twitch contractions, with an IC50 of 9.4 10−8M. By contrast, MNTX abolished the inhibitory effect of acute morphine at any concentration tested (1–30 μM) in the guinea pigs chronically treated with opiates. In vivo, MNTX (10–50 mg s.c.) did not affect GI transit in naïve guinea pigs when administered acutely or for 5 consecutive days, but reversed the GI transit delay induced by chronic morphine treatment. These findings show that MNTX is effective in reversing opiate-induced inhibition of GI motility acting at peripheral μORs, but does not exert a pharmacologic effect on GI transit in the absence of opiate stimulation. PMID:23361094

  20. Survey of endoparasites in pet guinea pigs in Italy.

    Science.gov (United States)

    d'Ovidio, Dario; Noviello, Emilio; Ianniello, Davide; Cringoli, Giuseppe; Rinaldi, Laura

    2015-03-01

    Little information is available on the occurrence of endoparasites in pet guinea pigs (Cavia porcellus). The purpose of this study was to evaluate the prevalence of intestinal parasites in cavies kept as pets in southern Italy. Fresh fecal samples were randomly collected from 60 guinea pigs housed in pet shops or privately owned. All fecal samples were processed using the FLOTAC pellet technique to identify and count helminthic eggs/larvae and protozoan cysts/oocysts. In addition, the specimens were analyzed also by the Remel Xpect® Giardia/Cryptosporidium immunoassay. Intestinal parasites were detected in 19 out of 60 guinea pigs (31.7 %). Paraspidodera uncinata eggs were found in 13.3 % (8/60) of the rodents examined, Nippostrongylus-like eggs in 10 % (6/60), and finally Eimeria caviae oocysts were found in 10 % (6/60) of the animals. In one case, both E. caviae oocysts and P. uncinata eggs were found. None of the samples was positive for Cryptosporidium or Giardia. To the authors' knowledge, this is the first survey of endoparasites in pet guinea pigs in Italy.

  1. Some liver function indicators in guinea pigs injected with cyanide

    Directory of Open Access Journals (Sweden)

    Idonije O. Blessing

    2013-08-01

    Full Text Available To determine the lethal effect of cyanide poisoning on the liver cells using ALP, AST, ALT and Bilirubin (Total and Conjugated as test indicators, eighteen (18 male guinea pigs, age matched were used for this study. This included 12 guinea pigs which served as test groups and injected with different concentrations of potassium cyanide saline solution while 6 guinea pigs without cyanide injection served as control group. Blood samples were collected from the guinea pigs three hours after the injections of the cyanide saline solution. The blood samples were analysed for liver enzymes and bilirubin using standard methods. The result of the plasma AST and ALT at the different concentrations showed decreased levels which were significant when compared with the controls. The plasma levels of Total and Conjugated bilirubin were also significantly decreased when compared with controls. However, the levels of the ALP in both test and control groups showed no significant difference. This study therefore highlighted the need to determine the levels of these liver function indicators in cases of cyanide poisoning to ensure efficient management of patients who are exposed to the cyanide.

  2. Reflections on the Fiftieth Reunion of the Guinea Pigs.

    Science.gov (United States)

    Loud, Oliver

    1988-01-01

    A member of the original faculty of the experimental Ohio State University Laboratory High School reflects at a fiftieth reunion of the first graduating class. Students were used as guinea pigs to determine the effects of providing teenagers with liberating, interesting, and customized education from university faculty. (SM)

  3. Guinea pig ductus arteriosus. II - Irreversible closure after birth.

    Science.gov (United States)

    Fay, F. S.; Cooke, P. H.

    1972-01-01

    To investigate the mechanism underlying irreversibility of ductal closure after birth, studies were undertaken to determine the exact time course for the onset of irreversible closure of the guinea pig ductus arteriosus. Parallel studies of the reactivity of ductal smooth muscle to oxygen and studies of the postpartum cellular changes within the vessel were also carried out.

  4. Non-terminal blood sampling techniques in Guinea pigs

    DEFF Research Database (Denmark)

    Birck, Malene Muusfeldt; Tveden-Nyborg, Pernille; Lindblad, Maiken Marie

    2014-01-01

    Guinea pigs possess several biological similarities to humans and are validated experimental animal models(1-3). However, the use of guinea pigs currently represents a relatively narrow area of research and descriptive data on specific methodology is correspondingly scarce. The anatomical feature...... not exceed guidelines for blood collection in laboratory animals(6). All the described methods have been thoroughly tested and applied for repeated in vivo blood sampling in studies within our research facility....... of guinea pigs are slightly different from other rodent models, hence modulation of sampling techniques to accommodate for species-specific differences, e.g., compared to mice and rats, are necessary to obtain sufficient and high quality samples. As both long and short term in vivo studies often require...... repeated blood sampling the choice of technique should be well considered in order to reduce stress and discomfort in the animals but also to ensure survival as well as compliance with requirements of sample size and accessibility. Venous blood samples can be obtained at a number of sites in guinea pigs e...

  5. Plague in Guinea Pigs and Its Prevention by Subunit Vaccines

    Science.gov (United States)

    Quenee, Lauriane E.; Ciletti, Nancy; Berube, Bryan; Krausz, Thomas; Elli, Derek; Hermanas, Timothy; Schneewind, Olaf

    2011-01-01

    Human pneumonic plague is a devastating and transmissible disease for which a Food and Drug Administration–approved vaccine is not available. Suitable animal models may be adopted as a surrogate for human plague to fulfill regulatory requirements for vaccine efficacy testing. To develop an alternative to pneumonic plague in nonhuman primates, we explored guinea pigs as a model system. On intranasal instillation of a fully virulent strain, Yersinia pestis CO92, guinea pigs developed lethal lung infections with hemorrhagic necrosis, massive bacterial replication in the respiratory system, and blood-borne dissemination to other organ systems. Expression of the Y. pestis F1 capsule was not required for the development of pulmonary infection; however, the capsule seemed to be important for the establishment of bubonic plague. The mean lethal dose (MLD) for pneumonic plague in guinea pigs was estimated to be 1000 colony-forming units. Immunization of guinea pigs with the recombinant forms of LcrV, a protein that resides at the tip of Yersinia type III secretion needles, or F1 capsule generated robust humoral immune responses. Whereas LcrV immunization resulted in partial protection against pneumonic plague challenge with 250 MLD Y. pestis CO92, immunization with recombinant F1 did not. rV10, a vaccine variant lacking LcrV residues 271-300, elicited protection against pneumonic plague, which seemed to be based on conformational antibodies directed against LcrV. PMID:21406168

  6. Streptococcus caviae sp. nov., isolated from Guinea pig faecal samples

    NARCIS (Netherlands)

    Palakawong Na Ayudthaya, Susakul; Hilderink, Loes J.; Oost, van der John; Vos, de Willem M.; Plugge, Caroline M.

    2017-01-01

    A novel cellobiose-degrading and lactate-producing bacterium, strain Cavy grass 6T, was isolated from faecal samples of guinea pigs (Cavia porcellus). Cells of the strain were ovalshaped, non-motile, non-spore-forming, Gram-stain-positive and facultatively anaerobic. The strain gr at 2

  7. Toluene-induced hearing loss in the guinea pig.

    Science.gov (United States)

    Waniusiow, Delphine; Campo, Pierre; Venet, Thomas; Cossec, Benoît; Cosnier, Frédéric; Beydon, Dominique; Rieger, Benoît; Burgart, Manuella; Ferrari, Luc; Parietti-Winkler, Cécile

    2009-10-01

    Toluene is a high-production industrial solvent, which can disrupt the auditory system in rats. However, toluene-induced hearing loss is species dependent. For instance, despite long-lasting exposures to high concentrations of aromatic solvent, no study has yet succeeded in causing convincing hearing loss in the guinea pig. This latter species can be characterized by two metabolic particularities: a high amount of hepatic cytochrome P-450s (P-450s) and a high concentration of glutathione in the cochlea. It is therefore likely that the efficiency of both the hepatic and cochlear metabolisms plays a key role in the innocuousness of the hearing of guinea pigs to exposure to solvent. The present study was carried out to test the auditory resistance to toluene in glutathione-depleted guinea pigs whose the P-450 activity was partly inhibited. To this end, animals on a low-protein diet received a general P-450 inhibitor, namely SKF525-A. Meanwhile, they were exposed to 1750 ppm toluene for 4 weeks, 5 days/week, 6 h/day. Auditory function was tested by electrocochleography and completed by histological analyses. For the first time, a significant toluene-induced hearing loss was provoked in the P-450-inhibited guinea pigs. However, the ototoxic process caused by the solvent exposure was different from that observed in the rat. Only the stria vascularis and the spiral fibers were disrupted in the apical coil of the cochlea. The protective mechanisms developed by guinea pigs are discussed in the present publication.

  8. Prevalence of fur mites (Chirodiscoides caviae) in pet guinea pigs (Cavia porcellus) in southern Italy.

    Science.gov (United States)

    d'Ovidio, Dario; Santoro, Domenico

    2014-04-01

    Chirodiscoides caviae is the most common fur mite affecting guinea pigs; infestation is generally asymptomatic. No studies have been published on the prevalence of such mites in guinea pigs in southern Italy. We sought to evaluate the prevalence and the clinical signs of C. caviae infestation in guinea pigs in southern Italy. Clinical records of guinea pigs evaluated from August 2012 to July 2013 were retrospectively searched. In this retrospective matched case-control study, records of guinea pigs with evidence of C. caviae infestation were selected. The prevalence of C. caviae infestation was evaluated and exposure variables were assessed among guinea pigs with and without infestation using stepwise conditional logistic regression. Guinea pigs seen during the same time period, but without a diagnosis of C. caviae, were included as control animals. The prevalence of C. caviae was 32% (42 of 131); 66.6% of affected guinea pigs (28 of 42) originated from pet shops, whereas 28% (14 of 42) were privately owned. Thirty-one guinea pigs (73.8%) were asymptomatic, whereas 11 (26.1%) showed clinical signs (pruritus, alopecia, erythema and scaling). The most frequently affected area was the lumbosacral region (38 of 42). Guinea pigs in pet shops were more likely to be affected by C. caviae than owned guinea pigs (odds ratio, 5.12; 95% confidence interval, 2.32-11.29; P < 0.0001). The results of this study indicate a high prevalence of C. caviae infestation in guinea pigs in southern Italy. Chirodiscoides mites should be sought in guinea pigs, particularly in animals coming from pet shops. © 2014 ESVD and ACVD.

  9. Characterization of fetal growth by repeated ultrasound measurements in the wild guinea pig (Cavia aperea).

    Science.gov (United States)

    Schumann, K; Guenther, A; Göritz, F; Jewgenow, K

    2014-08-01

    Fetal growth during pregnancy has previously been studied in the domesticated guinea pig (Cavia aperea f. porcellus) after dissecting pregnant females, but there are no studies describing the fetal growth in their wild progenitor, the wild guinea pig (C aperea). In this study, 50 pregnancies of wild guinea pig sows were investigated using modern ultrasound technique. The two most common fetal growth parameters (biparietal diameter [BPD] and crown-rump-length [CRL]) and uterine position were measured. Data revealed similar fetal growth patterns in the wild guinea pig and domesticated guinea pig in the investigated gestation period, although they differ in reproductive milestones such as gestation length (average duration of pregnancy 68 days), average birth weight, and litter mass. In this study, pregnancy lasted on average 60.2 days with a variance of less than a day (0.96 days). The measured fetal growth parameters are strongly correlated with each (R = 0.91; P guinea pig.

  10. Effect of estradiol on chlamydial genital infection of female guinea pigs.

    OpenAIRE

    Rank, R G; White, H. J.; Hough, A. J.; Pasley, J N; Barron, A L

    1982-01-01

    Female guinea pigs were treated daily with 1 mg of beta-estradiol-3-benzoate intramuscularly beginning 14 days before intravaginal inoculation with the chlamydial agent of guinea pig inclusion conjunctivitis and continuing during the course of the infection. Treatment with estradiol was found to markedly influence the course of genital infection with the chlamydial agent of guinea pig inclusion conjunctivitis, producing infections of greater intensity and longer duration than those in control...

  11. Validation of a Behavioral Ethogram for Assessing Postoperative Pain in Guinea Pigs (Cavia porcellus)

    OpenAIRE

    Dunbar, Misha L; David, Emily M; Aline, Marian R; Lofgren, Jennifer L.

    2016-01-01

    Although guinea pigs (Cavia porcellus) have been used in research for more than a century and remain the most prevalent USDA-covered species, little has been elucidated regarding the recognition of clinical pain or analgesic efficacy in this species. We sought to assess pain in guinea pigs by using newer, clinically relevant methods that have been validated in other rodent species: the behavioral ethogram and cageside proxy indicator. In this study, 10 male guinea pigs underwent electronic vo...

  12. Antibronchoconstrictor Effects of Securidaca Longipedunculata (Fresen.)Root Bark Methanolic Extract in Guinea-pigs

    OpenAIRE

    Ojewole, John AO; Ilesanmi, Olapade RS; Olayiwola, Gbola

    2001-01-01

    This study was designed to examine the antibronchoconstrictor effects of Securidaca longipedunculata (Fresen.) root bark methanolic extract (MESL) in guinea-pigs. The plant extract relaxed spasmogen-(acetylcholine-, histamine-, serotonin-, and potassium-) induced contractions of the guinea-pig isolated tracheal muscle prepations in a concentration-related manner. The plant extract also protected guinea-pigs against histamine aerosol-induced bronchospasm in vivo. Neither the relaxant effects o...

  13. Injuries caused by pigs in Papua New Guinea.

    Science.gov (United States)

    Barss, P; Ennis, S

    Pigs are intelligent animals that can be formidable adversaries to humans because of their sharp tusks and their ability to attack swiftly. Domestic and feral pigs have an important role in the ecology of village life in Melanesia. A six-year review of all injuries that were caused by pigs that were referred from the villages in Milne Bay Province, Papua New Guinea, to the Provincial Hospital was completed. Some of the injuries that were seen among the 20 patients who were studied included: three penetrating abdominal injuries with prolapse and strangulation of the intestine; a "sucking" chest wound; bilateral pneumothoraces; two infected open fractures of the radius and the ulna; a perforating injury of the knee with septic arthritis; a hand injury with laceration of multiple tendons; an arterial injury of the wrist; injury of a tibial nerve with foot drop; and a severe scrotal injury with exposure of the testicles. Most injuries resulted from the hunting of feral pigs. Adult male hunters who used dogs and carried only one spear were injured most frequently. Wounds from injuries by pigs are deep, often involve multiple critical structures, and are grossly contaminated. Resuscitation requires the administration of fluid and often blood. Treatment includes irrigation, debridement and closure of the wound. The principles of managing such injuries, the prevention of injuries, the ecology of pigs and humans, human infections originating from pigs, and safer methods of hunting pigs are discussed.

  14. Diseases in pet guinea pigs: a retrospective study in 1000 animals.

    Science.gov (United States)

    Minarikova, A; Hauptman, K; Jeklova, E; Knotek, Z; Jekl, V

    2015-08-22

    Guinea pigs are commonly kept as pet animals; however, information about particular disease prevalence is lacking. The objective of this article was to present disease prevalence in 1000 pet guinea pigs from private owners divided into three age groups: under two years; between two and five years; and above five years. Medical records of guinea pigs (Cavia aperea f. porcellus) that were presented to the authors' clinic in the period from January 2008 to August 2013 were reviewed. The most commonly diagnosed disease in guinea pigs was dental disease (36.3 per cent), with higher prevalence in the middle age group (Pguinea pigs (Pguinea pigs from a total of 1000 animals were healthy. This is the first study to describe the disease prevalence in three age groups of pet guinea pigs.

  15. Characterization of the guinea pig adipocyte thyrotropin receptor.

    Science.gov (United States)

    Gennick, S E; Thomas, C G; Nayfeh, S N

    1986-02-26

    125I-TSH binding to porcine thyroid and guinea pig fat resulted in curvilinear Scatchard plots with similar dissociation constants for the high and low affinity binding components. Antibodies from the sera of patients with Graves' disease inhibited binding to the high and low affinity binding components of both tissues. Covalent cross-linking of 125I-TSH to membranes from each tissue resulted in the specific labeling of two protein bands. The guinea pig fat receptor subunits have Mr values of 52,000 and 38,000, whereas the porcine thyroid receptor subunits have values of 46,000 & 35,000. The labeling of the receptor subunits was inhibited by preincubation with Graves' autoantibodies. Despite possessing a different subunit composition, the receptors from these tissues exhibit similar affinity for TSH and share similar antigenic determinants for Graves' autoantibodies.

  16. Spontaneous ameloblastic fibroma in a young Guinea pig.

    Science.gov (United States)

    Tanaka, Makoto; Sawamoto, Osamu

    2013-09-01

    A spontaneous ameloblastic fibroma was found in a 9-week-old guinea pig. Histopathologically, neoplastic cells consisted of two components: an odontogenic epithelium and odontogenic mesenchyme. The odontogenic epithelium formed strands, nests and islands that were interspersed within the odontogenic mesenchyme. In the marginal region, odontoblasts and scant dysplastic eosinophilic material were seen between these two components. Immunohistochemically, the odontogenic epithelium was positive for cytokeratin AE1/AE3, and the odontogenic mesenchyme and odontoblast were positive for vimentin, in the same manner as in the normal tooth germ (control). We could not obtain conclusive data suggesting that the eosinophilic material was dental hard tissue because the eosinophilic material was not stained specifically by any methods. Based on these histological characteristics, the tumor in the present case was diagnosed as an ameloblastic fibroma. This is the first report of ameloblastic fibroma in guinea pigs.

  17. Antispasmodic Activity of Fractions and Cynaropicrin from Cynara scolymus on Guinea-Pig Ileum

    National Research Council Canada - National Science Library

    Emendörfer, Fernanda; Emendörfer, Fabiane; Bellato, Fernanda; Noldin, Vânia Floriani; Cechinel-Filho, Valdir; Yunes, Rosendo Augusto; Monache, Franco Delle; Cardozo, Alcíbia Maia

    2005-01-01

    This study describes the antispasmodic activity of some fractions and cynaropicrin, a sesquiterpene lactone from Cynara scolymus, cultivated in Brazil, against guinea-pig ileum contracted by acetylcholine...

  18. Changes of gastrointestinal myoelectric activity and bile acid pool size after cholecystectomy in guinea pigs

    Institute of Scientific and Technical Information of China (English)

    Xue-Mei Zhang; Lei Dong; Li-Na Liu; Bi-Xia Chang; Qian He; Qian Li

    2005-01-01

    AIM: To investigate the bile acid pool size after cholecystectomy whether or not correlated to the gastrointestinal migrating myoelectric complex (MMC) in guinea pigs.METHODS: Gallbladder motilities were assessed before cholecystectomy. Furthermore, we continuously monitored interdigestive gastrointestinal motilities using bipolar electrodes in conscious guinea pigs before and after surgery at 4 wk in standard diet group and high cholesterol diet (cholesterol gallstone) group. Total bile acid pool sizes were measured by isotope dilution method at meantime.RESULTS: After cholecystectomy, there were parallel falls in duration of phase Ⅰ, Ⅱ, Ⅲ and MMC cycle duration but increase in amplitude in the guinea pigs with normal gallbladder function, and in the guinea pigs with cholesterol stones. However, There were not significantly differences. On the other hand, the bile acid pool was definitely small in the GS guinea pigs compared to normal guinea pigs and became slightly smaller after cholecystectomy. Similarly, bile acid in gallbladder bile, fecal bile acid was slightly increased in GS guinea pigs after cholecystectomy, to the same degree as normal. These differences, however, were not significant.CONCLUSION: It is concluded that in the guinea pigs with normal gallbladder function, and in the guinea pigs with cholesterol stones: (1) Cholecystectomy produce a similar but less marked trend in bile acid pool; and (2) MMC are linked to enterohepatic circulation of bile acids, rather than surgery, which is consistent with changes of the bile acid pool size. As a result, gastrointestinal dyskinesia is not involved in occurrence of postcholecystectomy syndrome.

  19. Hyperthyroidism in four guinea pigs: clinical manifestations, diagnosis, and treatment.

    Science.gov (United States)

    Künzel, F; Hierlmeier, B; Christian, M; Reifinger, M

    2013-12-01

    Hyperthyroidism was diagnosed in four guinea pigs by demonstration of an increased serum total thyroxine concentration. The main clinical signs were comparable with those observed in feline hyperthyroidism and included weight loss despite maintenance of appetite and a palpable mass in the ventral cervical region. Three animals were treated successfully with methimazole for between 13 and 28 months. Clinical signs and regular measurement of circulating total thyroxine concentrations appear to be convenient parameters for monitoring response to medical therapy.

  20. Pharmacokinetics and pharmacodynamics of 4-aminopyridine in awake guinea pigs.

    Science.gov (United States)

    Capacio, B R; Chang, F C; Spriggs, D; Byers, C E; Matthews, R L; Benton, B J

    1997-08-01

    The selective blockade of potassium channels on excitable membranes by 4-aminopyridine (4-AP) leads to facilitation of neurotransmitter release at a wide variety of synapses. This compound has been shown to be efficacious against lethality induced by saxitoxin (STX) and tetrodotoxin (TTX) in guinea pigs. To characterize the actions of 4-AP in guinea pigs we have investigated its pharmacokinetics (PK) and pharmacodynamics following a 2 mg/kg, intramuscular (im) dose in awake chronically instrumented (IN) animals. Animals were chronically instrumented for electrophysiologic recordings of diaphragmatic electromyogram (DEMG), lead II electrocardiogram (ECGII) and electrocorticogram (ECoG). Also, PK studies were carried out in uninstrumented (UN) guinea pigs. Blood and electrophysiologic data were collected at predetermined time intervals up to 4 hours post 4-AP administration. High performance liquid chromatography was used to determine plasma 4-AP concentrations. For IN and UN animals, plasma concentration-time data best fit a one-compartment model, and PK parameter estimates were similar for both groups. Peak plasma levels were found to occur between 16 and 17 min, and the half-lives of elimination were 65 and 71 min for IN and UN animals respectively. Heart and respiratory rates were elevated as early as 5 and 15 min respectively in response to 4-AP administration. The duration of action was approximately 1-1.5 half-lives of elimination beyond peak plasma levels. Maximum ECoG responses were observed between 12-15 min after 4-AP injection; some residual drug effects were still apparent at 240 min. The difference between the heart and respiratory rates and ECoG profiles suggests that these different physiological systems respond with varying degrees of sensitivity to plasma 4-AP concentrations. The stimulation of these systems is consistent with the action of 4-AP in reversing STX- and TTX-induced cardiorespiratory depression and decreased ECoG power in guinea pigs.

  1. Migration of craniofacial periosteum in growing guinea-pigs.

    OpenAIRE

    1985-01-01

    The use of a carbon particle tattoo provided stable periosteal markers and a means of recording periosteal movement both anteroposteriorly and transversely during growth in guinea-pigs. In general, the periosteum migrated toward the cranial sutures. The radial pattern, demonstrated on the frontal bones and indicated on the nasal and parietal bones, showed that a periosteal envelope is identifiable with each bone. The area of origin of this centrifugal pattern of migration coincided with the o...

  2. Beam-Beam Simulations with GUINEA-PIG

    CERN Document Server

    Schulte, Daniel

    1998-01-01

    While the bunches in a linear collider cross only once, due to their small size they experience a strong beam-beam effect. GUINEA-PIG is a code to simulate the impact of this effect on luminosity and back ground. A short overview of the program is given with examples of its application to the back ground strudies for TESLA, the top quark threshold scan and a possible luminosity monitor, as well as some results for CLIC.

  3. Novel antitussive effect of suplatast tosilate in guinea pigs.

    Science.gov (United States)

    Zhou, Jian-Rong; Syono, Ryo-ichi; Fukumi, Syu-ichi; Kimoto, Kenji; Shirasaki, Tetsuya; Soeda, Fumio; Takahama, Kazuo

    2015-01-01

    We studied the antitussive effects of suplatast, a Th2 cytokine inhibitor, and compared them with the effects of codeine using an experimental cough model in guinea pigs. Suplatast and codeine dose-dependently inhibited cough caused by mechanical stimulation of the larynx, but they did not inhibit cough caused by mechanical stimulation of the bifurcation of the trachea. In guinea pigs with bronchitis, suplatast had an antitussive effect on cough caused by stimulation of the larynx, whereas codeine did not inhibit such cough. In SO2-exposed guinea pigs, suplatast tended to inhibit cough caused by mechanical stimulation of the tracheal bifurcation. Further, suplatast inhibited citric acid-induced cough augmented by pretreatment with an angiotensin-converting enzyme inhibitor, whereas codeine did not inhibit such cough. Suplatast also inhibited bradykinin-induced discharges of airway vagal afferent nerves and significantly inhibited 4-aminopyridine-induced discharges of airway vagal afferent nerves. These findings indicate that the antitussive effects of suplatast are mediated by a novel mechanism involving the peripheral nervous system.

  4. Pathogenesis of Bolivian Hemorrhagic Fever in Guinea Pigs.

    Science.gov (United States)

    Bell, T M; Bunton, T E; Shaia, C I; Raymond, J W; Honnold, S P; Donnelly, G C; Shamblin, J D; Wilkinson, E R; Cashman, K A

    2016-01-01

    Machupo virus, the cause of Bolivian hemorrhagic fever, is a highly lethal viral hemorrhagic fever with no Food and Drug Administration-approved vaccines or therapeutics. This study evaluated the guinea pig as a model using the Machupo virus-Chicava strain administered via aerosol challenge. Guinea pigs (Cavia porcellus) were serially sampled to evaluate the temporal progression of infection, gross and histologic lesions, and sequential changes in serum chemistry and hematology. The incubation period was 5 to 12 days, and complete blood counts revealed leukopenia with lymphopenia and thrombocytopenia. Gross pathologic findings included congestion and hemorrhage of the gastrointestinal mucosa and serosa, noncollapsing lungs with fluid exudation, enlarged lymph nodes, and progressive pallor and friability of the liver. Histologic lesions consisted of foci of degeneration and cell death in the haired skin, liver, pancreas, adrenal glands, lymph nodes, tongue, esophagus, salivary glands, renal pelvis, small intestine, and large intestine. Lymphohistiocytic interstitial pneumonia was also present. Inflammation within the central nervous system, interpreted as nonsuppurative encephalitis, was histologically apparent approximately 16 days postexposure and was generally progressive. Macrophages in the tracheobronchial lymph node, on day 5 postexposure, were the first cells to demonstrate visible viral antigen. Viral antigen was detected throughout the lymphoid system by day 9 postexposure, followed by prominent spread within epithelial tissues and then brain. This study provides insight into the course of Machupo virus infection and supports the utility of guinea pigs as an additional animal model for vaccine and therapeutic development.

  5. On the morality of Guinea-pig recruitment.

    Science.gov (United States)

    Valdman, Mikhail

    2010-07-01

    ABSTRACT Can it be wrong to conduct medical research on human subjects even with their informed consent and even when the transaction between the subjects and researchers is expected to be mutually beneficial? This question is especially pressing today in light of the rise of a semi-professional class of 'guinea pigs'- human research subjects that sell researchers a right of access to their bodies in exchange for money. Can these exchanges be morally problematic even when they are consensual and mutually beneficial? I argue that there are two general kinds of concern one can have about such transactions - concerns about the nature of what is sold and concerns about the conditions in which the selling occurs. The former involves worries about degradation and the possible wrongness of selling a right of access to one's body. These worries, I argue, are not very serious. The latter involves worries about coercion, exploitation, and undue influence - about how, by virtue of their ignorance, impulsiveness, or desperation, guinea pigs can be taken advantage of by medical researchers. These worries are quite serious but I argue that, at least in cases where the exchange between guinea pigs and researchers is consensual and mutually beneficial, they do not raise insurmountable moral problems.

  6. Congenital guinea pig infection with attenuated Junin virus strains.

    Science.gov (United States)

    Boxaca, M C; Gómez, M M; Malumbres, E; de Guerrero, L B

    1985-01-01

    Guinea pigs born from mothers infected before or during pregnancy with 10(3) PFU of the attenuated XJC13 or XJ0 strains of Junin virus (JV) by the intramuscular route showed 31.5% mortality that was not attributable to the mothers' clinical condition or to lack of care. There was a slight drop in mortality rate when the mothers were infected at the beginning or end of their gestation period. JV isolation from the 9 offspring killed from 1 to 125 days of age proved that virus transmitted transplacentally or soon after birth was able to persist, although titers were not higher than 10(2.7) PFU/g of tissue in various organs, including brain. Cell-associated viremia could thus account for viral spread after birth. Since an active humoral response was detected in the same animals, although Nt antibody titers were below 1:16, a state of tolerance did not exist in these congenitally infected animals. The carrier state appeared to modify guinea pig susceptibility to JV; after challenge with the pathogenic XJ strain of JV, 2 animals survived and developed normal humoral responses, while half of the remaining animals did not show typical signs of Argentine hemorrhagic fever. Although JV persistence appeared to cause no deleterious effects in surviving guinea pigs, its long-term risk remains to be determined.

  7. Acute inhalation exposure of azodicarbonamide in the guinea pig.

    Science.gov (United States)

    Shopp, G M; Cheng, Y S; Gillett, N A; Bechtold, W E; Medinsky, M A; Hobbs, C H; Birnbaum, L S; Mauderly, J L

    1987-02-01

    Humans have been exposed to azodicarbonamide (ADA) by inhalation where bulk quantities of ADA are handled in the workplace. Responses of some workers have led to concern for the potential irritant and sensitizing properties of inhaled ADA. This study examined the effects of inhaling ADA on lung structure and function of guinea pigs during and after an acute exposure. Groups of 20 guinea pigs were exposed to each of 3 concentrations of ADA (19, 58, and 97 mg/m3), plus air as a control, for 1 hr. Pulmonary function was measured before exposure (baseline), during exposure, immediately after exposure and 24 hr after exposure. Dynamic compliance (Cdyn), total pulmonary resistance (RL), tidal volume (VT), respiratory frequency and minute volume were measured. In addition, gross necropsies and histological examinations of respiratory tract tissues were done either immediately following the exposure or 24 hr after exposure. There were no effects of ADA exposure on gross necropsy, histology, Cdyn, or RL. Some significant, concentration-related decreases in VT, respiratory frequency and minute volume were seen. The magnitudes of these changes were small: the largest change was seen in minute volume, amounting to a 24% decrease in the high concentration group. Inhalation exposure of guinea pigs to ADA at concentrations of up to 97 mg/m3 resulted in minor changes in pulmonary function without any changes in lung histology.

  8. Waltz's Theory of Theory

    DEFF Research Database (Denmark)

    Wæver, Ole

    2009-01-01

    Kenneth N. Waltz's 1979 book, Theory of International Politics, is the most influential in the history of the discipline. It worked its effects to a large extent through raising the bar for what counted as theoretical work, in effect reshaping not only realism but rivals like liberalism and refle......Kenneth N. Waltz's 1979 book, Theory of International Politics, is the most influential in the history of the discipline. It worked its effects to a large extent through raising the bar for what counted as theoretical work, in effect reshaping not only realism but rivals like liberalism...... and reflectivism. Yet, ironically, there has been little attention to Waltz's very explicit and original arguments about the nature of theory. This article explores and explicates Waltz's theory of theory. Central attention is paid to his definition of theory as ‘a picture, mentally formed' and to the radical anti......-empiricism and anti-positivism of his position. Followers and critics alike have treated Waltzian neorealism as if it was at bottom a formal proposition about cause-effect relations. The extreme case of Waltz being so victorious in the discipline, and yet being consistently mis-interpreted on the question of theory...

  9. Interstitial cells of Cajal and Auerbach's plexus. A scanning electron microscopical study of guinea-pig small intestine

    DEFF Research Database (Denmark)

    Jessen, Harry; Thuneberg, Lars

    1991-01-01

    Anatomy, interstitial cells of Cajal, myenteric plexus, small intestine, guinea-pig, scanning electron microscopy......Anatomy, interstitial cells of Cajal, myenteric plexus, small intestine, guinea-pig, scanning electron microscopy...

  10. Vaccination with Trypanosoma rangeli induces resistance of guinea pigs to virulent Trypanosoma cruzi.

    Science.gov (United States)

    Basso, B; Moretti, E; Fretes, R

    2014-01-15

    Chagas' disease, endemic in Latin America, is spread in natural environments through animal reservoirs, including marsupials, mice and guinea pigs. Farms breeding guinea pigs for food are located in some Latin-American countries with consequent risk of digestive infection. The aim of this work was to study the effect of vaccination with Trypanosoma rangeli in guinea pigs challenged with Trypanosoma cruzi. Animals were vaccinated with fixated epimastigotes of T. rangeli, emulsified with saponin. Controls received only PBS. Before being challenged with T. cruzi, parasitemia, survival rates and histological studies were performed. The vaccinated guinea pigs revealed significantly lower parasitemia than controls (pguinea pigs and dogs. The development of vaccines for use in animals, like domestic dogs and guinea pigs in captivity, opens up new opportunities for preventive tools, and could reduce the risk of infection with T. cruzi in the community.

  11. Cumulative irritancy in the guinea pig from low grade irritant vehicles and the angry skin syndrome

    DEFF Research Database (Denmark)

    Andersen, Klaus Ejner; Maibach, H I

    1980-01-01

    A 4-week open cumulative irritancy test in guinea pigs discriminated between two low grade irritant vehicles, nonionic base (anhydrous) and hydrophilic ointment. The procedure might be useful as a predictive test for low grade irritants. The angry skin syndrome was established in the guinea pigs...

  12. Molecular cloning, expression, and in silico structural analysis of guinea pig IL-17.

    Science.gov (United States)

    Dirisala, Vijaya R; Jeevan, Amminikutty; Ramasamy, Suresh K; McMurray, David N

    2013-11-01

    Interleukin-17A (IL-17A) is a potent proinflammatory cytokine and the signature cytokine of Th17 cells, a subset which is involved in cytokine and chemokine production, neutrophil recruitment, promotion of T cell priming, and antibody production. IL-17 may play an important role in tuberculosis and other infectious diseases. In preparation for investigating its role in the highly relevant guinea pig model of pulmonary tuberculosis, we cloned guinea pig IL-17A for the first time. The complete coding sequence of the guinea pig IL-17A gene (477 nucleotides; 159 amino acids) was subcloned into a prokaryotic expression vector (pET-30a) resulting in the expression of a 17 kDa recombinant guinea pig IL-17A protein which was confirmed by mass spectrometry analysis. Homology modeling of guinea pig IL-17A revealed that the three-dimensional structure resembles that of human IL-17A. The secondary structure predicted for this protein showed the presence of one extra helix in the N-terminal region. The expression profile of IL-17A was analyzed quantitatively in spleen, lymph node, and lung cells from BCG-vaccinated guinea pigs by real-time PCR. The guinea pig IL-17A cDNA and its recombinant protein will serve as valuable tools for molecular and immunological studies in the guinea pig model of pulmonary TB and other human diseases.

  13. Cartilage interposition in ossiculoplasty with hydroxylapatite prostheses - A histological study in the guinea pig

    NARCIS (Netherlands)

    Meijer, AGW; Verheul, J; Albers, FWJ; Segenhout, HM; Rosowski, JJ; Merchant, SN

    2000-01-01

    In this experimental animal study, a cartilage disc was interposed between a synthetic middle ear prosthesis and the tympanic membrane of guinea pigs to investigate its effect on the extrusion process of the implant. Two groups of guinea pigs were studied. One group consisted of animals in which the

  14. Cloning, pharmacological characterization, and polymorphism screening of the guinea pig β2-adrenoceptor

    NARCIS (Netherlands)

    Oostendorp, Jaap; Meurs, Herman; Nelemans, S. Adriaan; Zaagsma, Johan; Kauffman, Henk F.; Postma, Dirkje S.; Boddeke, Hendrikus W.G.M.; Biber, Knut

    2002-01-01

    In asthma, beta(2)-adrenoceptor agonist responsiveness has been associated with Arg16Gly and Gln27Glu polymorphisms of the beta(2)-adrenoceptor. Since the guinea pig is extensively used as an animal model for asthma, we investigated the occurrence of possible polymorphism of the guinea pig beta(2)-a

  15. Cartilage interposition in ossiculoplasty with hydroxylapatite prostheses : A histopathologic study in the guinea pig

    NARCIS (Netherlands)

    Meijer, AGW; Verheul, J; Albers, FWJ; Segenhout, HM

    2002-01-01

    In this experimental animal study, a cartilage disk was interposed between a synthetic middle ear prosthesis and the tympanic membrane in guinea pigs to investigate its effect on the extrusion process of the implant. Two groups of guinea pigs were studied. One group consisted of animals in which the

  16. Cartilage interposition in ossiculoplasty with hydroxylapatite prostheses - A histological study in the guinea pig

    NARCIS (Netherlands)

    Meijer, AGW; Verheul, J; Albers, FWJ; Segenhout, HM; Rosowski, JJ; Merchant, SN

    2000-01-01

    In this experimental animal study, a cartilage disc was interposed between a synthetic middle ear prosthesis and the tympanic membrane of guinea pigs to investigate its effect on the extrusion process of the implant. Two groups of guinea pigs were studied. One group consisted of animals in which the

  17. Nickel-sulphate-induced contact dermatitis in the guinea pig maximization test

    DEFF Research Database (Denmark)

    Rohold, A E; Nielsen, G D; Andersen, Klaus Ejner

    1991-01-01

    Nickel sulphate is a sensitizer in guinea pigs, but the frequency of sensitization varies from study to study. The dose-response relationship for NiSO4.6H2O was evaluated in the guinea pig maximization test in this study. 6 intradermal (0.01%-3.0% aq.) and 6 topical (0.25%-10.0% pet...

  18. Behavioral responses of deafened guinea pigs to intracochlear electrical stimulation: a new rapid psychophysical procedure

    NARCIS (Netherlands)

    Agterberg, M.J.H.; Versnel, H.

    2014-01-01

    In auditory research the guinea pig is often preferred above rats and mice because of the easily accessible cochlea and because the frequency range of its hearing is more comparable to that of humans. Studies of the guinea-pig auditory system primarily apply histological and electrophysiological mea

  19. The guinea pig maximization test--with a multiple dose design

    DEFF Research Database (Denmark)

    Andersen, Klaus Ejner; Vølund, A; Frankild, S

    1995-01-01

    The guinea pig maximization test (GPMT) is usually performed with one moderately irritant induction dose of the allergen and gives a qualitative assessment-hazard identification-of the allergenicity of the chemical. We refined the GPMT by applying a multiple dose design and used 30 guinea pigs...

  20. [Measurement of airway resistance and reactivity in guinea pigs using double-chamber plethysmography].

    Science.gov (United States)

    Yao, Wei-min; Lai, Ke-fang; Luo, Yuan-ming; Liu, Chun-li; Chen, Ru-chong; Luo, Wei; Zhong, Nan-shan

    2009-05-01

    To establish a method for measurement of airway resistance (sRaw) and reactivity in guinea pigs. Methacholine spray at gradient concentrations was given to guinea pigs. PC100 was defined as the concentration of methacholine when the sRaw doubled in the guinea pigs using a double-chamber plethysmograph. The time for the recovery of PC100 resistance to baseline levels was measured. The sRaw and PC100 were measured twice on days 1 and 15 (4 time points) in the guinea pigs before and after OVA challenge. PC100 in a normal guinea pig airway was shown to recover the baseline level within 1 h. Double-chamber plethysmographical measurement of the sRaw and PC100 in normal guinea pigs did not show significant differences between the time points [sRaw: 3.25-/+0.67, 3.33-/+0.58, 3.30-/+0.56, and 3.32-/+0.75 cm H2O.s; log2PC100: 8.48-/+0.94, 8.64-/+1.04, 8.56-/+0.67, and 8.64-/+0.60, respectively, P>0.05]. The sRaw and airway reactivity were significantly increased in guinea pigs challenged with OVA [sRaw: 7.08-/+1.82 vs 2.87-/+0.53 cmH2O.s, Pmeasurement of sRaw and airway reactivity in guinea pig is established successfully.

  1. A First Generation Comparative Chromosome Map between Guinea Pig (Cavia porcellus) and Humans.

    Science.gov (United States)

    Romanenko, Svetlana A; Perelman, Polina L; Trifonov, Vladimir A; Serdyukova, Natalia A; Li, Tangliang; Fu, Beiyuan; O'Brien, Patricia C M; Ng, Bee L; Nie, Wenhui; Liehr, Thomas; Stanyon, Roscoe; Graphodatsky, Alexander S; Yang, Fengtang

    2015-01-01

    The domesticated guinea pig, Cavia porcellus (Hystricomorpha, Rodentia), is an important laboratory species and a model for a number of human diseases. Nevertheless, genomic tools for this species are lacking; even its karyotype is poorly characterized. The guinea pig belongs to Hystricomorpha, a widespread and important group of rodents; so far the chromosomes of guinea pigs have not been compared with that of other hystricomorph species or with any other mammals. We generated full sets of chromosome-specific painting probes for the guinea pig by flow sorting and microdissection, and for the first time, mapped the chromosomal homologies between guinea pig and human by reciprocal chromosome painting. Our data demonstrate that the guinea pig karyotype has undergone extensive rearrangements: 78 synteny-conserved human autosomal segments were delimited in the guinea pig genome. The high rate of genome evolution in the guinea pig may explain why the HSA7/16 and HSA16/19 associations presumed ancestral for eutherians and the three syntenic associations (HSA1/10, 3/19, and 9/11) considered ancestral for rodents were not found in C. porcellus. The comparative chromosome map presented here is a starting point for further development of physical and genetic maps of the guinea pig as well as an aid for genome assembly assignment to specific chromosomes. Furthermore, the comparative mapping will allow a transfer of gene map data from other species. The probes developed here provide a genomic toolkit, which will make the guinea pig a key species to unravel the evolutionary biology of the Hystricomorph rodents.

  2. Growth failure after recurrent fever in young guinea pigs.

    Science.gov (United States)

    Madu, S C; Faurie, A; Pettifor, J M; Laburn, H P

    2007-03-16

    Infection causes fever and suppression of appetite, a combination of effects which threatens normal growth in infected children. We have used an animal model to study the effects on growth of recurrent simulated Gram-positive bacterial infection. After weaning, 10 guinea pig pups underwent surgery under general anaesthesia for the implantation of temperature-sensitive radiotelemeters and thereafter were assigned to receive intramuscular injections of either 50 microg/kg muramyl dipeptide (MDP), or sterile saline. During a 30-day period corresponding to their rapid growth phase, the pups were given eight injections. MDP resulted in fevers of about 1.5 degrees C on each occasion, but no significant change in body temperature occurred after saline injections. Food intake was suppressed during each febrile episode such that 24-h intake was significantly lower on days of injections of MDP, compared to days between MDP injections in the same animals, and compared to that of animals injected with saline. The rate of weight gain of the MDP-injected guinea pigs was significantly lower than that of the control group and failed even to achieve a rate similar to the saline-injected group in their more adult-like growth phase. Plasma zinc concentration was significantly lower in MDP-compared to saline-injected animals sampled 8 days after the last injection. Our results show that recurrent fever during the growth phase of young guinea pigs results in irreversible growth failure, and that reduced food intake on days when the animals were febrile was at least partly responsible for this reduced rate of growth.

  3. Ozone-Induced Hypertussive Responses in Rabbits and Guinea Pigs.

    Science.gov (United States)

    Clay, Emlyn; Patacchini, Riccardo; Trevisani, Marcello; Preti, Delia; Branà, Maria Pia; Spina, Domenico; Page, Clive

    2016-04-01

    Cough remains a major unmet clinical need, and preclinical animal models are not predictive for new antitussive agents. We have investigated the mechanisms and pharmacological sensitivity of ozone-induced hypertussive responses in rabbits and guinea pigs. Ozone induced a significant increase in cough frequency and a decrease in time to first cough to inhaled citric acid in both conscious guinea pigs and rabbits. This response was inhibited by the established antitussive drugs codeine and levodropropizine. In contrast to the guinea pig, hypertussive responses in the rabbit were not inhibited by bronchodilator drugs (β2 agonists or muscarinic receptor antagonists), suggesting that the observed hypertussive state was not secondary to bronchoconstriction in this species. The ozone-induced hypertussive response in the rabbit was inhibited by chronic pretreatment with capsaicin, suggestive of a sensitization of airway sensory nerve fibers. However, we could find no evidence for a role of TRPA1 in this response, suggesting that ozone was not sensitizing airway sensory nerves via activation of this receptor. Whereas the ozone-induced hypertussive response was accompanied by a significant influx of neutrophils into the airway, the hypertussive response was not inhibited by the anti-inflammatory phosphodiesterase 4 inhibitor roflumilast at a dose that clearly exhibited anti-inflammatory activity. In summary, our results suggest that ozone-induced hypertussive responses to citric acid may provide a useful model for the investigation of novel drugs for the treatment of cough, but some important differences were noted between the two species with respect to sensitivity to bronchodilator drugs.

  4. Attenuation of streptomycin ototoxicity by tetramethylpyrazine in guinea pig cochlea.

    Science.gov (United States)

    Cui, Cheng; Liu, Dajun; Qin, Xin

    2015-05-01

    Tetramethylpyrazine has been suggested to have a therapeutic effect on impaired hearing that is induced by aminoglycoside antibiotics. However, its effectiveness on streptomycin ototoxicity and its cellular mechanisms are relatively unknown. Here we investigate the protective effect of tetramethylpyrazine on streptomycin-induced ototoxicity in guinea pig cochlea. Prospective randomized laboratory study. Hearing Research Laboratory of China Medical University. Adult guinea pigs were randomized to 4 groups. Hearing sensitivity of guinea pigs was tested by auditory brainstem response measurements before streptomycin exposure and again 10 days later. The cochlear tissues were prepared for electron microscopy and immunohistochemical staining of heat shock protein 70 (HSP70). The effect of tetramethylpyrazine on streptomycin-induced activation of caspase-3 was evaluated by Western blotting. Co-therapy with tetramethylpyrazine reduced a profound streptomycin-induced auditory threshold shift compared with streptomycin treatment alone (P = .0002 or P = .00008). Tetramethylpyrazine also attenuated the structural disruption in streptomycin-treated outer hair cells and marginal cells of vascular stria by transmission electronic microscopy and scanning electronic microscopy, respectively. Moreover, tetramethylpyrazine decreased the streptomycin-stimulated expressions of HSP70 and caspase-3. The correlation analysis demonstrated that HSP70 expression had a positive correlation with auditory brainstem response thresholds (|R| = 0.6-0.9, P = .0073 or P = .0169). Our data suggest that the protective effect of tetramethylpyrazine on hearing function is associated with the reduction of stress response and inhibition of apoptosis. Tetramethylpyrazine may have therapeutic potential for patients with ototoxicity diseases. © American Academy of Otolaryngology-Head and Neck Surgery Foundation 2015.

  5. Citicoline retards myopia progression following form deprivation in guinea pigs

    Science.gov (United States)

    Liu, Shuangzhen; Fu, Chunyan

    2016-01-01

    The retinal dopaminergic system is involved in the myopic shift following form deprivation. Citicoline has been demonstrated to stimulate the dopaminergic system in the brain and retina. Furthermore, citicoline has been used in many neurogenic diseases, such as senile cognitive impairment, stroke and Parkinson's disease as well as in amblyopia and glaucoma. Our aim was to investigate the effect of citicoline on the refractive state and retinal dopamine level in form deprivation myopia of guinea pigs. Guinea pigs, at an age of four weeks, were randomly divided into normal control, deprivation, deprived + citicoline and deprived + vehicle groups. Form deprivation myopia was induced by a translucent eye shield covering the right eye. Citicoline was injected intraperitoneally twice a day (500 mg/kg, 9 am and 9 pm) for 10 days. In vitro, retinal explants were cultured with citicoline for 24 h, with a final citicoline concentration of 100 µmol/L. The ocular refractive parameters and retinal dopamine content were measured. After occlusion for 10 days, the form-deprived eyes became myopic with an increase in axial length and a decrease in retinal dopamine content. The intraperitoneal injection of citicoline reduced the myopic degree (from −3.25 ± 0.77D to −0.62 ± 0.47D, P citicoline, retinal dopamine content increased significantly (from 0.42 ± 0.14 ng to 0.62 ± 0.21 ng, P citicoline could retard the myopic shift induced by form deprivation in guinea pigs, which was mediated by an increase in the retinal dopamine levels. PMID:26979720

  6. Auditory effects of noise on infant and adult guinea pigs.

    Science.gov (United States)

    Danto, J; Caiazzo, A J

    1977-01-01

    This pilot study compared the susceptibility of the infant (48 hr) and adult (120 days) guinea pig to the effects of noise. Subjects were exposed to a narrow band of noise (center frequency 4 kHz) at an intensity of 115 dB sound pressure level (SPL) for 1 hr. Postexposure thresholds were obtained by a conditioned suppression technique. Results indicated that the infant animals displayed a mean hearing threshold of 25 dB SPL that significantly differed from the adult mean threshold of 7.5 dB SPL.

  7. Early histological maturation in the hippocampus of the guinea pig.

    Science.gov (United States)

    Nacher, J; Palop, J J; Ramirez, C; Molowny, A; Lopez-Garcia, C

    2000-06-01

    The vesicular zinc-rich synaptic systems of the principal neurons of the hippocampus are well developed in newborn guinea pigs, a precocial species. In addition, alvear and fimbrial myelinated fibers as well as significant inhibitory interneurons (i.e. somatostatin, parvalbumin and opioid immunoreactive hippocampal interneurons) are also well developed. On the contrary, neither vesicular zinc synapses nor myelinated fibers nor the above mentioned immunoreactive interneurons are detectable in newborn specimens of other related altricial species such as rats or rabbits. These data suggest that early maturation of a highly integrative center related to cognitive map building such as the hippocampus is characteristic of precocial species.

  8. Microbial flora of odontogenic abscesses in pet guinea pigs.

    Science.gov (United States)

    Minarikova, A; Hauptman, K; Knotek, Z; Jekl, V

    2016-10-01

    Abscesses of odontogenic origin in guinea pigs pose a serious health problem and need to be treated with a combination of surgical and medical therapy. The aim of this prospective study was to describe the microbial flora of odontogenic abscesses associated with osteomyelitis in 24 pet guinea pigs, to perform antibiotic sensitivity testing, and to make recommendations for practitioners on the antibiotics of first choice. Inclusion criteria for the study included the animal being diagnosed with an odontogenic abscess which underwent surgery and was not pre-treated with an antibiotic. Inclusion criteria matched for 24 guinea pigs. Samples (pus, capsule and affected tooth/bone) for bacteriological examination were collected under sterile conditions during the surgical procedure. The most commonly isolated bacteria from abscesses of odontogenic origin were Bacteroides fragilis in 12.8 per cent (6/47) of cases, Pasteurella multocida in 10.6 per cent (5/47) and Peptostreptococcus anaerobius in 8.5 per cent (4/47). Aerobic bacterial species only were isolated in 29.2 per cent (7/24) of cases, anaerobic bacteria only were isolated in 33.3 per cent (8/24), and mixed infection with anaerobic and aerobic bacterial species was seen in 37.5 per cent (9/24). Aerobes (n=20) were sensitive to enrofloxacin and marbofloxacin in 100 per cent of samples, benzylpenicillin potassium (penicillin G, PNCG) in 90 per cent, cephalotin in 85 per cent, amoxicillin-clavulanate in 75 per cent, doxycycline in 70 per cent, gentamicin in 65 per cent and trimethoprim-sulfamethoxazole in 55 per cent. Anaerobes (n=27) were sensitive to amoxicillin-clavulanate in 100 per cent of cases, clindamycin in 96.3 per cent, metronidazole in 92.6 per cent, PNCG in 92.6 per cent and cephalotin in 74.1 per cent. As guinea pigs are strictly herbivorous animals, based on the results of this study the recommended antibiotic treatment for odontogenic abscesses is a combination of fluoroquinolones and metronidazole.

  9. Molecular cloning and expression of the IL-10 gene from guinea pigs.

    Science.gov (United States)

    Dirisala, Vijaya R; Jeevan, Amminikutty; Bix, Gregory; Yoshimura, Teizo; McMurray, David N

    2012-04-25

    The Guinea pig (Cavia porcellus) is one of the most relevant small animals for modeling human tuberculosis (TB) in terms of susceptibility to low dose aerosol infection, the organization of granulomas, extrapulmonary dissemination and vaccine-induced protection. It is also considered to be a gold standard for a number of other infectious and non-infectious diseases; however, this animal model has a major disadvantage due to the lack of readily available immunological reagents. In the present study, we successfully cloned a cDNA for the critical Th2 cytokine, interleukin-10 (IL-10), from inbred Strain 2 guinea pigs using the DNA sequence information provided by the genome project. The complete open reading frame (ORF) consists of 537 base pairs which encodes a protein of 179 amino acids. This cDNA sequence exhibited 87% homology with human IL-10. Surprisingly, it showed only 84% homology with the previously published IL-10 sequence from the C4-deficient (C4D) guinea pig, leading us to clone IL-10 cDNA from the Hartley strain of guinea pig. The IL-10 gene from the Hartley strain showed 100% homology with the IL-10 sequence of Strain 2 guinea pigs. In order to validate the only published IL-10 sequence existing in Genbank reported from C4D guinea pigs, genomic DNA was isolated from tissues of C4D guinea pigs. Amplification with various sets of primers showed that the IL-10 sequence reported from C4D guinea pigs contained numerous errors. Hence the IL-10 sequence that is being reported by us replaces the earlier sequence making our IL-10 sequence to be the first one accurate from guinea pig. Recombinant guinea pig IL-10 proteins were subsequently expressed in both prokaryotic and eukaryotic cells, purified and were confirmed by N-terminal sequencing. Polyclonal anti-IL-10 antibodies were generated in rabbits using the recombinant IL-10 protein expressed in this study. Taken together, our results indicate that the DNA sequence information provided by the genome project

  10. Synaptic localization of. kappa. opioid receptors in guinea pig neostriatum

    Energy Technology Data Exchange (ETDEWEB)

    Jomary, C.; Beaudet, A. (McGill Univ., Montreal, Quebec (Canada)); Gairin, J.E. (Centre National de la Recherche Scientifique, Toulouse (France))

    1992-01-15

    Distribution of {kappa} opioid receptors was examined by EM radioautography in sections of guinea pig neostriatum with the selective {sup 125}I-labeled dynorphin analog (D-Pro{sup 10})dynorphin-(1-11). Most specifically labeled binding sites were found by probability circle analysis to be associated with neuronal membrane appositions. Because of limitations in resolution of the method, the radioactive sources could not be ascribed directly to either one of the apposed plasma membranes. Nevertheless, three lines of evidence favored a predominant association of ligand with dendrites of intrinsic striatal neurons: (1) the high frequency with which labeled interfaces implicated a dendrite, (2) the enrichment of dendrodendritic interfaces, and (3) the occurrence of dendritic profiles labeled at several contact points along their plasma membranes. A small proportion of labeled sites was associated with axo-axonic interfaces, which may subserve the {kappa} opioid-induced regulation of presynaptic dopamine and acetylcholine release documented in guinea pig neostriatum. These results support the hypothesis that in mammalian brain {kappa} opioid receptors are conformationally and functionally distinct from {mu} and {delta} types.

  11. Cutaneous sensitization to some polyisocyanate prepolymers in guinea pigs.

    Science.gov (United States)

    Zissu, D; Binet, S; Limasset, J C

    1998-11-01

    Isocyanates are used extensively in the polyurethane industry. Pulmonary and dermal sensitization resulting from exposure to diisocyanates has frequently been reported, but the potential effects of polyisocyanates on health are less well known. Thus, since 1978, occupational exposure limits have been established for diisocyanates only. Nevertheless, respiratory diseases and dermatitis have been reported in the polyurethane industry after accidental isocyanate contact during spills or splashes. The aim of this experimental work was to assess the dermal hypersensitivity of guinea pigs to some polyisocyanate prepolymers by means of a well-conducted standard predictive Buehler test. Our results showed that dicyclohexylmethane 4,4'-diisocyanate (HMDI), toluylene 2,4-diisocyanate (TDI), TDI adduct triol, TDI isocyanurate, 1,6-hexamethylene diisocyanate (HDI), HDI isocyanurate, HDI biuret and isophorone diisocyanate (IPDI) induced dermal sensitization while IPDI isocyanurate did not. In conclusion, the dermal hypersensitivity of guinea pigs to some polyisocyanates was similar to those of their corresponding monomers except for IPDI isocyanurate, suggesting that the results from diisocyanate monomers could not be a valuable approach for the detection of the sensitization potency of the corresponding prepolymers.

  12. Chlamydial salpingitis in female guinea pigs receiving oral contraceptives.

    Science.gov (United States)

    Barron, A L; Pasley, J N; Rank, R G; White, H J; Mrak, R E

    1988-01-01

    Female guinea pigs were given daily doses of a combination of oral contraceptive (OC) agents, consisting of mestranol and norethynodrel suspended in sesame oil or distilled H2O, and were infected in the genital tract with the chlamydial agent of guinea pig inclusion conjunctivitis (GPIC). Counts of chlamydial inclusions in cells of vaginal smears collected during infection, showed prolongation and enhancement of infection in OC-treated animals as compared with controls. Appearance of IgG and IgA antibodies to GPIC in genital secretions, as determined by enzyme-linked immunosorbent assay (ELISA), was also delayed in OC-treated animals as compared with controls. OC-treated infected animals were killed on days 15 and 43, and gross pathological evidence for ascending infection culminating in salpingitis was found in all of five and four of five animals, respectively. On the other hand, among untreated infected controls on each sacrifice day, only one of five animals had any evidence for ascending infection. Chlamydiae were detected by light and electron microscopy in fallopian tube tissue collected on day 15 following OC-treatment but not in tissue from control animals.

  13. Enzymic synthesis of leukotriene B4 in guinea pig brain.

    Science.gov (United States)

    Shimizu, T; Takusagawa, Y; Izumi, T; Ohishi, N; Seyama, Y

    1987-05-01

    Leukotriene B4 [5(S), 12(R)-dihydroxy-6, 14-cis-8,10-trans-eicosatetraenoic acid] was obtained from endogenous arachidonic acid when slices of the guinea pig brain cortex were incubated with the calcium ionophore A 23187. Enzymes involved in its synthesis, arachidonate 5-lipoxygenase [arachidonic acid to 5(S)-hydroperoxy-6-trans-8,11,14-cis-eicosatetraenoic acid and subsequently to leukotriene A4] and leukotriene A4 hydrolase (leukotriene A4 to B4), were present in the cytosol fraction. Arachidonate 5-lipoxygenase was Ca2+-dependent, and was stimulated by ATP and the microsomal membrane, as was noted for the enzyme from mast cells. The lipid hydroperoxides stimulated 5-lipoxygenase by four- to sixfold. The leukotriene A4 hydrolase activity was rich in brain, and the specific activity (0.4 nmol/min/mg of protein) was much the same as that of guinea pig leukocytes. High activities of these enzymes were detected in the olfactory bulb, pituitary gland, hypothalamus, and cerebral cortex. Since leukotriene B4 is enzymically synthesized in the brain, possible roles related to neuronal functions or dysfunctions deserve to be examined.

  14. Cortical evoked potentials recorded from the guinea pig without averaging.

    Science.gov (United States)

    Walloch, R A

    1975-01-01

    Potentials evoked by tonal pulses and recorded with a monopolar electrode on the pial surface over the auditory cortex of the guinea pig are presented. These potentials are compared with average potentials recorded in previous studies with an electrode on the dura. The potentials recorded by these two techniques have similar waveforms, peak latencies and thresholds. They appear to be generated within the same region of the cerebral cortex. As can be expected, the amplitude of the evoked potentials recorded from the pial surface is larger than that recorded from the dura. Consequently, averaging is not needed to extract the evoked potential once the dura is removed. The thresholds for the evoked cortical potential are similar to behavioral thresholds for the guinea pig at high frequencies; however, evoked potential thresholds are eleveate over behavioral thresholds at low frequencies. The removal of the dura and the direct recording of the evoked potential appears most appropriate for acute experiments. The recording of an evoked potential with dura electrodes empploying averaging procedures appears most appropriate for chronic studies.

  15. Spasmolytic effect of traditional herbal formulation on guinea pig ileum

    Science.gov (United States)

    Kumar, Dushyant; Ganguly, Kuntal; Hegde, H. V.; Patil, P. A.; Kholkute, S. D.

    2015-01-01

    Background: The herbal formulation consisting of Andrographis paniculata Nees., Cassia fistula L., Foeniculum vulgare Mill. and Cuminum cyminum L. is widely used by the local traditional practitioners in rural Northern Karnataka for spasmodic abdominal pain. Objective: The present study was undertaken to evaluate safety and spasmolytic effect of poly-herbal formulation. Materials and Methods: Acute toxicity studies were carried out in Swiss mice, as per the Organization for Economic Co-operation and Development (OECD) guidelines. The spasmolytic activity of the formulation was studied in isolated guinea pig ileum model using histamine and acetylcholine as agonists. The data were analyzed by one-way ANOVA, followed by Dunnetts post-hoc test and P ≤ 0.05 was considered as significant. Results: The formulation did not show any adverse toxic effects and found to be safe. It also showed significant (P < 0.05) relaxation in different agonist like histamine and acetylcholine-induced contractions in guinea pig ileum. Conclusion: Antispasmodic activity of the herbal formulation can be attributed to its atropine-like activity. The present findings, therefore, support its utility in spasmodic abdominal pain. PMID:26604555

  16. Placental transfer of ruthenium in rat and guinea-pig

    Energy Technology Data Exchange (ETDEWEB)

    Levack, V.M.; Pottinger, H.; Harrison, J.D. [National Radiological Protection Board, Chilton (United Kingdom)

    1994-12-01

    Ruthenium-106 in citrate solution was administered intravenously to rat at different stages of pregnancy and to guinea-pig either before conception or in late pregnancy. The results for rat showed that retention in the embryo/foetus measured at 3-5 days after administration increased from about 0.0002% of injected activity per embryo/foetus on day 12 of gestation to about 0.05% at birth. The relative concentrations of {sup 106}Ru in embryo/foetus and mother (C{sub f}/C{sub m} ratio) were about 0.1 in each case. Concentrations in the yolk sac on day 12 were about 1% g{sup -1} compared with 0.01% g{sup -1} kin the foetus/ Retention in the guinea-pig foetus in late gestation at 7 days after administration (days 50-57) was about 0.2% injected activity per foetus, corresponding to a C{sub f}/C{sub m} = 0.2. Retention in each foetoplacental unit was 2% of injected {sup 106}Ru with 50% in the yolk sac, 35% in the placenta and 10% in the foetus. For administration 4 weeks prior to conception, the level of {sup 106}Ru retained in the foetus on day 57 of gestation was two orders of magnitude lower than after short-term administration, with a C{sub f}/C{sub m} about 0.004. (author).

  17. Radiation effect on the middle ear of the guinea pig

    Energy Technology Data Exchange (ETDEWEB)

    Harada, Hirofumi; Nishizawa, Shinji; Hiraide, Fumihisa; Inoue, Tetsuzo

    1984-08-01

    It is known that radiation therapy of the head and neck causes otitis media with effusion. Otitis media with effusion was induced in guinea pigs by cobalt-60 irradiation. Twenty guinea pigs with intact drum and normal Preyer reflex were used. The animals were irradiated with doses of 2,000 rad, 4,000 rad, and 6,000 rad. They were sacrificed seven days after the irradiation. Other animals were irradiated with doses of 4,000 rad and sacrificed one day, three days, seven days, and fourteen days after the irradiation. Vascular permeability of the middle ear mucosa was observed by Majno's vascular labelling technique. Pathological change of the middle ear was examined under the light microscope. Vascular permeability increased in three days after 4,000 rad irradiation and small vessels were labelled with carbon particles. Seven days after irradiation, carbon labelling of small vessels was more extensive and extravascular blackening was present in the adjacent tissues. Edematous change of the middle ear mucosa and metaplasia of the epithelial cells were also observed. New bone formation of the tympanic bulla was increased by repeated irradiations. (author).

  18. Guinea Pig Maximization Test for Trichloroethylene and Its Metabolites

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Objectives To study the contact allergenic activities of trichloroethylene (TCE) and its three metabolites trichloroacetic acid, trichloroethanol and chloral hydrate. Methods A modified guinea pig maximization test (GPMT) was adopted. The skin sensitization (edema and erythema) was observed in trichloroethylene, trichloroacetic acid, trichloroethanol, chloral hydrate and 2,4-dinitrochlorobenzene. Results The allergenic rate of TCE, trichloroacetic acid and 2,4-dinitrochlorobenzene was 71.4%, 58.3% and 100.0% respectively, and that of trichloroethanol and chloral hydrate was 0%. The mean response score of TCE, trichloroacetic acid and 2,4-dinitrochlorobenzene was 2.3, 1.1, 6.0 respectively. The histopathological analysis also showed an induction of allergenic transfomation in guinea pig skin by both TCE and trichloroacetic acid. Conclusion TCE appears to be a strong allergen while trichloroacetic acid a moderate one. On the other hand, both trichloroethanol and chloral hydrate are weak sensitization potentials. Immunologic reaction induced by TCE might be postulated as the pathological process of this illness. Consequently, it is suggested that in the mechanism of Occupational Dermatitis Medicamentose-Like (ODML) induced by TCE, the chemical itself might be the main cause of allergy. As one of its metabolic products, trichloroacetic acid might be a subordinate factor.

  19. Spasmolytic effect of traditional herbal formulation on guinea pig ileum

    Directory of Open Access Journals (Sweden)

    Dushyant Kumar

    2015-01-01

    Full Text Available Background: The herbal formulation consisting of Andrographis paniculata Nees., Cassia fistula L., Foeniculum vulgare Mill. and Cuminum cyminum L. is widely used by the local traditional practitioners in rural Northern Karnataka for spasmodic abdominal pain. Objective: The present study was undertaken to evaluate safety and spasmolytic effect of poly-herbal formulation. Materials and Methods: Acute toxicity studies were carried out in Swiss mice, as per the Organization for Economic Co-operation and Development (OECD guidelines. The spasmolytic activity of the formulation was studied in isolated guinea pig ileum model using histamine and acetylcholine as agonists. The data were analyzed by one-way ANOVA, followed by Dunnetts post-hoc test and P ≤ 0.05 was considered as significant. Results: The formulation did not show any adverse toxic effects and found to be safe. It also showed significant (P < 0.05 relaxation in different agonist like histamine and acetylcholine-induced contractions in guinea pig ileum. Conclusions: Antispasmodic activity of the herbal formulation can be attributed to its atropine-like activity. The present findings, therefore, support its utility in spasmodic abdominal pain.

  20. A comparison of virulence of intraperitoneal infection of Burkholderia mallei strains in guinea-pigs

    Directory of Open Access Journals (Sweden)

    Eslampanah, M.

    2015-12-01

    Full Text Available Male guinea pigs show high susceptibility to Burkholderia mallei and have been used as animal models in glanders studies. The purpose of our study was to elucidate glanders comparative pathogenesis in guinea pigs. We present here the histological changes and bacterial isolation that develop over time in guinea pigs inoculated intraperitoneally (IP with two strain of B. mallei. Ten male guinea pigs were inoculated intraperitoneally with either the standard strain of Burkholderia mallei or B. mallei strain from Siberian tiger at the Tehran zoo individually, then euthanized at multiple time points post inoculation. Histopathologic changes were similar in both groups and consisted of pyogranulomatous inflammation. In the standard strain study guinea pigs, changes were first seen at 48 hours in liver and heart then in spleen, lung, and kidney at day 3. These changes generally reached maximal incidence and severity by day 3 but decreased by comparison in all tissues except the liver, lung and kidney. Changes were first seen in Siberian tiger strain study guinea pigs also at 48 hours in lung, liver and spleen. At day 3, changes were present in liver, spleen and mediastinal lymph nodes. These changes were maximal at day 4 and 5. In contrast there are differences in incidence and severity between the two strain study guinea pigs. Our findings based on histopathological study indicate that Siberian tiger strain has more severity in gross and necropsy examination but in pathologic lesion was qualitatively similar generally. Additionally, by bacterial isolation, we confirmed the presence of B. mallei.

  1. Hairless pigmented guinea pigs: a new model for the study of mammalian pigmentation.

    Science.gov (United States)

    Bolognia, J L; Murray, M S; Pawelek, J M

    1990-09-01

    A stock of hairless pigmented guinea pigs was developed to facilitate studies of mammalian pigmentation. This stock combines the convenience of a hairless animal with a pigmentary system that is similar to human skin. In both human and guinea pig skin, active melanocytes are located in the basal layer of the interfollicular epidermis. Hairless albino guinea pigs on an outbred Hartley background (CrI:IAF/HA(hr/hr)BR; designated hr/hr) were mated with red-haired guinea pigs (designated Hr/Hr). Red-haired heterozygotes from the F1 generation (Hr/hr) were then mated with each other or with hairless albino guinea pigs. The F2 generation included hairless pigmented guinea pigs that retained their interfollicular epidermal melanocytes and whose skin was red-brown in color. Following UV irradiation, there was an increase in cutaneous pigmentation as well as an increase in the number of active epidermal melanocytes. An additional strain of black hairless guinea pigs was developed using black Hr/Hr animals and a similar breeding scheme. These two strains should serve as useful models for studies of the mammalian pigment system.

  2. Investigation Into the Humaneness of Slaughter Methods for Guinea Pigs (Cavia porcelus) in the Andean Region.

    Science.gov (United States)

    Limon, Georgina; Gonzales-Gustavson, Eloy A; Gibson, Troy J

    2016-01-01

    Guinea pigs (Cavia porcelus) are an important source of nonhuman animal protein in the Andean region of South America. Specific guidelines regarding the welfare of guinea pigs before and during slaughter have yet to be developed. This study critically assessed the humaneness of 4 different stunning/slaughter methods for guinea pigs: cervical neck dislocation (n = 60), electrical head-only stunning (n = 83), carbon dioxide (CO2) stunning (n = 21), and penetrating captive bolt (n = 10). Following cervical neck dislocation, 97% of guinea pigs had at least 1 behavioral or cranial/spinal response. Six percent of guinea pigs were classified as mis-stunned after electrical stunning, and 1% were classified as mis-stunned after captive bolt. Increased respiratory effort was observed during CO2 stunning. Apart from this finding, there were no other obvious behavioral responses that could be associated with suffering. Of the methods assessed, captive bolt was deemed the most humane, effective, and practical method of stunning guinea pigs. Cervical neck dislocation should not be recommended as a slaughter method for guinea pigs.

  3. Temperature Preference in IAF Hairless and Hartley Guinea Pigs (Cavia porcellus).

    Science.gov (United States)

    Kleven, Gale A; Joshi, Prianca

    2016-03-01

    The Hairless strain of guinea pigs (Cavia porcellus) is the result of a spontaneous recessive mutation first identified at the Institute Armand Frappier (IAF) in 1978. Despite the longstanding availability of this strain, little is known about its thermoregulatory behavior. The aim of this study was to determine temperature preference in Hartley and Hairless guinea pigs by observing each strain in a ring-shaped apparatus containing a nonlinear temperature gradient. Temperatures were maintained by separately controlled heating mats lining the apparatus. Set point temperatures ranged from 24 to 38 °C. Guinea pigs (Hartley female, Hairless female, and Hairless male guinea pigs; n = 8 each group) were placed either singly or in pairs at 1 of the 8 randomized starting points within the apparatus. Subjects were observed for 30 min and coded for location within the temperature gradient by both frequency and duration. When placed singly in the apparatus, all 3 groups spent more time in the 30 °C zones. However, when placed as pairs with a cagemate, Hartley female guinea pigs spent more time in the cooler range of temperatures from 24 to 30 °C, whereas Hairless guinea pigs preferred a range of 30 to 38 °C. These results confirm a temperature preference of 30 ± 2 °C for both Hartley and Hairless guinea pigs when singly housed. However, data from the paired housing condition suggest that context plays an important role in thermoregulatory behavior.

  4. Clinical signs, therapy and zoonotic risk of pet guinea pigs with dermatophytosis.

    Science.gov (United States)

    Kraemer, A; Hein, J; Heusinger, A; Mueller, R S

    2013-03-01

    Systematic studies about pet guinea pigs with dermatophytosis are rare. The aim of this study was to evaluate clinical signs, therapy and zoonotic risk of pet guinea pigs with dermatophytosis. Questionnaires from both owners (n = 74) of pet guinea pigs with dermatophytosis and their veterinarians (n = 101) were analysed regarding clinical signs, therapy and data pertinent to zoonotic potential. Trichophyton (T.) mentagrophytes was found in 97% of cases. In the weeks preceding the onset of the clinical signs, a new guinea pig joined the household in 43% of cases. One third of the affected guinea pigs had lived in the household for less than 3 months. Predominant clinical signs were alopecia (83%), scaling (73%) and crusting (70%). The most commonly affected body site was the head (75%). In approximately one quarter of the cases humans showed clinical signs of dermatophytosis, in half the households, only children were affected. Skin lesions were seen most often on the face, the neck and the arms. Pet guinea pigs carrying dermatophytes must be considered a serious zoonotic risk for their owners, especially for children. A major risk factor for dermatophytosis seems to be a recent acquisition of a new guinea pig.

  5. Detection of antibodies against Theiler's murine encephalomyelitis virus GDVII strain in experimental guinea pigs.

    Science.gov (United States)

    Häger, C; Glage, S; Held, N; Bleich, E M; Burghard, A; Mähler, M; Bleich, André

    2016-10-01

    A disease affecting guinea pigs called 'guinea pig lameness' characterized by clinical signs of depression, lameness of limbs, flaccid paralysis, weight loss and death within a few weeks was first described by Römer in 1911. After a research group in our facility kept laboratory guinea pigs from two different origins together in one room, lameness was observed in two animals. Further investigations revealed a serological immune response against Theiler's murine encephalomyelitis virus (TMEV; GDVII strain) in these animals. Histopathology of the lumbar spinal cord of these animals showed mononuclear cell infiltration and necrotic neurons in the anterior horn. Therefore, all guinea pigs from this contaminated animal unit, from other units in our facility, as well as from different European institutions and breeding centres were screened for antibodies directed against GDVII. Our investigations showed that approximately 80% of all guinea pigs from the contaminated animal unit were seropositive for GDVII, whereas animals from other separate units were completely negative. In addition, 43% of tested sera from the different European institutions and breeding centres contained antibodies against GDVII. The present data confirm that an unknown viral infection causes an immune response in experimental guinea pigs leading to seroconversion against GDVII and that guinea pigs from a commercial breeder are the source of the infection.

  6. Pathogenesis of a Chinese strain of bovine adenovirus type 3 infection in albino guinea pigs.

    Science.gov (United States)

    Shi, Hong-Fei; Zhu, Yuan-Mao; Yan, Hao; Ma, Lei; Wang, Xue-Zhi; Xue, Fei

    2014-12-01

    Bovine adenovirus type 3 (BAV-3) is considered one of the most important respiratory tract agents of cattle and is widespread among cattle around the world. A BAV-3 strain was isolated from a bovine nasal swab for the first time in China in 2009 and named HLJ0955. Subsequently, BAV-3 has frequently been isolated from calves with respiratory diseases in China. To date, only limited study on the pathogenesis of BAV-3 infection in cotton rats has been conducted, and the pathogenesis of BAV-3 infection in guinea pigs has not been reported. Therefore, sixteen albino guinea pigs were inoculated intranasally with HLJ0955. All of the infected guinea pigs had apparently elevated rectal temperatures (39.2 °C-39.9 °C) at 2-7 days post-inoculation (PI). Consolidation and petechial hemorrhage were also observed in guinea pigs experimentally infected with HLJ0955. Viral replication was detectable by virus isolation and titration and by immunohistochemistry in the lungs of guinea pigs as early as 24 h PI. Viral DNA was detectable in the lungs of infected guinea pigs during 11 days of observation by real-time PCR. Virus-neutralizing antibodies against BAV-3 were detectable from 11 days PI and reached a peak titer at 15 days PI. Histopathological changes mainly occurred in the lungs of infected guinea pigs and were characterized by thickening of alveolar septa, mononuclear cell infiltration, hemorrhage and alveolar epithelial necrosis. These results indicate that HLJ0955 can replicate in the lungs of guinea pigs and cause fever and gross and histological lesions. The guinea pig infection model of BAV-3 would serve as a useful system for monitoring the infection process and pathogenesis of the Chinese BAV-3 strain HLJ0955, as well as immune responses to BAV-3 vaccines.

  7. Hematological Assessment in Pet Guinea Pigs (Cavia porcellus): Blood Sample Collection and Blood Cell Identification.

    Science.gov (United States)

    Zimmerman, Kurt; Moore, David M; Smith, Stephen A

    2015-09-01

    Pet guinea pigs are presented to veterinary clinics for routine care and treatment of clinical diseases. In addition to obtaining clinical history and exam findings, diagnostic testing may be required, including hematological assessments. This article describes common blood collection methods, including venipuncture sites, the volume of blood that can be safely collected, and handling of the blood. Hematological parameters for normal guinea pigs are provided for comparison with in-house or commercial test results. A description of the morphology of guinea pig leukocytes is provided to assist in performing a differential count.

  8. Citicoline retards myopia progression following form deprivation in guinea pigs.

    Science.gov (United States)

    Mao, Junfeng; Liu, Shuangzhen; Fu, Chunyan

    2016-06-01

    The retinal dopaminergic system is involved in the myopic shift following form deprivation. Citicoline has been demonstrated to stimulate the dopaminergic system in the brain and retina. Furthermore, citicoline has been used in many neurogenic diseases, such as senile cognitive impairment, stroke and Parkinson's disease as well as in amblyopia and glaucoma. Our aim was to investigate the effect of citicoline on the refractive state and retinal dopamine level in form deprivation myopia of guinea pigs. Guinea pigs, at an age of four weeks, were randomly divided into normal control, deprivation, deprived + citicoline and deprived + vehicle groups. Form deprivation myopia was induced by a translucent eye shield covering the right eye. Citicoline was injected intraperitoneally twice a day (500 mg/kg, 9 am and 9 pm) for 10 days. In vitro, retinal explants were cultured with citicoline for 24 h, with a final citicoline concentration of 100 µmol/L. The ocular refractive parameters and retinal dopamine content were measured. After occlusion for 10 days, the form-deprived eyes became myopic with an increase in axial length and a decrease in retinal dopamine content. The intraperitoneal injection of citicoline reduced the myopic degree (from -3.25 ± 0.77D to -0.62 ± 0.47D, P < 0.001) and partially raised retinal dopamine levels (from 0.55 ± 0.21 ng to 0.81 ± 0.24 ng, P < 0.01) in the form-deprived eyes. After 24 h of culturing retinal explants with citicoline, retinal dopamine content increased significantly (from 0.42 ± 0.14 ng to 0.62 ± 0.21 ng, P < 0.05). These results demonstrated that an intraperitoneal injection of citicoline could retard the myopic shift induced by form deprivation in guinea pigs, which was mediated by an increase in the retinal dopamine levels. © 2016 by the Society for Experimental Biology and Medicine.

  9. Ontogeny of fetal movements in the guinea pig.

    Science.gov (United States)

    van Kan, C M; de Vries, J I P; Lüchinger, A B; Mulder, E J H; Taverne, M A M

    2009-09-07

    Assessment of fetal motility is an approach to evaluate the development and function of the nervous system before birth. Reference values for the time of first occurrence and the incidence of normal fetal movements are indispensable for studies in which prenatal motor activity is applied as a model to study the central and peripheral nervous systems. Studies on fetal motility have been performed in a few species, particularly in the human. The aim of the present study is to describe the ontogeny of fetal motility in the guinea pig, a precocious polytocous species. After a pilot study to establish procedures for repeated ultasonographic scanning of guinea pigs, 10 domesticated animals were scanned (5.0 or 7.5 MHz convex transducer) at 2-4 day intervals between day 24 and 63 of gestation (term age 68 days). Per animal two selected fetuses were each scanned for 15 min. Images were stored on videotape and analyzed off-line for the first onset, presence and quality of fetal movement patterns, and quantity of sideway bendings, general movements, breathing movements and periods of fetal rest. Twenty-five different movement patterns could be characterized, 6 emerging at the onset of motor activity were performed only temporarily. The very first fetal movement was observed on day 24 gestational age, and subsequently most other movements developed during a period of only 5 days. Interfetal difference in onset of the frequently occurring sideway bendings, general movements, and front and hind limb movements was only 2 days. Sideway bendings and general movements co-existed during days 29 to 43. There were developmental trends in the course of pregnancy. Sideway bendings increased rapidly between 24 and 30 days and declined hereafter. General movements and fetal breathing increased during midpregnancy and declined towards parturition. Conversely, fetal rest was observed for approximately 60% of time at midgestation and a marked increase was found towards parturition. There

  10. Antispasmodic effect of hydroalcoholic extract of Thymus vulgaris on the guinea-pig ileum.

    Science.gov (United States)

    Babaei, Mehdi; Abarghoei, Mitra Emmami; Ansari, Reza; Vafaei, Abbas Ali; Taherian, Abbas Ali; Akhavan, Maziar Mohammad; Toussy, Gafar; Mousavi, Shahrokh

    2008-01-01

    The effects of Thymus vulgaris hydroalcoholic extract on the contractile responses of the isolated guinea-pig ileum were investigated. Contraction changes in the terminal ileum of guinea pigs were monitored using a force displacement transducer amplifier connected to a physiograph. Thymus vulgaris extract inhibited the contractile responses in a dose-dependent manner and also decreased the amplitude of peristaltic waves. It is concluded that T. vulgaris has an antispasmodic action on guinea pig ileum by decreasing the amplitudes of the muscle contractions during peristalsis. The EC50 was calculated as 1.7 mg mL(-1). In guinea-pig ileum the extract led to an antispasmodic effect, possibly by affecting the anticholinergic and serotoninergic pathways.

  11. Effect of Montelukast on bradykinin-induced contraction of isolated tracheal smooth muscle of guinea pig

    Directory of Open Access Journals (Sweden)

    A Noor

    2011-01-01

    Conclusion: It is concluded that montelukast significantly inhibits, in a dose-dependent manner, the bradykinin-induced contraction of the guinea pig tracheal smooth muscle, and alludes to an interaction between the bradykinin and leukotriene mediators.

  12. COMPARATIVE GENOTOXIC RESPONSES TO ARSENITE IN GUINEA PIG, MOUSE, RAT AND HUMAN LYMPHOCYTES

    Science.gov (United States)

    Comparative genotoxic responses to arsenite in guinea pig, mouse, rat and human lymphocytes.Inorganic arsenic is a known human carcinogen causing skin, lung, and bladder cancer following chronic exposures. Yet, long-term laboratory animal carcinogenicity studies have ...

  13. The effect of restraining on the heart rate in guinea pigs

    Science.gov (United States)

    Mikiskova, H.

    1980-01-01

    The emotional effect of different applications of electrodes and the fixation for cariographic examination was investigated using guinea pigs. The effect of the stress is discussed in terms of heart rhythm and behavior.

  14. In vivo effects of the IKr agonist NS3623 on cardiac electrophysiology of the guinea pig

    DEFF Research Database (Denmark)

    Hansen, Rie Schultz; Olesen, Søren-Peter; Rønn, Lars Christian B

    2008-01-01

    to examining the in vivo effects of NS3623. Injection of 30 mg/kg NS3623 shortened the corrected QT interval by 25 +/- 4% in anaesthetized guinea pigs. Accordingly, 50 mg/kg of NS3623 shortened the QT interval by 30 +/- 6% in conscious guinea pigs. Finally, pharmacologically induced QT prolongation by a h......ERG channel antagonist (0.15 mg/kg E-4031) could be reverted by injection of NS3623 (50 mg/kg) in conscious guinea pigs. In conclusion, the present in vivo study demonstrates that injection of the hERG channel agonist NS3623 results in shortening of the QTc interval as well as reversal of a pharmacologically...... induced QT prolongation in both anaesthetized and conscious guinea pigs....

  15. Induction of follicular luteinization by equine chorionic gonadotropin in cyclic guinea pigs.

    Science.gov (United States)

    Li, Jun-rong; Wang, Wei; Shi, Fang-xiong

    2015-12-01

    The effects of equine chorionic gonadotropin (eCG) on follicular development and ovulation in cyclic guinea pigs were investigated by histological and immunohistochemical analyses. Three groups of guinea pigs (n=12) were administrated subcutaneously with saline, 20 or 50 IU of eCG, respectively, on cyclic Day 12 (Day 1=vaginal openings). Ovaries were collected at 4 and 8 d after administration (6 animals per group each time). The eCG administration induced significant and distinct morphological changes in the ovaries, as it promoted the luteinization of granulosa cells, but not follicular development. In addition, proliferating cell nuclear antigen (PCNA) and steroidogenic acute regulatory protein (StAR) were immunolocalized specifically in luteinized follicles. Our experiments together indicate that eCG administration can induce follicular luteinization but not superovulation in guinea pigs. The eCG in cyclic guinea pigs functions similar to that of luteinizing hormone (LH), but not follicle-stimulating hormone (FSH).

  16. Papular dermatitis induced in guinea pigs by the biting midge Culicoides sonorensis (Diptera: Ceratopogonidae)

    Science.gov (United States)

    Histological, ultrastructural, and virological examinations were performed on abdominal skin from guinea pigs after a blood meal by colony-bred biting midges, Culicoides sonorensis. Small, superficial, cutaneous, crateriform ulcers with necrosis of superficial dermis developed at feeding sites and ...

  17. Family Outbreaks of Nontyphoidal Salmonellosis following a Meal of Guinea Pigs

    Directory of Open Access Journals (Sweden)

    John B. Fournier

    2015-01-01

    Full Text Available Salmonella outbreaks have been linked to a wide variety of foods, including recent nationwide outbreaks. Guinea pig (Cavia porcellus, also known as cuy or cobayo, has long been a popular delicacy and ceremonial food in the Andean region in South America. This case report describes three family outbreaks of nontyphoidal salmonellosis, each occurring after a meal of guinea pigs. We believe this case report is the first to describe a probable association between the consumption of guinea pig meat and human salmonellosis. Physicians should be aware of the association of Salmonella and the consumption of guinea pigs, given the increasing immigration of people from the Andean region of South America and the increasing travel to this region.

  18. Development of cholinephosphotransferase in guinea pig lung mitochondria and microsomes.

    Science.gov (United States)

    Stith, I E; Das, S K

    1982-02-02

    Development of mitochondrial and microsomal choline phosphotransferase in the fetal guinea pig lung was investigated. The activity in fetal mitochondria was more than twice of that in fetal microsomes. However, in adult lung, the enzyme was distributed mostly in microsomes. In fetal lung, both the mitochondrial and microsomal enzyme activity was greatest at approx. 81% of the total gestation period (55 days). The specific activity in the microsomal fraction than declined until term, but increased again in the 24-h newborn from 1.0 to 2.3 nmol/min per mg protein. The activity in the mitochondrial fraction declined after 61 days (2.8 nmol/min per mg) to a minimal level at term (0.6 nmol/min per mg). Although the enzyme activity decreased from day 55 (1.2 nmol/min per mg), the amount of phosphatidylcholine gradually increased between day 55 and term.

  19. linear accelerator simulation framework with placet and guinea-pig

    CERN Document Server

    Snuverink, Jochem; CERN. Geneva. ATS Department

    2016-01-01

    Many good tracking tools are available for simulations for linear accelerators. However, several simple tasks need to be performed repeatedly, like lattice definitions, beam setup, output storage, etc. In addition, complex simulations can become unmanageable quite easily. A high level layer would therefore be beneficial. We propose LinSim, a linear accelerator framework with the codes PLACET and GUINEA-PIG. It provides a documented well-debugged high level layer of functionality. Users only need to provide the input settings and essential code and / or use some of the many implemented imperfections and algorithms. It can be especially useful for first-time users. Currently the following accelerators are implemented: ATF2, ILC, CLIC and FACET. This note is the comprehensive manual, discusses the framework design and shows its strength in some condensed examples.

  20. Spontaneous behavior in noise and silence: a possible new measure to assess tinnitus in guinea pigs

    Directory of Open Access Journals (Sweden)

    Amarins Nieske Heeringa

    2014-10-01

    Full Text Available This study describes two experiments that were conducted in search for a behavioral paradigm to test for tinnitus in guinea pigs. Conditioning paradigms are available to determine the presence of tinnitus in animals and are based on the assumption that tinnitus impairs their ability to detect silent intervals in continuous noise. Guinea pigs have not been subjected to these paradigms yet, therefore we investigated whether guinea pigs could be conditioned in the two-way shuttle box paradigm to respond to silent intervals in noise. Even though guinea pigs could be trained relatively easy to respond to the presence of a noise interval, training guinea pigs to silent intervals in noise was unsuccessful. Instead, it appeared that they became immobile when the continuous stimulus was suddenly stopped. This was confirmed by the next experiment, in which we subjected guinea pigs to alternating intervals of noise and silence with a random duration between 30 – 120 s. Indeed, guinea pigs were significantly longer immobile during silence compared to during noise. By interpreting immobility as a signature of perceiving silence, we hypothesized that the presence of tinnitus would reduce immobility in silence. Therefore, we unilaterally exposed one group of guinea pigs to an 11-kHz tone of 124 dB SPL for 1 hour. A subset of the exposed animals was significantly more active in silence, but also more active in noise, as compared to the control group. The increased mobility during silent intervals might represent tinnitus. However, the increased mobility in noise of this group implies that the observed behavior could have derived from e.g. an overall increase in activity. Therefore, conducting validation experiments is very important before implementing this method as a new screening tool for tinnitus. Follow-up experiments are discussed to further elucidate the origin of the increased mobility in both silence and noise.

  1. Red cell amino acid transport. Evidence for the presence of system Gly in guinea pig reticulocytes.

    Science.gov (United States)

    Fincham, D A; Willis, J S; Young, J D

    1984-10-17

    Guinea pig reticulocytes are shown to possess an Na+-dependent glycine transporter which also requires Cl- for activity. Glycine transport by this route is saturable (apparent Km 98 microM; Vmax 24 mumol/g Hb per h) and inhibited by sarcosine. The properties of this carrier closely resemble those of System Gly previously demonstrated in pigeon and human erythrocytes. In contrast, no System Gly activity was detected in mature guinea pig erythrocytes.

  2. Allogeneic guinea pig mesenchymal stem cells ameliorate neurological changes in experimental colitis

    OpenAIRE

    Stavely, Rhian; Robinson, Ainsley M.; Miller, Sarah; Boyd, Richard; Sakkal, Samy; Nurgali, Kulmira

    2015-01-01

    Background The use of mesenchymal stem cells (MSCs) to treat inflammatory bowel disease (IBD) is of great interest because of their immunomodulatory properties. Damage to the enteric nervous system (ENS) is implicated in IBD pathophysiology and disease progression. The most commonly used model to study inflammation-induced changes to the ENS is 2,4,6-trinitrobenzene-sulfonate acid (TNBS)-induced colitis in guinea pigs; however, no studies using guinea pig MSCs in colitis have been performed. ...

  3. Spontaneous behavior in noise and silence: a possible new measure to assess tinnitus in Guinea pigs.

    Science.gov (United States)

    Heeringa, Amarins N; Agterberg, Martijn J H; van Dijk, Pim

    2014-01-01

    This study describes two experiments that were conducted in search for a behavioral paradigm to test for tinnitus in guinea pigs. Conditioning paradigms are available to determine the presence of tinnitus in animals and are based on the assumption that tinnitus impairs their ability to detect silent intervals in continuous noise. Guinea pigs have not been subjected to these paradigms yet; therefore, we investigated whether guinea pigs could be conditioned in the two-way shuttle-box paradigm to respond to silent intervals in noise. Even though guinea pigs could be trained relatively easy to respond to the presence of a noise interval, training guinea pigs to silent intervals in noise was unsuccessful. Instead, it appeared that they became immobile when the continuous stimulus was suddenly stopped. This was confirmed by the next experiment, in which we subjected guinea pigs to alternating intervals of noise and silence with a random duration between 30 and 120 s. Indeed, guinea pigs were significantly longer immobile during silence compared to during noise. By interpreting immobility as a signature of perceiving silence, we hypothesized that the presence of tinnitus would reduce immobility in silence. Therefore, we unilaterally exposed one group of guinea pigs to an 11-kHz tone of 124 dB sound pressure level for 1 h. A subset of the exposed animals was significantly more active in silence, but also more active in noise, as compared to the control group. The increased mobility during silent intervals might represent tinnitus. However, the increased mobility in noise of this group implies that the observed behavior could have derived from, e.g., an overall increase in activity. Therefore, conducting validation experiments is very important before implementing this method as a new screening tool for tinnitus. Follow-up experiments are discussed to further elucidate the origin of the increased mobility in both silence and noise.

  4. Relaxant effect of the H2-receptor antagonist oxmetidine on guinea-pig and human airways.

    OpenAIRE

    Advenier, C; Gnassounou, J. P.; Scarpignato, C.

    1987-01-01

    The effects of three different H2-receptor antagonists (cimetidine, ranitidine and oxmetidine) were tested on isolated preparations of guinea-pig trachea and human bronchus against contractions induced by acetylcholine, histamine and potassium chloride (KCl). In addition, their influence on calcium concentration-response curves in guinea-pig tracheal spirals was examined in a potassium-rich solution (30 mM). Finally, their effects were studied in vivo against acetylcholine and histamine-induc...

  5. Herpes simplex virus type 1 ribonucleotide reductase null mutants induce lesions in guinea pigs.

    Science.gov (United States)

    Turk, S R; Kik, N A; Birch, G M; Chiego, D J; Shipman, C

    1989-12-01

    Two herpes simplex virus type 1 ribonucleotide reductase null mutants, hrR3 and ICP6 delta, produced cutaneous lesions in guinea pigs as severe as those of wild-type strains. The lesions induced by hrR3 resulted from in vivo replication of the mutant virus, suggesting that this virus-encoded enzyme is nonessential for virus replication in guinea pigs.

  6. GABA-mediated inhibition of the anaphylactic response in the guinea-pig trachea.

    OpenAIRE

    Gentilini, G.; FRANCHI-MICHELI, S.; Mugnai, S.; Bindi, D.; Zilletti, L.

    1995-01-01

    1. In sensitized guinea-pigs, the effects of gamma-aminobutyric acid (GABA) and GABAmimetic drugs have been investigated on tracheal segments contracted by cumulative application of an allergen (ovoalbumin, OA) and on serosal mast cells. The same drugs have also been tested on activation of alveolar macrophages isolated from unsensitized guinea-pigs. 2. Superfusion with GABA (1-1000 microM) reduced the contraction intensity of tracheal strips. The effect of GABA (100 microM) was not affected ...

  7. Behavioral responses of deafened guinea pigs to intracochlear electrical stimulation: a new rapid psychophysical procedure.

    Science.gov (United States)

    Agterberg, Martijn J H; Versnel, Huib

    2014-07-01

    In auditory research the guinea pig is often preferred above rats and mice because of the easily accessible cochlea and because the frequency range of its hearing is more comparable to that of humans. Studies of the guinea-pig auditory system primarily apply histological and electrophysiological measures. Behavioral animal paradigms, in particular in combination with these histological and electrophysiological methods, are necessary in the development of new therapeutic interventions. However, the guinea pig is not considered an attractive animal for behavioral experiments. Therefore, the purpose of this study was to develop a behavioral task suitable for guinea pigs, that can be utilized in cochlear-implant related research. Guinea pigs were trained in a modified shuttle-box in which a stream of air was used as unconditioned stimulus (UCS). A stream of air was preferred over conventionally used methods as electric foot-shocks since it produces less stress, which is a confounding factor in behavioral experiments. Hearing guinea pigs were trained to respond to acoustic stimuli. They responded correctly within only five sessions of ten minutes. The animals maintained their performance four weeks after the right cochlea was implanted with an electrode array. After systemic deafening, the animals responded in the first session immediately to intracochlear electrical stimulation. These responses were not affected by daily chronic electrical stimulation (CES). In conclusion, the present study demonstrates that guinea pigs can be trained relatively fast to respond to acoustic stimuli, and that the training has a lasting effect, which generalizes to intracochlear electrical stimulation after deafening. Furthermore, it demonstrates that bilaterally deafened guinea pigs with substantial (∼50%) loss of spiral ganglion cells (SGCs), detect intracochlear electrical stimulation.

  8. Processing of communication calls in Guinea pig auditory cortex.

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    Jasmine M S Grimsley

    Full Text Available Vocal communication is an important aspect of guinea pig behaviour and a large contributor to their acoustic environment. We postulated that some cortical areas have distinctive roles in processing conspecific calls. In order to test this hypothesis we presented exemplars from all ten of their main adult vocalizations to urethane anesthetised animals while recording from each of the eight areas of the auditory cortex. We demonstrate that the primary area (AI and three adjacent auditory belt areas contain many units that give isomorphic responses to vocalizations. These are the ventrorostral belt (VRB, the transitional belt area (T that is ventral to AI and the small area (area S that is rostral to AI. Area VRB has a denser representation of cells that are better at discriminating among calls by using either a rate code or a temporal code than any other area. Furthermore, 10% of VRB cells responded to communication calls but did not respond to stimuli such as clicks, broadband noise or pure tones. Area S has a sparse distribution of call responsive cells that showed excellent temporal locking, 31% of which selectively responded to a single call. AI responded well to all vocalizations and was much more responsive to vocalizations than the adjacent dorsocaudal core area. Areas VRB, AI and S contained units with the highest levels of mutual information about call stimuli. Area T also responded well to some calls but seems to be specialized for low sound levels. The two dorsal belt areas are comparatively unresponsive to vocalizations and contain little information about the calls. AI projects to areas S, VRB and T, so there may be both rostral and ventral pathways for processing vocalizations in the guinea pig.

  9. Cortical representation of species-specific vocalizations in Guinea pig.

    Directory of Open Access Journals (Sweden)

    Daniel Suta

    Full Text Available We investigated the representation of four typical guinea pig vocalizations in the auditory cortex (AI in anesthetized guinea pigs with the aim to compare cortical data to the data already published for identical calls in subcortical structures - the inferior colliculus (IC and medial geniculate body (MGB. Like the subcortical neurons also cortical neurons typically responded to many calls with a time-locked response to one or more temporal elements of the calls. The neuronal response patterns in the AI correlated well with the sound temporal envelope of chirp (an isolated short phrase, but correlated less well in the case of chutter and whistle (longer calls or purr (a call with a fast repetition rate of phrases. Neuronal rate vs. characteristic frequency profiles provided only a coarse representation of the calls' frequency spectra. A comparison between the activity in the AI and those of subcortical structures showed a different transformation of the neuronal response patterns from the IC to the AI for individual calls: i while the temporal representation of chirp remained unchanged, the representations of whistle and chutter were transformed at the thalamic level and the response to purr at the cortical level; ii for the wideband calls (whistle, chirp the rate representation of the call spectra was preserved in the AI and MGB at the level present in the IC, while in the case of low-frequency calls (chutter, purr, the representation was less precise in the AI and MGB than in the IC; iii the difference in the response strength to natural and time-reversed whistle was found to be smaller in the AI than in the IC or MGB.

  10. Pharmacokinetics of activated protein C in guinea pigs

    Energy Technology Data Exchange (ETDEWEB)

    Berger, H. Jr.; Kirstein, C.G.; Orthner, C.L. (Wellcome Research Laboratories, Research Triangle Park, NC (USA))

    1991-05-15

    Protein C is a vitamin K-dependent zymogen of the serine protease, activated protein C (APC), an important regulatory enzyme in hemostasis. In view of the potential of human APC as an anticoagulant and profibrinolytic agent, the pharmacokinetics and tissue distribution of APC were studied in guinea pigs. The plasma elimination of a trace dose of {sup 125}I-APC was biphasic following an initial rapid elimination of approximately 15% of the injected dose within 1 to 2 minutes. This rapid removal of {sup 125}I-APC from the circulation was found to be a result of an association with the liver regardless of the route of injection. Essentially identical results were obtained with active site-blocked forms of APC generated with either diisopropylfluorophosphate or D-phenylalanyl-L-prolyl-L-arginine chloromethyl ketone, which indicates that the active site was not essential for the liver association. Accumulation of all three forms of APC in the liver peaked at 30 minutes and then declined as increasing amounts of degraded radiolabeled material appeared in the gastrointestinal tract and urine. Removal of the gamma-carboxyglutamic acid (gla) domain of diisopropylphosphoryl-APC resulted in a 50% reduction in the association with liver and an accumulation in the kidneys. Protein C and protein S were cleared from the circulation at rates approximately one-half and one-fourth, respectively, that of APC. Both in vitro and in vivo, APC was found to form complexes with protease inhibitors present in guinea pig plasma. Complex formation resulted in a more rapid disappearance of the enzymatic activity of APC than elimination of the protein moiety. These findings indicate two distinct mechanisms for the elimination of APC. One mechanism involves reaction with plasma protease inhibitors and subsequent elimination by specific hepatic receptors. (Abstract Truncated)

  11. Chlamydia caviae infection alters abundance but not composition of the guinea pig vaginal microbiota.

    Science.gov (United States)

    Neuendorf, Elizabeth; Gajer, Pawel; Bowlin, Anne K; Marques, Patricia X; Ma, Bing; Yang, Hongqiu; Fu, Li; Humphrys, Michael S; Forney, Larry J; Myers, Garry S A; Bavoil, Patrik M; Rank, Roger G; Ravel, Jacques

    2015-06-01

    In humans, the vaginal microbiota is thought to be the first line of defense again pathogens including Chlamydia trachomatis. The guinea pig has been extensively used as a model to study chlamydial infection because it shares anatomical and physiological similarities with humans, such as a squamous vaginal epithelium as well as some of the long-term outcomes caused by chlamydial infection. In this study, we aimed to evaluate the guinea pig-C. caviae model of genital infection as a surrogate for studying the role of the vaginal microbiota in the early steps of C. trachomatis infection in humans. We used culture-independent molecular methods to characterize the relative and absolute abundance of bacterial phylotypes in the guinea pig vaginal microbiota in animals non-infected, mock-infected or infected by C. caviae. We showed that the guinea pig and human vaginal microbiotas are of different bacterial composition and abundance. Chlamydia caviae infection had a profound effect on the absolute abundance of bacterial phylotypes but not on the composition of the guinea pig vaginal microbiota. Our findings compromise the validity of the guinea pig-C. caviae model to study the role of the vaginal microbiota during the early steps of sexually transmitted infection.

  12. Protective effects of isorhynchophylline on cardiac arrhythmias in rats and guinea pigs.

    Science.gov (United States)

    Gan, Runtao; Dong, Guo; Yu, Jiangbo; Wang, Xu; Fu, Songbin; Yang, Shusen

    2011-09-01

    As one important constituent extracted from a traditional Chinese medicine, Uncaria Rhynchophylla Miq Jacks, isorhynchophylline has been used to treat hypertension, epilepsy, headache, and other illnesses. Whether isorhynchophylline protects hearts against cardiac arrhythmias is still incompletely investigated. This study was therefore aimed to examine the preventive effects of isorhynchophylline on heart arrhythmias in guinea pigs and rats and then explore their electrophysiological mechanisms. In vivo, ouabain and calcium chloride were used to establish experimental arrhythmic models in guinea pigs and rats. In vitro, the whole-cell patch-lamp technique was used to study the effect of isorhynchophylline on action potential duration and calcium channels in acutely isolated guinea pig and rat cardiomyocytes. The dose of ouabain required to induce cardiac arrhythmias was much larger in guinea pigs administered with isorhynchophylline. Additionally, the onset time of cardiac arrhythmias induced by calcium chloride was prolonged, and the duration was shortened in rats pretreated with isorhynchophylline. The further study showed that isorhynchophylline could significantly decrease action potential duration and inhibit calcium currents in isolated guinea pig and rat cardiomyocytes in a dose-dependent manner. In summary, isorhynchophylline played a remarkably preventive role in cardiac arrhythmias through the inhibition of calcium currents in rats and guinea pigs.

  13. Efficacy of doramectin in Trixacarus caviae infestation in guinea pigs (Cavia porcellus).

    Science.gov (United States)

    Singh, Shanker K; Dimri, Umesh; Ahmed, Quazi Shahir; Sayedda, Kauser; Singh, Krishna Veer

    2013-04-01

    The present study was intended to evaluate the efficacy of doramectin against seven naturally Trixacarus caviae infested male guinea pigs. Multiple skin scrapings of all the seven guinea pigs were found microscopically positive for T. caviae mites. Clinically these animals revealed, more or less denuded, very red often thickened, and crustated cutaneous lesions restricted at the sacral region and back. Doramectin 1 % (w/v) was administered intramuscularly at a dose rate of 400 μg/kg once weekly, which resulted in profound improvements in clinical conditions within 14 days after the first doramectin application. It took almost 28 days for the cutaneous lesions to disappear and to witness partial hair coat regrowth. Two moderately infested guinea pigs required only single injection of doramectin to achieve complete parasitological cure, while remaining five (one moderately infested and four severely infested) guinea pigs required two injections of doramectin to achieve complete parasitological cure. No adverse effects were revealed by any of the doramectin treated guinea pigs during the study period. Thus, it can be concluded from the present study that guinea pigs naturally infested by T. caviae mites can be cured safely using two doses of doramectin once in a week.

  14. Anti-anaphylactic action of nordihydroguaiaretic acid in antigen sensitized guinea pigs.

    Science.gov (United States)

    Bergren, Dale R; Valentine, Jimmie L

    2016-12-01

    Therapeutic natural products and medicinal herbs has gained popularity. The anti-antigenic action of the plant alkaloid nordihydroguaiaretic acid (NDGA) was studied in ovalbumin (OA)-sensitized guinea pigs. In one series of experiments conscious, non-sedated guinea pigs were challenged with OA aerosol. Specific airway resistance (SRAW) was monitored using a two-chambered whole-body plethysmograph. OA aerosol increased SRAW above that produced by vehicle administration. Prior NDGA administration by a 1min 0.9% aerosol (w/vol) attenuated the increase in SRAW resulting from OA challenge. In the anesthetized guinea pig pretreated with indomethacin, pyrilamine and propranolol, intravenous OA injection increased intra-tracheal pressure above vehicle injection. Intravenous NDGA administration (5mg/kg) reduced the intra-tracheal pressure increases. In a third series of experiments plasma leukotriene C4 was measured by radio-immunoassay in 3 groups challenged with OA aerosol: vehicle-treated OA-sensitized, OA-sensitized receiving NDGA and vehicle treated guinea pigs. NDGA pretreatment reduced plasma LTC4 in response to OA challenge in OA sensitized guinea pigs. This study demonstrates that NDGA is an effective antigenic agent when given by aerosol or intravenous injection in either conscious or anesthetized guinea pigs, respectively. The mechanism of action of NDGA is presumed primarily be due to the blockage of 5-lipoxygenase and therefore the synthesis of leukotrienes.

  15. Inhalation and Percutaneous Toxicokinetics of Sulfur Mustard and Its Adducts in Hairless Guinea Pigs and Marmosets. Efficacy of Naval Scavengers

    Science.gov (United States)

    2005-08-01

    Marmosets . Efficacy of Nasal Scavengers PRINCIPAL INVESTIGATOR: Jan P. Langenberg, Ph.D., Pharm.D. Henk C. Trap CONTRACTING ORGANIZATION: TNO Prins...Inhalation and Percutaneous Toxicokinetics of Sulfur Mustard and Its Adducts in Hairless Guinea Pigs and Marmosets . Efficacy of Nasal Scavengers 5b. GRANT...inhalation toxicokinetics of sulfur mustard were studied in more detail in the hairless guinea pig as well as in the marmoset . Hairless guinea pigs were 5

  16. Pharmacological investigation into the effects of histamine and histamine analogues on guinea-pig and rat colon in vitro.

    OpenAIRE

    Aguilar, M. J.; MORALES-OLIVAS, F. J.; RUBIO, E.

    1986-01-01

    The effects of histamine and specific histamine agonists has been examined on isolated longitudinal colon strips of guinea-pig and rat. Histamine and 2-pyridyl-ethylamine but not 4 methylhistamine produced a concentration-related contractile response in the guinea-pig colon. The H1-antagonist clemizole antagonized competitively the effect of histamine but the H2-antagonist ranitidine did not modify the dose-response curve to histamine in the guinea-pig colon. Atropine, hexamethonium, prazosin...

  17. Molecular cloning, sequence identification and expression profile of domestic guinea pig (Cavia porcellus UGT1A1 gene

    Directory of Open Access Journals (Sweden)

    Yang Deming

    2016-01-01

    Full Text Available Domestic guinea pig is a model animal for human disease research. Uridine diphosphate glucuronosyltransferase 1 family, polypeptide A1 (UGT1A1 is an important human disease-related gene. In this study, the complete coding sequence of domestic guinea pig gene UGT1A1 was amplified by reverse transcription-polymerase chain reaction. The open reading frame of the domestic guinea pig UGT1A1 gene is 1602 bp in length and was found to encode a protein of 533 amino acids. Sequence analysis revealed that the UGT1A1 protein of domestic guinea pig shared high homology with the UGT1A1 proteins of degu (84%, damara mole-rat (84%, human (80%, northern white-cheeked gibbon (80%, Colobus angolensis palliatus (80% and golden snub-nosed monkey (79%. This gene contains five exons and four introns, as revealed by the computer-assisted analysis. The results also showed that the domestic guinea pig UGT1A1 gene had a close genetic relationship with the UGT1A1 gene of degu. The prediction of transmembrane helices showed that domestic guinea pig UGT1A1 might be a transmembrane protein. Expression profile analysis indicated that the domestic guinea pig UGT1A1 gene was differentially expressed in detected domestic guinea pig tissues. Our experiment laid a primary foundation for using the domestic guinea pig as a model animal to study the UGT1A1-related human diseases.

  18. Establishment of a leptospirosis model in guinea pigs using an epicutaneous inoculations route

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    Zhang Yan

    2012-01-01

    Full Text Available Abstract Background Leptospires are presumed to enter their host via small abrasions or breaches of the skin. The intraperitoneal route, although commonly used in guinea pig and hamster models of leptospirosis, does not reflect conditions encountered during natural infection. The aim of this study is to develop a novel leptospirosis guinea pig model through epicutaneous route and to elucidate the pathogenesis of leptospirosis in experimental guinea pigs by comparing the data from other studies using different infection routes. Methods The guinea pigs were inoculated with 5 × 108 Leptospira interrogans strain Lai onto either shaved-only or abraded skin. The guinea pigs were sacrificed at 2, 8, 24, 48, 72, 96 and 144 h post-infection (p.i. followed by harvest of the lungs, liver, kidneys, spleen, and the skin around the inoculated sites for further examinations. Hematoxylin and eosin (HE staining and electron microscopy were used to detect the pathologic changes. Real time PCR and immunohistochemistry staining were performed to detect dynamic distribution of leptospires in blood and tissues, respectively. Results In the guinea pigs with abraded skin inoculations, leptospires were detected in blood as early as 2 h post infection (p.i. and then disseminated to the liver, lungs and kidneys of almost all animals within 96 h p.i.. Leptospires were also detected engulfed in the swelling vascular endothelial cells and were frequently aggregated around the capillaries in the dermis and subcutaneous tissue under the inoculated site. For the guinea pigs with abraded skin inoculations, hemorrhage at the dermis around the inoculated site was found before the appearance of internal organs hemorrhage, severe lesions such as hemorrhages in the lungs, nephritis, jaundice, haematuria were also observed, and two of seven guinea pigs died at 144 h p.i. while no lesions and leptospires were detected in the shaved-only guinea pigs using the same dose of strain Lai

  19. Analysis of humoral immune responses to LM1 ganglioside in guinea pigs.

    Science.gov (United States)

    Gu, Yajuan; Chen, Zi-Wei; Siegel, Allan; Koshy, Ranie; Ramirez, Cristhian; Raabe, Timothy D; Devries, George H; Ilyas, Amjad A

    2012-05-15

    Guillain-Barré syndrome (GBS) is an autoimmune-mediated disease triggered by a preceding infection. A substantial body of evidence implicates antibodies to various gangliosides in subtypes of GBS. A significant proportion of patients with acute demyelinating subset of GBS have IgG antibodies against peripheral nervous system myelin specific neolactogangliosides such as LM1 and Hex-LM1. Although anti-neolactoganglioside antibodies in GBS were described more than two decades ago, their pathogenic role in neuropathy remains unknown due to the lack of suitable experimental models. In this study, we immunized ten guinea pigs with purified LM1 ganglioside mixed with keyhole limpet hemocyanin (KLH) and emulsified in complete Freund's adjuvant (CFA). Control guinea pigs were injected with KLH emulsified in CFA only. The animals were bled every four week intervals. The animals were boosted 3 times every four weeks. Experiments were terminated four months after initial immunization. Nine of 10 guinea pigs immunized with LM1 exhibited antibody responses to LM1. Anti-LM1 IgG titers in nine guinea pigs ranged from 1:400 to 1:12,800 at 16-weeks after initial immunization. Anti-LM1 antibodies were predominantly of IgG2 subclass. One guinea pig with the highest levels of IgG antibodies exhibited mild signs of neuropathy. There was no evidence of demyelination or inflammation in the sciatic nerves of LM1-immunized guinea pigs. Anti-LM1 antibodies bound to rat sciatic nerve myelin and to isolated rat Schwann cells. In summary, our findings suggest that relatively high levels of anti-LM1 IgG antibodies can be induced in guinea pigs and that LM1 is localized in peripheral nerve myelin and in Schwann cells. Further studies are needed to determine the pathogenic potential of anti-neolactoganglioside antibodies in neuropathy.

  20. The ototoxic effect of boric acid solutions applied into the middle ear of guinea pigs.

    Science.gov (United States)

    Oztürkcan, Sedat; Dündar, Riza; Katilmis, Hüseyin; Ilknur, Ali Ekber; Aktaş, Sinem; Haciömeroğlu, Senem

    2009-05-01

    This study analyzed the ototoxic effects of boric acid solutions. Boric acid solutions have been used as otologic preparations for many years. Boric acid is commonly found in solutions prepared with alcohol or distilled water but can also be found in a powder form. These preparations are used for both their antiseptic and acidic qualities in external and middle ear infections. We investigated the ototoxic effect of boric acid solutions on guinea pigs. We are unaware of any similar, previously published study of this subject in English. The study was conducted on 28 young albino guinea pigs. Prior to application of the boric acid solution under general anesthesia, an Auditory Brainstem Response (ABRs) test was applied to the right ear of the guinea pigs. Following the test, a perforation was created on the tympanic membrane of the right ear of each guinea pig and small gelfoam pieces were inserted into the perforated area. Test solutions were administered to the middle ear for 10 days by means of a transcanal route. Fifteen days after inserting the gelfoams in all of the guinea pigs, we anasthesized the guinea pigs and removed the gelfoams from the perforated region of the ear and then performed an ABRs on each guinea pig. The ABRs were within the normal range before the applications. After the application, no significant changes were detected in the ABRs thresholds in neither the saline group nor the group administered boric acid and distilled water solution; however, significant changes were detected in the ABRs thresholds of the Gentamicine and boric acid and alcohol solution groups. We believe that a 4% boric acid solution prepared with distilled water can be a more reliable preparation than a 4% boric acid solution prepared with alcohol.

  1. Airway hyperresponsiveness induced by repeated esophageal infusion of HCl in guinea pigs.

    Science.gov (United States)

    Cheng, Yan-Mei; Cao, Ai-Li; Zheng, Jian-Pu; Wang, Hong-Wei; Sun, Yong-Shun; Liu, Chun-Fang; Zhang, Bei-Bei; Wang, Yi; Zhu, Sheng-Liang; Wu, Da-Zheng

    2014-11-01

    Gastroesophageal reflux is a common disorder closely related to chronic airway diseases, such as chronic cough, asthma, chronic bronchitis, and chronic obstructive disease. Indeed, gastroesophageal acid reflux into the respiratory tract causes bronchoconstriction, but the underlying mechanisms have still not been clarified. This study aimed to elucidate functional changes of bronchial smooth muscles (BSMs) isolated from guinea pigs in an animal model of gastroesophageal reflux. The marked airway inflammation, hyperresponsiveness and remodeling were observed after guinea pigs were exposed to intraesophageal HCl infusion for 14 days. In addition, contractile responses to acetylcholine (ACh), KCl, electrical field stimulation, and extracellular Ca(2+) were greater in guinea pigs infused with HCl compared with control groups. The L-type voltage-dependent Ca(2+) channels (L-VDCC) blocker, nicardipine, significantly inhibited ACh- and Ca(2+)-enhanced BSM contractions in guinea pigs infused with HCl. The Rho-kinase inhibitor, Y27632, attenuated ACh-enhanced BSM contractions in guinea pigs infused with HCl. Moreover, mRNA and protein expressions for muscarinic M2 and M3 receptors, RhoA, and L-VDCC in BSM were detected by real-time PCR and Western blot. Expressions of mRNA and protein for muscarinic M3 receptors, RhoA, and L-VDCC were greater than in BSM of HCl-infused guinea pigs, whereas levels of muscarinic M2 receptors were unchanged. We demonstrate that acid infusion to the lower esophagus and, subsequently, microaspiration into the respiratory tract in guinea pigs leads to airway hyperresponsiveness and overactive BSM. Functional and molecular results indicate that overactive BSM is the reason for enhancement of extracellular Ca(2+) influx via L-VDCC and Ca(2+) sensitization through Rho-kinase signaling.

  2. Acute and subchronic dermal toxicity of nanosilver in guinea pig

    Directory of Open Access Journals (Sweden)

    Arbabi Bidgoli S

    2011-04-01

    Full Text Available M Korani1, SM Rezayat1,2,4, K Gilani3, S Arbabi Bidgoli4, S Adeli11Department of Pharmacology, Faculty of Medicine, Tehran University of Medical Sciences; 2Department of Nanotechnology, Faculty of Advanced Sciences and Technology in Medicine, Tehran University of Medical Sciences; 3Department of Pharmaceutics, Faculty of Pharmacy, Tehran University of Medical Sciences; 4Department of Toxicology & Pharmacology, Faculty of Pharmacy, Pharmaceutical Sciences Branch, Islamic Azad University (IAUPS, Tehran, IranAbstract: Silver has been used as an antimicrobial agent for a long time in different forms, but silver nanoparticles (nanosilver have recently been recognized as potent antimicrobial agents. Although nanosilver is finding diverse medical applications such as silver-based dressings and silver-coated medical devices, its dermal and systemic toxicity via dermal use has not yet been identified. In this study, we analyzed the potential toxicity of colloidal nanosilver in acute and subchronic guinea pigs. Before toxicity assessments, the size of colloidal nanosilver was recorded in sizes <100 nm by X-ray diffraction and transmission electron microscopy. For toxicological assessments, male guinea pigs weighing 350 to 400 g were exposed to two different concentrations of nanosilver (1000 and 10,000 µg/mL in an acute study and three concentrations of nanosilver (100, 1000, and 10,000 µg/mL in a subchronic study. Toxic responses were assessed by clinical and histopathologic parameters. In all experimental animals the sites of exposure were scored for any type of dermal toxicity and compared with negative control and positive control groups. In autopsy studies during the acute test, no significant changes in organ weight or major macroscopic changes were detected, but dose-dependent histopathologic abnormalities were seen in skin, liver, and spleen of all test groups. In addition, experimental animals subjected to subchronic tests showed greater

  3. Wild genius - domestic fool? Spatial learning abilities of wild and domestic guinea pigs

    Directory of Open Access Journals (Sweden)

    Sachser Norbert

    2010-03-01

    Full Text Available Abstract Background Domestic animals and their wild relatives differ in a wide variety of aspects. The process of domestication of the domestic guinea pig (Cavia aperea f. porcellus, starting at least 4500 years ago, led to changes in the anatomy, physiology, and behaviour compared with their wild relative, the wild cavy, Cavia aperea. Although domestic guinea pigs are widely used as a laboratory animal, learning and memory capabilities are often disregarded as being very scarce. Even less is known about learning and memory of wild cavies. In this regard, one striking domestic trait is a reduction in relative brain size, which in the domesticated form of the guinea pig amounts to 13%. However, the common belief, that such a reduction of brain size in the course of domestication of different species is accomplished by less learning capabilities is not at all very well established in the literature. Indeed, domestic animals might also even outperform their wild conspecifics taking advantage of their adaptation to a man-made environment. In our study we compared the spatial learning abilities of wild and domestic guinea pigs. We expected that the two forms are different regarding their learning performance possibly related to the process of domestication. Therefore wild cavies as well as domestic guinea pigs of both sexes, aged 35 to 45 days, were tested in the Morris water maze to investigate their ability of spatial learning. Results Both, wild cavies and domestic guinea pigs were able to learn the task, proving the water maze to be a suitable test also for wild cavies. Regarding the speed of learning, male as well as female domestic guinea pigs outperformed their wild conspecifics significantly. Interestingly, only domestic guinea pigs showed a significant spatial association of the platform position, while other effective search strategies were used by wild cavies. Conclusion The results demonstrate that domestic guinea pigs do not at all

  4. Possible mechanism(s) for relaxant effects of Foeniculum vulgare on guinea pig tracheal chains.

    Science.gov (United States)

    Boskabady, M H; Khatami, A; Nazari, A

    2004-07-01

    In a previous study the relaxant (bronchodilatory) effect of Foeniculum vulgare on isolated guinea pig tracheal chains was demonstrated. To study mechanisms responsible for this effect the present study evaluated the inhibitory effect of this plant on contracted tracheal chains of guinea pig. The relaxant effects of aqueous and ethanol extracts and an essential oil from Foeniculum vulgare were compared to negative controls (saline for aqueous extract and essential oil and ethanol for ethanol extract) and a positive control (diltiazem) using isolated tracheal chains of the guinea pig precontracted by 10 microM methacholine (group 1) and 60 mM KCl (group 2, n = 7 for each group). In the group 1, experiments diltiazem, ethanol extract, and essential oil from Foeniculum vulgare showed a significant relaxant effect on methacholine induced contraction of tracheal chains compared to those of negative controls (p Foeniculum vulgare. However with regard to the effect of KCl on calcium channels, the results indicated that the inhibitory effect of ethanol extracts and essential oil from Foeniculum vulgare on calcium channels is not contributing to their relaxant (bronchodilatory) effects on guinea pig tracheal chains. However the results suggest a potassium channel opening effect for this plant, which may contribute on its relaxant effect on guinea pig tracheal chains.

  5. Effects of Changing to Individually Ventilated Caging on Guinea Pigs (Cavia porcellus).

    Science.gov (United States)

    Giral, Marta; Armengol, Clara; Sánchez-Gómez, Sonia; Gavaldà, Amadeu

    2015-05-01

    The goal of this study was to evaluate the effect of changing to IVC housing on guinea pigs by recording several physiologic parameters in guinea pigs housed sequentially in open-top cages (OTC) and IVC. To register heart rate and locomotor activity, 10 male Dunkin-Hartley guinea pigs implanted with telemetric transmitters were moved from OTC to new, freshly prepared OTC or IVC and subsequently monitored by telemetry during the 4 d after the first cage change. Body weight and food consumption were measured twice during the study. Comparison of data from OTC- and IVC-housed guinea pigs showed no relevant differences in heart rate (mean ± 1 SD; 213 ± 10 bpm and 207 ± 9 bpm, respectively) at any time point. In contrast, locomotor activity varied: whereas activity during the first 4 h after the change of cage type was greater in IVC-housed animals, that during the following 24 h was greater in OTC but was similar between groups thereafter. Animals housed in OTC consumed more food than did those in IVC and, under both conditions, consumption was statistically related to body weight changes. Together, these results show that a change to IVC housing induced only transient increases in locomotor activity in guinea pigs without a marked increase in heart rate but with a decrease in food consumption. Because decreased food consumption was the only stress-associated sign during the 4-d observation, longer studies are needed to ascertain the importance of this finding.

  6. Congenital malformations caused by Stryphnodendron fissuratum (Leg. Mimosoideae) in guinea pigs (Cavia porcellus).

    Science.gov (United States)

    Macedo, Josenaldo S; Rocha, Brena P; Colodel, Edson M; Freitas, Sílvio H; Dória, Renata G S; Riet-Correa, Franklin; Evêncio-Neto, Joaquim; Mendonça, Fábio S

    2015-11-01

    The aim of this study was to evaluate the toxicity of Stryphnodendron fissuratum pods in guinea pigs (Cavia porcellus) and test the hypothesis that this plant has teratogenic effects. Thus, sixteen guinea pigs were randomly divided into four groups of four animals each. Groups 10, 20 and 40 consisted of guinea pigs that received commercial food that contained crushed pods of S. fissuratum at concentrations of 10, 20 and 40 g/kg, respectively, during the period of organogenesis. Control group consisted of guinea pigs under the same management conditions that did not receive crushed pods of S. fissuratum in their food. In all experimental groups, the main clinical signs of poisoning consisted of anorexia, prostration, absence of vocalizations, alopecia, diarrhea, and abortions within the adult guinea pigs. Those that did not abort gave birth to weak, malnourished pups, some of which had fetal malformations. The main teratogenic changes consisted of eventration, arthrogryposis, amelia of the forelimbs, anophthalmia, microphthalmia, anotia and agnathia. The reductions in the number of offspring and the malformations observed in the experimental groups suggest that S. fissuratum affects fetal development and is teratogenic.

  7. Phosphodiesterase 5 and effects of sildenafil on cerebral arteries of man and guinea pig

    DEFF Research Database (Denmark)

    Kruuse, Christina; Khurana, Tejvir S; Rybalkin, Sergei D

    2005-01-01

    and UK-114,542, and a PDE1 inhibitor UK-90,234 on cGMP hydrolysis were investigated in human and guinea pig cerebral arteries. The vasoactive responses of the compounds were evaluated in guinea pig basilar arteries in vitro, with concomitant measurements of cAMP and cGMP. PDE5 was found in human middle...... cerebral arteries. Sildenafil and UK-114,542 inhibited cGMP hydrolysis concentration-dependently in both species. In guinea pig arteries, sildenafil induced an endothelium-dependent vasodilatation only at concentrations above 10 nM, which was augmented by sodium nitroprusside and attenuated by reduction...... of cGMP, but was cGMP independent at high concentrations. UK-114,542 was more and UK-90,234 was less potent than sildenafil. In conclusion, PDE5 is present in human and guinea pig cerebral arteries, and is inhibited by sildenafil at micromolar levels. Sildenafil in vitro is a poor dilator of guinea pig...

  8. Expression of matrix metalloproteinases and ovarian morphological changes in androgenized cyclic female guinea pigs.

    Science.gov (United States)

    Li, Jun-rong; Shen, Ting; Wang, Yan-li; Wei, Quan-wei; Shi, Fang-xiong

    2016-02-01

    This study was conducted to investigate expression of matrix metalloproteinases (MMPs) and ovarian morphological changes in androgenized cyclic female guinea pigs. Adult cyclic female guinea pigs were injected daily for 28 days with medium doses of testosterone propionate (TP; 1 mg/100g), high doses of TP (2 mg/100g), or saline (control). Serum concentrations of testosterone, estradiol (E2), and progesterone (P4) were measured. Histologic sections of ovaries were stained with hematoxylin-eosin and by immunohistochemistry. Expressions of steroidogenic acute regulatory protein, proliferating cell nuclear antigen, and MMP-2 and MMP-9 in the ovary were characterized by immunohistochemistry. After 28 days of TP injection, serum testosterone concentrations were increased dose-dependently. An appropriate dosage of TP could induce permanent anovulation in guinea pigs, making them a potential model for human polycystic ovary syndrome. MMP-2 and MMP-9 are jointly involved in the growth and atresia of ovarian follicles in cyclic guinea pigs. Increased numbers of atretic antral follicles in the ovary might be associated with the observed high expression of MMP-2 in androgenized cyclic guinea pigs.

  9. Calibration and validation of a physiologically based model for soman intoxication in the rat, marmoset, guinea pig and pig.

    Science.gov (United States)

    Chen, Kaizhen; Seng, Kok-Yong

    2012-09-01

    A physiologically based pharmacokinetic and pharmacodynamic (PBPK/PD) model has been developed for low, medium and high levels of soman intoxication in the rat, marmoset, guinea pig and pig. The primary objective of this model was to describe the pharmacokinetics of soman after intravenous, intramuscular and subcutaneous administration in the rat, marmoset, guinea pig, and pig as well as its subsequent pharmacodynamic effects on blood acetylcholinesterase (AChE) levels, relating dosimetry to physiological response. The reactions modelled in each physiologically realistic compartment are: (1) partitioning of C(±)P(±) soman from the blood into the tissue; (2) inhibition of AChE and carboxylesterase (CaE) by soman; (3) elimination of soman by enzymatic hydrolysis; (4) de novo synthesis and degradation of AChE and CaE; and (5) aging of AChE-soman and CaE-soman complexes. The model was first calibrated for the rat, then extrapolated for validation in the marmoset, guinea pig and pig. Adequate fits to experimental data on the time course of soman pharmacokinetics and AChE inhibition were achieved in the mammalian models. In conclusion, the present model adequately predicts the dose-response relationship resulting from soman intoxication and can potentially be applied to predict soman pharmacokinetics and pharmacodynamics in other species, including human.

  10. CHOLINERGIC CONTRACTION OF THE GUINEA-PIG LUNG STRIP IS MEDIATED BY 9USCARINIC M(2)-LIKE RECEPTORS

    NARCIS (Netherlands)

    ROFFEL, AF; ELZINGA, CRS; ZAAGSMA, J

    1993-01-01

    The muscarinic receptor subtype mediating contraction of the guinea pig lung strip preparation was investigated and compared with that in guinea pig tracheal and human peripheral airway (small bronchi) smooth muscle preparations, using a number of subtype selective muscarinic receptor antagonists.

  11. Gender Differences in the Anatomy of the Perineal Glands in Guinea Pigs and the Effect of Castration

    DEFF Research Database (Denmark)

    Iburg, T. M.; Arnbjerg, J.; Ruelokke, M. L.

    2013-01-01

    Perineal glands in guinea pigs are part of the sebaceous glandular complex. Their secretions are used for scent marking. This is important for social status and can be seen in both sexes and castrated males. Discrepancy exits about the existence of these glands in female guinea pigs and knowledge...

  12. A comparative analysis of the intestinal metagenomes present in guinea pigs (Cavia porcellus) and humans (Homo sapiens)

    DEFF Research Database (Denmark)

    Hildebrand, Falk; Ebersbach, Tine; Nielsen, Henrik Bjørn

    2012-01-01

    Background: Guinea pig (Cavia porcellus) is an important model for human intestinal research. We have characterized the faecal microbiota of 60 guinea pigs using Illumina shotgun metagenomics, and used this data to compile a gene catalogue of its prevalent microbiota. Subsequently, we compared th...

  13. Spot-on Treatments of Diflubenzuron and Permethrin to Control a Guinea Pig Louse, Gliricola Porcelli (Phthiraptera: Gyropidae)

    Science.gov (United States)

    Guinea pigs (Cavia porcellus (L.)) (Rodentia: Caviidae) are pets and laboratory animals. They can be infested by a chewing louse, Gliricola porcelli (Schrank) (Phthiraptera: Gyropidae), which is fairly common in some animal rearing facilities, pet stores, and on wild guinea pigs. Infestation with G....

  14. Human Recombinant PLD2 Can Repress p65 Activity of Guinea Pigs of Chronic Asthma in vivo

    Institute of Scientific and Technical Information of China (English)

    Ling Zhu; Weibin Zou; Chuanxing Yu; Junjin Lin; Xiaoli He

    2006-01-01

    This article is to investigate the effect of human recombinant phospholipase D2 (rhPLD2) in vivo on the expression of nuclear transcription factor p65 in chronic asthma of guinea pigs. After treating the guinea pigs with chronic asthma by rhPLD2, the crude nuclear extraction was assayed with TransAM Transcription Factor Assay Kit for the activity of pulmo tissue nuclear transcription factor p65. Compared with the healthy guinea pigs, the activity of nuclear transcription factor p65 in guinea pigs of chronic asthma is much higher than that of control groups. Our results showed that rhPLD2 markedly depressed the activity of p65 when the guinea pigs were attacked by chronic asthma. Cellular & Molecular Immunology. 2006;3(4):307-310.

  15. The Potential Application of Hairless Guinea Pigs as a Replacement for the Yucatan Mini-pig in Animal Studies

    Science.gov (United States)

    2009-02-01

    was fed a standard guinea pig diet and given treats of cranberries and orange juice . Food was withheld for 12 hours prior to surgery, water was...electric clippers and then gently cleansed with surgical scrub and warm water. To assess the second goal of evaluating the animal’s ability to

  16. Erythropoietin and erythropoietin receptor expression in the guinea pig inner ear

    DEFF Research Database (Denmark)

    Cayé-Thomasen, Per; Wagner, Niels; Lidegaard Frederiksen, Birgitte

    2005-01-01

    The erythropoietin receptor (EPOR) is expressed in the brain and erythropoietin (EPO) has been shown to have neurotrophic and neuroprotective functions in the central nervous system and in the retina. These findings may be applied to the inner ear, pending EPO receptor presence. Accordingly......, this study determines expression of EPO and EPOR in the inner ear of the guinea pig. Normal guinea pig inner ears were processed for immunohistochemistry, using poly-clonal antibodies against EPO and the EPO receptor. EPO expression was exclusively found in most, but not all spiral ganglion neurons...... expressed by several cell types within the guinea pig cochlea. We hypothesize on the existence of a local paracrine system and that EPO treatment may be feasible following inner ear damage....

  17. Naturally occurring Parelaphostrongylus tenuis-associated choriomeningitis in a guinea pig with neurologic signs.

    Science.gov (United States)

    Southard, T; Bender, H; Wade, S E; Grunenwald, C; Gerhold, R W

    2013-05-01

    An adult male guinea pig (Cavia porcellus) with a 1-month history of hind limb paresis, torticollis, and seizures was euthanized and submitted for necropsy. Gross examination was unremarkable, but histologic examination revealed multifocal eosinophilic and lymphoplasmacytic choriomeningitis and cross sections of nematode parasites within the leptomeninges of the midbrain and diencephalon. Morphologic features of the nematode were consistent with a metastrongyle, and the parasite was identified as Parelaphostrongylus tenuis by polymerase chain reaction testing and nucleotide sequencing. Further questioning of the owner revealed that the guinea pig was fed grass from a yard often grazed by white-tailed deer (Odocoileus virginianus). To the authors' knowledge, this is the first report of a naturally occurring P. tenuis infection in a guinea pig.

  18. Transplacental transmission of antibodies to tubular basement membrane in guinea-pigs with autoimmune tubulointerstitial nephritis.

    Science.gov (United States)

    Albini, B; Milgrom, M; Noble, B; Albini, C; Ossi, E; Andres, G A

    1984-04-01

    The offspring of female guinea-pigs with tubulo-interstitial nephritis were studied for possible passive transfer of disease. Whereas no immune deposits were seen on or before day 30 of gestation, IgG was detected in the tubular basement membrane (TBM) of fetuses at and after day 44. Serum of offspring contained antibodies to TBM, albeit in much lower titres than found in circulation of the mother guinea-pigs. No histopathological changes were seen in fetal kidneys. Thus, autoantibodies induced by heteroimmunization of pregnant guinea-pigs may be transmitted to offspring in the last third of the gestation period and can bind to fetal TBM. However, this transfer of antibodies does not cause disease.

  19. Pathological and virological features of arenavirus disease in guinea pigs. Comparison of two Pichinde virus strains.

    Science.gov (United States)

    Aronson, J F; Herzog, N K; Jerrells, T R

    1994-07-01

    A guinea pig passage-adapted strain of the arena-virus Pichinde (adPIC) is highly virulent in inbred guinea pigs, whereas the related strain PIC3739 is attenuated. Both viruses were macrophage tropic and infected peritoneal, splenic, liver, and alveolar macrophages during experimental Pichinde virus infection. Infection with the virulent strain was associated with unlimited viral replication in the face of exaggerated delayed-type hypersensitivity response, manifested by the macrophage disappearance reaction. Histopathological lesions unique to adPIC-infected guinea pigs included intestinal villus blunting with mucosal infiltration by pyknotic debris-laden macrophages and apoptosis of crypt epithelial cells. Splenic red pulp necrosis was also significantly associated with adPIC infection but not PIC3739 infection. These findings may provide clues to the pathogenesis of a group of poorly understood human viral hemorrhagic fevers.

  20. Spasmolytic activity of a herbal drug isolated from Tephrosia purpurea in guinea pigs.

    Science.gov (United States)

    Soni, Kapil K; Khare, M L; Saxena, R C

    2004-04-01

    We investigated the spasmolytic activity of herbal drugs isolated from Tephrosia purpurea on guinea pigs for the treatment of asthma in India. For this investigation, the herbal drug was extracted with 70% ethanol in soxhlet apparatus. After purification and isolution, the drug was used in experimental animals to observe prophylactic activity. For anaphylactic activity, horse serum 0.5 ml along with triple antigen (0.5 ml) was induced in guinea pigs. To observe prophylactic activity, male guinea pigs weighing about 250-450 gms were killed by cervical dislocation and the trachea was isolated. Each trachea was cut in to six segments. Each segment consists of three cartilage rings. Each end of tracheal muscles was attached to the bronchospasm transducers for isometric recording of the tension charges on a polygraph. The results of experiments clearly showed the spasmolytic activity of the drug. The preliminary phytochemical investigation, however shows the presence of glycoside saponins.

  1. A Survey on the Gastrointestinal Parasites of Rabbit and Guinea Pig in a Laboratory Animal House

    Directory of Open Access Journals (Sweden)

    Motamedi, G.,

    2014-05-01

    Full Text Available There is documented evidence that infection in laboratory animals can often influence the outcome of experiments. All infections, apparent or inapparent, are likely to increase biological variability. As a research project concerning the diversity and distribution of parasites of rabbit and guinea pig in a conventional laboratory animal house, about 87 rabbits (from 700 and 105 guinea pigs (from 1500 were selected randomly from a Research, Production & Breeding of Laboratory Animals Department. Samples were collected between 19.02.2010 and 20.05.2011. The samples and animals were examined by dissection and flotation methods. In this study only one species of nematodes (Passalorus ambiguus: 6.9%; one species of protozoa (Eimeria spp.: 21.8% in rabbits and one species of nematodes (Paraspidodera Uncinata: 24.7%; one species of protozoa (Balantidium coli: 11.4% in guinea pigs were identified. However, there was not any cestodes or trematodes identified from this group of laboratory animals.

  2. GABAB Receptor Antagonist CGP46381 Inhibits Form-Deprivation Myopia Development in Guinea Pigs

    Directory of Open Access Journals (Sweden)

    Zhen-Ying Cheng

    2015-01-01

    Full Text Available The aim was to investigate the effects of the GABAB receptor antagonist, CGP46381, on form-deprivation myopia (FDM in guinea pigs. Twenty-four guinea pigs had monocular visual deprivation induced using a diffuser for 11 days (day 14 to 25. The deprived eyes were treated with daily subconjunctival injections (100 μl of either 2% CGP46381, 0.2% CGP46381, or saline or received no injection. The fellow eyes were left untreated. Another six animals received no treatment. At the start and end of the treatment period, ocular refractions were measured using retinoscopy and vitreous chamber depth (VCD and axial length (AL using A-scan ultrasound. All of the deprived eyes developed relative myopia (treated versus untreated eyes, P0.05. Subconjunctival injections of CGP46381 inhibit FDM development in guinea pigs in a dose-dependent manner.

  3. Disodium cromoglycate prevents ileum hyperreactivity to histamine in Toxocara canis-infected guinea pigs.

    Science.gov (United States)

    Sá-Nunes, A; Corrado, A P; Baruffi, M D; Faccioli, L H

    2003-11-01

    The aim of this study was to investigate whether Toxocara canis infection in guinea pigs provokes changes in ileum responsiveness to histamine. Ileum segments from control and T. canis-infected groups were placed at isometric conditions and submitted to various doses of histamine. No changes were observed between controls and T. canis-infected groups at days 3, 6 and 12 after infection. However, at days 18 and 24 after infection, there was a significant increase in ileum responsiveness to histamine in T. canis-infected group. Pre-incubation of ileum segments with 1mgml(-1) disodium cromoglycate (DSCG) prevented the increased responsiveness to histamine in T. canis-infected guinea pigs and did not affect ileum contractility in non-infected animals. These results indicate that T. canis-infected guinea pigs develop increased intestinal responsiveness to histamine and that DSCG prevents alterations in smooth-muscle contractility.

  4. Effect of Cerium on Cardiac Muscle of Rat and Guinea Pig

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The effect of Ce3+ on cardiac muscle of rat and guinea pig was studied. In vitro, 0.05 mmol.L-1 solution of Ce3+ inhibited the contraction of guinea pig atria. The change of action potential duration(APD) of guinea pig papillary muscle exposed to 0.4 mmol·L-1 Ce3+ was significant, and those exposed to 0.1 and 0.2 mmol·L-1 Ce3+ were not significant. In vivo, compared with the control group, the APD for rat cardiac muscle after long-term feed on Ce3+ was significantly delayed in high dose, and that was not significantly delayed in low dose. The results suggest that Ce3+ with long-term high dose intake might affect the influx of Ca2+, Na+ and outflow of K+ for rat cardiac muscle.

  5. Cross-sensitization patterns in guinea pigs between cinnamaldehyde, cinnamyl alcohol and cinnamic acid

    DEFF Research Database (Denmark)

    Weibel, H; Hansen, J; Andersen, Klaus Ejner

    1989-01-01

    Guinea pig maximization tests (GPMT) were performed with cinnamon substances. There was a certain degree of cross-reactivity between cinnamaldehyde, cinnamyl alcohol and cinnamic acid as animals sensitized to cinnamaldehyde reacted to the challenge with the three substances. Animals sensitized...... to cinnamyl alcohol reacted to cinnamyl alcohol and cinnamaldehyde, but not to cinnamic acid. Cinnamic acid did not sensitize guinea pigs. Compared to the challenge concentration for cinnamaldehyde, approximately a 15 times higher concentration of cinnamyl alcohol and a 25 times higher concentration...... of cinnamic acid were required to give positive reactions in animals sensitized to cinnamaldehyde. This could not be explained by differences in permeability properties, as the penetration profiles of the three substances through guinea pig skin in vitro showed permeability coefficients of the same order...

  6. Species differences in the localization and number of CNS beta adrenergic receptors: Rat versus guinea pig

    Energy Technology Data Exchange (ETDEWEB)

    Booze, R.M.; Crisostomo, E.A.; Davis, J.N.

    1989-06-01

    The localization and number of beta adrenergic receptors were directly compared in the brains of rats and guinea pigs. The time course of association and saturability of (125I)cyanopindolol (CYP) binding to slide-mounted tissue sections was similar in rats (Kd = 17 pM) and guinea pigs (Kd = 20 pM). The beta-1 and beta-2 receptor subtypes were examined through the use of highly selective unlabeled receptor antagonists, ICI 118,551 (50 nM) and ICI 89,406 (70 nM). Dramatic species differences between rats and guinea pigs were observed in the neuroanatomical regional localization of the beta adrenergic receptor subtypes. For example, in the thalamus prominent beta-1 and beta-2 receptor populations were identified in the rat; however, the entire thalamus of the guinea pig had few, if any, beta adrenergic receptors of either subtype. Hippocampal area CA1 had high levels of beta-2 adrenergic receptors in both rats and guinea pigs but was accompanied by a widespread distribution of beta-2 adrenergic receptors only in rats. Quantitative autoradiographic analyses of 25 selected neuroanatomical regions (1) confirmed the qualitative differences in CNS beta adrenergic receptor localization, (2) determined that guinea pigs had significantly lower levels of beta adrenergic receptors than rats and (3) indicated a differential pattern of receptor subtypes between the two species. Knowledge of species differences in receptor patterns may be useful in designing effective experiments as well as in exploring the relationships between receptor and innervation patterns. Collectively, these data suggest caution be used in extrapolation of the relationships of neurotransmitters and receptors from studies of a single species.

  7. Onset and duration of immunity in guinea pigs and mice induced with different Q fever vaccines.

    Science.gov (United States)

    Kazár, J; Votruba, D; Propper, P; Schramek, S

    1986-11-01

    Protective effects of different types of Q fever vaccines, namely untreated Coxiella burnetii phase I cells (Cb I) or Cb I cells treated with chloroform-methanol (CM) mixture (Cb I-CM) and of a Q fever chemovaccine obtained by trichloroacetic acid extraction (TCAE) from intact Cb I cells, were compared in mice and guinea pigs at different intervals after intraperitoneal (i.p.) or subcutaneous (s.c.) immunizations. The highest degree of protection at all intervals studied was achieved with Cb I cells, irrespective of the route of immunization and i.p. or aerosol challenge. This vaccine exerted a protective effect in guinea pigs and mice as early as after one or two weeks post-immunization, the effect lasting for at least 40 weeks in mice (i.p. challenge) and 12 months in guinea pigs (aerosol challenge). Addition of small amount of Cb I cells to TCAE increased resistance of guinea pigs to aerosol challenge. Degree, onset and duration of protection to either type of virulent challenge afforded by Cb I-CM cells and TCAE was similar, but when compared with that of Cb I cells it was lower, started later (from the 2nd week in guinea pigs and the 3rd week in mice), and in mice it lasted for a shorter period (20 weeks only). The resistance to virulent challenge in guinea pigs did not depend on the levels of microagglutination (MA) antibodies and in mice it was reflected by delayed type hypersensitivity (DTH) reaction and adoptively transferred splenocytes, rather than by MA antibody titres and passive transfer of immune sera to recipient mice.(ABSTRACT TRUNCATED AT 250 WORDS)

  8. Conjugated linoleic acid mitigates testosterone-related changes in body composition in male guinea pigs.

    Science.gov (United States)

    Yang, Susan Q; DeGuire, Jason R; Lavery, Paula; Mak, Ivy L; Weiler, Hope A; Santosa, Sylvia

    2016-05-01

    We hypothesize that conjugated linoleic acid (CLA) may be effective in preventing the changes in total and regional body composition and increases in interleukin (IL) 6 that occur as a result of hypogonadism. Male guinea pigs (n = 40, 70- to 72-week retired breeders) were block randomized by weight into 4 groups: (1) sham surgery (SHAM)/control (CTRL) diet, (2) SHAM/conjugated linoleic acid (CLA) diet (1%), (3) orchidectomy (ORX)/CTRL diet, and (4) ORX/CLA diet. Dual-energy x-ray absorptiometry scans were performed at baseline and week 16 to assess body composition. Serum IL-6 was analyzed using an enzyme-linked immune sorbent assay. Fatty acids (FAs) from visceral and subcutaneous adipose tissue were analyzed using gas chromatography. In ORX/CTRL guinea pigs, percent total body fat increased by 6.1%, and percent lean mass decreased by 6.7% over the 16-week treatment period, whereas no changes were observed for either parameter in ORX/CLA guinea pigs. Guinea pigs fed the CLA diet gained less percent total, upper, and lower body fat than those fed the CTRL diet regardless of surgical treatment. Regional adipose tissue FA composition was reflective of dietary FAs. Serum IL-6 concentrations were not different among groups. In this study, we observed that, in male guinea pigs, hypogonadism resulted in increased fat mass and decreased lean mass. In addition, CLA was effective in reducing gains in body fat and maintaining lean mass in both hypogonadal and intact guinea pigs.

  9. Adenosine transport systems on dissociated brain cells from mouse, guinea-pig, and rat

    Energy Technology Data Exchange (ETDEWEB)

    Johnston, M.E.; Geiger, J.D. (Univ. of Manitoba, Winnipeg (Canada))

    1990-09-01

    The kinetics and sodium dependence of adenosine transport were determined using an inhibitor-stop method on dissociated cell body preparations obtained from mouse, guinea-pig and rat brain. Transport affinity (KT) values for the high affinity adenosine transport systems KT(H) were significantly different between these three species; mean +/- SEM values were 0.34 +/- 0.1 in mouse, 0.9 +/- 0.2 in rat, and 1.5 +/- 0.5 microM in guinea-pig. The KT values for the low affinity transport system KT(L) were not different between the three species. Brain cells from rat displayed a significantly greater maximal capacity to accumulate (3H)adenosine (Vmax) than did mouse or guinea-pig for the high affinity system, or than did mouse for the low affinity system. When sodium chloride was replaced in the transport medium with choline chloride, the KT(H) values for guinea-pig and rat were both increased by approximately 100%; only in rat did the change reach statistical significance. The sodium-dependence of adenosine transport in mouse brain was clearly absent. The differences between KT(H) values in mouse and those in guinea-pig or rat were accentuated in the absence of sodium. The differences in kinetic values, ionic requirements, and pharmacological characteristics between adenosine transporters in CNS tissues of mouse, guinea-pig and rat may help account for some of the variability noted among species in terms of their physiological responses to adenosine.

  10. Optic nerve head and intraocular pressure in the guinea pig eye.

    Science.gov (United States)

    Ostrin, Lisa A; Wildsoet, Christine F

    2016-05-01

    The guinea pig is becoming an increasingly popular model for studying human myopia, which carries an increased risk of glaucoma. As a step towards understanding this association, this study sought to characterize the normal, developmental intraocular pressure (IOP) profiles, as well as the anatomy of the optic nerve head (ONH) and adjacent sclera of young guinea pigs. IOP was tracked in pigmented guinea pigs up to 3 months of age. One guinea pig was imaged in vivo with OCT and one with a fundus camera. The eyes of pigmented and albino guinea pigs (ages 2 months) were enucleated and sections from the posterior segment, including the ONH and surrounding sclera, processed for histological analyses - either hematoxylin and eosin (H&E) staining of paraffin embedded, sectioned tissue (n = 1), or cryostat sectioned tissue, processed for immunohistochemistry (n = 3), using primary antibodies against collagen types I-V, elastin, fibronectin and glial fibrillary acidic protein (GFAP). Transmission and scanning electron microscopy (TEM, SEM) studies of ONHs were also undertaken (n = 2 & 5 respectively). Mean IOPs ranged from 17.33 to 22.7 mmHg, increasing slightly across the age range studied, and the IOPs of individual animals also exhibited diurnal variations, peaking in the early morning (mean of 25.8, mmHg, ∼9 am), and decreasing across the day. H&E-stained sections showed retinal ganglion cell axons organized into fascicles in the prelaminar and laminar region of the ONHs, with immunostained sections revealing collagen types I, III, IV and V, as well as elastin, GFAP and fibronectin in the ONHs. SEM revealed a well-defined lamina cribrosa (LC), with radially-oriented collagen beams. TEM revealed collagen fibrils surrounding non-myelinated nerve fiber bundles in the LC region, with myelination and decreased collagen posterior to the LC. The adjacent sclera comprised mainly crimped collagen fibers in a crisscross arrangement. Both the sclera and LC were

  11. [Effect of estradiol on the course of ovalbumin sensitization in guinea pigs].

    Science.gov (United States)

    Wan, Y; Weng, S A

    1993-01-01

    The latent period of ovalbumin (Ova)-induced asthma in Ova-sensitized guinea pigs was shorter in the ovariectomized animals with sc estradiol (E2) 400 or 50 micrograms.d-1 x 14 d and in animals with intact ovary (84 +/- 35, 82 +/- 33, and 100 +/- 32 s, respectively) than in the ovariectomized animals (140 +/- 29 s) (P contraction of isolated tracheal strips induced by His and those of the relaxation by isoproterenol (Iso) were not affected. These findings suggest that the strengthened effect of E2 on the sensitization may be related to the content and the release of lung His in guinea pigs.

  12. Argyrophilic cells in the larynx of the guinea-pig demonstrated by the method of Grimelius

    DEFF Research Database (Denmark)

    Kirkeby, S; Romert, P

    1977-01-01

    Argyrophilic cells with branching processes are shown in both the surface epithelium and in the glands in the larynx of adult guinea-pigs using the Grimelius silver technique after GPA fixation. When Bouin's fixative or neutral formalin were used as fixatives argrophilic cells could not be identi......Argyrophilic cells with branching processes are shown in both the surface epithelium and in the glands in the larynx of adult guinea-pigs using the Grimelius silver technique after GPA fixation. When Bouin's fixative or neutral formalin were used as fixatives argrophilic cells could...

  13. Effect of isoorientin isolated from Arum palaestinum on uterine smooth muscle of rats and guinea pigs.

    Science.gov (United States)

    Afifi, F U; Khalil, E; Abdalla, S

    1999-05-01

    The phytochemical investigation of Arum palaestinum resulted in the isolation of two flavone C-glucosides, namely isoorientin (luteolin 6-C-glucoside) and vitexin (apigenin 8-C glucoside). The effects of isoorientin on rat isolated aorta, ileum, trachea and uterus and on guinea-pig uterus were studied. Isoorientin (10(-7)M-6 x 10(-4)M) caused concentration-dependent inhibition of the amplitude and the frequency of the phasic contractions of the rat and guinea-pig uterus but did not affect the isolated aorta, ileum or trachea. The results were discussed in relation to the effects of its aglycone luteolin reported in the literature.

  14. Feasibility study of marrow stromal cells transplantation into guinea pig cochlea

    Institute of Scientific and Technical Information of China (English)

    GE Sheng-lei; XIE Ding-hua; CHEN Zhu-chu; XIAO Zhi-qiang; YANG Xin-min

    2005-01-01

    Objective This pilot-study was designed to evaluate the feasibility of cell transplantation into guinea pig cochlea. Methods Marrow stromal cells were labeled with DAPI, and then implanted into the cochlea of guinea pig.The existence and differentiation trend were observed roughly two weeks later by histologic analysis. Results Transplant-derived marrow stem cells survived in cochlea two weeks later with a trend of attaching to cochlear architecture but not differentiate into neuron. Conclusions Transplant-derived marrow stem cells can survive in cochlea,and cell transplantation may be a useful strategy in inner ear diseases.

  15. Tumor Necrosis Factor and the Pathogenesis of Pichinde Virus Infection in Guinea Pigs

    OpenAIRE

    Aronson, Judith F.; Herzog, Norbert K.; Jerrells, Thomas R.

    1995-01-01

    Pichinde virus (PIC) is a reticuloendothelial arenavirus of the New World tropics. A guinea pig passage–adapted strain of this virus (adPIC) is uniformly lethal for inbred guinea pigs, while the related, prototype strain (PIC3739) has attenuated virulence. The abilities of adPIC and PIC3739 to induce tumor necrosis factor (TNF) in vivo and in cultured macrophages were compared. Infection with adPIC, but not PIC3739, was associated with detectable serum TNF that peaked in week 2 of infection. ...

  16. Evidence for a non-opioid sigma binding site din the guinea-pig myenteric plexus

    Energy Technology Data Exchange (ETDEWEB)

    Roman, F.; Pascaud, X.; Vauche, D.; Junien, J.

    1988-01-01

    The presence of a binding site to (+)-(/sup 3/H)SKF 10,047 was demonstrated in a guinea-pig myenteric plexus (MYP) membrane preparation. Specific binding to this receptor was saturable, reversible, linear with protein concentration and consisted of two components, a high affinity site and a low affinity site. Morphine and naloxone 10/sup -4/M were unable to displace (+)-(/sup 3/H)SKF 10,047 binding. Haloperidol, imipramine, ethylketocyclazocine and propranolol were among the most potent compounds to inhibit this specific binding. These results suggest the presence of a non-opioid haloperidol sensitive sigma receptor in the MYP of the guinea-pig.

  17. Normal development of refractive state and ocular dimensions in guinea pigs.

    Science.gov (United States)

    Zhou, Xiangtian; Qu, Jia; Xie, Ruozhong; Wang, Ruiqing; Jiang, Liqin; Zhao, Hailan; Wen, Jiquan; Lu, Fan

    2006-09-01

    This study investigated changes in refraction, corneal curvature, axial components and weight of posterior sclera in guinea pig eyes during the normal development from birth. Sixty-four guinea pigs were assigned to eight groups (n=8 each). Each group underwent a series of ocular measurements at one of the eight time-points (0, 1, 2, 3, 5, 7, 9 and 11 weeks), including refraction (streak retinoscopy), corneal radius of curvature (CRC; keratometry), anterior segment length (AS: corneal thickness and depth of the anterior chamber), thickness of the crystalline lens (CL), vitreous chamber length (VC; all A-scan ultrasonography) and dry weight of a circular 6mm diameter punch in the posterior sclera (electronic balance). Results of all the measurements were statistically compared between right eye and left eye, male and female and among different age groups. Artifacts of retinoscopy due to small eye artifact were also estimated at different ages. The refraction in guinea pig eyes was +5.22+/-0.23 D (Mean, SE) at birth. This value decreased rapidly during the first 3 weeks followed by a slow decline. The overall decrease in refraction was highly significant from birth to 11 weeks (pweeks. The guinea pig eyes were emmetropic by 3 weeks of age when the small eye artifact was taken into account. The CRC (3.24+/-0.01 mm at birth), AS (1.20+/-0.01 mm at birth), CL (2.72+/-0.03 mm at birth) and VC (3.28+/-0.01 mm at birth) increased within the first 3 weeks despite a transient decrease in the CRC within the first week. The increase in CRC, CL and VC continued after 3 weeks, however, the AS remained constant after this age. The increase in VC was better correlated to the decline of hyperopia (R(2)=0.70) than the other components (R(2)=0.33-0.39). Dry weight of the posterior sclera increased linearly from birth (pweeks) and had a moderately linear correlation with the VC (R(2)=0.60). There were no significant differences between the right eye and left eye or between male and

  18. Expression and in vitro properties of guinea pig IL-5: Comparison to human and murine orthologs

    OpenAIRE

    Scott, Clay W; Carol Budzilowicz; Stephen J. Hubbs; Mark Stein; Cindy Sobotka-Briner; Deidre E. Wilkins

    2000-01-01

    Interleukin-5 (IL-5) is a key mediator of eosinophilic inflammation. The biological role of this cytokine in an allergic airway inflammatory response has been widely demonstrated in guinea pigs, yet the interaction of guinea pig IL-5 (gpIL-5) with its receptor has not been studied. Experiments were performed to quantitate the interaction of gpIL-5 with gpIL-5r and to compare this affinity with that of hIL-5 and mIL-5 and their cognate receptors. The cross-species affinity and agonist efficacy...

  19. Effects of Homocysteine on Spontaneous Contractility of Pregnant Guinea-Pig Myometrium

    OpenAIRE

    Ayar, Ahmet; TUĞ, Niyazi; ÇELİK, Hüsnü; ÖZCAN, Mete

    2001-01-01

    Objective: The aim of this study was to investigate the effects of homocysteine on spontaneous contractions of guinea pig myometrium. Material and method: Full thickness myometrium strips were obtained from late-pregnant guinea pigs following decapitation and suspended in an isolated organ bath which was filled with physiological salt solution at pH 7.4 maintained at 37°C and continuously bubbled with 95 CO2 %-%5 O2. After manifestation of spontaneous contractions under one gram of restin...

  20. Guinea pig maximization tests with formaldehyde releasers. Results from two laboratories

    DEFF Research Database (Denmark)

    Andersen, Klaus Ejner; Boman, A; Hamann, K

    1984-01-01

    The guinea pig maximization test was used to evaluate the sensitizing potential of formaldehyde and 6 formaldehyde releasers (Forcide 78, Germall 115, Grotan BK, Grotan OX, KM 200 and Preventol D2). The tests were carried out in 2 laboratories (Copenhagen and Stockholm), and although we intended...... the procedures to be the same, discrepancies were observed, possibly due to the use of different animal strains, test concentrations and vehicles. The sensitizing potential was in general found to be stronger in Stockholm compared to Copenhagen: formaldehyde sensitized 50% of the guinea pigs in Copenhagen and 95...

  1. La3+ Transmembrane Research in Guinea Pig Ventricular Cells by Fura-2 Fluorescence

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Binding of La3+ to Fura-2 can change 340/380 nm fluorescence intensity ratio. Whether La3+ cross ventricular cell membrane was detected by this fluorescent probe technique. Fura-2 loaded isolated guinea pig ventricular cells were exposed to 0.01-0.1mM extracellular Lanthanum ion concentration, 340nm/380 nm fluorescence ratio was not changed. Using calcium channel agonist BAY K8644, KCL (35mM) depolarization to open the voltage-dependent calcium channel (VDCC); Adrenoceptor agonist to excite adrenoceptor, 340/380 ratio was not changed, suggesting that La3+can not enter guinea pig ventricular cells in this case.

  2. Angiotensin receptors and actions in guinea pig enteric nervous system.

    Science.gov (United States)

    Wang, Guo-Du; Wang, Xi-Yu; Hu, Hong-Zhen; Fang, Xiu-Cai; Liu, Sumei; Gao, Na; Xia, Yun; Wood, Jackie D

    2005-09-01

    Actions of ANG II on electrical and synaptic behavior of enteric neurons in the guinea pig small intestine were studied. Exposure to ANG II depolarized the membrane potential and elevated neuronal excitability. The number of responding neurons was small, with responses to ANG II in 32% of submucosal neurons and 25% of myenteric neurons. Hyperpolarizing responses were evoked by ANG II in 45% of the neurons. The hyperpolarizing responses were suppressed by alpha2-noradrenergic receptor antagonists, which suggested that the hyperpolarizing responses reflected stimulation of norepinephrine release from sympathetic neurons. Exposure to ANG II enhanced the amplitude and prolonged the duration of noradrenergic inhibitory postsynaptic potentials and suppressed the amplitude of both fast and slow excitatory postsynaptic potentials. The selective ANG II(1) receptor (AT1R) antagonists, ZD-7115 and losartan, but not a selective AT2R antagonist (PD-123319), suppressed the actions of ANG II. Western blot analysis and RT-PCR confirmed expression of AT1R protein and the mRNA transcript for the AT1R in the enteric nervous system. No expression of AT2R protein or mRNA was found. Immunoreactivity for AT1R was expressed by the majority of neurons in the gastric antrum and small and large intestine. AT1R immunoreactivity was coexpressed with calbindin, choline acetyltransferase, calretinin, neuropeptide Y, and nitric oxide synthase in subpopulations of neurons. The results suggest that formation of ANG II might have paracrine-like actions in the enteric nervous system, which include alterations in neuronal excitability and facilitated release of norepinephrine from sympathetic postganglionic axons. The enhanced presence of norepinephrine is expected to suppress fast and slow excitatory neurotransmission in the enteric microcircuits and to suppress neurogenic mucosal secretion.

  3. [+]-Huperzine A protects against soman toxicity in guinea pigs.

    Science.gov (United States)

    Wang, Ying; Wei, Yanling; Oguntayo, Samuel; Jensen, Neil; Doctor, Bhupendra P; Nambiar, Madhusoodana P

    2011-12-01

    The chemical warfare nerve agent (CWNA) soman irreversibly inhibits acetylcholinesterase (AChE) causing seizure, neuropathology and neurobehavioral deficits. Pyridostigmine bromide (PB), the currently approved pretreatment for soman, is a reversible AChE inhibitor that does not cross the blood-brain barrier (BBB) to protect against central nervous system damage. [-]-Huperzine A, a natural reversible AChE inhibitor, rapidly passes through the BBB and has numerous neuroprotective properties that are beneficial for protection against soman. However, [-]-Huperzine A is toxic at higher doses due to potent AChE inhibition which limits the utilization of its neuroprotective properties. [+]-Huperzine A, a synthetic stereoisomer of [-]-Huperzine A and a weak inhibitor of AChE, is non-toxic. In this study, we evaluated the efficacy of [+]-Huperzine A for protection against soman toxicity in guinea pigs. Pretreatments with [+]-Huperzine A, i.m., significantly increased the survival rate in a dose-dependent manner against 1.2× LD(50) soman exposures. Behavioral signs of soman toxicity were significantly reduced in 20 and 40 mg/kg [+]-Huperzine A treated animals at 4 and 24 h compared to vehicle and PB controls. Electroencephalogram (EEG) power spectral analysis showed that [+]-Huperzine A significantly reduces soman-induced seizure compared to PB. [+]-Huperzine A (40 mg/kg) preserved higher blood and brain AChE activity compared to PB in soman exposed animals. These data suggest that [+]-Huperzine A protects against soman toxicity stronger than PB and warrant further development as a potent medical countermeasure against CWNA poisoning.

  4. Stability of the guinea pigs personality - cognition - linkage over time.

    Science.gov (United States)

    Brust, Vera; Guenther, Anja

    2017-01-01

    In human psychological research, personality traits as well as cognitive traits are usually validated for both, their stability over time and contexts. While stability over time gives an estimate on how genetically fixated a trait can be, correlations across traits have the power to reveal linkages or trade - offs. In animals, these validations have widely been done for personality but not for cognitive traits. We tested guinea pigs in four consecutive discrimination tasks using four unique pairs of objects with two objects of the same form but different size in each pair. The same animals were tested twice each for three personality traits, i.e. boldness, aggression and sociopositive behaviour. The animals did not learn to "always choose the larger item" in the cognitive task but learned to discriminate the two objects of each stimulus pair anew, so that we did test for learning speed in four slightly different task setups. Performance over the four tasks was significantly repeatable as well as all tested personality traits. A stable linkage over time was found between sociopositive behaviour and learning performance, probably indicating an ecological relevance for a correlation between these two traits. Still, not all traits seem to be connected amongst each other, as in our case boldness and aggression are both not linked to individual learning performance. Future studies will hopefully further investigate the repeatability of various cognitive traits in several species and thus lead to a better understanding of the interdependence of personality and cognition. This will help to unravel which suites of traits facilitate individual life histories and hence improve our understanding of the emergence and maintenance of individual differences. Copyright © 2016 Elsevier B.V. All rights reserved.

  5. Biomechanical remodeling of the chronically obstructed Guinea pig small intestine.

    Science.gov (United States)

    Storkholm, Jan Henrik; Zhao, Jingbo; Villadsen, Gerda E; Hager, H; Jensen, Steen L; Gregersen, Hans

    2007-02-01

    Small intestinal obstruction is a frequently encountered clinical problem. To understand the mechanisms behind obstruction and the clinical consequences, data are needed on the relation between the morphologic and biomechanical remodeling that takes place in the intestinal wall during chronic obstruction. We sought to determine the effect of partial obstruction on mechanical and morphologic properties of the guinea pig small intestine. Partial obstruction was created surgically in 2 groups of animals living for 2 and 4 weeks. Controls were sham operated and lived for 4 weeks. A combined impedance planimetry-high-frequency ultrasound system was designed to measure the luminal cross-sectional area and wall thickness. These measures were used to compute the circumferential stress and strain of the excised intestinal segments. The incremental elastic modulus was obtained by using nonlinear fitting of the stress-strain curve. Histologic analysis and the measurements of total wall collagen were also performed. The luminal cross-sectional area, wall thickness, and elastic modulus in circumferential direction increased in a time-dependent manner proximal to the obstruction site (P 0.25). The circumferential stress-strain curves of the proximal segments in 2- and 4-week groups shifted to the left, indicating the intestinal wall became stiffer. Histologic examination revealed a massive increase in the thickness of the muscle layer especially the circular smooth muscle layer (P < 0.05). The collagen content proximal to the obstruction site was significantly larger in the partially obstructed animals compared to controls (P < 0.05). No difference was found distal to the obstruction site. Strong correlation was found between the collagen content and the elastic modulus at stress levels of 70 kPa stress (P < 0.01) and 10 kPa (P < 0.05) proximal to the obstruction site suggesting that the alteration of collagen has great impact on the mechanical remodeling. The morphologic and

  6. Glycine activates myenteric neurones in adult guinea-pigs.

    Science.gov (United States)

    Neunlist, M; Michel, K; Reiche, D; Dobreva, G; Huber, K; Schemann, M

    2001-11-01

    1. We studied the effects of glycine on myenteric neurones and muscle activity in the colon and stomach of adult guinea-pigs. 2. Intracellular recordings revealed that myenteric neurones responded to local microejection of glycine (1 mM) with a fast, transient membrane potential depolarisation (57 % of 191 colonic neurones and 26 % of 50 gastric neurones). Most glycine-sensitive neurones had ascending projections and were choline acetyltransferase immunoreactive. Glycine preferentially activated neurones with a late afterhyperpolarisation (AH-neurones) and tonic spiking neurones with fast synaptic inputs (tonic S-neurones) but less frequently phasic S-neurones and inexcitable (non-spiking) neurones. The depolarisation had a reversal potential at -19 +/- 13 mV, which was increased by 18 +/- 10 % upon lowering extracellular chloride concentration and decreased by 38 +/- 14 % in furosemide (frusemide, 2 mM). 3. Strychnine (300 nM) reversibly abolished the glycine-induced depolarisation and the Cl(-) channel blocker picrotoxin (100 microM) reduced the amplitude of the depolarisation by 55 +/- 5 %. The glycine effect was a postsynaptic response because it was not changed after nerve blockade with tetrodotoxin (1 microM) or blockade of synaptic transmission in reduced extracellular [Ca(2+)]. The effect was specific since the response was not changed by the nicotinic antagonists hexamethonium (200 microM) and mecamylamine (100 microM), the GABA(A) receptor antagonist bicuculline (10 microM), the NMDA antagonist MK-801 (20 microM) or the 5-HT(3) antagonist ICS 205930 (1 microM). 4. Glycine (1 mM) induced a tetrodotoxin- and strychnine-sensitive contractile response in the colon; the contractile response in the stomach was tetrodotoxin insensitive. 5. Glycine activated myenteric neurones in the adult enteric nervous system through strychnine-sensitive mechanisms. The glycine-evoked depolarisation was caused by Cl(-) efflux and the maintenance of relatively high

  7. Migration of craniofacial periosteum in growing guinea-pigs.

    Science.gov (United States)

    Wolf, G; Koskinen-Moffett, L; Kokich, V

    1985-01-01

    The use of a carbon particle tattoo provided stable periosteal markers and a means of recording periosteal movement both anteroposteriorly and transversely during growth in guinea-pigs. In general, the periosteum migrated toward the cranial sutures. The radial pattern, demonstrated on the frontal bones and indicated on the nasal and parietal bones, showed that a periosteal envelope is identifiable with each bone. The area of origin of this centrifugal pattern of migration coincided with the ossification centre of that bone. Trabeculae and vascular canals tended to point in the direction of periosteal migration. The anteroposterior periosteal migration was proportional to but less than the anteroposterior growth of the craniofacial bones studied. The absolute medial periosteal marker migration, similar on the frontal and parietal bones, was directed in the opposite direction from the slight transverse bone growth. This may indicate a biophysical response to tension on the fibrous periosteum from the principally anteroposterior craniofacial growth. The amount of growth at the frontonasal, coronal and midline sutures diminished from anterior to posterior. The observed histological and morphological sutural characteristics concurred with these growth changes which correlate with the decreased cranial and increased facial growth during the age period studied. Although the fibrous periosteum is continuous over the separate membranous bones its behaviour appears to be intimately related to the growth of the craniofacial bones which it covers. The blending of the fibrous periosteum within the transverse sutures may prevent significant migration across craniofacial bones. It seems that the observed migratory patterns result from a close association of the fibrous periosteum with each growing craniofacial bone. The relationship of the fibrous periosteum to the growth of the craniofacial bones is a question requiring further investigation. Images Fig. 1 Fig. 3 PMID:4077688

  8. Endogenous opiate analgesia induced by tonic immobility in guinea pigs

    Directory of Open Access Journals (Sweden)

    C.R.A. Leite-Panissi

    2001-02-01

    Full Text Available A function of the endogenous analgesic system is to prevent recuperative behaviors generated by tissue damage, thus preventing the emission of species-specific defensive behaviors. Activation of intrinsic nociception is fundamental for the maintenance of the behavioral strategy adopted. Tonic immobility (TI is an inborn defensive behavior characterized by a temporary state of profound and reversible motor inhibition elicited by some forms of physical restraint. We studied the effect of TI behavior on nociception produced by the formalin and hot-plate tests in guinea pigs. The induction of TI produced a significant decrease in the number of flinches (18 ± 6 and 2 ± 1 in phases 1 and 2 and lickings (6 ± 2 and 1 ± 1 in phases 1 and 2 in the formalin test when compared with control (75 ± 13 and 22 ± 6 flinches in phases 1 and 2; 28 ± 7 and 17 ± 7 lickings in phases 1 and 2. In the hot-plate test our results also showed antinociceptive effects of TI, with an increase in the index of analgesia 30 and 45 min after the induction of TI (0.67 ± 0.1 and 0.53 ± 0.13, respectively when compared with control (-0.10 ± 0.08 at 30 min and -0.09 ± 0.09 at 45 min. These effects were reversed by pretreatment with naloxone (1 mg/kg, ip, suggesting that the hypoalgesia observed after induction of TI behavior, as evaluated by the algesimetric formalin and hot-plate tests, is due to activation of endogenous analgesic mechanisms involving opioid synapses.

  9. Distribution of cocaine- and amphetamine-regulated transcript in the hippocampal formation of the guinea pig and domestic pig.

    Science.gov (United States)

    Kolenkiewicz, M; Robak, A; Równiak, M; Bogus-Nowakowska, K; Całka, J; Majewski, M

    2009-02-01

    This study provides a detailed description concerning the distribution of cocaineand amphetamine-regulated transcript (CART) subunits - CART(61-102) and rhCART(28-116) - in the hippocampal formation (HF) of the guinea pig and domestic pig, focussing on the dentate gyrus (DG) and hippocampus proper (HP). Although in both studied species CART-immunoreactive (CART-IR) neuronal somata and processes were present generally in the same layers, some species-specific differences were still found. In the granular layer (GL) of both species, the ovalshaped neurons and some thick varicose fibres were encountered. In the guinea pig there was an immunoreactive "band of dots", probably representing crosssectioned terminals within the DG molecular layer (MOL), whereas in the domestic pig, some varicose fibres were detected, thus suggesting a different orientation of, at least, some nerve terminals. Furthermore, some CART-positive cells and fibres were observed in the hilus (HL) of the guinea pig, whereas in the analogical part of the domestic pig only nerve terminals were labelled. In both species, in the pyramidal layer (PL) of the hippocampus proper, CART-IR triangular somata were observed in the CA3 sector, as well as some positive processes in MOL; however, a few immunoreactive perikarya were found only in the CA1 sector of the guinea pig. As regards the localization patterns of two isoforms of CART in the guinea pig, both peptide fragments were present simultaneously in each of the labelled neurons or fibres, whereas in the domestic pig three types of fibres may be distinguished within the area of the DG. In the hilus and MOL of the dentate gyrus, there were fibres expressing both isoforms of CART in their whole length (fibres of the first type). Fibres of the second type (in GL) coexpressed both peptides only on their short segments, and the last ones (in MOL) expressed solely rhCART(28-116). These results indicate that the distribution of the two CART isoforms are

  10. Assessment of gastrointestinal pH, fluid and lymphoid tissue in the guinea pig, rabbit and pig, and implications for their use in drug development.

    Science.gov (United States)

    Merchant, Hamid A; McConnell, Emma L; Liu, Fang; Ramaswamy, Chandrasekaran; Kulkarni, Rucha P; Basit, Abdul W; Murdan, Sudaxshina

    2011-01-18

    Laboratory animals are often used in drug delivery and research. However, basic information about their gastrointestinal pH, fluid volume, and lymphoid tissue is not completely known. We have investigated these post-mortem in healthy guinea pigs, rabbits and pigs, to assess their suitability for pre-clinical studies by comparing the results with reported human literature. The mean gastric pH (fed ad libitum) was 2.9 and 4.4 in guinea pig and pig, respectively. In contrast, a very low pH (1.6) was recorded in the rabbits. The small intestinal pH was found in the range of 6.4-7.4 in the guinea pigs and rabbits, whereas lower pH (6.1-6.7) was recorded in the pig, which may have consequences for ionisable or pH responsive systems when tested in pig. A relatively lower pH than in the small intestine was found in the caecum (6.0-6.4) and colon (6.1-6.6) of the guinea pig, rabbit and the pig. The water content in the gastrointestinal tract of guinea pig, rabbit and pig was 51g, 153g and 1546g, respectively. When normalized to the body weight, the guinea pig, had larger amounts of water compared to the rabbit and the pig (guinea pig>rabbit>pig); in contrast, a reverse order was found when normalized to per unit length of the gut (guinea pigpig). The lymphoid tissue distribution (lymphoid follicles, Peyer's patches and long strips) along the length of the gut in these animals is presented; in particular, an abundance of lymphoid tissue was found in pig's stomach, small intestine and caecum, and rabbit's appendix. Their ample presence indicated the potential utility of these animal species in oral and colonic vaccination. These differences in the gastrointestinal parameters of the guinea pig, rabbit and pig reiterates the crucial importance of correctly selecting animal models for pre-clinical studies.

  11. Studies on vertical transmission of Trichinella spp. in experimentally infected ferrets (Mustela putorius furo), foxes (Vulpes vulpes), pigs, guinea pigs and mice.

    Science.gov (United States)

    Webster, P; Kapel, C M O

    2005-06-30

    Vertical transmission of Trichinella spiralis was evaluated in ferrets (n=21), foxes (n=11), pigs (n=12), guinea pigs (n=16), and mice (n=41). The placental barrier to be crossed by migratory Trichinella larvae varies structurally in different animal species. Ferrets and foxes have an endotheliochorial placenta structure, guinea pigs and mice a haemochorial, and pigs an epitheliochorial placenta. The non-encapsulating Trichinella pseudospiralis larvae have an extended muscle migration prior to entering a muscle cell. To evaluate if T. pseudospiralis was more likely to be transmitted to offspring, an additional group of foxes (n=11) infected with T. pseudospiralis was included. Two different dose levels were used for ferrets, pigs, guinea pigs, and mice. In pigs and guinea pigs, infection was given at different times of the gestation period. Vertical transmission, measured as recovery of muscle larvae in the offspring, was demonstrated in both ferrets groups, in all four guinea pig groups, and in the high dose mouse group, but not in any fox or pig groups.

  12. Development of a novel, guinea pig-specific IFN-γ ELISPOT assay and characterization of guinea pig cytomegalovirus GP83-specific cellular immune responses following immunization with a modified vaccinia virus Ankara (MVA)-vectored GP83 vaccine.

    Science.gov (United States)

    Gillis, Peter A; Hernandez-Alvarado, Nelmary; Gnanandarajah, Josephine S; Wussow, Felix; Diamond, Don J; Schleiss, Mark R

    2014-06-30

    The guinea pig (Cavia porcellus) provides a useful animal model for studying the pathogenesis of many infectious diseases, and for preclinical evaluation of vaccines. However, guinea pig models are limited by the lack of immunological reagents required for characterization and quantification of antigen-specific T cell responses. To address this deficiency, an enzyme-linked immunospot (ELISPOT) assay for guinea pig interferon (IFN)-γ was developed to measure antigen/epitope-specific T cell responses to guinea pig cytomegalovirus (GPCMV) vaccines. Using splenocytes harvested from animals vaccinated with a modified vaccinia virus Ankara (MVA) vector encoding the GPCMV GP83 (homolog of human CMV pp65 [gpUL83]) protein, we were able to enumerate and map antigen-specific responses, both in vaccinated as well as GPCMV-infected animals, using a panel of GP83-specific peptides. Several potential immunodominant GP83-specific peptides were identified, including one epitope, LGIVHFFDN, that was noted in all guinea pigs that had a detectable CD8+ response to GP83. Development of a guinea pig IFN-γ ELISPOT should be useful in characterization of additional T cell-specific responses to GPCMV, as well as other pathogens. This information in turn can help focus future experimental evaluation of immunization strategies, both for GPCMV as well as for other vaccine-preventable illnesses studied in the guinea pig model.

  13. Cell-mediated and humoral immune responses to chlamydial antigens in guinea pigs infected ocularly with the agent of guinea pig inclusion conjunctivitis.

    Science.gov (United States)

    Senyk, G; Kerlan, R; Stites, D P; Schanzlin, D J; Ostler, H B; Hanna, L; Keshishyan, H; Jawetz, E

    1981-04-01

    Cell-mediated immune response and humoral response to chlamydial antigens were investigated in guinea pigs infected with the agent of guinea pig inclusion conjunctivitis (GPIC). Pronounced cell-mediated immune response to the homologous antigen, as well as to two other chlamydial antigens, 6BC (Chlamydia psittaci) and LB-1 (C. trachomatis), occurred in all infected animals. Cell-mediated immune response to GPIC, and to a lesser extent to 6BC and LB-1 as well, was enhanced with time after infection even without the re-inoculation of the infectious agent. Extensive cross-reactions among the three chlamydial antigens during the cell-mediated immune response appeared to be due to shared species-specific and group-reactive antigens. Serum antibody response was pronounced and uniform to GPIC; it was less marked to 6BC and LB-1, with fewer cross-reactions than seen in tests for cell-mediated immunity.

  14. Prokaryotic expression and in vitro functional analysis of IL-1β and MCP-1 from guinea pig.

    Science.gov (United States)

    Dirisala, Vijaya R; Jeevan, Amminikutty; Ly, Lan H; McMurray, David N

    2013-06-01

    The Guinea pig (Cavia porcellus) is an excellent animal model for studying human tuberculosis (TB) and also for a number of other infectious and non-infectious diseases. One of the major roadblocks in effective utilization of this animal model is the lack of readily available immunological reagents. In order to address this issue, guinea pig interleukin 1 beta (IL-1β) and monocyte chemoattractant protein-1 (MCP-1) were efficiently cloned and expressed in a prokaryotic expression vector, and the expressed proteins in soluble form from both the genes were confirmed by N-terminal sequencing. The biological activity of recombinant guinea pig IL-1β was demonstrated by its ability to drive proliferation in thymocytes, and the recombinant guinea pig MCP-1 exhibited chemotactic activity for guinea pig resident peritoneal macrophages. These biologically active recombinant guinea pig proteins will facilitate an in-depth understanding of the role they play in the immune responses of the guinea pig to TB and other diseases.

  15. An Investigation into the Relationship between Owner Knowledge, Diet, and Dental Disease in Guinea Pigs (Cavia porcellus).

    Science.gov (United States)

    Norman, Rosemary; Wills, Alison P

    2016-11-14

    Recent studies have highlighted a high prevalence of dental disease in domestic guinea pigs, yet the aetiology of this multi-factorial disease is still unclear. Factors that have been associated with dental disease include feeding a diet that is high in energy but low in fibre, feeding an insufficiently abrasive diet, a lack of dietary calcium, and genetics. As many of these factors relate to the husbandry requirements of guinea pigs, owner awareness of dietary requirements is of the utmost importance. An online questionnaire was created based on previous research into the husbandry and feeding of rabbits. Guinea pig owners were asked to answer questions on the clinical history of their animals and their diet and management. In total, 150 surveys were completed for 344 guinea pigs, where owners of multiple animals could complete the survey for individuals. According to the owners, 6.7% of guinea pigs had been clinically diagnosed with dental disease, but 16.6% had signs consistent with dental disease. The specific clinical signs of having difficulty eating (Exp(B) = 33.927, Nagelkerke R ² = 0.301, p guinea pig diet, and dental disease in the study population. This study highlights the importance of access to the outdoors for the health and welfare of guinea pigs in addition to the need for owners to be alert to key clinical signs. A relationship between diet and dental disease was not identified in this study; however, the underlying aetiological causes of this condition require further investigation.

  16. Human mast cell mediator cocktail excites neurons in human and guinea-pig enteric nervous system.

    Science.gov (United States)

    Schemann, M; Michel, K; Ceregrzyn, M; Zeller, F; Seidl, S; Bischoff, S C

    2005-04-01

    Neuroimmune interactions are an integral part of gut physiology and involved in the pathogenesis of inflammatory and functional bowel disorders. Mast cells and their mediators are important conveyors in the communication from the innate enteric immune system to the enteric nervous system (ENS). However, it is not known whether a mediator cocktail released from activated human mast cells affects neural activity in the ENS. We used the Multi-Site Optical Recording Technique to image single cell activity in guinea-pig and human ENS after application of a mast cell mediator cocktail (MCMC) that was released from isolated human intestinal mucosa mast cells stimulated by IgE-receptor cross-linking. Local application of MCMC onto individual ganglia evoked an excitatory response consisting of action potential discharge. This excitatory response occurred in 31%, 38% or 11% neurons of guinea-pig submucous plexus, human submucous plexus, or guinea-pig myenteric plexus, respectively. Compound action potentials from nerve fibres or fast excitatory synaptic inputs were not affected by MCMC. This study demonstrates immunoneural signalling in the human gut and revealed for the first time that an MCMC released from stimulated human intestinal mast cells induces excitatory actions in the human and guinea-pig ENS.

  17. Treatment efficacy in a soman-poisoned guinea pig model: Added value of physostigmine?

    NARCIS (Netherlands)

    Joosen, M.J.A.; Smit, A.B.; Helden, H.P.M. van

    2011-01-01

    Current treatment of organophosphate poisoning is insufficient, and survivors may suffer from long-lasting adverse effects, such as cognitive deficits and sleep-wake disturbances. In the present study, we aimed at developing a guinea pig model to investigate the benefits of immediate and delayed sta

  18. Certain dietary carbohydrates promote Listeria infection in a guinea pig model, while others prevent it

    DEFF Research Database (Denmark)

    Ebersbach, Tine; Jørgensen, Julie Boeck; Heegaard, Peter M. H.;

    2010-01-01

    of five non-digestible carbohydrates on the resistance of guinea pigs to Listeria monocytogenes infections. Animals were fed a diet supplemented with 10% xylooligosaccharides (XOS), galactooligosaccharides (GOS), inulin, apple pectin or polydextrose for three weeks before oral infection with a mixture...

  19. Effects of polylactic acid film on middle ear mucosa and cochlear function in Guinea pigs.

    Science.gov (United States)

    Ensari, Nuray; Tutar, Hakan; Ekinci, Ozgur; Ugur, Mehmet Birol; Bayazıt, Yıldırım A; Gokdogan, Cagil; Goksu, Nebil

    2015-05-01

    Our aim was to assess the effects of polylactic acid (PLA) on middle ear mucosa and cochlea, to be used as a film barrier for postoperative adhesion prevention in the middle ear. Twenty-one albino Guinea pigs were included in the study. A window was opened on both tympanic bulla and on one side PLA material was placed in the middle ear and on the other side only fenestration was performed and used as a control. All Guinea pigs underwent evaluation of tympanic membranes microscopically; functional hearing was analyzed by auditory brainstem responses preoperatively, in the first and the sixth month. All Guinea pigs were killed on the sixth month for histopathologic evaluation of their temporal bones. There was no statistical difference between both groups regarding hearing thresholds, interpeak wave latencies preoperatively and on first and the sixth months postoperatively. Histopathological evaluation revealed no specific changes. There was a mild local inflammation both in the PLA implanted and control ears. PLA film barrier most likely has no toxic effects on Guinea pig middle ear and does not show any ototoxic side effects.

  20. Streptomycin action to the mammalian inner ear vestibular organs: comparison between pigmented guinea pigs and rats.

    Science.gov (United States)

    Meza, Graciela; Aguilar-Maldonado, Beatriz

    2007-01-01

    Streptomycin is the antibiotic of choice to treat tuberculosis and other infectious diseases but it causes vestibular malfunction and hipoacusia. Rodents are usually employed as models of drug action to the inner ear and results are extrapolated to what happens in humans. In rats, streptomycin destroys macular sensory cells and does not affect cochlear ones, whereas in guinea pigs the contrary is true. Action on the vestibular cristae cells involved in vestibulo-ocular reflex integrity is less clear. Thus, we compared this response in both pigmented guinea pigs (Cavia cobaya) and rats (Rattus norvegicus) after parallel streptomycin chronic treatment. In guinea pigs, the reflex was obliterated along treatment time; in rats this behavior was not observed, suggesting that the end organ target was diverse. In recent studies, streptidine, a streptomycin derivative found in the blood of humans and rats treated with streptomycin, was the actual ototoxic agent. The putative streptomycin vestibular organ target observed in humans corresponds with the guinea pig observations. Results observed in rats are controversial: streptidine did not cause any damage either to vestibular cristae nor auditory cells. We hypothesize differential drug metabolism and distribution and conclude that results in laboratory animals may not always be applicable in the human situation.

  1. CROSS-REACTION PATTERNS IN GUINEA-PIGS SENSITIZED TO ACRYLIC-MONOMERS

    DEFF Research Database (Denmark)

    Clemmensen, S.

    1984-01-01

    The cross-reaction patterns of selected acrylate and methacrylate esters were investigated using the guinea pig maximization test. Methacrylates were less potent sensitizers than acrylates. Cross-sensitization was found between (meth)acrylates with closely related core structures, most extensively...

  2. The effect of changes in perilymphatic K+ on the vestibular evoked potential in the guinea pig

    NARCIS (Netherlands)

    Kingma, C. M.; Wit, H. P.

    2010-01-01

    To investigate the effect on the functioning of the vestibular system of a rupture of Reissner's membrane, artificial endolymph was injected in scala media of ten guinea pigs and vestibular evoked potentials (VsEPs), evoked by vertical acceleration pulses, were measured. Directly after injection of

  3. Endogenous histamine and promethazine-induced gastric ulcers in the guinea pig

    Science.gov (United States)

    Djahanguiri, B.; Hemmati, M.

    1978-01-01

    Experiments performed with an inhibitor of diaminoxydase, aminoguanidine and an inhibitor of histidine decarboxylase, NSD 1055, showed that the frequency of gastric ulcers induced by promethazine was increased with the first inhibitor and decreased with the second. It is suggested that ulcers induced by promethazine in guinea pigs might be due to histamino-liberator effect of the antihistaminio compound.

  4. SELECTION OF PHYLOGENETICALLY CLOSELY-RELATED YERSINIA PESTIS STRAINS DIFFERING IN THEIR VIRULENCE FOR GUINEA PIGS

    Directory of Open Access Journals (Sweden)

    N. V. Anisimov

    2015-01-01

    Full Text Available Genomic, transcriptome or (and proteomic comparison of closely related virulent and avirulent microbial strains underlies the search for new pathogenicity factors, potential molecular targets for etiotropic therapy, vaccine prevention and immunotherapy of infectious diseases. This investigation was aimed in testing the ability of method of testicular animalization to select phylogenetically close pairs of Y. pestis strains, which dramatically differ in their pathogenicity for guinea pigs, from the populations of as a rule subcutaneously avirulent for guinea pigs “vole” strains of the plague pathogen. Animalization of Y. pestis cultures were performed on guinea pig males by fourfold testicular passage with reducing infective dose. There was no correlation between the ability to cause generalized infectious process (death after testicular and subcutaneous infection of guinea pigs, but testicular passages made it possible to enrich bacterial culture with a portion of microbes displaying high virulence after subcutaneous infection of this animal species. The methodical approach under study can be successfully applied for selection of pairs of phylogenetically closely related bacterial strains, dramatically differing in their degrees of selective virulence. 

  5. CONDITIONAL INVOLVEMENT OF MUSCARINIC M(1) RECEPTORS IN VAGALLY MEDIATED CONTRACTION OF GUINEA-PIG BRONCHI

    NARCIS (Netherlands)

    TENBERGE, REJ; ROFFEL, AF; ZAAGSMA, J

    The involvement of ganglionic muscarinic M(1) receptors in vagally induced bronchoconstriction in guinea-pig airways is controversial. Therefore, we studied the effects of the M(1)-selective muscarinic receptor antagonist pirenzepine on vagus nerve (VNS, preganglionic) and electrical field

  6. Olfactory experience modulates immature neuron development in postnatal and adult guinea pig piriform cortex.

    Science.gov (United States)

    He, X; Zhang, X-M; Wu, J; Fu, J; Mou, L; Lu, D-H; Cai, Y; Luo, X-G; Pan, A; Yan, X-X

    2014-02-14

    Immature neurons expressing doublecortin (DCX+) are present around cortical layer II in various mammals including guinea pigs and humans, especially enriched in the paleocortex. However, little is known whether and how functional experience affects the development of this population of neurons. We attempted to explore a modulation by experience to layer II DCX+ cells in the primary olfactory cortex in postnatal and adult guinea pigs. Neonatal and 1-year-old guinea pigs were subjected to unilateral naris-occlusion, followed 1 and 2months later by morphometry of DCX+ cells in the piriform cortex. DCX+ somata and processes were reduced in the deprived relative to the non-deprived piriform cortex in both age groups at the two surviving time points. The number of DCX+ cells was decreased in the deprived side relative to internal control at 1 and 2months in the youths and at 2months in the adults post-occlusion. The mean somal area of DCX+ cells showed a trend of decrease in the deprived side relative to the internal control in the youths. In addition, DCX+ cells in the deprived side exhibited a lower frequency of colocalization with the neuron-specific nuclear antigen (NeuN) relative to counterparts. These results suggest that normal olfactory experience is required for the maintenance and development of DCX+ immature neurons in postnatal and adult guinea pig piriform cortex.

  7. The effect of changes in perilymphatic K+ on the vestibular evoked potential in the guinea pig

    NARCIS (Netherlands)

    Kingma, C. M.; Wit, H. P.

    2010-01-01

    To investigate the effect on the functioning of the vestibular system of a rupture of Reissner's membrane, artificial endolymph was injected in scala media of ten guinea pigs and vestibular evoked potentials (VsEPs), evoked by vertical acceleration pulses, were measured. Directly after injection of

  8. Acute endolymphatic hydrops has no direct effect on the vestibular evoked potential in the guinea pig

    NARCIS (Netherlands)

    Kingma, C. M.; Wit, H. P.

    2009-01-01

    To investigate the effect of an acute endolymphatic hydrops on the functioning of the vestibular system a hydrops was created by microinjection of artificial endolymph through the basilar membrane into scala media in 10 guinea pigs. To control for the effect of perforation of the basilar membrane, t

  9. Evidence for a role of CCK as neurotransmitter in the guinea-pig enteric nervous system.

    NARCIS (Netherlands)

    Schutte, I.W.M.; Hollestein, K.B.C.W.; Akkermans, L.M.A.; Kroese, A.B.A.

    1997-01-01

    Intracellular recordings were made of neurons in the myenteric plexus of the guinea-pig distal ileum. Slow excitatory post-synaptic potentials (sEPSPs) were evoked by electrical stimulation of an interganglionic fibre tract. The effect of cholecystokinin (CCK) receptor antagonists on the sEPSPs was

  10. Pathogenesis of Aerosolized Eastern Equine Encephalitis Virus Infection in Guinea Pigs

    Science.gov (United States)

    2009-01-01

    Steele5 Address: 1Division of Microbiology , Tulane National Primate Research Center, Covington, Louisiana, USA, 2Center for Vaccine Research, University...included rare positive cells that appeared to be osteoblasts in the skulls of four guinea pigs, small foci of positive subgingival or periodontal connective

  11. [Development of a cytological method to detect pregnancy in guinea pigs].

    Science.gov (United States)

    Gómez, M D; Boxaca, M C

    1982-01-01

    Diagnosis of guinea pig pregnancy by the inhibition hemagglutination test used to detect chorionic gonadotrophin in urine showed to be unreliable after the 57% false positive and 3% false negative results obtained over 79 urine samples tested. On the other hand, by comparing the cell morphology of about 60 vaginal smears taken from 20 non-pregnant guinea pigs, stained by a Papanicolaou modified technique, the 4 estrous cycle stages were characterized. The subsequent study of many vaginal smears taken from 15 pregnant guinea pigs showed no pathognomic cells but a picture where 60-70% proestrus and 40-30% diestrus cells appeared. This proestrus-diestrus (Pd) picture was accepted as typical for pregnancy, because it showed up in every pregnant guinea pig lasting all the gestation period, changing only after delivery or abortion. Fecundation does not change the estrous cycle sequence which, as it was proved, progressed normally until it reached this Pd picture. Therefore, the persistence of a Pd picture during +/- 6 days should be considered as diagnosis for pregnancy; when estrus has been detected a Pd picture 12-14 days post estrus as prognosis, and at 16-19 days post-estrus as diagnosis for pregnancy. This cytologic assay proved to be reliable. Besides, once cell characterization has been performed, the staining procedure can be substituted by a direct observation of wet specimen, saving time without loosing accuracy.

  12. Haemophilus influenzae induces a potentiated increase in guinea-pig pulmonary resistance to histamine

    NARCIS (Netherlands)

    Folkerts, G.; Nijkamp, F.P.

    1985-01-01

    The human respiratory pathogen Haemophilus influenzae (H.i.) induced bronchial hyperreactivity to histamine (1.0–8.0 μg/100 g b.w. i.v.) in vivo in anaesthetized spontaneously breathing guinea-pigs. This hyperreactivity was caused by a potentiated increase in pulmonary resistance. Decreases in dynam

  13. Monitoring inner ear pressure changes in normal guinea pigs induced by the Meniett (R) 20

    NARCIS (Netherlands)

    Feijen, RA; Segenhout, JM; Wit, HP; Albers, FWJ

    2000-01-01

    The inner ear fluid pressure of guinea pigs was measured during a series of complex escalating middle ear pressure changes induced by the Meniett(R)20 (Pascal Medical, Sweden), a possible therapeutic pressure generator to be used by patients with Meniere's disease. Middle ear pressure changes were t

  14. Case Report of a Satin Guinea Pig with Fibrous Osteodystrophy That Resembles Human Pseudohypoparathyroidism

    Directory of Open Access Journals (Sweden)

    Miguel Gallego

    2017-01-01

    Full Text Available A case report of a 2-year-old female satin guinea pig with a history of dental overgrowth and lameness and radiological lesions of fibrous osteodystrophy is presented. The most relevant clinical findings were bone demineralization, high level of parathyroid hormone (PTH, normophosphatemia, normal ionized calcium, and low total thyroxine (tT4 with a normal renal function. Long-term treatment was based on teeth coronal reduction and maintaining a balanced diet. PTH measurement was performed with a kit suitable for rats to test 4 different paired samples of guinea pigs and resulted in similar results for each pair of measurements. Two kits routinely employed in dogs and cats failed in measuring PTH in guinea pig serum samples. The ionized calcium, PTH, and tT4 values, not previously reported in similar cases, were obtained. The determination of tT4 could be useful in the diagnosis of fibrous osteodystrophy in guinea pigs. The observed findings show similarity with human pseudohypoparathyroidism type Ia, a disease caused by an inactivating heterozygous mutation of the stimulatory G protein α subunit from the maternal genome that induces multiple hormone resistance and that courses with a syndrome called Albright hereditary osteodystrophy. Naturally occurring pseudohypoparathyroidism in animals has been reported previously only in a ferret.

  15. Pharmacokinetics of Niacinamide in Blood and Skin of Hairless Guinea Pigs

    Science.gov (United States)

    1993-05-13

    Products Division. Maumee, Ohio/ Delphi , ID, U.S.A.) which was changed three times per week. Commercial certified guinea pig ration (Ziegler Bros.. Inc...HPLC Equipment included an LC-6A chromatograph equipped %vith an SIC- 6B auto injector , SCL-6B system controller, SPD-6A UV Detector (D2 lamp 254 nm

  16. Diet Restriction and Fasting Exacerbate the Toxicity of Soman in Young and Old Guinea Pigs

    Science.gov (United States)

    2012-09-01

    be an important predictor of human health effects in a CWNA-exposure scenario, with individuals of different body composition exhibiting different...carboxylesterase levels found in guinea pigs result in toxicological responses to a given dose of CWNA that are more similar to those of non- human ...Aas P, Johnsen H. Carboxylesterases, importance for detoxification of organophosphorus anticholinesterases and trichothecenes . Fundam Appl Toxicol

  17. Argyrophilic cells in the larynx of the guinea-pig demonstrated by the method of Grimelius

    DEFF Research Database (Denmark)

    Kirkeby, S; Romert, P

    1977-01-01

    Argyrophilic cells with branching processes are shown in both the surface epithelium and in the glands in the larynx of adult guinea-pigs using the Grimelius silver technique after GPA fixation. When Bouin's fixative or neutral formalin were used as fixatives argrophilic cells could not be identi...

  18. Gastrointestinal motility, prokinetic benzamides and serotonin : a study on the guinea-pig colon

    NARCIS (Netherlands)

    Briejer, M.R.

    1995-01-01

    The prokinetic substituted benzamides stimulate gastrointestinal motility in animal models and in man. Studies done on the isolated guinea-pig ileum have led to the hypothesis that the benzamides act through facilitation of cholinergic transmission due to stimulation of serotonin4 (5-HT

  19. Differential susceptibility of rats and guinea pigs to the ototoxic effects of ethyl benzene

    NARCIS (Netherlands)

    Cappaert, NLM; Klis, SFL; Muijser, H; Kulig, BM; Ravensberg, LC; Smoorenburg, GF

    2002-01-01

    The present study was designed to compare the ototoxic effects of volatile ethyl benzene in guinea pigs and rats. Rats showed deteriorated auditory thresholds in the mid-frequency range, based on electrocochleography, after 550-ppm ethyl benzene (8 h/day, 5 days). Outer hair cell (OHC) loss was foun

  20. Change of guinea pig inner ear pressure by square wave middle ear cavity pressure variation

    NARCIS (Netherlands)

    Feijen, RA; Segenhout, JM; Albers, FWJ; Wit, HP

    The inner ear fluid pressure of guinea pigs was measured during square wave middle ear cavity pressure variation. Time constants were derived for the slopes of the inner ear pressure recovery curves after middle ear pressure change. A "single exponential" function did not fit well and therefore more

  1. Monitoring inner ear pressure changes in normal guinea pigs induced by the Meniett (R) 20

    NARCIS (Netherlands)

    Feijen, RA; Segenhout, JM; Wit, HP; Albers, FWJ

    2000-01-01

    The inner ear fluid pressure of guinea pigs was measured during a series of complex escalating middle ear pressure changes induced by the Meniett(R)20 (Pascal Medical, Sweden), a possible therapeutic pressure generator to be used by patients with Meniere's disease. Middle ear pressure changes were

  2. Effect of estradiol on chlamydial genital infection of female guinea pigs.

    Science.gov (United States)

    Rank, R G; White, H J; Hough, A J; Pasley, J N; Barron, A L

    1982-11-01

    Female guinea pigs were treated daily with 1 mg of beta-estradiol-3-benzoate intramuscularly beginning 14 days before intravaginal inoculation with the chlamydial agent of guinea pig inclusion conjunctivitis and continuing during the course of the infection. Treatment with estradiol was found to markedly influence the course of genital infection with the chlamydial agent of guinea pig inclusion conjunctivitis, producing infections of greater intensity and longer duration than those in control animals. Moreover, pathogenesis was altered in that ascending infection was observed, resulting in endometritis, cystic salpingitis, and cystitis. Infection in the controls was limited to the cervix and vagina. Estradiol treatment increased the apparent number of infected cells in the cervix and vagina as detected by histopathology and immunofluorescent staining. Humoral and cell-mediated immune responses to the chlamydial agent of guinea pig inclusion conjunctivitis were comparable in estradiol-treated and untreated animals. These data indicate that hormonal manipulation may have profound effects on the course of chlamydial genital infections.

  3. Sparing effects of selenium and ascorbic acid on vitamin C and E in guinea pig tissues

    Directory of Open Access Journals (Sweden)

    Hayward Stephen

    2007-03-01

    Full Text Available Abstract Background Selenium (Se, vitamin C and vitamin E function as antioxidants within the body. In this study, we investigated the effects of reduced dietary Se and L-ascorbic acid (AA on vitamin C and α-tocopherol (AT status in guinea pig tissues. Methods Male Hartley guinea pigs were orally dosed with a marginal amount of AA and fed a diet deficient (Se-D/MC, marginal (Se-M/MC or normal (Se-N/MC in Se. An additional diet group (Se-N/NC was fed normal Se and dosed with a normal amount of AA. Guinea pigs were killed after 5 or 12 weeks on the experimental diets at 24 and 48 hours post AA dosing. Results Liver Se-dependent glutathione peroxidase activity was decreased (P P > 0.05 by reduction in dietary Se or AA. All tissues examined showed a decrease (P P P Conclusion Together, these data demonstrate sparing effects of Se and AA on vitamin C and AT in guinea pig tissues.

  4. Morphology and electrophysiology of the vestibular organ in the guinea pig

    NARCIS (Netherlands)

    Oei, Markus Lee Yang Murti

    2003-01-01

    To obtain more information about the anatomy and function of the vestibular organ in normal and pathological conditions, evaluation methods are needed. For experimental purposes, the vestibular organ of the guinea pig is often used as a model for the human vestibular organ. The purpose of the resear

  5. Change of guinea pig inner ear pressure by square wave middle ear cavity pressure variation

    NARCIS (Netherlands)

    Feijen, RA; Segenhout, JM; Albers, FWJ; Wit, HP

    2002-01-01

    The inner ear fluid pressure of guinea pigs was measured during square wave middle ear cavity pressure variation. Time constants were derived for the slopes of the inner ear pressure recovery curves after middle ear pressure change. A "single exponential" function did not fit well and therefore more

  6. Macrophage Chemotaxis in Anti-tubular Basement Membrane-Induced Interstitial Nephritis in Guinea Pigs

    NARCIS (Netherlands)

    Kennedy, Thomas L.; Merrow, Martha; Phillips, S. Michael; Norman, Michael; Neilson, Eric G.

    1985-01-01

    Interstitial renal lesions containing T cells and macrophages develop after 14 days in guinea pigs immunized to produce anti-tubular basement membrane-induced interstitial nephritis. We serially examined the renal venous and systemic arterial sera from such animals to determine if chemotactic factor

  7. Specificity of antibodies to nitric oxide synthase isoforms in human, guinea pig, rat, and mouse tissues

    NARCIS (Netherlands)

    Coers, W; Timens, W; Kempinga, C; Klok, PA; Moshage, H

    1998-01-01

    Ten commercially available rabbit polyclonal anti-NOS antibodies were tested for their immunohistological applicability in normal human, guinea pig, rat, and mouse organs. Most antibodies reacted as expected and described in the literature with various tissues of the investigated species. Several an

  8. Gastrointestinal motility, prokinetic benzamides and serotonin - a study on the guinea pig colon.

    NARCIS (Netherlands)

    Briejer, M.R.

    1995-01-01

    The prokinetic substituted benzamides stimulate gastrointestinal motility in animal models and in man. Studies done on the isolated guinea-pig ileum have led to the hypothesis that the benzamides act through facilitation of cholinergic transmission due to stimulation of serotonin4 (5-HT 4

  9. Results of Acellular Dermis Matrix Graft Used for Tympanoplasty in Guinea Pig Model

    Directory of Open Access Journals (Sweden)

    Farhad Farahani

    2015-03-01

    Full Text Available Introduction: To describe the underlay tympanoplasty technique using an acellular dermal graft(AlloDerm for tympanic membrane (TM reconstruction in a guinea pig model and to demonstrate the feasibility of the technique using AlloDerm tissue harvested from the prepuce as a source of tissue for future grafting in human TM reconstruction.   Materials and Methods: The prepuce was divided during circumcision and the acellular dermis was prepared using a number of standard processes. Two groups of guinea pigs were prepared. In the case group (20 guinea pigs and 40 ears removal of TM was performed with tympanoplasty using AlloDerm, and in the control group (eight guinea pigs and 16 ears, removal of TM was performed without tympanoplasty. In each group, the TM was completely removed in one ear and partially removed on the other side, and the integrity of the TMs was re-evaluated after 8 weeks.   Results: In the case group, the healing rates in the completely and partially removed TMs were 83.3% and 94.4%, respectively. The difference in healing rate (0% and 66.7%, respectively was statistically significant (P

  10. Intravenous and inhalation toxicokinetics of sarin stereoisomers in atropinized guinea pigs

    NARCIS (Netherlands)

    Spruit, W.E.T.; Langenberg, J.P.; Trap, H.C.; Wiel, H.J. van der; Helmich, R.B.; Helden, H.P.M. van; Benschop, H.P.

    2000-01-01

    We report the first toxicokinetic studies of (±)-sarin. The toxicokinetics of the stereoisomers of this nerve agent were studied in anesthetized, atropinized, and restrained guinea pigs after intravenous bolus administration of a dose corresponding to 0.8 LD50 and after nose-only exposure to vapor c

  11. Frequency response for electromotility of isolated outer hair cells of the guinea pig

    NARCIS (Netherlands)

    Wit, HP; vanDijk, P; Segenhout, HM

    1996-01-01

    Frequency and impulse responses were determined for isolated guinea pig outer hair cells by electrically stimulating the cells between two wire electrodes with white noise. Cells were attached to the bottom of a small culture dish at one end while the other end was freely moving. Results have the ch

  12. Stereomicroscopic and histologic changes in the colon of guinea pigs fed degraded carrageenan

    DEFF Research Database (Denmark)

    Poulsen, Steen Seier

    1980-01-01

    A colitis-like state induced in Guinea Pigs fed degraded carrageenan orally. By means of a combined semimacroscopic and histologic technique the course of the disease was followed during 28 days. The changes were primarily seen and became most prominent in the caecum. The first lesions were...

  13. THE IMPACT OF ULTRAVIOLET IRRADIATION ON MORPHO-FUNCTIONAL STATE OF SKIN IN GUINEA PIGS.

    Science.gov (United States)

    Myronchenko, S; Naumova, O; Zvyagintseva, T

    2016-11-01

    The purpose of this study was to assess the impact of ultraviolet irradiation (UV) on morphological and functional condition of the skin in guinea pigs. The study involved 30 albino guinea pigs weighing 400-500 g subjected to local exposure to UV irradiation. Control group consisted of intact guinea pigs. Histological studies of the skin were carried out at different stages of the trial (2 hours, 4 hours, 3 days, 8 days following the exposure). Microscopic examination showed morphological signs of acute inflammation in the skin of animals within the first three days following the exposure to UV irradiation. Within 2 hours following the exposure to UV irradiation these changes were minimal with signs of mild exudative changes. In 4 hours after the exposure histological changes increased. The specimens were also found to contain altered apoptotic keratinocytes (sunburn cells). Histopathological changes persisted and reached maximum severity by the 3rd day. Within post-erythema period (the 8th day) proliferative, hyperplastic, degenerative and dystrophic changes in the skin persisted. The prolonged nature of the changes in the skin is suggestive of the development of chronic inflammation in the skin of guinea pigs subjected to local exposure to UV irradiation.

  14. The Validity of Osteoarthritis Model Induced by Bilateral Ovariectomy in Guinea Pig

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    To evaluate the validity of osteoarthritis model induced by bilateral ovariectomy in guinea pig, 32-month-old female guinea pigs were randomly divided into two groups: a sham operation group (control group) and an ovariectomized group (OVX group). The animals were killed 6 or 12 weeks after the operation and the degeneration of the knees were assessed microscopically and histologically by scanning electron microscope (SEM), transmission electron microscope (TEM) and light microscope. The serum levels of estrogen and gestone were detected by immune contest assay.The scoring of articular cartilage histopathology of tibial plateau was performed by histopathological examination. The blood serum levels of estrogen and gestone were decreased significantly in the OVX group as compared with the control group 6 or 12 weeks after the operation. Joint cartilage degeneration as detected by SEM and TEM could be found at the 6th week, but severe degenerative lesions were observed at the 12th week in the OVX group as compared with the control group (P<0.01).The histopathological score of articular cartilage in tibial plateau in OVX group was higher than that of control group, which was coincident with the changes of estrogen and the ultrastructure (P<0.01).The findings suggested that bilateral ovariectomy in guinea pig can induce the severe osteoarthritis that is similar to the aging-induced OA in human. Therefore, the model of the osteoarthritis by bilateral ovariectomy in guinea pig in this study is valid.

  15. Decreased delayed hypersensitivity to tuberculin demonstrated in experimental leptospirosis in guinea pigs

    DEFF Research Database (Denmark)

    Colding, H; Johansen, K S; Bentzon, M W

    1976-01-01

    Skin reactivity to tuberculin has been studied during the course of experimental leptospirosis in guinea pigs. A depression of the delayed hypersensitivity to tuberculin was demonstrated in the infected animals. The depression was most pronounced when icterus had developed. The depression...

  16. Do young guinea pigs (Cavia porcellus) develop an attachment to inanimate objects?

    NARCIS (Netherlands)

    Janzen, MID; Timmermans, PJA; Kruijt, JP; Vossen, JMH

    1999-01-01

    Filial imprinting has been studied extensively in precocial birds. In these studies, inanimate objects were used as imprinting objects. Although attachment to the parents is common in mammals, experiments with inanimate objects are rare and mostly restricted to guinea pigs (Cavia porcellus). The res

  17. Papular Dermatitis Induced in Guinea Pig by Biting Midge Culicoides Sonorensis (Diptera: Ceratopogonidaie)

    Science.gov (United States)

    Histological, ultrastructural, and virological examinations were performed on abdominal skin from guinea pigs after a blood meal by colony-bred biting midges, Culicoides sonorensis. Small, superficial, cutaneous, crateriform ulcers with necrosis of superficial dermis developed at feeding sites and h...

  18. Hypervitaminosis D and Metastatic Calcification in a Colony of Inbred Strain 13 Guinea Pigs, Cavia porcellus.

    Science.gov (United States)

    Holcombe, H; Parry, N M; Rick, M; Brown, D E; Albers, T M; Refsal, K R; Morris, J; Kelly, R; Marko, S T

    2015-07-01

    A commercial diet fed to a colony of inbred strain 13 guinea pigs for approximately 6 weeks was subsequently recalled for excessive levels of vitamin D. Twenty-one of 62 animals exhibited clinical signs, including anorexia, lethargy, and poor body condition. Nine affected and 4 clinically normal animals were euthanized for further evaluation, including serum chemistry, urinalysis, and gross and/or histopathology. Macroscopic findings included white discoloration in multiple organs in 8 animals, and microscopic evaluation confirmed multiorgan mineralization in tissues from 7 animals. Serum 25-hydroxyvitamin D levels were elevated in 10 animals. Serum inorganic phosphorus and alkaline phosphatase levels were increased in all exposed animals; however, total calcium and ionized calcium levels were not significantly higher in exposed animals than in control strain 13 guinea pigs from a different institution. The data support a diagnosis of hypervitaminosis D with metastatic calcification. Following the diet recall, the remaining guinea pigs increased their food intake and regained body condition. Diagnostic testing of 8 animals euthanized approximately 3 months after returning to a normal diet demonstrated that serum parathyroid hormone remained significantly lower, and ionized calcium and ionized magnesium were significantly higher, in recovered animals compared to controls and exposed animals. These results indicate that diagnostic tests other than serum calcium are necessary for a diagnosis of hypervitaminosis D in guinea pigs.

  19. HORMONAL INFLUENCES ON THE OVARIAN FUNCTION AND THE IMPLANTATION PROCESS IN GUINEA PIGS

    Institute of Scientific and Technical Information of China (English)

    LIUCheng-Quan; DAIMao-Zheng; SHENShu-Ren; WANGZhong-Xing

    1989-01-01

    The influence of peptides and steroid hormones on ovarian function and implantation was studied in guinea pigs. Results show that injections of 5ng LHRH in pulses of onc-hour interval 10 times per day, starting from 20-30 days of age, could induce the first vaginal

  20. Spontaneous behavior in noise and silence : a possible new measure to assess tinnitus in Guinea pigs

    NARCIS (Netherlands)

    Heeringa, Amarins N; Agterberg, Martijn J H; van Dijk, Pim

    2014-01-01

    This study describes two experiments that were conducted in search for a behavioral paradigm to test for tinnitus in guinea pigs. Conditioning paradigms are available to determine the presence of tinnitus in animals and are based on the assumption that tinnitus impairs their ability to detect silent

  1. The influence of starvation upon hepatic drug metabolism in rats, mice, and guinea pigs.

    Science.gov (United States)

    Furner, R. L.; Feller, D. D.

    1971-01-01

    Male rats, mice, and guinea pigs were starved for 1, 2, or 3 days, and the metabolism of ethylmorphine, p-nitroanisole, and aniline was studied. Results suggest that the oxidative enzyme systems studied are not interdependent, and the pathways studied appear to be species dependent.

  2. Mitochondria-Targeted Antioxidant Mitoquinone Reduces Cisplatin-Induced Ototoxicity in Guinea Pigs.

    Science.gov (United States)

    Tate, Alan D; Antonelli, Patrick J; Hannabass, Kyle R; Dirain, Carolyn O

    2017-03-01

    Objective To determine if mitoquinone (MitoQ) attenuates cisplatin-induced hearing loss in guinea pigs. Study Design Prospective and controlled animal study. Setting Academic, tertiary medical center. Subjects and Methods Guinea pigs were injected subcutaneously with either 5 mg/kg MitoQ (n = 9) or normal saline (control, n = 9) for 7 days and 1 hour before receiving a single dose of 10 mg/kg cisplatin. Auditory brainstem response thresholds were measured before MitoQ or saline administration and 3 to 4 days after cisplatin administration. Results Auditory brainstem response threshold shifts after cisplatin treatment were smaller by 28 to 47 dB in guinea pigs injected with MitoQ compared with those in the control group at all tested frequencies (4, 8, 16, and 24 kHz, P = .0002 to .04). Scanning electron microscopy of cochlear hair cells showed less outer hair cell loss and damage in the MitoQ group. Conclusion MitoQ reduced cisplatin-induced hearing loss in guinea pigs. MitoQ appears worthy of further investigation as a means of preventing cisplatin ototoxicity in humans.

  3. The effect of ileotransversostomy on carrageenan-induced colitis in guinea pigs

    DEFF Research Database (Denmark)

    Poulsen, Steen Seier

    1983-01-01

    By oral administration of degraded carrageenan a colitis-like disease can be induced in guinea pigs which almost exclusively affects the caecum. To study the effect of degraded carrageenan on the distal colon and rectum, an ileotransversostomy was performed. In the non-operated group of animals...

  4. Spontaneous behavior in noise and silence: a possible new measure to assess tinnitus in Guinea pigs

    NARCIS (Netherlands)

    Heeringa, A.N.; Agterberg, M.J.H.; Dijk, P. van

    2014-01-01

    This study describes two experiments that were conducted in search for a behavioral paradigm to test for tinnitus in guinea pigs. Conditioning paradigms are available to determine the presence of tinnitus in animals and are based on the assumption that tinnitus impairs their ability to detect silent

  5. Short-term toxicity studies with triphenyltin compounds in rats and guinea-pigs

    NARCIS (Netherlands)

    Verschuuren, H.G.; Kroes, R.; Vink, H.H.; Esch, G.J. van

    1966-01-01

    Short-term toxicity studies have been carried out in rats and guinea-pigs fed diets containing triphenyltin acetate (TPTA), triphenyltin hydroxide (TPTH) or triethyltin hydroxide (TETH) for 90 days at levels ranging from 0 to 50 ppm. The lowest dietary levels found to retard growth in rats and guin

  6. Sensitivity and subsequent "down regulation" of sensitivity induced by chlorocresol in guinea pigs

    DEFF Research Database (Denmark)

    Andersen, Klaus Ejner

    1985-01-01

    Chlorocresol was shown to have great potential for contact sensitization in the guinea-pig maximization test at the Day-21 challenge; 2 weeks later, the reactivity was significantly decreased. Cyclophosphamide (250 mg/kg) was interperitoneally injected and used as a modulator for the immune...

  7. Contractility of the guinea pig bladder measured in situ and in vitro

    NARCIS (Netherlands)

    J.M. Groen (Jan); R. van Mastrigt (Ron); J.L.H.R. Bosch (Ruud)

    1994-01-01

    textabstractTo study the relative importance of neurogenic factors in detrusor contractility and to relate a total bladder in vitro contractility model to a previously described bladder wall strip model, active intravesical pressure values were compared in situ and in vitro in eight male guinea pigs

  8. Cyclic nucleotide phosphodiesterase isoenzymes in guinea-pig tracheal muscle and bronchorelaxation by alkylxanthines.

    Science.gov (United States)

    Miyamoto, K; Kurita, M; Sakai, R; Sanae, F; Wakusawa, S; Takagi, K

    1994-09-15

    In this study the phosphodiesterase (PDE) isoenzymes in guinea-pig trachealis smooth muscle were separated by DEAE-Sepharose anion exchange chromatography, identified, and characterized. Furthermore the effect of theophylline and 1-n-butyl-3-n-propylxanthine (BPX) on the isolated PDE isoenzymes and on their tracheal relaxant effect were investigated and compared with the nonxanthine PDE inhibitors amrinone and Ro 20-1724. We identified five distinct isoenzymes in guinea-pig tracheal muscle; calcium/calmodulin-stimulated cyclic AMP PDE (PDE I), cyclic GMP-stimulated cyclic AMP PDE (PDE II), cyclic GMP-inhibited and amrinone-sensitive cyclic AMP PDE (PDE III), cyclic AMP-specific and Ro 20-1724-sensitive PDE (PDE IV), and cyclic GMP-specific PDE (PDE V). BPX strongly inhibited the PDE IV isoenzyme with high selectivity, while the inhibitory effect of theophylline was weak. The PDE IV inhibitors BPX and Ro 20-1724 synergistically increased the relaxant effect of the beta 2-adrenoceptor agonist salbutamol in carbachol-contracted trachea much more strongly than theophylline. In contrast, amrinone, a PDE III inhibitor, hardly influenced the relaxant effect of salbutamol, suggesting that the PDE IV isoenzyme is functionally associated with beta 2-adrenoceptors in guinea-pig trachea and that inhibition of this enzyme potentiates the ability of salbutamol to increase the intracellular cyclic AMP content. These results indicate that the PDE IV isoenzyme plays a significant role in alkylxanthine-mediated relaxation of guinea-pig trachea.

  9. Nickel contact sensitivity in the guinea pig. An efficient open application test method

    DEFF Research Database (Denmark)

    Nielsen, G D; Rohold, A E; Andersen, Klaus Ejner

    1992-01-01

    Nickel contact sensitivity was successfully induced in guinea pigs using an open epicutaneous application method. Immediately after pretreatment with 1% aqueous sodium lauryl sulfate, upper back skin was treated daily for 4 weeks with 0.3%-3% nickel sulfate in either a 1% lanolin cream (Vaseline, p...

  10. Morphological analysis of the vestibular system of guinea pigs poisoned by organophosphate

    Directory of Open Access Journals (Sweden)

    Lícia Assunção Cogo

    2016-02-01

    Full Text Available ABSTRACT INTRODUCTION: The vestibular system is responsible for body balance. There are substances that damage it, causing dizziness; these are termed vestibulotoxic substances. Agrochemicals have been investigated for ototoxicity because of studies that identified dizziness as a recurrent symptom among rural workers' complaints. OBJECTIVE: To histopathologically evaluate the vestibular system in guinea pigs exposed to an organophosphate, and to identify the drug's effects on this system. METHODS: Experimental clinical study. Eighteen guinea pigs were used; six of them poisoned with the organophosphate chlorpyrifos at doses of 0.5 mg/kg/day and seven of them at 1 mg/kg/day; and a control group of five guinea pigs was exposed to distilled water, all for 10 consecutive days. Later, ciliary tufts of saccule and utricle maculae were counted by scanning electron microscopy. RESULTS: Comparing the groups, a one-way ANOVA test for the variable "saccule" ( p = 0.0569 and a Kruskal-Wallis test for the variable "utricle" ( p = 0.8958 were performed, revealing no difference among groups in both variables. CONCLUSION: The histopathologic analysis of the vestibular system of guinea pigs exposed to an organophosphate showed no difference in the amount of ciliary tufts of saccule and utricle maculae at the doses tested, although the result for the variable "saccule" was considered borderline, showing a trend for significance.

  11. THE INFLUENCE OF THE "DIAPLYTE" ANTIGEN OF DREYER ON TUBERCULOSIS OF THE GUINEA PIG.

    Science.gov (United States)

    Bronfenbrenner, J J; Straub, E L

    1925-01-31

    We have prepared "diaplyte" antigen according to Dreyer's procedure and have studied its therapeutic and prophylactic value in experimental tuberculosis of guinea pigs. In our hands it has failed to yield beneficial effects. The animals treated with the antigen tended in general to develop lesions more quickly and to die earlier than the controls.

  12. Propagation of pacemaker activity in the guinea-pig antrum.

    Science.gov (United States)

    Hennig, G W; Hirst, G D S; Park, K J; Smith, C B; Sanders, K M; Ward, S M; Smith, T K

    2004-04-15

    Cyclical periods of depolarization (slow waves) underlie peristaltic contractions involved in mixing and emptying of contents in the gastric antrum. Slow waves originate from a myenteric network of interstitial cells of Cajal (ICC-MY). In this study we have visualized the sequence and propagation of Ca(2+) transients associated with pacemaker potentials in the ICC network and longitudinal (LM) and circular muscle (CM) layers of the isolated guinea-pig gastric antrum. Gastric antrum was dissected to reveal the ICC-MY network, loaded with Fluo-4 AM and activity was monitored at 37 degrees C. Ca(2+) waves propagated throughout the ICC-MY network at an average velocity of 3.24 +/- 0.12 mm s(-1) at a frequency of 4.87 +/- 0.16 cycles min(-1) (n= 4). The propagation of the Ca(2+) wave often appeared 'step-like', with separate regions of the network being activated after variable delays. The direction of propagation was highly variable (Delta angle of propagation 44.3 +/- 10.9 deg per cycle) and was not confined to the axes of the longitudinal or circular muscle. Ca(2+) waves appeared to spread out radially from the site of initiation. The initiating Ca(2+) wave in ICC-MY was correlated to secondary Ca(2+) waves in intramuscular interstitial cells of Cajal, ICC-IM, and smooth muscle cells, and the local distortion (contraction) in a field of view. TTX (1 microm) had little effect on slow wave or pacemaker potential activity, but 2-APB (50 microm) blocked all Ca(2+) waves, indicating a pivotal role for intracellular Ca(2+) stores. Nicardipine (2 microm) eliminated the Ca(2+) transient generated by smooth muscle, but did not affect the fast upstroke associated with ICC-MY. These results indicate that slow waves follow a sequence of activation, beginning with the ICC-MY and ICC-IM network, followed later by a sustained Ca(2+) transient in the muscle layers that is responsible for contraction.

  13. Recognition of modified conditioning sounds by competitively trained guinea pigs

    Directory of Open Access Journals (Sweden)

    Hisayuki eOjima

    2016-01-01

    Full Text Available The guinea pig (GP is an often-used species in hearing research. However, behavioral studies are rare, especially in the context of sound recognition, because of difficulties in training these animals. We examined sound recognition in a social competitive setting in order to examine whether this setting could be used as an easy model. Two starved GPs were placed in the same training arena and compelled to compete for food after hearing a conditioning sound (CS, which was a repeat of almost identical sound segments. Through a two-week intensive training, animals were trained to demonstrate a set of distinct behaviors solely to the CS. Then, each of them was subjected to generalization tests for recognition of sounds that had been modified from the CS in spectral, fine temporal and tempo (i.e., intersegment interval, ISI dimensions. Results showed that they discriminated between the CS and band-rejected test sounds but had no preference for a particular frequency range for the recognition. In contrast, sounds modified in the fine temporal domain were largely perceived to be in the same category as the CS, except for the test sound generated by fully reversing the CS in time. Animals also discriminated sounds played at different tempos. Test sounds with ISIs shorter than that of the multi-segment CS were discriminated from the CS, while test sounds with ISIs longer than that of the CS segments were not. For the shorter ISIs, most animals initiated apparently positive food-access behavior as they did in response to the CS, but discontinued it during the sound-on period probably because of later recognition of tempo. Interestingly, the population range and mean of the delay time before animals initiated the food-access behavior were very similar among different ISI test sounds. This study, for the first time, demonstrates a wide aspect of sound discrimination abilities of the GP and will provide a way to examine tempo perception mechanisms using this

  14. Enhanced oxidative stress in neutrophils from hyperlipidemic guinea pig.

    Science.gov (United States)

    Maeda, Kensaku; Yasunari, Kenichi; Sato, Eisuke F; Inoue, Masayasu

    2005-07-01

    Inhibitors of 3-hydroxy-3-methylglutaryl CoA (HMG-CoA) reductase are antilipidemic agents (statins) widely used for the prevention of cardiovascular diseases. Recent studies have suggested that the overall benefits of statin therapy cannot be accounted for solely by its antilipidemic effect. To obtain further insight into the mechanism of action of statins, we studied the effect of pitavastatin on the generation of reactive oxygen species (ROS) by peritoneal polymorphonuclear leukocytes (PMN) obtained from control and hyperlipidemic guinea pigs. Flow cytometric analysis revealed that the amount of ROS generated by PMN from the hyperlipidemic animals that had been administered a laurate-containing diet (LD) for 4 weeks was larger than that from the normal diet (ND) group (837% increase, ND; 82.17 arbitrary units, LD; 688.10 arbitrary units, P < 0.01, n = 6). Administration of pitavastatin to the LD group significantly decreased plasma levels of total cholesterol (TC) and low-density lipoprotein (LDL) with a reduction in ROS generation by PMN (19% decrease, LD control; 688.10 arbitrary units, LD + pitavastatin; 556.87 arbitrary units, P < 0.01, n = 6). Western blotting analysis revealed that the expression of protein kinase C alpha (PKC alpha) and betaI was higher in PMN from the LD group than in PMN from the ND group (PKC alpha; 74% increase, PKC betaI; 339% increase, P < 0.05, n = 4, respectively). Furthermore, expression of NADPH oxidase gp91phox in PMN from the LD group was higher than that in PMN from the ND group (18% increase, P < 0.05, n = 4). By administration of pitavastatin to the LD group, the expression of PKC alpha, betaI and gp91phox was suppressed compared with the control LD group (PKC alpha; 41% decrease, PKC beta; 28% decrease, gp91phox; 56% decrease, P < 0.05, n = 4, respectively). These results indicate that PMN from hyperlipidemic animals is associated with an accelerated respiratory burst of ROS by increasing the expression of PKC alpha, beta

  15. Computed tomography analysis of guinea pig bone: architecture, bone thickness and dimensions throughout development.

    Science.gov (United States)

    Witkowska, Agata; Alibhai, Aziza; Hughes, Chloe; Price, Jennifer; Klisch, Karl; Sturrock, Craig J; Rutland, Catrin S

    2014-01-01

    The domestic guinea pig, Cavia aperea f. porcellus, belongs to the Caviidae family of rodents. It is an important species as a pet, a source of food and in medical research. Adult weight is achieved at 8-12 months and life expectancy is ∼5-6 years. Our aim was to map bone local thickness, structure and dimensions across developmental stages in the normal animal. Guinea pigs (n = 23) that had died of natural causes were collected and the bones manually extracted and cleaned. Institutional ethical permission was given under the UK Home Office guidelines and the Veterinary Surgeons Act. X-ray Micro Computed Tomography (microCT) was undertaken on the left and right scapula, humerus and femur from each animal to ascertain bone local thickness. Images were also used to undertake manual and automated bone measurements, volumes and surface areas, identify and describe nutrient, supratrochlear and supracondylar foramina. Statistical analysis between groups was carried out using ANOVA with post-hoc testing. Our data mapped a number of dimensions, and mean and maximum bone thickness of the scapula, humerus and femur in guinea pigs aged 0-1 month, 1-3 months, 3-6 months, 6 months-1 year and 1-4 years. Bone dimensions, growth rates and local bone thicknesses differed between ages and between the scapula, humerus and femur. The microCT and imaging software technology showed very distinct differences between the relative local bone thickness across the structure of the bones. Only one bone showed a singular nutrient foramen, every other bone had between 2 and 5, and every nutrient canal ran in an oblique direction. In contrast to other species, a supratrochlear foramen was observed in every humerus whereas the supracondylar foramen was always absent. Our data showed the bone local thickness, bone structure and measurements of guinea pig bones from birth to 4 years old. Importantly it showed that bone development continued after 1 year, the point at which most guinea pigs have

  16. Computed tomography analysis of guinea pig bone: architecture, bone thickness and dimensions throughout development

    Directory of Open Access Journals (Sweden)

    Agata Witkowska

    2014-10-01

    Full Text Available The domestic guinea pig, Cavia aperea f. porcellus, belongs to the Caviidae family of rodents. It is an important species as a pet, a source of food and in medical research. Adult weight is achieved at 8–12 months and life expectancy is ∼5–6 years. Our aim was to map bone local thickness, structure and dimensions across developmental stages in the normal animal. Guinea pigs (n = 23 that had died of natural causes were collected and the bones manually extracted and cleaned. Institutional ethical permission was given under the UK Home Office guidelines and the Veterinary Surgeons Act. X-ray Micro Computed Tomography (microCT was undertaken on the left and right scapula, humerus and femur from each animal to ascertain bone local thickness. Images were also used to undertake manual and automated bone measurements, volumes and surface areas, identify and describe nutrient, supratrochlear and supracondylar foramina. Statistical analysis between groups was carried out using ANOVA with post-hoc testing. Our data mapped a number of dimensions, and mean and maximum bone thickness of the scapula, humerus and femur in guinea pigs aged 0–1 month, 1–3 months, 3–6 months, 6 months–1 year and 1–4 years. Bone dimensions, growth rates and local bone thicknesses differed between ages and between the scapula, humerus and femur. The microCT and imaging software technology showed very distinct differences between the relative local bone thickness across the structure of the bones. Only one bone showed a singular nutrient foramen, every other bone had between 2 and 5, and every nutrient canal ran in an oblique direction. In contrast to other species, a supratrochlear foramen was observed in every humerus whereas the supracondylar foramen was always absent. Our data showed the bone local thickness, bone structure and measurements of guinea pig bones from birth to 4 years old. Importantly it showed that bone development continued after 1 year, the point

  17. Vitamin C deficiency in early postnatal life impairs spatial memory and reduces the number of hippocampal neurons in guinea pigs

    DEFF Research Database (Denmark)

    Tveden-Nyborg, Pernille Yde; Johansen, Louise Kruse; Raida, Zindy

    2009-01-01

    C deficiency and neuronal damage in newborn guinea pigs. DESIGN: Thirty 6- to 7-d-old guinea pigs were randomly assigned to 2 groups to receive either a vitamin C-sufficient diet or the same diet containing a low concentration of vitamin C (but adequate to prevent scurvy) for 2 mo. Spatial memory...... in spatial memory in guinea pigs. We speculate that this unrecognized effect of vitamin C deficiency may have clinical implications for high-risk individuals, such as in children born from vitamin C-deficient mothers....

  18. Uptake and accumulation of oxidized low-density lipoprotein during Mycobacterium tuberculosis infection in guinea pigs.

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    Gopinath S Palanisamy

    Full Text Available The typical host response to infection of humans and some animals by M. tuberculosis is the accumulation of reactive oxygen species generating inflammatory cells into discrete granulomas, which frequently develop central caseous necrosis. In previous studies we showed that infection of immunologically naïve guinea pigs with M. tuberculosis leads to localized and systemic oxidative stress that results in a significant depletion of serum total antioxidant capacity and the accumulation of malondialdehyde, a bi-product of lipid peroxidation. Here we show that in addition, the generation of excessive reactive oxygen species in vivo resulted in the accumulation of oxidized low density lipoproteins (OxLDL in pulmonary and extrapulmonary granulomas, serum and lung macrophages collected by bronchoalveolar lavage. Macrophages from immunologically naïve guinea pigs infected with M. tuberculosis also had increased surface expression of the type 1 scavenger receptors CD36 and LOX1, which facilitate the uptake of oxidized host macromolecules including OxLDL. Vaccination of guinea pigs with Bacillus Calmette Guerin (BCG prior to aerosol challenge reduced the bacterial burden as well as the intracellular accumulation of OxLDL and the expression of macrophage CD36 and LOX1. In vitro loading of guinea pig lung macrophages with OxLDL resulted in enhanced replication of bacilli compared to macrophages loaded with non-oxidized LDL. Overall, this study provides additional evidence of oxidative stress in M. tuberculosis infected guinea pigs and the potential role OxLDL laden macrophages have in supporting intracellular bacilli survival and persistence.

  19. Antagonist profile of ibodutant at the tachykinin NK2 receptor in guinea pig isolated bronchi.

    Science.gov (United States)

    Santicioli, Paolo; Meini, Stefania; Giuliani, Sandro; Lecci, Alessandro; Maggi, Carlo Alberto

    2013-10-24

    In this study we have characterized the pharmacological profile of the non-peptide tachykinin NK2 receptor antagonist ibodutant (MEN15596) in guinea pig isolated main bronchi contractility. The antagonist potency of ibodutant was evaluated using the selective NK2 receptor agonist [βAla(8)]NKA(4-10)-mediated contractions of guinea pig isolated main bronchi. In this assay ibodutant (30, 100 and 300nM) induced a concentration-dependent rightward shift of the [βAla(8)]NKA(4-10) concentration-response curves without affecting the maximal contractile effect. The analysis of the results yielded a Schild-plot linear regression with a slope not different from unity (0.95, 95% c.l. 0.65-1.25), thus indicating a surmountable behaviour. The calculated apparent antagonist potency as pKB value was 8.31±0.05. Ibodutant (0.3-100nM), produced a concentration-dependent inhibition of the nonadrenergic-noncholinergic (NANC) contractile response induced by electrical field stimulation (EFS) of intrinsic airway nerves in guinea pig isolated main bronchi. At the highest concentration tested (100nM) ibodutant almost abolished the EFS-induced bronchoconstriction (95±4% inhibition), the calculated IC50 value was 2.98nM (95% c.l. 1.73-5.16nM). In bronchi from ovalbumin (OVA) sensitized guinea pigs ibodutant (100nM) did not affect the maximal contractile response to OVA, but completely prevented the slowing in the fading of the motor response induced by phosphoramidon pretreatment linked to the endogenous neurokinin A release. Altogether, the present study demonstrate that ibodutant is a potent NK2 receptor antagonist in guinea pig airways.

  20. Structural and kinetic characterization of guinea pig L-asparaginase type III.

    Science.gov (United States)

    Schalk, Amanda M; Lavie, Arnon

    2014-04-15

    We investigated whether an uncharacterized protein from guinea pig could be the enzyme behind Kidd's serendipitous discovery, made over 60 years ago, that guinea pig serum has cell killing ability. It has been long known that an enzyme with l-asparaginase activity is responsible for cell killing, although astonishingly, its identity remains unclear. Bacterial asparaginases with similar cell killing properties have since become a mainstay therapy of certain cancers such as acute lymphoblastic leukemia. By hydrolyzing asparagine to aspartate and ammonia, these drugs deplete the asparagine present in the blood, killing cancer cells that rely on extracellular asparagine uptake for survival. However, bacterial asparaginases can elicit an adverse immune response. We propose that replacement of bacterial enzymes with the guinea pig asparaginase responsible for serum activity, by its virtue of being more closely related to human enzymes, will be less immunogenic. To this goal, we investigated whether an uncharacterized protein from guinea pig with putative asparaginase activity, which we call gpASNase3, could be that enzyme. We examined its self-activation process (gpASNase3 requires autocleavage to become active), kinetically characterized it for asparaginase and β-aspartyl dipeptidase activity, and elucidated its crystal structure in both the uncleaved and cleaved states. This work reveals that gpASNase3 is not the enzyme responsible for the antitumor effects of guinea pig serum. It exhibits a low affinity for asparagine as measured by a high Michaelis constant, KM, in the millimolar range, in contrast to the low KM (micromolar range) required for asparaginase to be effective as an anticancer agent.

  1. Pathology and Pathophysiology of Inhalational Anthrax in a Guinea Pig Model

    Science.gov (United States)

    Savransky, Vladimir; Sanford, Daniel C.; Syar, Emily; Austin, Jamie L.; Tordoff, Kevin P.; Anderson, Michael S.; Stark, Gregory V.; Barnewall, Roy E.; Briscoe, Crystal M.; Lemiale-Biérinx, Laurence; Park, Sukjoon; Ionin, Boris

    2013-01-01

    Nonhuman primates (NHPs) and rabbits are the animal models most commonly used to evaluate the efficacy of medical countermeasures against anthrax in support of licensure under the FDA's “Animal Rule.” However, a need for an alternative animal model may arise in certain cases. The development of such an alternative model requires a thorough understanding of the course and manifestation of experimental anthrax disease induced under controlled conditions in the proposed animal species. The guinea pig, which has been used extensively for anthrax pathogenesis studies and anthrax vaccine potency testing, is a good candidate for such an alternative model. This study was aimed at determining the median lethal dose (LD50) of the Bacillus anthracis Ames strain in guinea pigs and investigating the natural history, pathophysiology, and pathology of inhalational anthrax in this animal model following nose-only aerosol exposure. The inhaled LD50 of aerosolized Ames strain spores in guinea pigs was determined to be 5.0 × 104 spores. Aerosol challenge of guinea pigs resulted in inhalational anthrax with death occurring between 46 and 71 h postchallenge. The first clinical signs appeared as early as 36 h postchallenge. Cardiovascular function declined starting at 20 h postexposure. Hematogenous dissemination of bacteria was observed microscopically in multiple organs and tissues as early as 24 h postchallenge. Other histopathologic findings typical of disseminated anthrax included suppurative (heterophilic) inflammation, edema, fibrin, necrosis, and/or hemorrhage in the spleen, lungs, and regional lymph nodes and lymphocyte depletion and/or lymphocytolysis in the spleen and lymph nodes. This study demonstrated that the course of inhalational anthrax disease and the resulting pathology in guinea pigs are similar to those seen in rabbits and NHPs, as well as in humans. PMID:23357384

  2. Morphometrical Study of the Temporal Bone and Auditory Ossicles in Guinea Pig

    Directory of Open Access Journals (Sweden)

    Ahmadali Mohammadpour

    2011-03-01

    Full Text Available In this research, anatomical descriptions of the structure of the temporal bone and auditory ossicles have been performed based on dissection of ten guinea pigs. The results showed that, in guinea pig temporal bone was similar to other animals and had three parts; squamous, tympanic and petrous .The tympanic part was much better developed and consisted of oval shaped tympanic bulla with many recesses in tympanic cavity. The auditory ossicles of guinea pig concluded of three small bones; malleus, incus and stapes but the head of the malleus and the body of incus were fused and forming a malleoincudal complex. The average of morphometric parameters showed that the malleus was 3.53 ± 0.22 mm in total length. In addition to head and handle, the malleus had two distinct process; lateral and muscular. The incus had a total length 1.23 ± 0.02mm. It had long and short crus although the long crus was developed better than short crus. The lenticular bone was a round bone that articulated with the long crus of incus. The stapes had a total length 1.38 ± 0.04mm. The anterior crus(0.86 ± 0.08mm was larger than posterior crus (0.76 ± 0.08mm. It is concluded that, in the guinea pig, the malleus and the incus are fused, forming a junction called incus-malleus, while in the other animals these are separate bones. The stapes is larger and has a triangular shape and the anterior and posterior crus are thicker than other rodents. Therefore, for otological studies, the guinea pig is a good lab animal.

  3. Gap prepulse inhibition and auditory brainstem evoked potentials as objective measures for tinnitus in guinea pigs.

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    Susanne eDehmel

    2012-05-01

    Full Text Available Tinnitus or ringing of the ears is a subjective phantom sensation necessitating behavioral models that objectively demonstrate the existence and quality of the tinnitus sensation. The gap detection test uses the acoustic startle response elicited by loud noise pulses and its gating or suppression by preceding sub-startling prepulses. Gaps in noise bands serve as prepulses, assuming that ongoing tinnitus masks the gap and results in impaired gap detection. This test has shown its reliability in rats, mice, and gerbils. No data exists for the guinea pig so far, although gap detection is similar across mammals and the acoustic startle response is a well-established tool in guinea pig studies of psychiatric disorders and in pharmacological studies. Here we investigated the startle behavior and prepulse inhibition (PPI of the guinea pig and showed that guinea pigs have a reliable startle response that can be suppressed by 15 ms gaps embedded in narrow noise bands preceding the startle noise pulse. After recovery of auditory brainstem response (ABR thresholds from a unilateral noise over-exposure centered at 7 kHz, guinea pigs showed diminished gap-induced reduction of the startle response in frequency bands between 8 and 18 kHz. This suggests the development of tinnitus in frequency regions that showed a temporary threshold shift (TTS after noise over-exposure. Changes in discharge rate and synchrony, two neuronal correlates of tinnitus, should be reflected in altered ABR waveforms, which would be useful to objectively detect tinnitus and its localization to auditory brainstem structures. Therefore we analyzed latencies and amplitudes of the first five ABR waves at suprathreshold sound intensities and correlated ABR abnormalities with the results of the behavioral tinnitus testing. Early ABR wave amplitudes up to N3 were increased for animals with tinnitus possibly stemming from hyperactivity and hypersynchrony underlying the tinnitus percept.

  4. Trimellitic anhydride (TMA) dust induces airway obstruction and eosinophilia in non-sensitized guinea pigs.

    Science.gov (United States)

    Larsen, Christen P; Regal, Jean F

    2002-09-02

    Trimellitic anhydride (TMA) causes asthma after a latency period of sensitization. In non-sensitized humans and animals, limited studies indicate that TMA exposure may also cause symptoms of asthma without a latency period. Our previous studies (J. Pharmacol. Exp. Ther. 296 (2001) 284) in a guinea pig model of TMA-induced asthma demonstrated that sensitization and the complement system were required for eosinophilia. TMA conjugated to guinea pig serum albumin (TMA-GPSA) was used to elicit the response. Since occupational exposure to TMA occurs by inhalation of dust, the present studies determined if exposure to TMA dust in a non-sensitized guinea pig elicited airway obstruction and inflammation, and whether a significantly greater response occurred after a latency period of sensitization. Guinea pigs were intradermally injected with either corn oil (non-sensitized animals) or 30% TMA (sensitized animals). Three weeks later they were challenged by intratracheal insufflation with 1 mg TMA dust or lactose dust (control) using a dry powder delivery device. Pulmonary resistance, dynamic lung compliance, mean arterial blood pressure and heart rate were monitored for 10 min. In non-sensitized guinea pigs, significant increases in pulmonary resistance and decreases in dynamic lung compliance and blood pressure occurred after TMA challenge. In sensitized animals, the same dose of TMA caused significantly greater effects compared to non-sensitized animals. In a separate experiment, cellular infiltration into the lung was determined 24 h after challenge with TMA dust or lactose dust. In both non-sensitized and sensitized animals, eosinophils in the lung tissue were increased after TMA dust challenge compared to controls. Thus, these studies suggest that the response in non-sensitized animals differs depending on whether TMA dust or TMA-GPSA is used to elicit the response. TMA dust elicits significant airway obstruction and eosinophilia in a non-sensitized animal, with even

  5. Antiasthmatic activity of a novel thromboxane A2 antagonist, S-1452, in guinea pigs.

    Science.gov (United States)

    Arimura, A; Asanuma, F; Kurosawa, A; Harada, M

    1992-01-01

    We examined the effect of a potent thromboxane (Tx) A2 receptor antagonist, calcium (1R, 2S, 3S, 4S)-(5Z)-7-(((phenylsulfonyl)amino)bicyclo[2.2.1] hept-2-yl)-5-heptenoate dihydrate (S-1452), on antigen- and various allergic-spasmogen-induced contractions of guinea pig lung parenchymal strips and on the increase in insufflation pressure, an index of bronchoconstriction, in anesthetized guinea pigs. In isolated guinea pig lung parenchymal strips, S-1452 showed competitive antagonism of the contractile activity of U-46619, a TxA2 mimetic, with a pA2 value of 8.9. The compound also inhibited the contraction induced by prostaglandin (PG) D2 and PGF2 alpha, but a TxA2 synthetase inhibitor, OKY-046, did not. In contrast, both drugs inhibited not only leukotriene (LT) D4-induced contraction but also antigen-induced contraction in the presence of a histamine antagonist. In anesthetized guinea pigs, oral administration of S-1452 markedly inhibited the bronchoconstrictions induced by intravenous injection of U-46619, PGD2, PGF2 alpha, LTD4 and platelet-activating factor (PAF) with ED50 values of 0.006, 0.031, 0.112, 0.033 and 0.115 mg/kg, respectively, but OKY-046 inhibited only that by LTD4 and PAF. Additionally, bronchoconstriction following intravenous injection of antigen was almost completely suppressed by S-1452 (0.1 mg/kg) and partially by OKY-046 (300 mg/kg) in passively sensitized guinea pigs which were treated with diphenydramine and propranolol. The inhibitory effect of S-1452 against U-46619-induced broncho-constriction persisted up to 7 h after oral administration.(ABSTRACT TRUNCATED AT 250 WORDS)

  6. Effects of 900 MHz electromagnetic field emitted by cellular phones on electrocardiograms of guinea pigs.

    Science.gov (United States)

    Meral, I; Tekintangac, Y; Demir, H

    2014-02-01

    This study was carried out to determine the effects of electromagnetic field (EMF) emitted by cellular phones (CPs) on electrocardiograms (ECGs) of guinea pigs. A total of 30 healthy guinea pigs weighing 500-800 g were used. After 1 week of adaptation period, animals were randomly divided into two groups: control group (n = 10) and EMF-exposed group (n = 20). Control guinea pigs were housed in a separate room without exposing them to EMFs of CPs. Animals in second group were exposed to 890-915 MHz EMF (217 Hz of pulse rate, 2 W of maximum peak power and 0.95 wt kg(-1) of specific absorption rate) for 12 h day(-1) (11 h 45 min stand-by and 15 min speaking mode) for 30 days. ECGs of guinea pigs in both the groups were recorded by a direct writing electrocardiograph at the beginning and 10th, 20th and 30th days of the experiment. All ECGs were standardized at 1 mV = 10 mm and with a chart speed of 50 mm sec(-1). Leads I, II, III, lead augmented vector right (aVR), lead augmented vector left (aVL) and lead augmented vector foot (aVF) were recorded. The durations and amplitudes of waves on the trace were measured in lead II. The data were expressed as mean with SEM. It was found that 12 h day(-1) EMF exposure for 30 days did not have any significant effects on ECG findings of guinea pigs. However, this issue needed to be further investigated in a variety of perspectives, such as longer duration of exposure to be able to elucidate the effects of mobile phone-induced EMFs on cardiovascular functions.

  7. The daily pattern of heart rate, body temperature, locomotor activity, and autonomic nervous activity in congenitally bronchial-hypersensitive (BHS) and bronchial-hyposensitive (BHR) guinea pigs.

    Science.gov (United States)

    Akita, Megumi; Kuwahara, Masayoshi; Nishibata, Ryoji; Mikami, Hiroki; Tsubone, Hirokazu

    2004-04-01

    We studied the characteristics of the rhythmicity of heart rate (HR), body temperature (BT), locomotor activity (LA) and autonomic nervous activity in bronchial-hypersensitive (BHS) and bronchial-hyposensitive (BHR) guinea pigs. For this purpose, HR, BT, LA, and electrocardiogram (ECG) were recorded from conscious and unrestrained guinea pigs using a telemetry system. Autonomic nervous activity was analyzed by power spectral analysis of heart rate variability. Nocturnal patterns, in which the values in the dark phase (20:00-06:00) were higher than those in the light phase (06:00-20:00), were observed in HR, BT and LA in both strains of guinea pigs. The autonomic nervous activity in BHS guinea pigs showed a daily pattern, although BHR guinea pigs did not show such a rhythmicity. The high frequency (HF) power in BHS guinea pigs was higher than that in BHR guinea pigs throughout the day. Moreover, the low frequency/high frequency (LF/HF) ratio in BHS guinea pigs was lower than that in BHR guinea pigs throughout the day. These results suggest that parasympathetic nervous activity may be predominant in BHS guinea pigs.

  8. Isolation and characterisation of a dinucleotide microsatellite set for a parentage and biodiversity study in domestic guinea pig (Cavia porcellus

    Directory of Open Access Journals (Sweden)

    Diana Aviles

    2015-10-01

    Full Text Available The domestic guinea pig is a valuable genetic resource because it is part of local folklore and food tradition in many South American countries. The economic importance of the guinea pig is due to its high feed efficiency and the quality of animal protein produced. For these reasons, our study is aimed to design a complete dinucleotide microsatellite marker set following international recommendation to assess the genetic diversity and genealogy management of guinea pigs. We selected a total of 20 microsatellites, looking for laboratory efficiency and good statistical parameters. The set was tested in 100 unrelated individuals of guinea pigs from Ecuador, Peru, Colombia, Bolivia and Spain. Our results show a high degree of polymorphisms with a total of 216 alleles and a mean number of 10.80±3.49 for markers with a combined exclusion probability of 0.99.

  9. Administration of angiotensin II and a bradykinin B2 receptor blocker in midpregnancy impairs gestational outcome in guinea pigs

    National Research Council Canada - National Science Library

    Valdés, Gloria; Schneider, Daniela; Corthorn, Jenny; Ortíz, Rita; Acuña, Stephanie; Padilla, Oslando

    2014-01-01

    ...) was antagonized in pregnant guinea-pigs. We hypothesized that disrupting the RAS/KKS balance during the period of maximal trophoblast invasion and placental development would provoke increased blood pressure, defective trophoblast invasion...

  10. Oxidative DNA damage in vitamin C-supplemented guinea pigs after intratracheal instillation of diesel exhaust particles

    DEFF Research Database (Denmark)

    Moller, P.; Daneshvar, B.; Loft, S.

    2003-01-01

    The health effects of diesel exhaust particles (DEP) are thought to involve oxidative damage. We have investigated the effect of intratracheal DEP instillation to guinea pigs in three groups of 12 animals each given 0, 0.7, or 2.1 mg. Five days later guinea pigs exposed to DEP had increased level...... for the study of oxidative damage induced by particulate matter. (C) 2003 Elsevier Science (USA). All rights reserved........ The concentrations of ascorbate in liver, lung, and plasma were unaltered by the DEP exposure. The results indicate that in guinea pigs DEP causes oxidative DNA damage rather than bulky DNA adducts in the lung. Guinea pigs, which are similar to humans with respect to vitamin C metabolism, may serve as a new model...

  11. Confocal Raman Microspectroscopy: The Measurement of VX Depth Profiles in Hairless Guinea Pig Skin and the Evaluation of RSDL

    Science.gov (United States)

    2015-02-01

    neurotransmitter acetylcholine. This neurotransmitter then accumulates at synaptic sites, causing cholinergic system hyperactivity. Symptoms of VX...The use of clipped haired guinea pigs was initially planned in this project. Using training animals from the Veterinary Medicine and Surgery

  12. A model of type 2 diabetes in the guinea pig using sequential diet-induced glucose intolerance and streptozotocin treatment

    Directory of Open Access Journals (Sweden)

    Brendan K. Podell

    2017-02-01

    Full Text Available Type 2 diabetes is a leading cause of morbidity and mortality among noncommunicable diseases, and additional animal models that more closely replicate the pathogenesis of human type 2 diabetes are needed. The goal of this study was to develop a model of type 2 diabetes in guinea pigs, in which diet-induced glucose intolerance precedes β-cell cytotoxicity, two processes that are crucial to the development of human type 2 diabetes. Guinea pigs developed impaired glucose tolerance after 8 weeks of feeding on a high-fat, high-carbohydrate diet, as determined by oral glucose challenge. Diet-induced glucose intolerance was accompanied by β-cell hyperplasia, compensatory hyperinsulinemia, and dyslipidemia with hepatocellular steatosis. Streptozotocin (STZ treatment alone was ineffective at inducing diabetic hyperglycemia in guinea pigs, which failed to develop sustained glucose intolerance or fasting hyperglycemia and returned to euglycemia within 21 days after treatment. However, when high-fat, high-carbohydrate diet-fed guinea pigs were treated with STZ, glucose intolerance and fasting hyperglycemia persisted beyond 21 days post-STZ treatment. Guinea pigs with diet-induced glucose intolerance subsequently treated with STZ demonstrated an insulin-secretory capacity consistent with insulin-independent diabetes. This insulin-independent state was confirmed by response to oral antihyperglycemic drugs, metformin and glipizide, which resolved glucose intolerance and extended survival compared with guinea pigs with uncontrolled diabetes. In this study, we have developed a model of sequential glucose intolerance and β-cell loss, through high-fat, high-carbohydrate diet and extensive optimization of STZ treatment in the guinea pig, which closely resembles human type 2 diabetes. This model will prove useful in the study of insulin-independent diabetes pathogenesis with or without comorbidities, where the guinea pig serves as a relevant model species.

  13. Opioid binding sites in the guinea pig and rat kidney: Radioligand homogenate binding and autoradiography

    Energy Technology Data Exchange (ETDEWEB)

    Dissanayake, V.U.; Hughes, J.; Hunter, J.C. (Parke-Davis Research Unit, Addenbrookes Hospital Site, Cambridge (England))

    1991-07-01

    The specific binding of the selective {mu}-, {delta}-, and {kappa}-opioid ligands (3H)(D-Ala2,MePhe4,Gly-ol5)enkephalin ((3H) DAGOL), (3H)(D-Pen2,D-Pen5)enkephalin ((3H)DPDPE), and (3H)U69593, respectively, to crude membranes of the guinea pig and rat whole kidney, kidney cortex, and kidney medulla was investigated. In addition, the distribution of specific 3H-opioid binding sites in the guinea pig and rat kidney was visualized by autoradiography. Homogenate binding and autoradiography demonstrated the absence of {mu}- and {kappa}-opioid binding sites in the guinea pig kidney. No opioid binding sites were demonstrable in the rat kidney. In the guinea pig whole kidney, cortex, and medulla, saturation studies demonstrated that (3H)DPDPE bound with high affinity (KD = 2.6-3.5 nM) to an apparently homogeneous population of binding sites (Bmax = 8.4-30 fmol/mg of protein). Competition studies using several opioid compounds confirmed the nature of the {delta}-opioid binding site. Autoradiography experiments demonstrated that specific (3H)DPDPE binding sites were distributed radially in regions of the inner and outer medulla and at the corticomedullary junction of the guinea pig kidney. Computer-assisted image analysis of saturation data yielded KD values (4.5-5.0 nM) that were in good agreement with those obtained from the homogenate binding studies. Further investigation of the {delta}-opioid binding site in medulla homogenates, using agonist ((3H)DPDPE) and antagonist ((3H)diprenorphine) binding in the presence of Na+, Mg2+, and nucleotides, suggested that the {delta}-opioid site is linked to a second messenger system via a GTP-binding protein. Further studies are required to establish the precise localization of the {delta} binding site in the guinea pig kidney and to determine the nature of the second messenger linked to the GTP-binding protein in the medulla.

  14. Characterisation of the sarcomeric myosin heavy chain multigene family in the laboratory guinea pig

    Directory of Open Access Journals (Sweden)

    Bardsley Ronald G

    2010-06-01

    Full Text Available Abstract Background Several chronic conditions leading to skeletal muscle dysfunction are known to be associated with changes in the expression of myosin heavy chain (MHC isoforms at both the mRNA and protein level. Many of these conditions are modelled, pre-clinically, in the guinea pig due to similar disease onset and progression to the human condition, and their generally well-characterised anatomy. MHC composition is amenable to determination by protein and mRNA based methodologies, the latter quantifying the expression of MHC isoform-specific gene transcripts allowing the detection of earlier, and more subtle changes. As such, the MHC mRNAs, and specific oligonucleotide primers of all common laboratory species have been available for some time. However, due to incomplete genomic annotation, assessment of guinea pig MHC mRNA expression has not been previously possible, precluding the full characterisation of early changes in skeletal muscle in response to disease and disease modulation. The purpose of this study was to characterise the multigenic structure of the sarcomeric MHC family in the guinea pig, and to design and validate specific oligonucleotide primers to enable the assessment of the predominant adult-muscle associated MHC mRNAs in relevant disease models. Results Using a combination of ligase-mediated rapid amplification of 5' and 3' cDNA ends (RACE and bioinformatics, mRNAs to the four main skeletal-muscle isoforms of MHC were determined. Specific oligonucleotide primers were designed, and following verification of their specificity, found to successfully determine the expression of each MHC mRNA independently. Conclusions Because of their utilisation in the in vivo modelling of disease, there is a requirement to develop molecular methods that accurately differentiate the different MHC mRNAs in the guinea pig to enable rapid profiling of muscle composition in appropriate disease models. The methods developed here are suitable for

  15. A combined deficiency of vitamins E and C causes severe central nervous system damage in guinea pigs.

    Science.gov (United States)

    Burk, Raymond F; Christensen, Joani M; Maguire, Mark J; Austin, Lori M; Whetsell, William O; May, James M; Hill, Kristina E; Ebner, Ford F

    2006-06-01

    A short period of combined deficiency of vitamins E and C causes profound central nervous system (CNS) dysfunction in guinea pigs. For this report, CNS histopathology was studied to define the nature and extent of injury caused by this double deficiency. Weanling guinea pigs were fed a vitamin E-deficient or -replete diet for 14 d. Then vitamin C was withdrawn from the diet of some guinea pigs. Four diet groups were thus formed: replete, vitamin E deficient, vitamin C deficient, and both vitamin E and C deficient. From 5 to 11 d after institution of the doubly deficient diet, 9 of 12 guinea pigs developed paralysis, and 2 more were found dead. The remaining guinea pig in the doubly deficient group and all animals in the other 3 groups survived without clinical impairment until the experiment was terminated at 13-15 d. Brains and spinal cords were serially sectioned and stained for examination. Only the combined deficiency produced damage in the CNS. The damage consisted mainly of nerve cell death, axonal degeneration, vascular injury, and associated glial cell responses. The spinal cord and the ventral pons in the brainstem were most severely affected, often exhibiting asymmetric cystic lesions. Several features of the lesions suggest that the primary damage was to blood vessels. These results indicate that the paralysis and death caused by combined deficiency of vitamins E and C in guinea pigs is caused by severe damage in the brainstem and spinal cord.

  16. Conventional anticonvulsant drugs in the guinea-pig kindling model of partial seizures: effects of acute phenytoin.

    Science.gov (United States)

    Gilbert, T H; Bharadia, V; Teskey, G C

    2001-10-01

    This study addressed some of the controversial issues surrounding the anticonvulsant effect of phenytoin, and the predictive validity of the guinea-pig kindling model for the screening of anticonvulsant drugs. Following an intraperitoneal injection of either 50 or 75 mg/kg phenytoin, we analysed plasma concentrations of phenytoin at various time intervals. Behavioural toxicity was assessed at 0.5 h postinjection using quantitative locomotor tests, as well as scores on a sedation/muscle relaxation rating index. The anticonvulsant efficacy of phenytoin was evaluated from measurements of afterdischarge threshold (ADT), afterdischarge duration (ADD) and behavioural seizure severity at three phases of kindling: non-kindled, kindling acquisition (early and late) and kindled (50+ ADs). ADD and seizure severity were also measured in response to both threshold and suprathreshold kindling stimulation. Plasma levels of phenytoin corresponded to the human therapeutic range at the time of behavioural testing and kindling. Phenytoin did not exert significant adverse effects in guinea-pigs on both the behavioural tests and rating index. Phenytoin increased ADT in non-kindled and kindled guinea-pigs and effectively reduced ADD and seizure severity, indicating that the guinea-pig model correctly predicted phenytoin's anticonvulsant effect. Phenytoin produced reliable anticonvulsant activity in the guinea-pig at threshold stimulation but a somewhat reduced efficacy on seizure severity at suprathreshold stimulation intensities. Kindling in the guinea-pig is a valid model of human partial seizures.

  17. Coagulation and fibrinolysis in capybara (Hydrochaeris hydrochaeris), a close relative of the guinea-pig (Cavia porcellus).

    Science.gov (United States)

    Leitão, D P; Polizello, A C; Rothschild, Z

    2000-01-01

    Fibrinolytic and coagulation properties of capybara (Hydrochaeris hydrochaeris, LINNAEUS, 1766) plasma were analysed and the results compared to the guinea-pig (Cavia porcellus), a close relative. Capybara fibrinogen was isolated and fibrinolysis of its plasma was carried out in a homologous system and with bovine fibrin. Undiluted plasma did not have fibrinolytic activity on fibrin plates; euglobulins gave a dose-related response. Zymography of capybara and guinea-pig plasma gave the same patterns of activity as human or bovine plasma. Human urokinase (UK) and tissue plasminogen activator (t-PA) produced lysis in capybara fibrin plates. Streptokinase (SK) (500 IU/ml) did not activate capybara or guinea-pig plasma. In this system, human plasma was extensively activated. Coagulation tests for both species of rodent were prolonged. The capybara showed values for prothrombin time (PT) shorter than activated thromboplastin time (APTT). The guinea-pig, as already shown, had longer PT values. Factors X and VII were very low for capybara and guinea-pig when tested using reference curves and diagnostic kits for human plasma. It is suggested that the capybara could be a valuable laboratory animal considering its size and closeness to the guinea-pig, and this could allow for the provision of materials from one single animal when convenient or necessary.

  18. Retinal and choroidal expression of BMP-2 in lens-induced myopia and recovery from myopia in guinea pigs.

    Science.gov (United States)

    Li, Honghui; Wu, Juan; Cui, Dongmei; Zeng, Junwen

    2016-03-01

    The present study investigated the retinal and choroidal expression of bone morphogenetic protein-2 (BMP-2) in myopia and in myopia recovery in a guinea pig model. For this investigation, two groups of guinea pigs, lens‑induced myopia and recovery from myopia, were used, and defocused myopia was induced the guinea pigs wearing ‑4.00 D lenses on the right eyes for 3 weeks, with the left eyes serving as the contralateral. In the following week, the lenses of the guinea pigs in the recovery group were removed, and the refractive power and axial length were measured. The expression of BMP‑2 in the eyeballs was observed using immunohistochemistry and analyzed using Western blot analysis. After 3 weeks, the eyes acquired relative myopia and longer axial lengths in the two groups of guinea pigs. After 1 week without lenses in the recovery group, the myopia and axial lengths regressed. Immunofluorescence staining showed that BMP‑2 was expressed in the posterior retina, RPE, choroid and sclera. The expression of BMP‑2 decreased in the myopic retina of the guinea pigs. Following the regression of myopia in the recovery group, no difference in the expression of BMP‑2 was observed between the recovered treated eyes and the contralateral eyes. The choroidal expression level of BMP‑2 in the treated eyes showed no significant changes in either group. Therefore, BMP‑2 may be involved in the development of myopia, however, it does not have a primary role in the retinal and choroidal signals regulating scleral remodeling.

  19. Increased severity of tuberculosis in Guinea pigs with type 2 diabetes: a model of diabetes-tuberculosis comorbidity.

    Science.gov (United States)

    Podell, Brendan K; Ackart, David F; Obregon-Henao, Andres; Eck, Sarah P; Henao-Tamayo, Marcela; Richardson, Michael; Orme, Ian M; Ordway, Diane J; Basaraba, Randall J

    2014-04-01

    Impaired glucose tolerance and type 2 diabetes were induced in guinea pigs to model the emerging comorbidity of Mycobacterium tuberculosis infection in diabetic patients. Type 2 diabetes mellitus was induced by low-dose streptozotocin in guinea pigs rendered glucose intolerant by first feeding a high-fat, high-carbohydrate diet before M. tuberculosis exposure. M. tuberculosis infection of diabetic guinea pigs resulted in severe and rapidly progressive tuberculosis (TB) with a shortened survival interval, more severe pulmonary and extrapulmonary pathology, and a higher bacterial burden compared with glucose-intolerant and nondiabetic controls. Compared with nondiabetics, diabetic guinea pigs with TB had an exacerbated proinflammatory response with more severe granulocytic inflammation and higher gene expression for the cytokines/chemokines interferon-γ, IL-17A, IL-8, and IL-10 in the lung and for interferon-γ, tumor necrosis factor-α, IL-8, and monocyte chemoattractant protein-1 in the spleen. TB disease progression in guinea pigs with impaired glucose tolerance was similar to that of nondiabetic controls in the early stages of infection but was more severe by day 90. The guinea pig model of type 2 diabetes-TB comorbidity mimics important features of the naturally occurring disease in humans. This model will be beneficial in understanding the complex pathogenesis of TB in diabetic patients and to test new strategies to improve TB and diabetes control when the two diseases occur together.

  20. DNA Vaccines delivered by dermal electroporation elicit durable protective immunity against individual or simultaneous infections with lassa and ebola viruses in guinea pigs.

    Science.gov (United States)

    2017-08-22

    DNA vaccines elicit durable protective immunity against individual or simultaneous 1  infections with Lassa and Ebola viruses in guinea pigs 2  3...previously developed optimized DNA vaccines against both Lassa fever and Ebola 15  hemorrhagic fever viruses and demonstrated that they were protective...individually in 16  guinea pig and nonhuman primate models. In this study, we vaccinated groups of strain 17  13 guinea pigs two times, four weeks apart

  1. Carvacrol attenuates serum levels of total protein, phospholipase A2 and histamine in asthmatic guinea pig

    Directory of Open Access Journals (Sweden)

    Mohammad Hossein Boskabady

    2016-11-01

    Full Text Available Objective: Pharmacological effects of carvacrol such as its anti-inflammatory activities have been shows. In this study the effects of carvacrol on serum levels of total protein (TP, phospholipase A2 (PLA2 and histamine in sensitized guinea pigs was evaluated. Materials and Methods: Sensitized guinea pigs were given drinking water alone (group S, drinking water containing three concentrations of carvacrol (40, 80 and 160 µg/ml or dexamethasone. Serum levels of TP, PLA2 and histamine were examined I all sensitized groups as well as a non-sensitized control group (n=6 for each group. Results: In sensitized animals, serum levels of TP, PLA2 and histamine were significantly increased compared to control animals (p

  2. Impaired T-cell functions in aged guinea-pigs restored by thymostimulin (TS).

    Science.gov (United States)

    Falchetti, R; Cafiero, C; Caprino, L

    1982-01-01

    The age-related changes of different T-cell activities in guinea pigs and the effect of Thymostimulin (TS), a thymus extract, on the immunocompetence of these cells was studied. Mitogen-induced proliferation of peripheral blood lymphocytes was increased by TS in vitro. The intraperitoneal administration of TS (5 mg/kg) to aged animals restored the helper function of T lymphocytes and enhanced the reactivity to mitogens of both peripheral blood lymphocytes and spleen lymphocytes. The data obtained suggest that as in other species, there is an age-associated decline of immunological response, in guinea pigs too, probably due to a deficiency of thymic hormone(s) and that TS could correct this deficiency.

  3. [Breeding and management of mycobacteria-free guinea pigs (author's transl)].

    Science.gov (United States)

    Kazda, J

    1976-08-01

    A number of mycobacterial species are detectable under conventional holding condition of guinea pigs. These mycobacteria originating in drinking water and litter caused cross reactions in the Jones-Mote hypersensitivity test. Using suitable precautions it was possible to breed and hold the animals mycobacteria-free. The precautions depend mainly in alteration of the wire mesh floor in cages to avoide the contact of the animals with the litter, in cleaning and desinfection of water bottles, in using of heated water and food and in the prevention of mycobacterial contamination from the staff. The control examination on mycobacteria without treating is given in details. Cases are refered in which a oral rece ption of mycobacteria can alter the immune response. The modification of guinea pigs management to the mycobacteria-free ones is possible in a short time and with minimal cost.

  4. "Rickettsia amblyommii" induces cross protection against lethal Rocky Mountain spotted fever in a guinea pig model.

    Science.gov (United States)

    Blanton, Lucas S; Mendell, Nicole L; Walker, David H; Bouyer, Donald H

    2014-08-01

    Rocky Mountain spotted fever (RMSF) is a severe illness caused by Rickettsia rickettsii for which there is no available vaccine. We hypothesize that exposure to the highly prevalent, relatively nonpathogenic "Rickettsia amblyommii" protects against R. rickettsii challenge. To test this hypothesis, guinea pigs were inoculated with "R. amblyommii." After inoculation, the animals showed no signs of illness. When later challenged with lethal doses of R. rickettsii, those previously exposed to "R. amblyommii" remained well, whereas unimmunized controls developed severe illness and died. We conclude that "R. amblyommii" induces an immune response that protects from illness and death in the guinea pig model of RMSF. These results provide a basis for exploring the use of low-virulence rickettsiae as a platform to develop live attenuated vaccine candidates to prevent severe rickettsioses.

  5. Quantitative analysis of squamous epithelium of normal palatal mucosa in guinea pigs.

    Science.gov (United States)

    Andersen, L; Schroeder, H E

    1978-07-01

    The epithelium of intact guinea pig palate was subjected to stereologic analysis in a study of structural alterations in the keratinizing epithelium in response to wounding. Point counting procedures were employed to analyse electron micrographs sampled from three epithelial strata in biopsies collected from five animals. The differentiation pattern of the guinea pig palate epithelium displayed the following structural density gradients from basal to granular layers: descending gradients of metabolically active organelles, ascending gradient of bundled filaments coupled with the appearance of membrane coating granules and keratohyalin granules, and a plateau-like gradient of cytoplasmic ground substance. This pattern of epithelial differentiation is basically identical to that of human hard palate epithelium and epidermis. Regional and species variations in structure of keratinizing epithelia are suggested based on interepithelial differences in morphometric parameters.

  6. Production of High Potency Anti-Teschen Disease Serum From Rabbits and Guinea Pigs.

    Science.gov (United States)

    Dardiri, A H; Delay, P D

    1964-01-01

    An antiserum of high antibody content against Teschen disease Konratice virus was obtained by inoculating rabbits and guinea pigs with an antigen composed of aluminum gel and virus propagated in swine kidney cell cultures. The rabbit and guinea pig serums neutralized 1,500 TCID(50) of virus at dilutions of 1:5,120 and 1:2,048, respectively. The antibody level in the rabbit serum was tenfold greater than that in convalescent swine serum. Rabbit serum neutralized 2.8 x 10(6) plaque-forming units of the Konratice virus. At a dilution of 1:5,120, this serum neutralized 1,500 TCID(50) of the Reporyje virus. The methods used to prepare and assay the serum are described.

  7. Diet-induced dyslipidemia leads to nonalcoholic fatty liver disease and oxidative stress in guinea pigs

    DEFF Research Database (Denmark)

    Tveden-Nyborg, Pernille; Birck, Malene Muusfeldt; Ipsen, David Højland

    2016-01-01

    Chronic dyslipidemia imposed by a high-fat and high-caloric dietary regime leads to debilitating disorders such as obesity, nonalcoholic fatty liver disease (NAFLD), and insulin resistance. As disease rates surge, so does the need for high validity animal models to effectively study the causal...... and either 15% or 20% sucrose) compared with isocaloric standard chow in adult guinea pigs. Biochemical markers confirmed dyslipidemia in agreement with dietary regimens; however, both high-fat groups displayed a decreased tissue fat percentage compared with controls. Macroscopic appearance, histopathologic....... Evaluation of glucose tolerance showed no indication of insulin resistance. The 5% increase in sucrose between the 2 high-fat diets did not lead to significant differences between groups. In conclusion, we find the dyslipidemic guinea pig to be a valid model of diet imposed dyslipidemia, particularly...

  8. Mast cell expression of the serotonin1A receptor in guinea pig and human intestine.

    Science.gov (United States)

    Wang, Guo-Du; Wang, Xi-Yu; Zou, Fei; Qu, Meihua; Liu, Sumei; Fei, Guijun; Xia, Yun; Needleman, Bradley J; Mikami, Dean J; Wood, Jackie D

    2013-05-15

    Serotonin [5-hydroxytryptamine (5-HT)] is released from enterochromaffin cells in the mucosa of the small intestine. We tested a hypothesis that elevation of 5-HT in the environment of enteric mast cells might degranulate the mast cells and release mediators that become paracrine signals to the enteric nervous system, spinal afferents, and secretory glands. Western blotting, immunofluorescence, ELISA, and pharmacological analysis were used to study expression of 5-HT receptors by mast cells in the small intestine and action of 5-HT to degranulate the mast cells and release histamine in guinea pig small intestine and segments of human jejunum discarded during Roux-en-Y gastric bypass surgeries. Mast cells in human and guinea pig preparations expressed the 5-HT1A receptor. ELISA detected spontaneous release of histamine in guinea pig and human preparations. The selective 5-HT1A receptor agonist 8-hydroxy-PIPAT evoked release of histamine. A selective 5-HT1A receptor antagonist, WAY-100135, suppressed stimulation of histamine release by 5-HT or 8-hydroxy-PIPAT. Mast cell-stabilizing drugs, doxantrazole and cromolyn sodium, suppressed the release of histamine evoked by 5-HT or 8-hydroxy-PIPAT in guinea pig and human preparations. Our results support the hypothesis that serotonergic degranulation of enteric mast cells and release of preformed mediators, including histamine, are mediated by the 5-HT1A serotonergic receptor. Association of 5-HT with the pathophysiology of functional gastrointestinal disorders (e.g., irritable bowel syndrome) underlies a question of whether selective 5-HT1A receptor antagonists might have therapeutic application in disorders of this nature.

  9. Evidence for oxidative stress and defective antioxidant response in guinea pigs with tuberculosis.

    Directory of Open Access Journals (Sweden)

    Gopinath S Palanisamy

    Full Text Available The development of granulomatous inflammation with caseous necrosis is an important but poorly understood manifestation of tuberculosis in humans and some animal models. In this study we measured the byproducts of oxidative stress in granulomatous lesions as well as the systemic antioxidant capacity of BCG vaccinated and non-vaccinated guinea pigs experimentally infected with Mycobacterium tuberculosis. In non-vaccinated guinea pigs, oxidative stress was evident within 2 weeks of infection as measured by a decrease in the serum total antioxidant capacity and blood glutathione levels accompanied by an increase in malondialdehyde, a byproduct of lipid peroxidation, within lesions. Despite a decrease in total and reduced blood glutathione concentrations, there was an increase in lesion glutathione by immunohistochemistry in response to localized oxidative stress. In addition there was an increase in the expression of the host transcription factor nuclear erythroid 2 p45-related factor 2 (Nrf2, which regulates several protein and non-proteins antioxidants, including glutathione. Despite the increase in cytoplasmic expression of Nrf2, immunohistochemical staining revealed a defect in Nrf2 nuclear translocation within granulomatous lesions as well as a decrease in the expression of the Nrf2-regulated antioxidant protein NQO1. Treating M. tuberculosis-infected guinea pigs with the antioxidant drug N-acetyl cysteine (NAC partially restored blood glutathione concentrations and the serum total antioxidant capacity. Treatment with NAC also decreased spleen bacterial counts, as well as decreased the lung and spleen lesion burden and the severity of lesion necrosis. These data suggest that the progressive oxidative stress during experimental tuberculosis in guinea pigs is due in part to a defect in host antioxidant defenses, which, we show here, can be partially restored with antioxidant treatment. These data suggest that the therapeutic strategies that

  10. Early microvascular changes in the preterm neonate: a comparative study of the human and guinea pig.

    Science.gov (United States)

    Dyson, Rebecca M; Palliser, Hannah K; Lakkundi, Anil; de Waal, Koert; Latter, Joanna L; Clifton, Vicki L; Wright, Ian M R

    2014-09-17

    Dysfunction of the transition from fetal to neonatal circulatory systems may be a major contributor to poor outcome following preterm birth. Evidence exists in the human for both a period of low flow between 5 and 11 h and a later period of increased flow, suggesting a hypoperfusion-reperfusion cycle over the first 24 h following birth. Little is known about the regulation of peripheral blood flow during this time. The aim of this study was to conduct a comparative study between the human and guinea pig to characterize peripheral microvascular behavior during circulatory transition. Very preterm (≤28 weeks GA), preterm (29-36 weeks GA), and term (≥37 weeks GA) human neonates underwent laser Doppler analysis of skin microvascular blood flow at 6 and 24 h from birth. Guinea pig neonates were delivered prematurely (62 day GA) or at term (68-71 day GA) and laser Doppler analysis of skin microvascular blood flow was assessed every 2 h from birth. In human preterm neonates, there is a period of high microvascular flow at 24 h after birth. No period of low flow was observed at 6 h. In preterm animals, microvascular flow increased after birth, reaching a peak at 10 h postnatal age. Blood flow then steadily decreased, returning to delivery levels by 24 h. Preterm birth was associated with higher baseline microvascular flow throughout the study period in both human and guinea pig neonates. The findings do not support a hypoperfusion-reperfusion cycle in the microcirculation during circulatory transition. The guinea pig model of preterm birth will allow further investigation of the mechanisms underlying microvascular function and dysfunction during the initial extrauterine period.

  11. Myocardial KChIP2 Expression in Guinea Pig Resolves an Expanded Electrophysiologic Role.

    Science.gov (United States)

    Nassal, Drew M; Wan, Xiaoping; Liu, Haiyan; Deschênes, Isabelle

    2016-01-01

    Cardiac ion channels and their respective accessory subunits are critical in maintaining proper electrical activity of the heart. Studies have indicated that the K+ channel interacting protein 2 (KChIP2), originally identified as an auxiliary subunit for the channel Kv4, a component of the transient outward K+ channel (Ito), is a Ca2+ binding protein whose regulatory function does not appear restricted to Kv4 modulation. Indeed, the guinea pig myocardium does not express Kv4, yet we show that it still maintains expression of KChIP2, suggesting roles for KChIP2 beyond this canonical auxiliary interaction with Kv4 to modulate Ito. In this study, we capitalize on the guinea pig as a system for investigating how KChIP2 influences the cardiac action potential, independent of effects otherwise attributed to Ito, given the endogenous absence of the current in this species. By performing whole cell patch clamp recordings on isolated adult guinea pig myocytes, we observe that knock down of KChIP2 significantly prolongs the cardiac action potential. This prolongation was not attributed to compromised repolarizing currents, as IKr and IKs were unchanged, but was the result of enhanced L-type Ca2+ current due to an increase in Cav1.2 protein. In addition, cells with reduced KChIP2 also displayed lowered INa from reduced Nav1.5 protein. Historically, rodent models have been used to investigate the role of KChIP2, where dramatic changes to the primary repolarizing current Ito may mask more subtle effects of KChIP2. Evaluation in the guinea pig where Ito is absent, has unveiled additional functions for KChIP2 beyond its canonical regulation of Ito, which defines KChIP2 as a master regulator of cardiac repolarization and depolarization.

  12. THE EFFECT OF SOME NEW ANTIHISTAMINES ON THE ANAPHYLACTIC MICROSHOCK OF THE GUINEA-PIG.

    Science.gov (United States)

    HERXHEIMER, H; STRESEMANN, E

    1963-12-01

    The dose/response curves for the protective effects of the new antihistamine compounds trimeprazine, 10-(3-diethylamino-2-methylpropyl)phenothiazine 1,1-dioxide hydrochloride (oxomemazine hydrochloride), cyproheptadine, homochlorcyclizine and methotrimeprazine against the anaphylactic microshock of the guinea-pig were similar to that of promethazine. The first three compounds, however, protected at lower doses than promethazine (5 to 10 mug/kg). The protective effect of cyproheptadine lasted longer than 24 hr.

  13. Potential immunomodulation effect of the extract of Nigella sativa on ovalbumin sensitized guinea pigs

    Institute of Scientific and Technical Information of China (English)

    Mohammad-Hossein BOSKABADY; Rana KEYHANMANESH; Saeed KHAMENEH; Yousef DOOSTDAR; Mohammad-Reza KHAKZAD

    2011-01-01

    Several different pharmacological effects have been described for Nigella sativa (Siah-Daneh), including an anti-inflammatory effect. In the present study, the effect of the extract of N. saliva on lung pathology and blood interleukin-4 (IL-4) and interferon-γ (IFN-γ) of sensitized guinea pigs was examined. Three groups (n=8 for each group)of guinea pigs sensitized to ovalbumin (OA) were given drinking water alone, and drinking water containing low and high concentrations of the plant extract, respectively. The animals of the control group (n=8) were treated with saline instead of OA and were given drinking water. The pathological changes of the lung, including infiltration of eosinophils and lymphocytes, local epithelial necrosis, the presence of oedema, thickening of the basement membrane, smooth muscle layer hypertrophy, mucosal secretion, and the presence of mucosal plug, and blood IL-4 and IFN-γ of sensitized guinea pigs were evaluated. The lungs of the sensitized group showed significant pathological changes (P<0.001). Blood IL-4 and IFN-γ were increased in sensitized animals compared to the controls (P<0.01 and P<0.001,respectively). Treatment of sensitized animals with the extract led to a significant decrease in pathological changes of the lung (P<0.01 to P<0.001), except for the oedema in the sensitized group treated with low concentration of the extract, but an increased IFN-γ. These results confirm a preventive effect of N. sativa extract on lung inflammation of sensitized guinea pigs.

  14. Effect of pirenzepine ophthalmic solution on form-deprivation myopia in the guinea pigs.

    Science.gov (United States)

    Le, Qi-hua; Cheng, Neng-neng; Wu, Wei; Chu, Ren-yuan

    2005-04-05

    Nonselective muscarinic receptor antagonist, atropine, was believed to inhibit myopic progression. The purpose of this study was to determine the efficacy, through topical administration, of the M1-selective muscarinic antagonist pirenzepine in preventing experimentally induced form-deprivation myopia in guinea pigs. Fifty-three guinea pigs, which underwent monocular deprivation with their eyelids sutured, were divided into 6 groups. Three groups were treated with 1%, 2% or 4% pirenzepine ophthalmic solutions; the fourth group with atropine; the fifth with saline and the last group left untreated. Ocular refraction, in vivo biometric measurements and wet eye weight were collected before and after the experiment. All the eyes were finally enucleated for histopathological examination to evaluate the possible toxic effects on ocular structures. Animals untreated or treated with saline produced (-2.31+/-1.47) D and (-2.25+/-0.88) D of axial myopia respectively. Those treated with 1% pirenzepine ophthalmic solution produced relative myopia of (-1.63+/-0.48) D, and those under the treatment of 2% and 4% pirenzepine ophthalmic solution only developed a relative myopia of (-0.89+/-0.42) D and (-0.70+/-0.41) D (F=9.56, Ppirenzepine treated animals was caused by significantly less vitreous chamber elongation and axial elongation of the deprived eyes [2% group: (0.009+/-0.052) mm, 4% group: (0.006+/-0.078) mm] when compared with untreated, saline treated or 1% pirenzepine treated guinea pigs (0.057+/-0.056) mm, (0.064+/-0.053) mm and (0.033+/-0.035) mm, respectively]. Histological examinations revealed no obviously toxic effects on the eyes treated with pirenzepine. Topical administration of the M1-selective muscarinic antagonist, pirenzepine, can prevent induced form-deprivation myopia in guinea pigs by inhibiting axial elongation without obvious damage to ocular tissues.

  15. Autoradiographic visualization of muscarinic receptor subtypes in human and guinea pig lung

    Energy Technology Data Exchange (ETDEWEB)

    Mak, J.C.; Barnes, P.J. (National Heart and Lung Institute, London (England))

    1990-06-01

    Muscarinic receptor subtypes have been localized in human and guinea pig lung sections by an autoradiographic technique, using (3H)(-)quinuclidinyl benzilate (( 3H)QNB) and selective muscarinic antagonists. (3H)QNB was incubated with tissue sections for 90 min at 25 degrees C, and nonspecific binding was determined by incubating adjacent serial sections in the presence of 1 microM atropine. Binding to lung sections had the characterization expected for muscarinic receptors. Autoradiography revealed that muscarinic receptors were widely distributed in human lung, with dense labeling over submucosal glands and airway ganglia, and moderate labeling over nerves in intrapulmonary bronchi and of airway smooth muscle of large and small airways. In addition, alveolar walls were uniformly labeled. In guinea pig lung, labeling of airway smooth muscle was similar, but in contrast to human airways, epithelium was labeled but alveolar walls were not. The muscarinic receptors of human airway smooth muscle from large to small airways were entirely of the M3-subtype, whereas in guinea pig airway smooth muscle, the majority were the M3-subtype with a very small population of the M2-subtype present. In human bronchial submucosal glands, M1- and M3-subtypes appeared to coexist in the proportions of 36 and 64%, respectively. In human alveolar walls the muscarinic receptors were entirely of the M1-subtype, which is absent from the guinea pig lung. No M2-receptors were demonstrated in human lung. The localization of M1-receptors was confirmed by direct labeling with (3H)pirenzepine. With the exception of the alveolar walls in human lung, the localization of muscarinic receptor subtypes on structures in the lung is consistent with known functional studies.

  16. A small animal model study of perlite and fir bark dust on guinea pig lungs.

    Science.gov (United States)

    McMichael, R F; DiPalma, J R; Blumenstein, R; Amenta, P S; Freedman, A P; Barbieri, E J

    1983-05-01

    Fir bark (Abies) and perlite (noncrystalline silicate) dusts have been reported to cause pulmonary disease in humans. Guinea pigs were exposed to either fir bark or perlite dust in a special chamber. Severe pathologic changes occurred in the lungs, consisting of lymphoid aggregated and a perivascular inflammatory response. Both dusts caused similar changes although one was vegetable (fir bark) and the other mineral (perlite). Fir bark and perlite dust appeared to be more than just nuisance dusts.

  17. Insulin-like growth factors I and II in maternal and fetal guinea pig serum.

    Science.gov (United States)

    Daughaday, W H; Yanow, C E; Kapadia, M

    1986-08-01

    The role of insulin-like growth factors (IGFs) in fetal development has been the subject of much speculation. We undertook studies of maternal and fetal IGF I and II in the guinea pig because the long gestation period and greater size of the fetuses permitted blood sampling over a longer period of gestation and maturation than is possible in the rat. Acid gel filtrates of fetal and maternal serum were prepared, and the IGF I was measured by RIA; IGF II was measured by rat placental membrane radioreceptor assay. Fetal IGF I levels were lower than maternal levels from the 33rd day of estimated gestation to term. Fetal IGF II levels from the 33rd day to the 49th day of gestation were not significantly different from those of maternal serum [1597 +/- 377 (SE) ng/ml vs. 1295 +/- 224] ng/ml. Very high levels of IGF II, in excess of 5000 ng/ml, were observed in fetuses at 50, 55, and 60 days of gestation. Thereafter, fetal IGF II levels fell markedly before term. Fetal and maternal IGFs after 49, 50, 60, and 65 days of pregnancy were compared by isoelectric focusing. The guinea pig normally has two major basic peaks of IGF I, which were present both in maternal and fetal serum. Most maternal and fetal guinea pig sera contained only a single, slightly acidic peak of IGF II. No evidence of a unique fetal IGF was detected by our methods. The very high levels of IGF II reached in fetal guinea pig sera suggest that it may have a role in fetal development.

  18. Actions of genistein on contractile response of smooth muscle isolated from guinea pig gallbladder

    Institute of Scientific and Technical Information of China (English)

    Ya-Li Luo; Ya-Li Wang; Neng-Lian Li; Tian-Zhen Zheng; Li Zhang; Ya-Li She; Shu-Ming Hu

    2009-01-01

    BACKGROUND: Defective contractile motility of the gallbladder is an important factor for gallstone formation. Estrogen might increase the risk of gallstones and cholecystitis, and estradiol inhibits the contractile activity of isolated strips of guinea pig gallbladder. The potential risks associated with hormone replacement therapy (HRT) include symptomatic gallstones. Phytoestrogen have been used to treat menopause syndromes by replacing traditional estrogen. This experiment aimed to determine the effects of the phytoestrogen genistein on the contractile response of smooth muscle strips isolated from guinea pig gallbladder and its possible mechanism of action. METHODS: Guinea pigs were sacriifced to remove the whole gallbladder. Two or three smooth muscle strips were cut longitudinally. Each strip was suspended in a tissue chamber containing Krebs solution. After 2 hours of equilibration, contractile response indexes were recorded. Different concentrations of genistein were added to the chamber and the contractile responses were measured. Each antagonist was added 2 minutes before genistein to study possible mechanisms. The effect of genistein on calcium-dependent contraction curves and biphasic contraction in calcium-free Krebs solution were measured. RESULTS: Genistein decreased the resting tension dose-dependently, and reduced the mean contractile amplitude and frequency in gallbladder strips. Ranitidine partly inhibited the effect of genistein, but methylene blue, Nω-nitro-L-arginine, and propranolol hydrochloride did not inlfuence this action. Genistein had no signiifcant effects on calcium-dependent contraction. Genistein reduced the ifrst contraction induced by acetylcholine chloride, but did not affect the second contraction caused by CaCl2. CONCLUSIONS: Genistein relaxed smooth muscle isolated from the gallbladder of guinea pigs and this might contribute to the formation of gallstones. The inhibitory action might be related to H2 receptors and

  19. Cyclic cidofovir (cHPMPC prevents congenital cytomegalovirus infection in a guinea pig model

    Directory of Open Access Journals (Sweden)

    McGregor Alistair

    2006-03-01

    Full Text Available Abstract Background Congenital cytomegalovirus (CMV infection is a major public health problem. Antiviral therapies administered during pregnancy might prevent vertical CMV transmission and disease in newborns, but these agents have not been evaluated in clinical trials. The guinea pig model of congenital CMV infection was therefore used to test the hypothesis that antiviral therapy, using the agent agent cyclic cidofovir (cHPMPC, could prevent congenital CMV infection. Results Pregnant outbred Hartley guinea pigs were challenged in the early-third trimester with guinea pig CMV (GPCMV and treated with placebo, or the antiviral agent, cyclic cidofovir. To optimize detection of vertical infection, an enhanced green fluorescent protein (eGFP-tagged virus was employed. Compared to placebo, cyclic cidofovir-treated dams and pups had reduced mortality following GPCMV challenge. The magnitude of GPCMV-induced maternal and fetal mortality in this study was reduced from 5/25 animals in the placebo group to 0/21 animals in the treatment group (p = 0.05, Fisher's exact test. By viral culture assay, antiviral therapy was found to completely prevent GPCMV transmission to the fetus. In control pups, 5/19 (26% were culture-positive for GPCMV, compared to 0/16 of pups in the cyclic cidofovir treatment group (p Conclusion Antiviral therapy with cyclic cidofovir improves pregnancy outcomes in guinea pigs, and eliminates congenital CMV infection, following viral challenge in the third trimester. This study also demonstrated that an eGFP-tagged recombinant virus, with the reporter gene inserted into a dispensable region of the viral genome, retained virulence, including the potential for congenital transmission, facilitating tissue culture-based detection of congenital infection. These observations provide support for clinical trials of antivirals for reduction of congenital CMV infection.

  20. Migration of craniofacial periosteum in guinea-pigs with unilateral masticatory muscle paralysis.

    OpenAIRE

    1985-01-01

    The amount and direction of movement of the fibrous periosteum of the nasal, frontal, and parietal bones in the guinea-pig have been documented after experimentally induced unilateral paralysis of the masticatory muscles. Marked craniofacial asymmetries and muscle atrophy were observed after electrolytic lesions of the trigeminal motor nucleus were made. The induced muscle paralysis had only a small effect on the periosteal migration. The direction of migration was slightly less medial on the...

  1. Evaluating of the Anticonvulsant Gabapentin against Nerve Agent-Induced Seizures in a Guinea Pig Model

    Science.gov (United States)

    2010-07-01

    this drug or similar compounds of this class (e.g., pregabalin, Lyrica®) would be considered as a replacement for, or a supplement to, diazepam or...L.W., Talbot, B.G., Anderson, D.R. Relationship between reversible acetylcholinesterase inhibition and efficacy against soman lethality. Life Science...treatment of nerve agent seizures: anticholinergics vs diazepam in soman- intoxicated guinea pigs. Epilepsy Research, 2000, 38:1-14. McDonough, J.H

  2. Pharmacokinetics of tritiated ouabain, digoxin and digitoxin in guinea-pigs.

    Science.gov (United States)

    Proppe, D

    1975-01-01

    1. Elimination rates of tritiated ouabain, digoxin and digitoxin after single intravenous administrations were investigated in guinea-pigs, the total radioactivity in whole blood being traced for a period of up to 2 weeks. 2. In the initial rapid phase of elimination between 2 and 30 min following intravenous glycoside administration, the concentration decline of radioactivity in the blood was found to be identical for the three glycosides investigated, this part of the elimination curve displaying a hyperbolic shape. 3. During this early elimination phase, rapid metabolic degradation and excretion of digoxin had already taken place. The maximum concentration of radioactivity in the bile was reached 4 min following intravenous administration of 3H-digoxin. The positive inotropic response occurred in the cat heart-lung preparation 1.5 min after intravenous injection of a therapeutic dose of digoxin, indicating a quick occupation of binding sites in the tissues. 4. The biological half-lives of tritiated ouabain, digoxin and digitoxin averaged 11 h, 2.5 days and 4.1 days, respectively, as determined by the terminal exponential elimination phase, in guinea-pigs. This terminal phase was attained 6-12, 7-24, and 24-48 h after administration of ouabain, digoxin and digitoxin, respectively. 5. The findings reveal that in guinea-pig, as has been demonstrated in man, the elimination rates of the three glycosides increase according to their hydrophobic properties. 6. The biological half-lives of tritiated ouabain, digoxin and digitoxin obtained in the guinea-pig closely resemble those found in healthy man.

  3. Effect of salbutamol on pulmonary responsiveness in chronic pulmonary allergic inflammation in guinea pigs

    Directory of Open Access Journals (Sweden)

    Kasahara D.I.

    2005-01-01

    Full Text Available Beta-2-agonists have been widely used by asthmatic subjects to relieve their obstructive symptoms. However, there are reports that continuous use could lead to loss of bronchial protection and exacerbation of asthma symptoms. We evaluated the effect of two regimens of salbutamol administration (twice and five times a week in a model of chronic airway inflammation in male Hartley guinea pigs (protocol starting weight: 286 ± 30 g induced by repeated exposures to aerosols of ovalbumin (OVA. After sensitization, guinea pigs were exposed to aerosols of 0.1 mg/ml salbutamol solution twice a week (OVA + S2x, N = 7 or five times a week (OVA + S5x, N = 8. We studied allergen-specific (OVA inhalation time and -nonspecific (response to methacholine respiratory system responsiveness. Seventy-two hours after the last OVA challenge, guinea pigs were anesthetized and tracheostomized, respiratory system resistance and elastance were measured and a dose-response curve to inhaled methacholine chloride was obtained. Specific IgG1 was also quantified by the passive cutaneous anaphylactic technique. OVA-sensitized guinea pigs (N = 8 showed reduction of the time of OVA exposure before the onset of respiratory distress, at the 5th, 6th and 7th exposures (P < 0.001. The OVA + S2x group (but not the OVA + S5x group showed a significant increase in OVA inhalation time. There were no significant differences in pulmonary responsiveness to methacholine among the experimental groups. OVA + S2x (but not OVA + S5x animals showed a decrease in the levels of IgG1-specific anaphylactic antibodies compared to the OVA group (P < 0.05. Our results suggest that, in this experimental model, frequent administration of ß2-agonists results in a loss of some of their protective effects against the allergen.

  4. Synthetic detergents induced-biochemical and histological changes in skin of guinea pigs.

    Science.gov (United States)

    Agarwal, C; Mathur, A K; Gupta, B N; Singh, A; Shanker, R

    1990-06-01

    The linear alkylbenzene sulphonate (LAS) based synthetic detergents-induced decrease in lipid peroxydation and increase in histamine content in exposed skin of guinea pigs in a dose-dependent manner. Histopathological alterations of exposed skin included moderate degree of hyperkeratinization at lower concentration but necrosis, scarring, sloughing as well as discontinuity of epidermis at higher concentrations. The results shows that the contact of skin with detergents causes dermal toxicity.

  5. Protection of Guinea Pigs against Leptospira interrogans Serovar Lai by LipL21 DNA Vaccine

    Institute of Scientific and Technical Information of China (English)

    Hanjiang He; Wenyu Wang; Zhongdao Wu; Zhiyue Lv; Jun Li; Lizhi Tan

    2008-01-01

    In this study,the full lipL21 gene fragment encoding outer membrane protein LipL21 was cloned from L. Interrogans serovar Lai and inserted into eukaryotic expression vector pcDNA3.1(+).The guinea pigs were immunized with pcDNA3.1(+)-lipL21,pcDNA3.1(+) or PBS.Six weeks after the second immunization,the splenocytes were isolated to detect their proliferative ability by lymphocyte transformation experiments.In addition,microscopic agglutination test was used for quantitative detection of specific antibodies.The rest guinea pigs were challenged intraperitoneally with L.interogans sorevar Lai.Then,protective effect was evaluated on the basis of survival and histopathological lesions in the kidneys,lungs,and liver.The lipL21 gene Was successfully expressed in COS-7 cells through recombinant pcDNA3.1(+)-lipL21.The titer of specific antibodies substantially increased,and the stimulation index of splenocytes increased significantly.Hence,the pcDNA3.1(+)-lipL21 could protect the immunized guinea pigs from homotypic Leptospira infection.Furthermore,no obvious pathologic changes were observed in the pcDNA3.1(+)-lipL21 immunized guinea pigs.The results showed that the protective effect with pathogenic strains of Leptospira was shared by LipL21 mediated through a plasmid vector. Consequently,these results indicated that the lipL21 DNA vaccine Was a promising candidate for the prevention of leptospirosis.

  6. Transdermal delivery of isoniazid and rifampin in guinea pigs by electro-phonophoresis.

    Science.gov (United States)

    Chen, Suting; Han, Yi; Yu, Daping; Huo, Fengmin; Wang, Fen; Li, Yunxu; Dong, Lingling; Liu, Zhidong; Huang, Hairong

    2017-11-01

    Electro-phonophoresis (EP) has been used as a drug delivery approach in clinical fields. The objective of the present study is to evaluate the skin permeability of isoniazid and rifampin in guinea pigs by EP to provide reference basis for clinical applications of such transdermal delivery system in the treatment of patients with superficial tuberculosis. Isoniazid and rifampin solutions were delivered transdermally with or without EP in health guinea pigs for 0.5 h. Local skin and blood samples were collected serially at 0, 1/2, 1, 2, 4, 6 and 24 h after dosing. Drug concentrations in local skin and blood were evaluated by high-performance liquid chromatography. Isoniazid concentrations in local skin of guinea pigs receiving isoniazid through EP transdermal delivery were significantly higher than in animals receiving only isoniazid with transdermal patch. However, for rifampin, patches alone group presented almost uniform concentration versus time curve with that of EP group, and both groups had concentrations much higher than the therapeutic concentration of the drug over sustainable time. After EP transdermal delivery, the mean peak concentrations of isoniazid and rifampin in skin were 771.0 ± 163.4 μg/mL and 81.2 ± 17.3 μg/mL respectively. Neither isoniazid nor rifampin concentration in blood could be detected (below the lower detection limit of 1 μg/mL) at any time point. The present study showed that application of EP significantly enhanced INH penetration through skin in guinea pigs, while RIF patch alone obtained therapeutic concentration in local skin. Our work suggests several possible medication approaches for efficient treatment of superficial tuberculosis.

  7. Validation of a Behavioral Ethogram for Assessing Postoperative Pain in Guinea Pigs (Cavia porcellus).

    Science.gov (United States)

    Dunbar, Misha L; David, Emily M; Aline, Marian R; Lofgren, Jennifer L

    2016-01-01

    Although guinea pigs (Cavia porcellus) have been used in research for more than a century and remain the most prevalent USDA-covered species, little has been elucidated regarding the recognition of clinical pain or analgesic efficacy in this species. We sought to assess pain in guinea pigs by using newer, clinically relevant methods that have been validated in other rodent species: the behavioral ethogram and cageside proxy indicator. In this study, 10 male guinea pigs underwent electronic von Frey testing of nociception, remote videorecording of behavior, and cageside assessment by using time-to-consumption (TTC) of a preferred treat test. These assessments were performed across 2 conditions (anesthesia only and castration surgery under anesthesia) at 3 time points (2, 8, and 24 h after the event). The anesthesia only condition served to control for the nonpainful but potentially distressing components of the surgical experience. Compared with those after anesthesia only conditions, subtle body movements were increased and nociceptive thresholds were decreased at 2 and 8 h after surgery. At 24 h, neither subtle body movement behaviors nor nociceptive thresholds differed between the 2 conditions. In contrast, TTC scores did not differ between the anesthesia only and surgery conditions at any time point, underscoring the challenge of identifying pain in this species through cageside evaluation. By comparing ethogram scores with measures of nociception, we validated select behaviors as pain-specific. Therefore, our novel ethogram allowed us to assess postoperative pain and may further serve as a platform for future analgesia efficacy studies in guinea pigs.

  8. Fetal guinea pig brain 15-hydroxyprostaglandin dehydrogenase: Ontogeny and effect of ethanol

    Energy Technology Data Exchange (ETDEWEB)

    Treissman, D.; Brien, J.F. (Department of Pharmacology and Toxicology, Faculty of Medicine, Queen' s University, Kingston, Ontario (Canada))

    1991-03-01

    The objectives of this study were to determine the ontogeny of 15-hydroxyprostaglandin dehydrogenase (15-OH-PGDH) activity in the brain of the fetal guinea pig and to test the hypothesis that acute in vitro ethanol exposure produces concentration-dependent inhibition of fetal brain 15-OH-PGDH activity. Enzyme activity was determined in vitro by measuring the rate of oxidation of PGE2 to 15-keto-PGE2 using an optimized radiometric procedure. The study was conducted utilizing the whole brain of the fetal guinea pig at mean gestational ages of 34, 43 and 62 days (term, about 66 days) and the brain stem (pons and medulla) of the fetal guinea pig at mean gestational ages of 43 and 62 days. The direct effect of acute in vitro exposure to ethanol was assessed by incubating 15-OH-PGDH with ethanol in the concentration range of 10 to 80 mM. 15-OH-PGDH was measurable in the whole brain and brain stem, and the enzyme activity was similar for the gestational ages examined. There was no significant ethanol-induced inhibition of 15-OH-PGDH activity in the whole brain or brain stem. The data demonstrate that the whole brain and brain stem of the fetal guinea pig have the capacity to metabolize PGE2 to 15-keto-PGE2, an inactive metabolite, during the second half of gestation. The data apparently are not consistent with the hypothesis that acute in vitro exposure to ethanol directly inhibits 15-OH-PGDH activity in fetal brain.

  9. Intraocular Pressure, Tear Production, and Ocular Echobiometry in Guinea Pigs (Cavia porcellus).

    Science.gov (United States)

    Rajaei, Seyed Mehdi; Mood, Maneli Ansari; Sadjadi, Reza; Azizi, Farzaneh

    2016-01-01

    The purpose of this study was to evaluate intraocular pressure (IOP) by means of rebound tonometry, to assess tear production by using the endodontic absorbent paper point tear test (EAPTT) and phenol red thread test (PRTT), and to determine the effects of time of day on IOP and tear production in guinea pigs. The study population comprised 24 healthy adult guinea pigs (12 male, 12 female; 48 eyes) of different breeds and ranging in age from 12 to 15 mo. IOP and tear production were measured at 3 time points (0700, 1500, and 2300) during a 24-h period. Overall values (mean ± 1 SD) were: IOP, 6.81 ± 1.41 mm Hg (range, 4.83 to 8.50); PRTT, 14.33 ± 1.35 mm (range, 12.50 to 16.83); and EAPTT, 8.54 ± 1.08 mm (range, 7.17 to 10.0 mm). In addition, ultrasound biometry was performed by using a B-mode system with linear 8-MHz transducer. This study reports reference values for IOP and tear production in guinea pigs.

  10. Spontaneous Healing of Mycobacterium ulcerans Lesions in the Guinea Pig Model

    Science.gov (United States)

    Silva-Gomes, Rita; Marcq, Elly; Trigo, Gabriela; Gonçalves, Carine M.; Longatto-Filho, Adhemar; Castro, António G.; Pedrosa, Jorge; Fraga, Alexandra G.

    2015-01-01

    Buruli Ulcer (BU) is a necrotizing skin disease caused by Mycobacterium ulcerans infection. BU is characterized by a wide range of clinical forms, including non-ulcerative cutaneous lesions that can evolve into severe ulcers if left untreated. Nevertheless, spontaneous healing has been reported to occur, although knowledge on this process is scarce both in naturally infected humans and experimental models of infection. Animal models are useful since they mimic different spectrums of human BU disease and have the potential to elucidate the pathogenic/protective pathway(s) involved in disease/healing. In this time-lapsed study, we characterized the guinea pig, an animal model of resistance to M. ulcerans, focusing on the macroscopic, microbiological and histological evolution throughout the entire experimental infectious process. Subcutaneous infection of guinea pigs with a virulent strain of M. ulcerans led to early localized swelling, which evolved into small well defined ulcers. These macroscopic observations correlated with the presence of necrosis, acute inflammatory infiltrate and an abundant bacterial load. By the end of the infectious process when ulcerative lesions healed, M. ulcerans viability decreased and the subcutaneous tissue organization returned to its normal state after a process of continuous healing characterized by tissue granulation and reepethelialization. In conclusion, we show that the experimental M. ulcerans infection of the guinea pig mimics the process of spontaneous healing described in BU patients, displaying the potential to uncover correlates of protection against BU, which can ultimately contribute to the development of new prophylactic and therapeutic strategies. PMID:26625302

  11. Anatomical study of blood supply to the cervical spinal cord in the guinea pig.

    Science.gov (United States)

    Mazensky, David; Danko, Jan; Petrovova, Eva; Flesarova, Slavka; Supuka, Peter; Supukova, Anna; Luptakova, Lenka; Purzyc, Halina

    2015-06-01

    The aim of this study was to describe the arterial arrangement of the cervical spinal cord in the guinea pig. The study was carried out on 20 adult English self guinea pigs using corrosion and dissection technique. Batson's corrosion casting kit no. 17(©) was used as a casting medium. The origin of the ventral spinal artery from the left vertebral artery was found on average in 35% of the cases and from the right vertebral artery on average in 40% of the cases. The ventral spinal artery with origin from the anastomosis of two medial branches was found on average in 25% of the cases. The presence of ventral radicular branches of rami spinales entering the ventral spinal artery in the cervical region was observed in 42% of the cases on the right side and in 58% of the cases on the left side. The presence of dorsal radicular branches of rami spinales that reached the spinal cord was observed in 63% of the cases on the left side and in 37% of the cases on the right side. The number of radicular branches supplying the spinal cord is greater in guinea pig than in humans.

  12. Analysis of anabolic steroids in hair: time courses in guinea pigs.

    Science.gov (United States)

    Shen, Min; Xiang, Ping; Yan, Hui; Shen, Baohua; Wang, Mengye

    2009-09-01

    Sensitive, specific, and reproducible methods for the quantitative determination of eight anabolic steroids in guinea pig hair have been developed using LC/MS/MS and GC/MS/MS. Methyltestosterone, stanozolol, methandienone, nandrolone, trenbolone, boldenone, methenolone and DHEA were administered intraperitoneally in guinea pigs. After the first injection, black hair segments were collected on shaved areas of skin. The analysis of these segments revealed the distribution of anabolic steroids in the guinea pig hair. The major components in hair are the parent anabolic steroids. The time courses of the concentrations of the steroids in hair (except methenolone, which does not deposit in hair) demonstrated that the peak concentrations were reached on days 2-4, except stanozolol, which peaked on day 10 after administration. The concentrations in hair appeared to be related to the physicochemical properties of the drug compound and to the dosage. These studies on the distribution of drugs in the hair shaft and on the time course of their concentration changes provide information relevant to the optimal time and method of collecting hair samples. Such studies also provide basic data that will be useful in the application of hair analysis in the control of doping and in the interpretation of results.

  13. Blocking Dopaminergic Signaling Soon after Learning Impairs Memory Consolidation in Guinea Pigs.

    Directory of Open Access Journals (Sweden)

    Kiera-Nicole Lee

    Full Text Available Formation of episodic memories (i.e. remembered experiences requires a process called consolidation which involves communication between the neocortex and hippocampus. However, the neuromodulatory mechanisms underlying this neocortico-hippocampal communication are poorly understood. Here, we examined the involvement of dopamine D1 receptors (D1R and D2 receptors (D2R mediated signaling on memory consolidation using the Novel Object Recognition (NOR test. We conducted the tests in male Hartley guinea pigs and cognitive behaviors were assessed in customized Phenotyper home cages utilizing Ethovision XT software from Noldus enabled for the 3-point detection system (nose, center of the body, and rear. We found that acute intraperitoneal injections of either 0.25 mg/kg SCH23390 to block D1Rs or 1.0 mg/kg sulpiride to block D2Rs soon after acquisition (which involved familiarization to two similar objects attenuated subsequent discrimination for novel objects when tested after 5-hours in the NOR test. By contrast guinea pigs treated with saline showed robust discrimination for novel objects indicating normal operational processes undergirding memory consolidation. The data suggests that involvement of dopaminergic signaling is a key post-acquisition factor in modulating memory consolidation in guinea pigs.

  14. [Effects of pirenzepine on lens-induced myopia in the guinea-pig].

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    Ouyang, Chao-hu; Chu, Ren-yuan; Hu, Wen-zheng

    2003-06-01

    To determine the efficacy of the M(1)-selective muscarinic antagonist, pirenzepine, in preventing lens-induced myopia in the guinea-pig and to study the mechanism and the possibility of treatment of myopia with pirenzepine. Fifteen 4-week-old guinea-pigs were monocularly fitted with -10.00 D lenses for a period of 11 days. In Group I (n = 7), both eyes received topical administration of 0.24% saline vehicle as the controls. In Group II (n = 8), the lens-fitted eyes were topically treated with 10% pirenzepine, while the other eyes received the vehicle control. Ocular refraction and biometric measurements were collected on the first and the 11th days. All eyes were finally enucleated for histopathological examination to evaluate the possible toxic effects of pirenzepine. In Group I, 11 days of lens-fitting produced -2.45 D myopia (t = 3.141, P pirenzepine-treated eyes. Topical administration of the M(1)-selective muscarinic antagonist, pirenzepine, prevents lens-induced experimental myopia in guinea-pig by inhibiting the elongation of axial dimension with no obvious damage to the ocular tissues.

  15. Specificity and structural analysis of a guinea pig transfer factor-like activity.

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    Dunnick, W A; Bach, F H

    1977-06-01

    A transfer factor-like activity was prepared by Sephadex G-25 chromatography of immune guinea pig leukocyte lysates. This isolated material leads to antigen-dependent migration inhibition and thymidine uptake by nonimmune lymphoid cells. Tests of the "transfer factor" from guinea pigs immunized to either ovalbumin or bovine gamma-globulin demonstrated the donor specificity of the in vitro activity. The activity is susceptible to heat (56 degrees C), alkali (0.5 M sodium hydroxide), pronase, and phosphodiesterase. The pronase susceptibility is blocked by traysylol, a protease inhibitor; the phosphodiesterase susceptibility is not bocked by traysylol. The guinea pig factor was purified further by alkaline phosphatase treatment. Sephadex G-25 chromatography, and DEAE-cellulose chromatography. The final product, active in vitro, represents about 0.03% of the cellular material absorbing 260 nm light, and contains polymerized amines and phosphate. Gel electrophoresis of the fluram-reactive components suggests a limited heterogeneity of the DEAE-cellulose-purified material. These data are consistent with the active "transfer factor" molecule including both peptide and phosphate-containing components.

  16. Effect of aqueous fraction of Rosa damascena on ileum contractile response of guinea pigs

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    Karim Dolati

    2013-05-01

    Full Text Available Objective: The use of drugs with herbal origin is increasing for treatment of gastrointestinal (GI disorders. Rosa damascena (R. damascena is a well-known plant suggested to have beneficial effect on GI system. In this study, the effect of aqueous fraction of R. damascena on the contractionsofisolated guinea pig ileum was investigated. Materials and Methods: Aqueous fraction of plant was obtained from ethanolic extract after ethyl acetate and n-butanol fractions were discarded. To evaluate effect of this fraction on ileum contraction, guinea pig ileum was removed and mounted on organ bath and its contraction was recorded. Effect of various concentrations (0.66, 0.83, and 1.3 mg/ml of aqueous fraction on ileum contraction in comparison with Ach in presence and absense of atropine, a muscarinic antagonist of cholinergic, was evaluated. The response of ileum to 1 µg/ml of acetylcholine was considered as 100% response. Results:Our results showed that aqueous fractions of R. damascena dose-dependently increased basal guinea pigs ileum contractions (pConclusion: It is concluded that aqueous fraction of R. damascena has mild excitatory effect on ileum contraction and this fraction may be beneficial as a mild laxative agent.

  17. Captain America, Tuskegee, Belmont, and Righteous Guinea Pigs: Considering Scientific Ethics through Official and Subaltern Perspectives

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    Weinstein, Matthew

    2008-09-01

    With an eye towards a potential scientific ethics curriculum, this paper examines four contrasting discourses regarding the ethics of using human subjects in science. The first two represent official statements regarding ethics. These include the U.S.’s National Science Education Standards, that identify ethics with a professional code, and the Belmont Report, that conceptualizes ethics in three principles to guide research oversight boards. Contrasting this view of ethics as decorum and practice in line with a priori principles is the conception of ethics from unofficial sources representing populations who have been human subjects. The first counter-discourse examined comes from Guinea Pig Zero, an underground magazine for professional human subjects. Here ethics emerges as a question of politics over principle. The good behavior of the doctors and researchers is an effect of the politics and agency of the communities that supply science with subjects. The second counter-discourse is a comic book called Truth, which tells the story of Black soldiers who were used as guinea pigs in World War II. Ethics is both more political and more uncertain in this narrative. Science is portrayed as complicit with the racism of NAZI Germany; at the same time, and in contrast to the professional guinea pigs, neither agency nor politics are presented as effective tools for forcing the ethical conduct of the scientific establishment. The conclusion examines the value of presenting all of these views of scientific ethics in science education.

  18. Predominant involvement of the cerebellum in guinea pigs infected with bovine spongiform encephalopathy (BSE).

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    Furuoka, H; Horiuchi, M; Yamakawa, Y; Sata, T

    2011-05-01

    This study reports the experimental transmission of bovine spongiform encephalopathy (BSE) to guinea pigs and describes the cerebellar lesions in these animals. Guinea pigs were inoculated intracerebrally with 10% brain homogenates from BSE-affected cattle. These animals were designated as the first passage. Second and third passages were subsequently performed. All guinea pigs developed infection at each passage. The mean incubation period of the first passage was 370 days post-infection (dpi) and this decreased to 307 dpi and 309 dpi for the second and third passages, respectively. Mild to severe spongiform degeneration and gliosis were observed in the cerebral cortex, thalamus and brainstem. In addition, the affected animals had marked pathological changes in the cerebellum characterized by severe cortical atrophy associated with Bergmann radial gliosis of the molecular layer and reduction in the width of the granular cell layer. Immunohistochemically, intense PrP(Sc) deposition and scattered plaque-like deposits were observed in the molecular and granular cell layers. Cerebellar lesions associated with severe atrophy of the cortex have not been reported in animal prion diseases, including in the experimental transmission of PrP(Sc) to small rodents. These lesions were similar to the lesions of human kuru or the VV2 variant of sporadic Creutzfeldt-Jakob disease, although typical kuru plaques or florid plaques were not observed in the affected animals.

  19. Some effects of mastectomy on reproductive success in the guinea-pig.

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    Peaker, M; Taylor, E

    1990-07-01

    Virgin guinea-pigs were mastectomized in two stages between 11 and 18 weeks of age and then mated, starting 19 weeks after final surgery. In the subsequent first pregnancy, the incidence of still-births and neonatal deaths was significantly higher in the mastectomized animals (6 out of 12 mothers (50%) and 14 out of 49 young (29%) compared with intact guinea-pigs (1 out of 15 mothers (7%) and 1 out of 58 young (2%)). There was no significant effect of mastectomy on litter size and weight or on gestation period. The still-born were not significantly different in weight from those born alive. A significant relation was found between maternal weight changes in the period 20 to 5 days before parturition and the occurrence of still-births and neonatal deaths; still-births were associated with a period of reduced weight gain. No effect of mastectomy on the length of the oestrous cycle was apparent but a significant increase in the incidence of non-pregnancy was found. The results provide further evidence that mastectomy influences reproductive success in the guinea-pig and suggest that parturition is a key process affected.

  20. Dietary regulation of maternal and fetal cholesterol metabolism in the guinea pig.

    Science.gov (United States)

    Yount, N Y; McNamara, D J

    1991-08-20

    Studies to determine the effects of pre-natal interventions on maternal and fetal cholesterol homeostasis were carried out in the guinea pig. Guinea pig dams were fed either non-purified guinea pig diet or diet supplemented with either 1.1% of the bile acid binding resin cholestyramine or 0.25% cholesterol. Whole body rates of endogenous cholesterol synthesis were determined by quantitation of [3H]water incorporation into digitonin precipitable sterols in non-pregnant animals and at 40 and 60 days of gestation in the dam and fetus. Maternal hepatic cholesterol synthesis was reduced 87% by dietary cholesterol and was increased 3.5-fold with cholestyramine feeding. Fetal hepatic and peripheral tissue cholesterol synthesis rates peaked at 40 days gestation when peripheral tissue cholesterol synthesis was 5.7-fold higher and hepatic synthesis 6.2-fold greater than the near adult levels observed at 60 days. Cholesterol synthesis in the fetus was relatively insensitive to dietary manipulations; however, maternal cholestyramine treatment did result in a 1.4-fold increase in fetal carcass cholesterol synthesis at 60 days gestation. These data demonstrate that maternal cholesterogenic systems maintain responsiveness to dietary regulation during pregnancy; whereas fetal cholesterol homeostasis is relatively insensitive to dietary cholesterol throughout gestation yet may respond to induction by maternal cholestyramine treatment during the late gestation period.

  1. Leucocyte kinesis in blood, bronchoalveoli and nasal cavities during late asthmatic responses in guinea-pigs.

    Science.gov (United States)

    Nabe, T; Shinoda, N; Yamashita, K; Yamamura, H; Kohno, S

    1998-03-01

    Recently, we reported a reproducible model of asthma in guinea-pigs in vivo, which developed a late asthmatic response (LAR) as well as an early response. In this study, time-related changes in the occurrence of the LAR and leucocyte kinesis were assessed. Furthermore, the state of the activation of eosinophils that migrated into the lower airways was characterized in vitro. Guinea-pigs were alternately sensitized/challenged by inhalation with aerosolized ovalbumin adsorbed on aluminium hydroxide and ovalbumin alone, once every 2 weeks. At defined times before and after the fifth challenge, airway resistance was measured, blood was drawn and bronchoalveolar lavage (BAL) and nasal cavity lavage (NCL) were performed. Superoxide anion (.O2-) production of eosinophils was measured with cytochrome c. Occurrence of LAR and considerable increases in circulating eosinophils coincided with each other 5-7 h after the challenge. After 7 h, eosinophil infiltrations into bronchoalveolar spaces were observed. The capacity of eosinophils from the sensitized animals to produce .O2- was higher than those from the non-sensitized ones, when eosinophils were stimulated by platelet-activating factor. Although an increased number of eosinophils in the NCL fluid was observed, it was much less than that in the BAL fluid. Thus, it has been concluded that eosinophilia in the blood and the lung may participate in the occurrence of the late asthmatic response, which is thought to be preferentially evoked in the lower airways in guinea-pigs in vivo.

  2. Ethanolic extract of Anredera cordifolia (Ten. Steenis leaves improved wound healing in guinea pigs

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    Isnatin Miladiyah

    2012-04-01

    Full Text Available BACKGROUND Wound healing is a normal biological process in response to skin injury. Anredera cordifolia (Ten. Steenis is used traditionally to treat various diseases, including skin disease, hypertension, inflammation and gout. The aim of this study was to evaluate the wound healing activity of the leaves of binahong or Anredera cordifolia (Ten. Steenis in guinea pigs. Methods Thirty guinea pigs (1.5-2 kg, 3-4 months old were randomly divided into 5 groups. Group I was given distilled water (negative control, group II was treated with povidone iodine 10% (positive control, while groups III-V were treated with ethanolic extract of binahong leaves at concentrations of 10%, 20%, and 40%, respectively. Before treatment, a 2 cm long excision wound was made on each animal. All interventions were given by the topical route, twice daily for 15 days. At the end of 15th day, the wound lengths in each group were measured and compared to baseline wound lengths. Data were analyzed with one-way Anova to compare wound healing activity between groups. Results This study showed that groups treated with ethanolic extract of binahong leaves at concentrations of 20% and 40% experienced better wound healing activity than negative and positive controls. There were significant differences (p=0.000 between treatments and negative and positive controls. Conclusions This research has succesfully show significance of the Binahong leaf extract has a potential for wound healing in guinea pig.

  3. Treatment outcome of Paederus dermatitis due to rove beetles (Coleoptera: Staphylinidae) on guinea pigs.

    Science.gov (United States)

    Fakoorziba, M R; Eghbal, F; Azizi, K; Moemenbellah-Fard, M D

    2011-08-01

    Linear dermatitis (or dermatitis linearis, DL) is a skin blistering inflammatory lesion caused by exposure to the pederin toxin from rove beetles. Although it is prevalent in many countries of the Middle East region, this is not a notifiable disease. In recent years, a number of clinical symptoms outbreaks of DL has been reported from a few neighboring countries of Iran, but no report of experimental treatment among small laboratory rodents is known. This is a prerequisite to ascertain the nature of the best treatment strategy in cases of infestation with these beetles, as it occurs among local settlers during hot seasons in certain parts of the southern Iranian province of Fars. Live Paederus beetles were collected, identified to species level, sexed apart and partly processed to obtain their hemolymph toxin pederin in ethanol for dermal application on guinea pigs. Two Paederus species were found. Paederus ilsae (Bernhauer) (Coleoptera: Staphylinidae) was more abundant than P. iliensis (Coiffait). Recovery from DL due to live P. ilsae beetles was quicker and less complex than that of pederin in ethanol on guinea pigs. The application of potassium permanganate with calamine to heal DL was also more effective than fluocinolone treatment. This topical corticosteroid is thus considered less able to avert the cytotoxic action of pederin on the skin of guinea pigs than the antipruritic and cleansing agents. It seems likely that fluocinolone has certain effects which delays the recovery period for the treated skin.

  4. Neuronal release of endogenous dopamine from corpus of guinea pig stomach.

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    Shichijo, K; Sakurai-Yamashita, Y; Sekine, I; Taniyama, K

    1997-11-01

    Neuronal release of endogenous dopamine was identified in mucosa-free preparations (muscle layer including intramural plexus) from guinea pig stomach corpus by measuring tissue dopamine content and dopamine release and by immunohistochemical methods using a dopamine antiserum. Dopamine content in mucosa-free preparations of guinea pig gastric corpus was one-tenth of norepinephrine content. Electrical transmural stimulation of mucosa-free preparations of gastric corpus increased the release of endogenous dopamine in a frequency-dependent (3-20 Hz) manner. The stimulated release of dopamine was prevented by either removal of external Ca2+ or treatment with tetrodotoxin. Dopamine-immunopositive nerve fibers surrounding choline acetyltransferase-immunopositive ganglion cells were seen in the myenteric plexus of whole mount preparations of gastric corpus even after bilateral transection of the splanchnic nerve proximal to the junction with the vagal nerve (section of nerves between the celiac ganglion and stomach). Domperidone and sulpiride potentiated the stimulated release of acetylcholine and reversed the dopamine-induced inhibition of acetylcholine release from mucosa-free preparations. These results indicate that dopamine is physiologically released from neurons and from possible dopaminergic nerve terminals and regulates cholinergic neuronal activity in the corpus of guinea pig stomach.

  5. Tumor necrosis factor and the pathogenesis of Pichinde virus infection in guinea pigs.

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    Aronson, J F; Herzog, N K; Jerrells, T R

    1995-03-01

    Pichinde virus (PIC) is a reticuloendothelial arenavirus of the New World tropics. A guinea pig passage-adapted strain of this virus (adPIC) is uniformly lethal for inbred guinea pigs, while the related, prototype strain (PIC3739) has attenuated virulence. The abilities of adPIC and PIC3739 to induce tumor necrosis factor (TNF) in vivo and in cultured macrophages were compared. Infection with adPIC, but not PIC3739, was associated with detectable serum TNF that peaked in week 2 of infection. Tumor necrosis factor was found in the spleens of adPIC- and PIC3739-infected animals in week 1 of infection; TNF alpha mRNA levels in spleens and livers of adPIC infected animals increased and remained high throughout infection, whereas PIC3739-infected organs showed down regulation of TNF alpha mRNA late in infection. Peritoneal macrophages explanted from adPIC-infected animals showed enhanced lipopolysaccharide-inducible TNF production. Altered regulation of TNF production may play a role in the pathogenesis of guinea pig arenavirus disease.

  6. BIOCHEMICAL AND HISTOLOGICAL EFFECTS OF TETRACYCLINES ON SPONTANEOUS OSTEOARTHRITIS IN GUINEA PIGS

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    Edin De Bri

    2011-05-01

    Full Text Available Matrix metalloproteinases (MMPs are mediators in connective tissue destruction in a variety of pathologic processes. Recently discovered chemically modified tetracyclines have been found to be effective inhibitors of MMP mediated connective tissue degradation in both rheumatoid arthritis (RA and osteoarthritis (OA. The Hartley guinea pig model has been described with a high incidence of spontaneous OA-like changes in the knee joint. Therefore we have studied the effect of two tetracyclines, doxycycline (Dox and chemically modified tetracycline-7 (CMT-7 which have both previously been shown as potent MMP inhibitors. We found that prophylactic orally given CMT-7 decreases OA changes in the knee joints both in vitro and in vivo in the guinea pig OA model. OA changes were most severe in the central compartment of the medial condyle in the control group. Cartilage fibrillation and destruction, in addition to subchondral bone sclerosis and cyst formation were all less in the CMT-7 treated group compared with controls. Collagen, hyaluronan and proteoglycan content in cartilage was higher in the CMT-7 treated group compared with controls. In contrast, OA changes were not decreased in the Dox group. These results show that tetracyclines, but not all tetracyclines, can reduce the severity of OA in the guinea pig model of spontaneous OA.

  7. Prostaglandins in the perilymph of guinea pig with type II collagen induced ear diseases

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    Takeda, T.; Chiang, T.; Kitano, H.; Sudo, N.; Kim, S.Y.; Ha, S.; Woo, V.; Wolf, B.; Floyd, R.; Yoo, T.J.

    1986-03-01

    The authors have studied the prostaglandins (PGs) in the perilymph from guinea pig with type II collagen induced autoimmune ear disease. Hartly guinea pigs were immunized with type II collagen in CFA and auditory brain stem responses (ABR) were measured at 2, 3, 4, and 6 months after initial immunization perilymph was obtained and the levels of PGE2 and 6 keto-PGFl..cap alpha.. were measured by radioimmunoassays. Temporal bones were examined for the histopathologic changes. Immunized guinea pigs showed the evidence of hearing loss by ABR. The temporal bones showed the following changes: spiral ganglia degeneration, mild to moderate degree of degeneration in organ of Corti, infrequent very mild endolymphatic hydrops and labrynthitis. The perilymph from immunized animals contained about 5 times more PGE2 and about 3 times more 6 keto-PGFl..cap alpha.. than control animals. However, between these two groups, there was no difference in the CSF and sera levels of PGE2 and 6 keto-PGFl..cap alpha... Thus, this study suggests that these inflammatory mediators might be involved in the pathogenesis of collagen induced autoimmune inner ear disease.

  8. Effect of otologic drill noise on ABR thresholds in a guinea pig model.

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    Suits, G W; Brummett, R E; Nunley, J

    1993-10-01

    The noise generated by the otologic drill has been implicated as a cause of sensorineural hearing loss after ear surgery. However, clinical studies on this subject are contradictory and difficult to interpret. Therefore a guinea pig model was used to study whether the level of noise generated by the otologic drill can cause threshold shifts in the auditory brainstem response (ABR). The source noise was a recording obtained during a human cadaver mastoidectomy using a microphone and an accelerometer. Ten female Topeka-strain guinea pigs were exposed to the recorded drill noise for a period of 55 minutes. Exposure included both air-conducted energy from a speaker and bone-conducted energy from a bone vibrator applied directly to the skull. ABR threshold measurements were taken pre-exposure (baseline), immediately after exposure, and at weekly intervals thereafter for 3 weeks. Three control animals were subjected to the same procedure without the sound exposure. A significant threshold shift (p < 0.0001) was seen for each frequency tested (2, 4, 8, 16, 20, and 32 kHz) immediately after exposure to noise in all experimental animals. Thresholds returned to baseline within 3 weeks. We conclude that the level of noise generated by the otologic drill in mastoid surgery can cause a temporary threshold shift in this guinea pig model.

  9. Absence of progesterone effects on chlamydial genital infection in female guinea pigs.

    Science.gov (United States)

    Pasley, J N; Rank, R G; Hough, A J; Cohen, C; Barron, A L

    1985-01-01

    The effect of progesterone alone and in combination with estradiol was investigated in ovariectomized and gonadally intact female guinea pigs infected with the chlamydial agent of guinea pig inclusion conjunctivitis (GPIC). The course of the infection, as determined by the percentage of cells with GPIC (chlamydia) inclusions in Giemsa-stained vaginal scrapings, was not affected in animals receiving 5.0 mg of progesterone daily. Progesterone had no influence on the enhancement of infection by estradiol. In comparison with sesame oil-treated controls, infection was prolonged by four to six days (P less than .05) in animals receiving a combination of 5.0 mg of progesterone plus 1.0 microgram of estradiol or 1.0 microgram of estradiol alone each day. In ovariectomized animals, estradiol delayed the appearance of IgA antibody in genital secretions, whereas progesterone alone had no effect. Guinea pigs treated with estradiol or progesterone plus estradiol manifested an acute endometritis not observed in animals treated with progesterone alone or in controls receiving sesame oil. Although cervical ectopy, analogous to that seen in women with high levels of progesterone, was identified by histopathology in animals treated with progesterone, no enhancement of the chlamydial infection was observed.

  10. Anatomy of the liver of Guinea pig fetuses in late gestation (Cavia porcellus [Linnaeus, 1758

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    Mariangela de Toledo Barbino

    2011-09-01

    Full Text Available To describe the anatomy of the liver of Guinea pig (Cavia porcellus [Linnaeus, 1758] fetuses in late gestation and to obtain anatomical characteristics that can support and help the understanding of the physiology of fetal circulation. Three fetuses of Guinea pig in late gestation have been used, which were dissected and had their livers removed. These were analized, described, and photographed macroscopically and microscopically through light microscopy in HE and scanning electronic microscopy. Macroscopically, the fetuses livers have a reddish brown color and their division into lobes is clearly seen, as well as the presence of the gallbladder. The liver is divided into left lateral lobe, left medial lobe, right lateral lobe, right medial lobe, quadrate lobe, and caudate lobe with caudate and papillary processes. Through light microscopy, highly vascularized tissue is observed, and the left portion of the liver receive blood from the placenta through the umbilical vein, and the right portion is irrigated by the portal vein. The structures found on the liver of Guinea pig fetuses in late gestation are anatomically similar to those of other mammalian species.

  11. Analysis of normal and denerved laryngeal vocalization in guinea pigs (Cavia porcellus).

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    Arch-Tirado, Emilio; Verduzco-Mendoza, Antonio; Taboada-Picazo, Verónica; Mota-Rojas, Daniel; Alonso-Spilsbury, Maria de Lourdes; Alfaro-Rodríguez, Alfonso

    2009-01-01

    Paralysis of the left vocal chord is frequent in human clinical practice; because of its anatomic similarity with human, the guinea pig might be a suitable biological model to analyze the phoniatric behavior in denerved animals. Forty newborn guinea pigs were used (20 control and 20 experimental); an incision was made in the ventricular region with the animals under general anesthesia over the middle line of the neck, until the lower left laryngeal nerve was found, the same was secured with alligator clips so that afterward a two-part dissection could be performed and the middle section could be removed (1cm) from the nerve endings (distal and proximal) before they were separated from the laryngeal structure. After recovery from surgery, vocal emissions were recorded in solitary for 6 minutes. The animals that had nerves removed showed an increase in fundamental vocalization frequency compared with the controls. F test was carried out (P=0.05) and no significant difference was found. When analyzing functional recovery, we found that the guinea pigs compensated vocal emissions at 20 days. With regard to the unilateral paralysis, the motility was frequently compensated by the healthy vocal chord, improving voice emission, and loss of air inhalation.

  12. The role of computed tomography in the assessment of dental disease in 66 guinea pigs.

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    Schweda, M C; Hassan, J; Böhler, A; Tichy, A; Reiter, A M; Künzel, F

    2014-11-29

    Sixty-six guinea pigs with dental disease were presented to the University of Veterinary Medicine, Vienna, Austria, from 2006 to 2010. Almost all patients had a history of eating difficulties (95 per cent) and underwent clinical and oral examination as well as CT of the head. Findings on extra- and intraoral examination were asymmetric elongation (n=28) and symmetric bridging (n=24) of cheek teeth, obliquely worn incisors (n=17), palpable lower jaw swellings (n=13), exophthalmos (n=10) and incisor macrodontia (n=6). Eighty per cent of guinea pigs with exophthalmos showed ipsilateral periapical disease of the maxillary cheek teeth on CT. Ninety-two per cent of patients with palpable lower jaw swellings showed corresponding dental pathologies on CT. Periapical disease of incisors (n=11) and cheek teeth (n=32) were the most common findings on CT. All abnormally large incisors were found on oral examination and CT, but macrodontia of cheek teeth could only be visualised by CT. Deviation of the lower jaw evaluated in awake animals by visual inspection appeared to correlate with cheek teeth abnormalities. Results emphasise the importance of diagnostic imaging, in particular CT, in guinea pigs with dental disease in order to localise lesions and underlying aetiologies.

  13. Oxytocin receptors in guinea pig myometrium near term and during labor.

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    Schellenberg, J C; Pliska, V; Lutz, R A

    2000-02-01

    Oxytocin receptors in myometrium of women, rats, and rabbits rise markedly before the onset of labor, suggesting a role in the initiation of labor. In guinea pigs, a previous study reported no such rise by one-point determination of oxytocin binding. The purpose of this study was to use a more rigorous method to determine whether the binding characteristics of myometrial oxytocin receptors change in relation to labor in guinea pigs. Competitive binding studies were carried out in microsomes from inner and outer myometrium between 42 days of gestation and labor. Binding to analogs was also tested. Data were analyzed with affinity spectra and LIGAND. Oxytocin bound to one site with a dissociation constant of 6.3 +/- 0.65 x 10(-9) M. Binding capacity was 1.0 +/- 0.1 x 10(-12) mol/mg protein. The Hill coefficient was near unity. No significant changes occurred with gestation or labor in dissociation constant, binding capacity, or Hill coefficient (all P >/= 0.2, nested ANOVA). Binding capacity was higher in the outer than in the inner layer (1.2 +/- 0.2 vs. 0.8 +/- 0.1 x 10(-12) mol/mg protein, P = 0.02), but the dissociation constants were similar. Differences existed in the dissociation constants of the analogs tested. The main conclusion is that oxytocin receptors are unlikely to have a regulatory role in the initiation of labor in guinea pigs.

  14. Cardiac actions of phencyclidine in isolated guinea pig and rat heart: possible involvement of slow channels

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    Temma, K.; Akera, T.; Ng, Y.C.

    1985-03-01

    The mechanisms responsible for the positive inotropic effect of phencyclidine were studied in isolated preparations of guinea pig and rat heart. In electrically paced left atrial muscle preparations, phencyclidine increased the force of contraction; rat heart muscle preparations were more sensitive than guinea pig heart muscle preparations. The positive inotropic effect of phencyclidine was not significantly reduced by a combination of phentolamine and nadolol; however, the effect was competitively blocked by verapamil in the presence of phentolamine and nadolol. Inhibition of the outward K+ current by tetraethylammonium chloride also produced a positive inotropic effect; however, the effect of tetraethylammonium was reduced by phentolamine and nadolol, and was almost insensitive to verapamil. The inotropic effect of phencyclidine was associated with a marked prolongation of the action potential duration and a decrease in maximal upstroke velocity of the action potential, with no change in the resting membrane potential. The specific (/sup 3/H)phencyclidine binding observed with membrane preparations from guinea pig ventricular muscle was saturable with a single class of high-affinity binding site. This binding was inhibited by verapamil, diltiazem, or nitrendipine, but not by ryanodine or tetrodotoxin. These results suggest that the positive inotropic effect of phencyclidine results from enhanced Ca/sup 2 +/ influx via slow channels, either by stimulation of the channels or secondary to inhibition of outward K/sup +/ currents.

  15. NEGATIVE EFFECTS OF ETHANOL ON ISOLATED GUINEA PIG LEFT ATRIUM AND PAPILLARY MUSCLES

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    胡浩; 臧伟进; 于晓江; 王昌利; 张凤杰; 孙强; 张春虹

    2002-01-01

    Objective To investigate the effects of ethanol on physiologic al characteristics of the isolated guinea pig left atrium and papillary muscles.Methods The effects of ethanol on contractility, post-rest potentiatio n and positive staircase phenomenon were observed in isolated left atrium and pa pillary muscles of guinea pig.Results Ethanol(50.0,100.0,200.0mmol*L-1)prominently inhibited the con traction of papillary muscles. Ethanol(12.5,25.0,50.0,100.0,200.0mmol*L-1 ) inhibited the contraction of left atrium, and markedly decreased the post-r est potentiation of myocardial contractility in left atrium. High concentration of ethanol(100,200mmol*L-1) depressed the positive staircase phenomenon of isolated guinea pig left atrium.Conclusion These results suggest that ethanol induces inhibitor y effects of the contractility, post-rest potentiation, positive staircase phen omenon of left atrium. The mechanism by which ethanol induces the negative inotr opic effects may be related to decrease the amount of calcium released from the intracellular stores.

  16. Reduced Airway Hyperresponsiveness by Phosphodiesterase 3 and 4 Inhibitors in Guinea-Pigs

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    Nöella Germain

    1999-01-01

    Full Text Available The aim of the present study was to compare the effects of selective phosphodiesterase (PDE 3, 4 and 5 inhibitors on antigen-induced airway hyperresponsiveness in sensitized guinea-pigs. When the sensitized guinea-pigs were orally pre-treated with the selective PDE4 inhibitor, Ro 20-1724 (30 mg/kg, and studied 48 h after OA, a significant reduction (p<0.01 of the leftward shift of the dose-response curve to ACh was noted, whereas it was ineffective at the lower dose (10 mg/kg. Administration of the selective PDE3 inhibitor, milrinone (30 mg/kg also elicited a significant reduction (p<0.01 of the airway hyperresponsiveness, whereas the PDE5 inhibitor zaprinast (30 mg/kg was ineffective. These results show that both PDE3 and PDE4 inhibitors are able to inhibit the antigen-induced airway hyperresponsiveness in sensitized guinea-pigs and support the potential utility of selective PDE inhibitors in the treatment of asthma.

  17. NEGATIVE EFFECTS OF ETHANOL ON ISOLATED GUINEA PIG LEFT ATRIUM AND PAPILLARY MUSCLES

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Objective :To investigate the effects of ethanol on physiological characteristics of the isolated guinea pig left atrium and papillary muscles,Methods:The effects of ethanol on contractility,post-rest potentiation and positive staircase phenomenon were observed in isolated left atrium and papillary muscles of guinea pig.Results:Ethanol(50.0,100.0,200.0mmol.L-1) prominently inhibited the contraction of papillary muscles.Ethanol(12.5,25.0,50.0,100.0,200.0mmol.L-1)inhibited the contraction of left atrium,and markedly decreased the post-rest potentiation of myocardial contractility in left atrium.High concentration of ethanol(100,200mmol.L-1)depressed the positive staircase phenomenon of isolated guinea pig left atrium.Conclusion:These results suggest that ethanol induces inhibitory effects of the contractility,post-rest potentiation,positive staircase phenomenon of letf atrium.The mechanism by which ethanol induces the negative inotropic effects may be related to decrease the amount of calcium released from the intracellular stores.

  18. EFFECT OF FK224 ON THE BRONCHOCONSTRICTION INDUCED BY ISOCAPNIC HYPERPNEA IN GUINEA PIGS

    Institute of Scientific and Technical Information of China (English)

    陶梦非; 梁永杰

    2005-01-01

    Objective To evaluate effect of Neurokinin receptor antagonist on the prevention from hyperpnea-induced bronchoconstriction using a dual Neurokinin receptor antagonist FK224. Methods 12 pathogenfree Hartley guinea pigs were divided into two groups randomly: Dimethyl sulfoxide (DMSO) control group (n =6)and FK224 group (n =6). Guinea pigs were anesthetized with pentobarbital sodium. A cervical tracheostomy was performed and a polyethylene tube was inserted into the trachea. After measuring baseline value of the lung resistance (RL) and dynamic compliance of respiratory system (Cdyn) , DMSO (0. 3ml/kg) and FK224 ( 1mg/kg) were administered by injection through jugular vein respectively. A rodent respirator with dry 5% CO2-95% O2 mixture at room temperature provided mechanical ventilation ( VT 8ml/animal, 100breaths/min ) for 5min. RL and Cdyn of 2groups were measured after isocapnic hyperpnea challenge. Results In DMSO control group, isocapnic hyperpnea of dry gas elicited a marked increase in RL and decrease in Cdyn. RL and Cdyn of FK224 group did not change significantly. Conclusion FK224 can inhibit the increase in RL and decrease in Cdyn caused by isocapnic hyperpnea in guinea pigs. And antagonists of tachykinins receptors might have effect on prophylaxis and treatment in exercise-induced asthma.

  19. INHIBITORY EFFECTS OF ADENOSINE 5' -TRIPHOSPHATE ON COCHLEAR FUNCTION OF GUINEA PIG

    Institute of Scientific and Technical Information of China (English)

    杨军; 李吉平; 钱敏飞; 徐秀玲; 王家东; 丁大连

    2005-01-01

    Objective To study effects of adenosine 5'-triphosphate (ATP) on cochlear function of guinea pig. Methods After perfusion of ATP into perilymphatic spaces of the guinea pig cochlea, summating potential (SP), cochlear microphonic (CM) , auditory nerve compound action potential ( CAP ) , distortion product otoacoustic emission (DPOAE) and auditory brainstem response (ABR) were measured. Results The results showed concentration-dependent effect of ATP on the response alterations of bioelectric activity in cochlea. Administration of lmmol/L ATP caused an increase both in the amplitude of the SP and in the threshold of ABR, a decrease in amplitude of the CAP and DPOAE. In addition, response alterations of the CAP and DPOAE showed in an intensity- and frequency-dependent manner, respectively. At levels of 20 -70dB nHL sound intensity, lmmol/L ATP caused a significant decrease in the CAP amplitude, while at moderate and high frequency ranges of 2 -8kHz it reduced DPOAE amplitude significantly. 330μmol/L ATP also increased the threshold of ABR. Conclusion ATP through perilymphatic perfusion could inhibit cochlear function of guinea pig.

  20. EFFICACY OF ANTIHISTAMINE AGENTS ON MODEL FOR EXERCISE-INDUCED ASTHMA IN GUINEA PIGS

    Institute of Scientific and Technical Information of China (English)

    TAO Meng-Fei; REN Tao; LIANG Yong-Jie

    2006-01-01

    Objective To investigate the effects of antihistamine agents, loratadine and ketotifen, on the model of exercise-induced asthma in guinea pigs with lipopolysaccharide ( LPS) and metyapone. Methods Nineteen guinea pigs were injected peritoneolly with LPS (1mg/kg, i. p. ) and metyapone ( 50mg/kg, i. p. ). Then they were randomized into 3 groups. The control group ( n =7) did not take any drug, ketotifen group ( n =6) adminisd-1 ) for 4 days. On the fifth day, lung resistance (RL) and dynamic compliance of respiratory system (Cdyn) of 3 groups were measured before and after exercise challenge. The total number of leukocytes in bronchoalveolar lavage fluid (BALF) from 3 groups was counted and differentiated cell type count was measured. Morphometric examination of the animal lungs was performed. Results In control group, RLincreased and Cdyn decreased significantly after exercise challenge. In ketotifen group and loratadine group with no change. There was a significant increase in the number of neutrophils, macrophages and eosinophils in BALF from control group. The infiltration of neutrophils in the bronchial mucosa was shown in control group in the morphometric study. Conclusion Loratadine and ketotifen can inhibit the exercise-indaced bronchoconstriction in guinea pigs pretreated with LPS and metyrapone. Inhibiting the formation of inflammation in airway may be the therapeutic mechanism of these H-1 receptor antagonists.

  1. Infant guinea pig retina model of glutamate toxicity and intervention of basic fibroblast growth factor

    Institute of Scientific and Technical Information of China (English)

    Yunzhi Shi; Lihua Wei; Mingshan Song; Min Chen; Changqing Du; Baoliang Sun

    2011-01-01

    Impaired vision with oligemic ophthalmopathy is a result of excitotoxicity caused by excitatory amino acids, resulting in pathological changes, such as loss of retinal neurons and in particular retinal ganglionic cells. The present study utilized infant guinea pigs, aged 45-50 days, to establish injury models via intrapedtoneal injection of fixed sodium glutamate doses. Results from hematoxylin- eosin staining revealed significantly reduced retinal ganglionic cell numbers and retinal damage at 10 days after 7 consecutive days of 3 g/kg sodium glutamate treatment; these animals sewed as the injury model group. In addition, models of moderate injury (glutamate 3 g/kg daily, for 7 consecutive days) were intrapedtoneally pretreated with basic fibroblast growth factor (800 U/kg daily). Immunohistochemistry results confirmed reduced anti-apoptotic gene bcl-2 expression in the ganglion cell layer of glutamate-injured guinea pigs. Expression of the pro-apoptotic gene caspase-3 was increased in the ganglion cell layer and inner plexiform layer. Somatostatin expression was primadly distributed in the ganglion cell layer and inner nuclear layer. Expression of the presynaptic element synaptophysin was weak. However, following basic fibroblast growth factor injection, expressions of the above-described bioactive molecules were reversed, which suggested that basic fibroblast growth factor exerted protective effects on sodium glutamate-induced retinal injury in infant guinea pigs by regulating expression of synaptophysin, somatostatin, Bcl-2, and caspase-3.

  2. Catecholamine secretion by chemical hypoxia in guinea-pig, but not rat, adrenal medullary cells: differences in mitochondria.

    Science.gov (United States)

    Harada, K; Endo, Y; Warashina, A; Inoue, M

    2015-08-20

    The effects of mitochondrial inhibitors (CN(-), a complex IV inhibitor and CCCP, protonophore) on catecholamine (CA) secretion and mitochondrial function were explored functionally and biochemically in rat and guinea-pig adrenal chromaffin cells. Guinea-pig chromaffin cells conspicuously secreted CA in response to CN(-) or CCCP, but rat cells showed a little, if any, secretory response to either of them. The resting metabolic rates in rat adrenal medullae did not differ from those in guinea-pig adrenal medullae. On the other hand, the time course of depolarization of the mitochondrial membrane potential (ΔΨm) in guinea-pig chromaffin cells in response to CN(-) was slower than that in rat chromaffin cells, and this difference was abolished by oligomycin, an F1F0-ATPase inhibitor. The extent of CCCP-induced decrease in cellular ATP in guinea-pig chromaffin cells, which was indirectly measured using a Mg(2+) indicator, was smaller than that in rat chromaffin cells. Relative expression levels of F1F0-ATPase inhibitor factor in guinea-pig adrenal medullae were smaller than in rat adrenal medullae, and the opposite was true for F1F0-ATPase α subunit. The present results indicate that guinea-pig chromaffin cells secrete more CA in response to a mitochondrial inhibitor than rat chromaffin cells and this higher susceptibility in the former is accounted for by a larger extent of reversed operation of F1F0-ATPase with the consequent decrease in ATP under conditions where ΔΨm is depolarized.

  3. NK3 receptors mediate an increase in firing rate of midbrain dopamine neurons of the rat and the guinea pig.

    Science.gov (United States)

    Werkman, Taco R; McCreary, Andrew C; Kruse, Chris G; Wadman, Wytse J

    2011-08-01

    This in vitro study investigates and compares the effects of NK3 receptor ligands on the firing rate of rat and guinea pig midbrain dopamine neurons. The findings are discussed in the light of choosing suitable animal models for investigating pharmacological properties of NK3 receptor antagonists, which have been proposed to possess therapeutic activity in neuropsychiatric diseases like e.g. schizophrenia. In vitro midbrain slice preparations of both species were used to record (extracellularly) the firing rates of dopamine neurons located in the substantia nigra (SN) and ventral tegmental area (VTA). Furthermore, the effect of the D2 receptor agonist quinpirole on guinea pig SN and VTA dopamine neurons was investigated. The efficacy of quinpirole in inhibiting guinea pig dopamine neuron firing activity was much less as compared to that of rat dopamine neurons, suggesting a lower dopamine D2 autoreceptor density on the guinea pig neurons. The NK3 receptor agonist senktide induced in subpopulations of rat SN (55%) and VTA (79%) and guinea pig SN (50%) and VTA (21%) dopamine neurons an increase in firing rate. In responsive neurons this effect was concentration-dependent with EC₅₀ values of 3-5 nM (for both species). The selective NK3 receptor antagonist osanetant (100 nM) was able to partly block the senktide-induced increase in firing rates of dopamine neurons and shifted the concentration-response relation curves for senktide to the right (pA₂ values were ~7.5). The fractional block of the senktide responses by osanetant appeared to be larger in guinea pig dopamine neurons, indicating that osanetant is a more potent blocker of NK3 receptor-mediated responses with noncompetitive properties in the guinea pig.

  4. PCO(2) in the large intestine of mice, rats, guinea pigs, and dogs and effects of the dietary substrate.

    Science.gov (United States)

    Rasmussen, Henrik; Mirtaheri, Peyman; Dirven, Hubert; Johnsen, Helge; Kvarstein, Gunnvald; Tønnessen, Tor Inge; Midtvedt, Tore

    2002-01-01

    PCO(2) in the lumen and serosa of cecum and colon was measured in rats, guinea pigs, and dogs to examine the relationship between serosal PCO(2) and the incidence of intestinal necrotic lesions after administration of gas-carrier contrast agents in rodents. The effects of the dietary substrate were tested in a group of mice maintained on a diet based on glucose as the only carbohydrate source. The anesthetic used was a fentanyl-fluanison-midazolam mixture (rodents) and pentobarbital (dogs). PCO(2) was measured in vivo and postmortem, and the kinetics of the postmortem serosal PCO(2) [transmural CO(2) flux (J(CO(2)))] was calculated. PCO(2) in the cecal serosa and lumen, respectively, was 64 +/- 4 and 392 +/- 18 Torr in rats, 67 +/- 3 and 276 +/- 17 Torr in guinea pigs, and 73 +/- 6 and 137 +/- 7 Torr in mice on glucose-based diet. In the colon serosa and lumen of dogs, PCO(2) was 30 +/- 6 and 523 +/- 67 Torr, respectively. Serosal PCO(2) increased rapidly after death in rats and slower in guinea pigs and mice, and the slowest change was observed in dogs. Compared with dogs, serosal PCO(2) and J(CO(2)) of rats and guinea pigs were significantly higher. Serosal PCO(2) of guinea pigs was similar to that of rats, whereas the J(CO(2)) of guinea pigs was significantly lower. These data suggest a causal relationship between the ability of the cecal and colonic wall to act as a barrier to CO(2) diffusion and the presence of characteristic gas-carrier contrast agent-induced intestinal lesions in mice and rats and their absence in guinea pigs, dogs, and other species.

  5. Comparative observation of protective effects of earplug and barrel on auditory organs of guinea pigs exposed to experimental blast underpressure

    Institute of Scientific and Technical Information of China (English)

    LI Chao-jun; ZHU Pei-fang; LIU Zhao-hua; WANG Zheng-guo; YANG Cheng; CHEN Hai-bin; NING Xin; ZHOU Ji-hong; Chen Jian

    2006-01-01

    Objective: To explore the protective effects of earplug and barrel on auditory organs of guinea pigs exposed to experimental blast underpressure (BUP).Methods: The hearing thresholds of the guinea pigs were assessed with auditory brainstem responses (ABR).The traumatic levels of tympanic membrane and ossicular chain were observed under stereo-microscope. The rate of outer hair cells (OHCs) loss was analyzed using a light microscope. The changes of guinea pigs protected with barrel and earplug were compared with those of the control group without any protection.Results: An important ABR threshold shift of the guinea pigs without any protection was detected from 8h to 14d after being exposed to BUP with a peak ranging from -64.5kPa to -69.3kPa (P<0.01). The rate of perforation of tympanic membrane reached 87.5 % and that of total OHCs loss was 19.46% + 5.38% at 14d after exposure. The guinea pigs protected with barrel and earplug had lower ABR threshold and total OHCs loss rate compared with the animals without any protection (P < 0.01 ). All of the tympanic membrane and ossicular chain of the protected animals maintained their integrities.Meanwhile, the guinea pigs protected with the barrel had lower ABR threshold and total OHCs loss rate than those with earplug (P<0.01).Conclusions: The earplug and barrel have protective effects against BUP-induced trauma on auditory organs of the guinea pigs and the protective effects of barrel are better than those of earplug.

  6. Inhibitory effect of dendroaspis natriuretic peptide on spontaneous contraction in gastric antral circular smooth muscles of guinea pigs

    Institute of Scientific and Technical Information of China (English)

    Hui-shu GUO; Zheng-xu CAI; Tai-hua WU; Jing XU; Yang QIU; Wen-xie XU

    2007-01-01

    Aim:To determine whether the natriuretic peptide receptor (NPR) is present in the stomach of guinea pigs and to investigate the effect of dendroaspis natriuretic peptide (DNP) on the gastric motility of guinea pigs and its mechanism. Methods:The distribution of the NPR was analyzed by autoradioimmunography. The spontaneous contraction of gastric antral circular muscles of guinea pigs was recorded by a 4-channel physiograph. The whole cell patch-clamp technique was introduced to record calcium-activated potassium currents in the gastric myocytes isolated by collagenase. Results:The NPR existed in the gastric fundus,gastric body,and gastric antrum of guinea pigs,and its density was largest in the gastric antrum. DNP inhibited spontaneous contraction and exhibited a dose-dependent manner. The DNP-induced inhibition was diminished by LY83583 (a guanylate cyclase inhibitor) and was potentiated by zaprinast (a cGMP-sensitive phosphoesterase inhibitor). The inhibitory effect of DNP on spontaneous contraction was also inhibited by tetraethylammonium (a non-selective potassium channel blocker);10 nmol/L DNP increased the calcium-activated potassium currents in the gastric circular myocytes of guinea pigs. Conclusion:The NPR is most common in the gastric antrum of guinea pigs. DNP significantly inhibits gastric motility in the gastric antrum of guinea pigs. The inhibitory effect occurs via a cGMP-dependent pathway,and a calcium-activated potassium channel may be also involved in the relaxation induced by DNP in gastric antral circular smooth muscles.

  7. Thrombocytopenia in the experimental leptospirosis of guinea pig is not related to disseminated intravascular coagulation

    Directory of Open Access Journals (Sweden)

    HU Bao-Yu

    2006-02-01

    Full Text Available Abstract Background Thrombocytopenia is commonly observed in severe leptospirosis. However, previous studies on coagulation alterations during leptospirosis resulted in inconsistent conclusions. Some findings showed that the prominent levels of thrombocytopenia observed in severe leptospirosis did not reflect the occurrence of disseminated intravascular coagulation (DIC syndrome, while the others reached the conclusion that the hemorrhages observed in leptospirosis were due to DIC. The aim of this study is to elucidate whether DIC is an important feature of leptospirosis. Methods The leptospirosis model of guinea pig was established by intraperitoneal inoculation of Leptospira interrogans strain Lai. Hematoxylin and eosin (HE staining, electron microscopy and immunohistochemistry staining were used to detect the pathologic changes. Platelet thrombus or fibrin thrombus was detected by HE, Martius Scarlet Blue (MSB staining and electron microscopy. Hemostatic molecular markers such as 11-dehydrogenate thromboxane B2 (11-DH-TXB2, thrombomodulin (TM, thrombin-antithrombin III complex (TAT, D-Dimer and fibrin (ogen degradation products (FDPs in the plasma were examined by quantitative enzyme-linked immunosorbent assay (ELISA to evaluate the hematological coagulative alterations in leptospirosis models. Results Pulmonary hemorrhage appeared in the model guinea pig 24 hours after leptospires intraperitoneal inoculation, progressing to a peak at 96 hours after the infection. Leptospires were detected 24 hours post-inoculation in the liver, 48 hours in the lung and 72 hours in the kidney by immunohistochemistry staining. Spiral form of the bacteria was initially observed in the liver, lung and kidney suggestive of intact leptospires, granular form of leptospires was seen as the severity increased. Platelet aggregation in hepatic sinusoid as well as phagocytosis of erythrocytes and platelets by Kupffer cells were both observed. Neither platelet thrombus

  8. Absorption of the nerve agent VX (O-ethyl-S-[2(di-isopropylamino)ethyl] methyl phosphonothioate) through pig, human and guinea pig skin in vitro.

    Science.gov (United States)

    Dalton, Christopher H; Hattersley, Ian J; Rutter, Stephen J; Chilcott, Robert P

    2006-12-01

    The physico-chemical properties of VX make the skin the most likely route of absorption into the human body. The development of effective medical countermeasures against such percutaneous threat agents relies on the use of appropriate animal models, as the inherent toxicity of nerve agents precludes the use of human volunteers. Previous studies have characterised the mechanism of nerve agent toxicity in rodent models, however, it is generally accepted that one of the most appropriate animal models for human skin absorption is the domestic pig. The purpose of the present study was to measure and compare the skin absorption kinetics of VX in vitro using pig, human and guinea pig skin to highlight any potential species differences in skin permeability. When undiluted VX was applied directly to the skin, the permeability of guinea pig skin was approximately 7-fold greater than human skin. There was no significant difference in the permeability of pig and human skin. When VX diluted with isopropyl alcohol was applied to the skin, the permeability of guinea pig skin was approximately 4-fold greater than human skin. There was no significant difference in the permeability of pig and human skin. From this data it may be inferred that dermatomed, abdominal pig skin is an appropriate model for the human skin absorption of VX.

  9. Pathogenesis of a genotype C strain of bovine parainfluenza virus type 3 infection in albino guinea pigs.

    Science.gov (United States)

    Shi, Hong-Fei; Zhu, Yuan-Mao; Dong, Xiu-Mei; Cai, Hong; Ma, Lei; Wang, Shu; Yan, Hao; Wang, Xue-Zhi; Xue, Fei

    2014-08-08

    Bovine parainfluenza virus type 3 (BPIV3) is one of the most important of the known viral respiratory tract agents of both young and adult cattle and widespread among cattle around the world. Up to present, three genotypes A, B and C of BPIV3 have been described on the basis of genetic and phylogenetic analysis and only limited studies on the pathogenesis of the genotype A of BPIV3 infection in calves and laboratory animals have been performed. The report about experimental infections of the genotypes B and C of BPIV3 in laboratory animals and calves was scant. Therefore, an experimental infection of guinea pigs with the Chinese BPIV3 strain SD0835 of the genotype C was performed. Sixteen guinea pigs were intranasally inoculated with the suspension of SD0835, while eight control guinea pigs were also intranasally inoculated with the same volume of supernatant from uninfected MDBK cells. The virus-inoculated guinea pigs displayed a few observable clinical signs that were related to the respiratory tract disease and two of the sixteen experimentally infected guinea pigs died at 2 and 3 days post inoculation (PI), respectively, and apparent gross pneumonic lesions were observed at necropsy. The gross pneumonic lesions in guinea pigs inoculated with SD0835 consisted of dark red, slightly depressed, irregular areas of consolidation in the lung lobes from the second to 9th day of infection at necropsy, and almost complete consolidation and atelectasis of the lung lobes were seen at 7 days PI. Histopathological changes including alveoli septa thickening and focal cellulose pneumonia were also observed in the lungs of guinea pigs experimentally infected with SD0835. Viral replication was detectable by virus isolation and titration, real-time RT-PCR and immunohistochemistry (IHC) staining in the respiratory tissues of guinea pigs as early as 24h after intranasal inoculation with SD0835. The results of virus isolation and titration showed that guinea pigs were permissive for

  10. Comparison of hepatotoxicity and metabolism of butyltin compounds in the liver of mice, rats and guinea pigs

    Energy Technology Data Exchange (ETDEWEB)

    Ueno, Shunji; Kashimoto, Takashige; Susa, Nobuyuki; Ishii, Masamitsu; Chiba, Toshikazu [Laboratory of Veterinary Public Health, School of Veterinary Medicine and Animal Sciences, Kitasato University, Higashi 23-35-1, 034-8628, Towada-shi, Aomori (Japan); Mutoh, Ken-ichiro [Laboratory of Veterinary Anatomy, School of Veterinary Medicine and Animal Sciences, Kitasato University, Higashi 23-35-1, 034-8628, Towada-shi, Aomori (Japan); School of Veterinary Medicine and Animal Sciences, Kitasato University, Higashi 23-35-1, 034-8628, Towada-shi, Aomori (Japan); Hoshi, Fumio [Laboratory of Veterinary Anatomy, School of Veterinary Medicine and Animal Sciences, Kitasato University, Higashi 23-35-1, 034-8628, Towada-shi, Aomori (Japan); Suzuki, Takashi [Laboratory of Environmental Health and Toxicology, Kyoto Prefectural University, Hangi-cho, Shimogamo, Sakyo-ku, 606-5822, Kyoto (Japan); Sugiyama, Masayasu [Sugiyama Pharmacy, 1335-1 Shimotama, Tamagawa-cho, 759-3112, Yamaguchi (Japan)

    2003-03-01

    The hepatotoxicity of tributyltin chloride (TBTC) and dibutyltin dichloride (DBTC) was compared among mice, rats and guinea pigs in vivo. Further, the metabolism of these butyltin compounds in the liver was also investigated in these species. The oral administration of TBTC and DBTC to mice induced obvious liver injury, as demonstrated by both serodiagnosis and histopathological diagnosis. The concentrations of TBTC and DBTC that induced hepatotoxicity in mice at 24 h after oral administration were 180 and 60 {mu}mol/kg, respectively. In the case of rats, the liver injury induced by TBTC and DBTC was detected at 24 h by the serodiagnosis, but not by histopathological diagnosis. On the other hand, in guinea pigs, TBTC and DBTC administration did not produce any clear liver injury at 24 h, as evaluated by these two diagnostic methods. Thus, the following ranking was obtained with regard to increasing order of sensitivity to liver injury caused by TBTC and DBTC: mice, rats and guinea pigs. The total butyltin contents in the liver of mice were equivalent at 3 h and 24 h after the administration of TBTC or DBTC; however, the contents in the liver of rats and guinea pigs were relatively lower at 3 h and higher at 24 h than those of mice, although there were no differences between rats and guinea pigs in the total liver butyltin content. Concerning the liver metabolism of these butyltin compounds, the main form of butyltin compounds in these animals treated with TBTC was DBTC within 3 h after oral administration, while the main metabolites at 24 h were different in each species, indicating that the liver metabolism of TBTC might vary by animal type. When the animals were treated with DBTC orally, DBTC was hardly metabolized in the livers of these animals even at 24 h, and the liver levels of DBTC were two times greater in mice and guinea pigs than in rats at 3 h and were lower in mice at 24 h than in rats and guinea pigs. The analysis of cellular distributions of DBTC in

  11. ATP-ase activity in the human oral mucous membrane, the guinea pig and the rabbit epidermis. A light- and electronmicroscopical investigation

    DEFF Research Database (Denmark)

    Zelander, T; Kirkeby, S

    1984-01-01

    The activity for ATP-ase was investigated in cells of rabbit and guinea pig epidermis and human oral mucosa. Observations both in the light- and electron microscope indicate that the ATP-ase positive cells of guinea pig and human epithelia are Langerhans cells while in the rabbit epidermis...

  12. [Effects of Yanggan Lidan Granule on rate of gallstone formation and content of plasma cholecystokinin in guinea pigs with induced cholesterol gallstones].

    Science.gov (United States)

    Zhang, Si-bo; Fang, Bang-jiang

    2008-04-01

    To explore the effects of Yanggan Lidan Granule (YGLDG), a compound traditional Chinese herbal medicine for nourishing liver and improving choleresis, on the rate of gallstone formation and content of plasma cholecystokinin in guinea pigs with induced cholesterol gallstones. Eighty guinea pigs were randomly divided into 4 groups, which were normal control group, untreated group, YGLDG-treated group and ursodeoxycholic acid (UDCA)-treated group (n=20). Except the normal control group, gallstones were induced by high-cholesterol diet in the guinea pigs. YGLDG (1.81 g/kg daily) and UDCA (30.12 mg/kg daily) were given orally to guinea pigs in the corresponding group respectively for seven weeks; however, the guinea pigs of normal control group and untreated group were administered with normal saline. The physical signs of the guinea pigs and the rates of gallstone formation were examined, and the content of cholecystokinin (CCK) in the plasma was detected by radio-immunoassay. YGLDG could obviously improve the ethological signs of the guinea pigs. Gallstone formation rate of the untreated group (82.35%) was significantly increased as compared with that of the normal control group (5.26%) (Pgallstone formation rates of the YGLDG-treated group (27.28%) and UDCA-treated group (38.89%) were lower than that of the untreated group (P0.05). YGLDG can significantly decrease the rate of gallstone formation in guinea pigs. It may be related to elevating the content of CCK in the plasma.

  13. ATP-ase activity in the human oral mucous membrane, the guinea pig and the rabbit epidermis. A light- and electronmicroscopical investigation

    DEFF Research Database (Denmark)

    Zelander, T; Kirkeby, S

    1984-01-01

    The activity for ATP-ase was investigated in cells of rabbit and guinea pig epidermis and human oral mucosa. Observations both in the light- and electron microscope indicate that the ATP-ase positive cells of guinea pig and human epithelia are Langerhans cells while in the rabbit epidermis...

  14. Expression of the secreted FAD-dependent sulfydryl oxidase (QSOX) in the guinea pig central nervous system.

    Science.gov (United States)

    Amiot, C; Musard, J F; Hadjiyiassemis, M; Jouvenot, M; Fellmann, D; Risold, P Y; Adami, P

    2004-06-18

    cpQSOx1 is a member of the QSOx family of proteins, expressed in the guinea pig (Cavia porcellus) and ortholog of the rat rQSOx1. In this study, in vitro experiments were conducted and showed that, as other member of this family, cpQSOx1 has a sulfydryl oxidase activity, and is a secreted protein. Then, the expression of this enzyme was researched in the guinea pig brain, as very little information exists yet on the expression of QSOx family members in the central nervous system. By immunohistochemistry, RT-PCR and in situ hybridization, cpQSOx1 is synthesized by neurons throughout the whole guinea pig central nervous system. Reticular structures as the basal forebrain, reticular thalamic nucleus and reticular nuclei of the brainstem contained the densest labeling. These results are discussed in terms of putative roles of this protein in synaptic strengthening and in redox activities.

  15. Poor antioxidant status exacerbates oxidative stress and inflammatory response to Pseudomonas aeruginosa lung infection in Guinea Pigs

    DEFF Research Database (Denmark)

    Jensen, Peter Østrup; Lykkesfeldt, Jens; Bjarnsholt, Thomas

    2012-01-01

    Considerable evidence supports the presence of oxidative stress in cystic fibrosis (CF). The disease has long been associated with both increased production of reactive oxygen species and impaired antioxidant status, in particular during the chronic pulmonary infection with Pseudomonas aeruginosa......, which is the main cause of morbidity and mortality in CF. Guinea pigs are unable to synthesize ascorbate (ASC) or vitamin C, a major antioxidant of the lung, and thus like human beings rely on its presence in the diet. On this basis, guinea pigs receiving ASC-deficient diet have been used as a model...... of oxidative stress. The aim of our study was to investigate the consequences of a 7-day biofilm-grown P. aeruginosa lung infection in 3-month-old guinea pigs receiving either ASC-sufficient or ASC-deficient diet for at least 2 months. The animals receiving ASC-deficient diet showed significantly higher...

  16. Oxidative DNA damage in vitamin C-supplemented guinea pigs after intratracheal instillation of diesel exhaust particles

    DEFF Research Database (Denmark)

    Moller, P.; Daneshvar, B.; Loft, S.

    2003-01-01

    of oxidized amino acids (gamma-glutamyl semialdehyde), DNA strand breaks, and 7-hydro-8-oxo-2'-deoxyguanosine (8-oxodG) in the lung. Bulky DNA ad- ducts were not significantly elevated in the lung. The antioxidant enzyme activity of glutathione reductase was increased in the lung of DEP-exposed guinea pigs......The health effects of diesel exhaust particles (DEP) are thought to involve oxidative damage. We have investigated the effect of intratracheal DEP instillation to guinea pigs in three groups of 12 animals each given 0, 0.7, or 2.1 mg. Five days later guinea pigs exposed to DEP had increased levels......, whereas glutathione peroxidase and superoxide dismutase enzyme activities were unaltered. There was no difference in DNA strand breaks in lymphocytes or urinary excretion of 8-oxodG at the two doses tested. Protein oxidations in plasma and in erythrocytes were not altered by DEP exposure...

  17. Immunogenicity of two adjuvant formulations of an inactivated African horse sickness vaccine in guinea-pigs and target animals

    Directory of Open Access Journals (Sweden)

    Gaetano Federico Ronchi

    2012-03-01

    Full Text Available Monovalent, inactivated and adjuvanted vaccines against African horse sickness, prepared with serotypes 5 and 9, were tested on guinea-pigs to select the formulation that offered the greatest immunity. The final formulation of the vaccines took into account the immune response in the guinea-pig and the inflammatory properties of two types of adjuvant previously tested on target animals. A pilot study was subsequently conducted on horses using a vaccine prepared with serotype 9. The vaccine stimulated neutralising antibodies from the first administration and, after the booster dose, 28 days later; high antibody levels were recorded for at least 10 months. The guinea-pig appears to be a useful laboratory model for the evaluation of the antigenic properties of African horse sickness vaccines.

  18. The effect of natural adjuvants (G2, G2F on lung inflammation of sensitized guinea pigs

    Directory of Open Access Journals (Sweden)

    Ali Neamati

    2013-07-01

    Full Text Available Objective: The effects of natural adjuvants were examined on total and differential WBC counts in lung lavage of sensitized guinea pigs. Materials and Methods: In three sensitized groups of guinea pigs including: untreated sensitized animals (S, sensitized animals treated with adjuvant G2 (S+G2 and G2F (S+G2F as well as non-sensitized group (C (n=6 for each group, total and differential WBC counts of lung lavage were examined. Sensitization of animals was achieved by injection and inhalation of ovalbumin (OA. Results: The results showed increased total WBC, eosinophil, neutrophil, and basophil counts, and decreased lymphocytes in lung lavage of sensitized animals compared with the control group (pConclusion: These results indicate important preventive effects of two natural adjuvants, especially G2, on lung inflammation of sensitized guinea pigs.  

  19. Immunological and serological diversity of Neisseria gonorrhoeae: immunotyping of gonococci by cross-protein in guinea pig subcutaneous chambers.

    Science.gov (United States)

    Arko, R J; Wong, K H; Bullard, J C; Logan, L C

    1976-01-01

    An in vivo typing system for studying the immunological relationship of gonococcal strains was established. Nine gonococcal strains of proven virulence for guinea pig subcutaneous chambers were selected, and these isolates were used to immunize groups of guinea pigs that were subsequently cross-challenged with graduated numbers of gonococci from these isolates. Resistance to infection was determined by culture of fluid from challenged chambers; results were expressed as the median dose, in colony-forming units, of gonococci required to produce infection in each group of immunized guinea pigs. This information was then used to develop immunotypes of gonococci based on the cross-protection results obtained. Four cross-protecting immunotypes were established from the preliminary nine strains tested. PMID:826482

  20. Effects of Electrical Stimulation During Absolute Refractory Period on Contraction and Relaxation of Cardiomyocytes from Normal Guinea-pigs

    Institute of Scientific and Technical Information of China (English)

    赵晓静; 崔长琮; 张海柱

    2003-01-01

    Objectives To investi- gate the effect of electrical stimulation during absoluterefractory period on contraction and relaxation of ven-tricular myocytes from normal guinea-pigs. MethodsThe guinea -pig ventricular myocytes were obtainedby enzyme digesting, and the extent of its contractionand relaxation and Ca2+ transient were recordedthrough the motion edge detection system. Resultsmyocytes increased 15.45±6.48%, and the peakvelocity of shorting (contraction) and the peak velocity of relengthening (relaxation) increased 15.97±8.37% and 21.63 ± 8.06% respectively ( n = 10 );tio(360/380) (F360/F380) increased 22. 55 ± 9.08%,and the peak velocity of ventricular myocytes F360/F380 increased 36.75 ± 9.77% and 23.62 ± 4.47%during shorting and relengthening respectively (n =6) . Conclusions Appropriate electrical stimulationmay strengthen the contracting and relaxing function ofnormal guinea- pig ventricular myocytes.

  1. Neurectomia vestibular e coclear no guinea pig vivo: uma via occipital Vestibular and cochlear neurectomy in the alive guinea pig: an occipital approach

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    Ricardo David

    2001-09-01

    Full Text Available Forma de estudo: Experimental. Objetivo: Este artigo descreve uma nova via cirúrgica para atingir a inervatura vestíbulo-coclear (VIII par no Guinea pig vivo. Essa via é totalmente óssea (exceto o acesso ao próprio osso, o que implica em poucos danos às estruturas nobres do animal, o qual é passível de recuperação para estudos posteriores do sistema vestibular e coclear e todas as suas referências, com o ouvido interno, médio e externo. Conclusão: Mesmo exigindo precisão e controle, dada a proximidade com estruturas vitais, ela se mostra bastante viável do ponto de vista prático e muito menos invasiva e danosa em relação a outras cirurgias realizadas com a mesma finalidade, por permitir exames de imitanciometria, Bera, vemp, reflexos estapediais e do tensor do tímpano, entre outros físicos ou fisioelétricos.Study design: Experimental. Aim: This paper describes a new surgery neurectomy technique to the VIII pair in Guinea pig alive. This is a full boned way, except for the access to the bone itself, what implies in minor damage to important structures of the animal. The animal recuperation is pretty good for later studies of the vestibular and cochlear system, and all its references to inner, middle and external ears. Conclusion: Even though the precision and control necessary, because of the neighbourhoods vital structures, it shows enough availability from the practice sight, and much less invasible and damage than other surgeries with the same finality. It allows imitaciometry, bera, vemp, stapediun and tympanic tensor reflexes and others (physicals or physioelectric.

  2. Effect of motilin on the contractility of gastric smooth muscle via NO pathway in guinea pig

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    Luo XU

    2009-02-01

    Full Text Available This study investigates the gastroprokinetic effects of motilin and erythromycin A (EM-A and its potential mechanism in guinea pigs Cavia porcellus in vitro. Guinea pig stomach strips were mounted under organ baths containing Krebs solution. Motilin, EM-A, Nω- Nitro-L-arginine (L-NNA, L-arginine (L-AA were added to the bathing solution in a non-cumulative way. Then the effects of motilin and EM-A was studied during electrical field stimulation (EFS in the absence and presence of L-NNA and L-AA in the gastric anturm and fundus of guinea pigs. In addition, we observed the co-expression of motilin receptors and neuronal nitric oxide synthase (nNOS in the gastric myenteric plexus of guinea pigs by fluo-immunohistochemistry. The results showed that the Circular muscle tissues of the gastric fundus generated on-relaxations and off-contractions with the frequency of 1–16 Hz. The on-responses induced a relaxation, partially mediated by the release of nitric oxide (NO because addition of L-NNA turned the relaxations into cholinergically mediated contractions. The off-contractions were also cholinergically mediated as they disappeared under non-adrenergic, non-cholinergic (NANC conditions using atropine and guanethidine. In fundic strips, motilin and EM-A induced on-relaxation and off-contraction and both motilin (1 µmol/L and EM-A (100 µmol/L may significantly increased on-response and reduced off-response (P<0.05–0.001. And the effects of motilin on strip responses were significantly enhanced compared with EM-A. The on-responses could be reversed into a cholinergically mediated contraction by addition of NOS inhibitors L-NNA. In contrast, administration of substrate of NOS, L-AA, significantly increased on-relaxations and reduced cholinergic motor responses which were induced by motilin or EM-A. However D-arginine (D-AA did not change the above response induced by motilin or EM-A. In the antral strips, motilin and EM-A only increased off

  3. Effect of motilin on the contractility of gastric smooth muscle via NO pathway in guinea pigs

    Institute of Scientific and Technical Information of China (English)

    Zhiming WANG; Luo XU; Jiang LU

    2009-01-01

    This study investigates the gastroprnkinetie effects of motilin and erythromycin A (EM-A) and its potential mechanism in guinea pigs Cavia porceUus in vitro. Guinea pig stomach strips were mounted under organ baths containing Krebs solution.Motilin,EM-A,N'-Nitrn-L-arginine (L-NNA),L-arginine (L-AA) were added to the bathing solution in a non-cumulative way.Then the effects of motilin and EM-A was studied during electrical field stimulation (EFS) in the absence and presence of L-NNA and L-AA in the gastric anturm and fundus of guinea pigs. In addition,we observed the co-expression of motilin receptors and neuronal nitric oxide synthase (nNOS) in the gastric myenteric plexus of guinea pigs by fluo-immunohistochemistry. The results showed that the circular muscle tissues of the gastric fundus generated on-relaxations and off-contractions with the frequency of 1 -16 Hz. The on-responses induced a relaxation,partially mediated by the release of nitric oxide (NO) because addition of L-NNA turned the relaxations into cholinergically mediated contractions. The off-contractions were also cholinergically mediated as they disappeared under non-adrenergic,non-cholinergic (NANC) conditions using atropine and guanethidine. In fundic strips,motilin and EM-A induced on-relaxation and off-contraction and beth motilin ( 1 μmol/L) and EM-A ( 100 μmol/L) may significandy increased on-response and reduced off-response ( P < 0.05 ). And the effects of motilin on strip responses were significantly enhanced compared with EM-A. The on-responses could be reversed into a cholinergically mediated contraction by addition of NOS inhibitors L-NNA. In contrast,administration of substrate of NOS,L-AA,significantly increased on-relaxations and reduced cholinergic motor responses which were induced by motilin or EM-A. However D-arginine (D-AA) did not change the above response induced by motilin or EM-A. In the antral strips,motilin and EM-A only increased off-contractions. The response to

  4. Central activation of the sympathetic nervous system including the adrenals in anaesthetized guinea pigs by the muscarinic agonist talsaclidine.

    Science.gov (United States)

    Walland, A; Pieper, M P

    1998-04-01

    Talsaclidine, a novel M1-receptor selective muscarinic agonist for cholinergic substitution therapy of Alzheimer's disease, activates the sympathetic nervous system in guinea pigs and dogs at the orthosympathic ganglia and the paraganglionic adrenals. Results from guinea pigs provide indirect evidence for an additional central site of action. The present investigation in anaesthetized and vagotomized guinea pigs intended to demonstrate central activation of the sympathetic nervous system directly by comparing the blood pressure effects of intracerebroventricular and intravenous injections of small doses of talsaclidine. Increasing doses of 0.2 and 0.6 mg/kg talsaclidine were injected alternately into the third cerebral ventricle and intravenously in 6 guinea pigs before and after blockade of peripheral muscarinic receptors with 1 mg/kg ipratropium bromide i.v. In another group of 6 animals the injections were given into the cisterna cerebellomedullaris using the same protocol. In both groups central administration of talsaclidine caused dose-related hypertension while intravenous injections were hypotensive. Ipratropium bromide, a peripheral antimuscarinic drug, reversed this hypotensive action of intravenous talsaclidine into hypertension, but did not inhibit the effects of central administration. In contrast, atropine, an antimuscarinic drug which passes the blood-brain barrier, abolished the effect of 0.6 mg/kg talsaclidine injected into the cisterna cerebellomedullaris of 8 guinea pigs. The hypertensive effect of a first injection of 0.6 mg/kg talsaclidine into the cisterna cerebellomedullaris of 6 guinea pigs was approximately twice as large as that of a second given 90 min after bilateral adrenalectomy. Sham operation in another 6 animals was not inhibitory. The results demonstrate that talsaclidine, a selective muscarinic M1-receptor agonist, activates central parts of the sympathetic nervous system, including central projections of the adrenals by an action

  5. The multidrug resistance 1 gene Abcb1 in brain and placenta: comparative analysis in human and guinea pig.

    Science.gov (United States)

    Pappas, Jane J; Petropoulos, Sophie; Suderman, Matthew; Iqbal, Majid; Moisiadis, Vasilis; Turecki, Gustavo; Matthews, Stephen G; Szyf, Moshe

    2014-01-01

    The Multidrug Resistance 1 (MDR1; alternatively ABCB1) gene product P-glycoprotein (P-gp), an ATP binding cassette transporter, extrudes multiple endogenous and exogenous substrates from the cell, playing an important role in normal physiology and xenobiotic distribution and bioavailability. To date, the predominant animal models used to investigate the role of P-gp have been the mouse and rat, which have two distinct genes, Abcb1a and Abcb1b. In contrast, the human has a single gene, ABCB1, for which only a single isoform has been validated. We and others have previously shown important differences between Abcb1a and Abcb1b, limiting the extrapolation from rodent findings to the human. Since the guinea pig has a relatively long gestation, hemomonochorial placentation and neuroanatomically mature offspring, it is more similar to the human, and may provide a more comparable model for investigating the regulation of P-gp in the brain and placenta, however, to date, the Abcb1 gene in the guinea pig remains to be characterized. The placenta and fetal brain are barrier sites that express P-gp and that play a critical role of protection of the fetus and the fetal brain from maternally administered drugs and other xenobiotics. Using RNA sequencing (RNA-seq), reverse transcription-polymerase chain reaction (RT-PCR) and quantitative PCR (QPCR) to sequence the expressed isoforms of guinea pig Abcb1, we demonstrate that like the human, the guinea pig genome contains one gene for Abcb1 but that it is expressed as at least three different isoforms via alternative splicing and alternate exon usage. Further, we demonstrate that these isoforms are more closely related to human than to rat or mouse isoforms. This striking, overall similarity and evolutionary relatedness between guinea pig Abcb1 and human ABCB1 indicate that the guinea pig represents a relevant animal model for investigating the function and regulation of P-gp in the placenta and brain.

  6. Characterization of guinea pig antibody responses to salivary proteins of Triatoma infestans for the development of a triatomine exposure marker.

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    Veronika Dorňáková

    2014-04-01

    Full Text Available BACKGROUND: Salivary proteins of Triatoma infestans elicit humoral immune responses in their vertebrate hosts. These immune responses indicate exposure to triatomines and thus can be a useful epidemiological tool to estimate triatomine infestation. In the present study, we analyzed antibody responses of guinea pigs to salivary antigens of different developmental stages of four T. infestans strains originating from domestic and/or peridomestic habitats in Argentina, Bolivia, Chile and Peru. We aimed to identify developmental stage- and strain-specific salivary antigens as potential markers of T. infestans exposure. METHODOLOGY AND PRINCIPAL FINDINGS: In SDS-PAGE analysis of salivary proteins of T. infestans the banding pattern differed between developmental stages and strains of triatomines. Phenograms constructed from the salivary profiles separated nymphal instars, especially the 5th instar, from adults. To analyze the influence of stage- and strain-specific differences in T. infestans saliva on the antibody response of guinea pigs, twenty-one guinea pigs were exposed to 5th instar nymphs and/or adults of different T. infestans strains. Western blot analyses using sera of exposed guinea pigs revealed stage- and strain-specific variations in the humoral response of animals. In total, 27 and 17 different salivary proteins reacted with guinea pig sera using IgG and IgM antibodies, respectively. Despite all variations of recognized salivary antigens, an antigen of 35 kDa reacted with sera of almost all challenged guinea pigs. CONCLUSION: Salivary antigens are increasingly considered as an epidemiological tool to measure exposure to hematophagous arthropods, but developmental stage- and strain-specific variations in the saliva composition and the respective differences of immunogenicity are often neglected. Thus, the development of a triatomine exposure marker for surveillance studies after triatomine control campaigns requires detailed

  7. Characterization of Guinea Pig Antibody Responses to Salivary Proteins of Triatoma infestans for the Development of a Triatomine Exposure Marker

    Science.gov (United States)

    Dorňáková, Veronika; Salazar-Sanchez, Renzo; Borrini-Mayori, Katty; Carrion-Navarro, Oscar; Levy, Michael Z.; Schaub, Günter A.; Schwarz, Alexandra

    2014-01-01

    Background Salivary proteins of Triatoma infestans elicit humoral immune responses in their vertebrate hosts. These immune responses indicate exposure to triatomines and thus can be a useful epidemiological tool to estimate triatomine infestation. In the present study, we analyzed antibody responses of guinea pigs to salivary antigens of different developmental stages of four T. infestans strains originating from domestic and/or peridomestic habitats in Argentina, Bolivia, Chile and Peru. We aimed to identify developmental stage- and strain-specific salivary antigens as potential markers of T. infestans exposure. Methodology and Principal Findings In SDS-PAGE analysis of salivary proteins of T. infestans the banding pattern differed between developmental stages and strains of triatomines. Phenograms constructed from the salivary profiles separated nymphal instars, especially the 5th instar, from adults. To analyze the influence of stage- and strain-specific differences in T. infestans saliva on the antibody response of guinea pigs, twenty-one guinea pigs were exposed to 5th instar nymphs and/or adults of different T. infestans strains. Western blot analyses using sera of exposed guinea pigs revealed stage- and strain-specific variations in the humoral response of animals. In total, 27 and 17 different salivary proteins reacted with guinea pig sera using IgG and IgM antibodies, respectively. Despite all variations of recognized salivary antigens, an antigen of 35 kDa reacted with sera of almost all challenged guinea pigs. Conclusion Salivary antigens are increasingly considered as an epidemiological tool to measure exposure to hematophagous arthropods, but developmental stage- and strain-specific variations in the saliva composition and the respective differences of immunogenicity are often neglected. Thus, the development of a triatomine exposure marker for surveillance studies after triatomine control campaigns requires detailed investigations. Our study resulted

  8. L-dehydroascorbic acid can substitute l-ascorbic acid as dietary vitamin C source in guinea pigs.

    Science.gov (United States)

    Frikke-Schmidt, Henriette; Tveden-Nyborg, Pernille; Lykkesfeldt, Jens

    2016-04-01

    Vitamin C deficiency globally affects several hundred million people and has been associated with increased morbidity and mortality in numerous studies. In this study, bioavailability of the oxidized form of vitamin C (l-dehydroascorbic acid or DHA)-commonly found in vitamin C containing food products prone to oxidation-was studied. Our aim was to compare tissue accumulation of vitamin C in guinea pigs receiving different oral doses of either ascorbate or DHA. In all tissues tested (plasma, liver, spleen, lung, adrenal glands, kidney, muscle, heart, and brain), only sporadic differences in vitamin C accumulation from ascorbate or DHA were observed except for the lowest dose of DHA (0.25mg/ml in the drinking water), where approximately half of the tissues had slightly yet significantly less vitamin C accumulation than from the ascorbate source. As these results contradicted data from rats, we continued to explore the ability to recycle DHA in blood, liver and intestine in guinea pigs, rats and mice. These investigations revealed that guinea pigs have similar recycling capacity in red blood cells as observed in humans, while rats and mice do not have near the same ability to reduce DHA in erythrocytes. In liver and intestinal homogenates, guinea pigs also showed a significantly higher ability to recycle DHA compared to rats and mice. These data demonstrate that DHA in guinea pigs-as in humans-is almost as effective as ascorbate as vitamin C source when it comes to taking up and storing vitamin C and further suggest that the guinea pig is superior to other rodents in modeling human vitamin C homeostasis.

  9. Attitudes towards perception and management of pain in rabbits and guinea pigs by a sample of veterinarians in New Zealand.

    Science.gov (United States)

    Keown, A J; Farnworth, M J; Adams, N J

    2011-11-01

    To determine the perceptions of a sample of veterinarians in New Zealand regarding pain and pain management in rabbits and guinea pigs. Questionnaires were distributed to all members of the Companion Animal Society, part of the New Zealand Veterinary Association. The questionnaire gathered information on the demographics of respondents, obtained an assessment by veterinarians of the level of pain associated with clinical procedures for rabbits and guinea pigs, established the willingness of respondents to perform these, obtained information on the anaesthetics and analgesics used during these procedures, and the factors associated with selecting different types of drug. The level of knowledge of respondents and interest in continuing education regarding pain recognition and management in these species was also assessed. A total of 155/610 (25.4%) responses were obtained. Rodents and lagomorphs accounted for 0-5% of the total caseload in the practices of most (133/155; 86%) respondents. Anticipated pain scores differed for different procedures (pveterinarians felt their level of knowledge regarding the recognition and treatment of pain in rabbits and guinea pigs was inadequate. Rabbits and guinea pigs represented a small percentage of the caseload of veterinarians in this study. From an animal welfare perspective this may be of concern as, anecdotally, these species are common pets. However, further study regarding the actual number of these animals kept as pets in New Zealand is required for validation. Veterinary perception of anticipated pain, and willingness to perform procedures, varied between procedures, but was not influenced by gender of veterinarian. Many respondents felt their knowledge of issues relating to pain recognition, anaesthesia and analgesia in rabbits and guinea pigs was inadequate. Understanding how veterinarians choose to provide analgesia or when they decline to perform surgeries for rabbits and guinea pigs may provide significant

  10. Immediate post-dosing paralysis following severe soman and VX toxicosis in guinea pigs.

    Science.gov (United States)

    Bide, R W; Schofield, L; Risk, D J

    2005-01-01

    There have been numerous studies of the central nervous system (CNS) involvement in organophosphate (OP) poisoning showing status epilepticus and/or 'electrographic seizures'. Brain damage has been demonstrated as 'neuronal necrosis' primarily in the cortex, thalamus and hippocampus. To the authors' knowledge there have been no reports of partial/total paralysis following close upon OP exposure although delayed paralysis has been reported. This report summarizes the immediate, OP induced paralytic events recorded in guinea pigs during development of the Canadian reactive skin decontaminant lotion (RSDL). As part of the development work, supra-lethal cutaneous doses of OP were applied to large numbers of guinea pigs followed by decontamination with the RSDL or predecessor lotions and solvents. Soman (pinacolyl methylphosphonofluoridate; GD) challenges were applied to 1277 animals and S-(2-diisopropyl-aminoethyl) methylphosphorothiolate (VX) challenges to 108. The classic sequence of clinical signs--ptyalism, tremors, fasciculations, convulsions, apnea and flaccid paralysis before death--was seen in the 658 animals that died and in many of the survivors. Eighty-four of 688 survivors of GD and 4 of 39 survivors of VX showed random paralysis of various distal regions following recovery from an insult which produced convulsions and/or flaccid paralysis. Because the experiments were designed to assess the decontamination procedures, there were no apparent relationships between the amounts of OP applied and the sequellae recorded. The observations of paralysis were also incidental to the prime focus of the experiments. Because of this, only ten animals paralysed following GD exposure were examined for histological effects. The pathologist diagnosed 'encephalomalacia' and 'focal necrotic lesions' in the cerebral cortex and 'focal necrotic lesions' in one spinal cord. Of the 84 guinea pigs paralysed after GD challenge, one was not decontaminated and the decontaminants used

  11. Interstitial cells of Cajal mediate excitatory sympathetic neurotransmission in guinea pig prostate.

    Science.gov (United States)

    Wang, Jiang-ping; Ding, Guo-fu; Wang, Qin-zhang

    2013-06-01

    Morphological and functional studies have confirmed that interstitial cells of Cajal (ICCs) are involved in many enteric motor neurotransmission pathways. Recent investigations have demonstrated that human and guinea pig prostate glands possess a distinct cell type with morphological and immunological similarities to ICCs. These prostate ICCs have a close relationship with nerve bundles and smooth muscle cells. Prostate smooth muscle tone is largely induced by stimulation from the sympathetic nervous system, which releases excitatory norepinephrine (NE) to act on the α1-adrenoceptor. We have performed morphological and functional experiments to determine the role of ICCs in sympathetic neurotransmission in the guinea pig prostate based on the hypothesis that prostate ICCs act as mediators of sympathetic neurotransmission. Immunohistochemistry revealed many close points of contact between ICCs and sympathetic nerve bundles and smooth muscle cells. Double-labeled sections revealed that α1-adrenoceptor and the gap junction protein connexin 43 were expressed in prostate ICCs. Surprisingly, prostate ICCs co-expressed tyrosine hydroxylase and dopamine β-hydroxylase, two markers of sympathetic neurons. Functionally, the application of NE evoked a large single inward current in isolated prostate ICCs in a dose-dependent manner. The inward current evoked by NE was mediated via the activation of α1-adrenoceptors, because it was abolished by the non-specific α-adrenoceptor antagonist, phentolamine and the specific α1-adrenoceptor antagonist, prazosin. Thus, ICCs in the guinea pig prostate are target cells for prostate sympathetic nerves and possess the morphological and functional characteristics required to mediate sympathetic signals.

  12. Distribution of adrenergic receptors in the enteric nervous system of the guinea pig, mouse, and rat.

    Science.gov (United States)

    Nasser, Yasmin; Ho, Winnie; Sharkey, Keith A

    2006-04-10

    Adrenergic receptors in the enteric nervous system (ENS) are important in control of the gastrointestinal tract. Here we describe the distribution of adrenergic receptors in the ENS of the ileum and colon of the guinea pig, rat, and mouse by using single- and double-labelling immunohistochemistry. In the myenteric plexus (MP) of the rat and mouse, alpha2a-adrenergic receptors (alpha2a-AR) were widely distributed on neurons and enteric glial cells. alpha2a-AR mainly colocalized with calretinin in the MP, whereas submucosal alpha2a-AR neurons colocalized with vasoactive intestinal polypeptide (VIP), neuropeptide Y, and calretinin in both species. In the guinea pig ileum, we observed widespread alpha2a-AR immunoreactivity on nerve fibers in the MP and on VIP neurons in the submucosal plexus (SMP). We observed extensive beta1-adrenergic receptor (beta1-AR) expression on neurons and nerve fibers in both the MP and the SMP of all species. Similarly, the beta2-adrenergic receptor (beta2-AR) was expressed on neurons and nerve fibers in the SMP of all species, as well as in the MP of the mouse. In the MP, beta1- and beta2-AR immunoreactivity was localized to several neuronal populations, including calretinin and nitrergic neurons. In the SMP of the guinea pig, beta1- and beta2-AR mainly colocalized with VIP, whereas, in the rat and mouse, beta1- and beta2-AR were distributed among the VIP and calretinin populations. Adrenergic receptors were widely localized on specific neuronal populations in all species studied. The role of glial alpha2a-AR is unknown. These results suggest that sympathetic innervation of the ENS is directed toward both enteric neurons and enteric glia.

  13. Non-diabetic hyperglycemia exacerbates disease severity in Mycobacterium tuberculosis infected guinea pigs.

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    Brendan K Podell

    Full Text Available Hyperglycemia, the diagnostic feature of diabetes also occurs in non-diabetics associated with chronic inflammation and systemic insulin resistance. Since the increased risk of active TB in diabetics has been linked to the severity and duration of hyperglycemia, we investigated what effect diet-induced hyperglycemia had on the severity of Mycobacterium tuberculosis (Mtb infection in non-diabetic guinea pigs. Post-prandial hyperglycemia was induced in guinea pigs on normal chow by feeding a 40% sucrose solution daily or water as a carrier control. Sucrose feeding was initiated on the day of aerosol exposure to the H37Rv strain of Mtb and continued for 30 or 60 days of infection. Despite more severe hyperglycemia in sucrose-fed animals on day 30, there was no significant difference in lung bacterial or lesion burden until day 60. However the higher spleen and lymph node bacterial and lesion burden at day 30 indicated earlier and more severe extrapulmonary TB in sucrose-fed animals. In both sucrose- and water-fed animals, serum free fatty acids, important mediators of insulin resistance, were increased by day 30 and remained elevated until day 60 of infection. Hyperglycemia mediated by Mtb infection resulted in accumulation of advanced glycation end products (AGEs in lung granulomas, which was exacerbated by sucrose feeding. However, tissue and serum AGEs were elevated in both sucrose and water-fed guinea pigs by day 60. These data indicate that Mtb infection alone induces insulin resistance and chronic hyperglycemia, which is exacerbated by sucrose feeding. Moreover, Mtb infection alone resulted in the accumulation tissue and serum AGEs, which are also central to the pathogenesis of diabetes and diabetic complications. The exacerbation of insulin resistance and hyperglycemia by Mtb infection alone may explain why TB is more severe in diabetics with poorly controlled hyperglycemia compared to non-diabetics and patients with properly controlled

  14. Cholinergic facilitation of neurotransmission to the smooth muscle of the guinea-pig prostate gland.

    Science.gov (United States)

    Lau, W A; Pennefather, J N; Mitchelson, F J

    2000-07-01

    1. Functional experiments have been conducted to assess the effects of acetylcholine and carbachol, and the receptors on which they act to facilitate neurotransmission to the stromal smooth muscle of the prostate gland of the guinea-pig. 2. Acetylcholine and carbachol (0.1 microM - 0.1 mM) enhanced contractions evoked by trains of electrical field stimulation (20 pulses of 0.5 ms at 10 Hz every 50 s with a dial setting of 60 V) of nerve terminals within the guinea-pig isolated prostate. In these concentrations they had negligible effects on prostatic smooth muscle tone. 3. The facilitatory effects of acetylcholine, but not those of carbachol, were further enhanced in the presence of physostigmine (10 microM). 3. The facilitatory effects of carbachol were unaffected by the neuropeptide Y Y(1) receptor antagonist BIBP 3226 ((R)-N(2)-(diphenylacetyl)-N-[(4-hydroxyphenyl)methyl]-arginina mide) (0.3 microM, n=3) or suramin (100 microM, n=5). Prazosin (0.1 microM, n=5) and guanethidine (10 microM, n=5) alone and in combination (n=4), reduced responses to field stimulation and produced rightward shifts of the log concentration-response curves to carbachol. 4. The rank orders of potency of subtype-preferring muscarinic receptor antagonists in inhibiting the facilitatory actions of acetylcholine and carbachol were: pirenzepine > HHSiD (hexahydrosiladifenidol) > pF-HHSiD (para-fluoro-hexahydrosiladifenidol)>/= 5 himbacine, and pirenzepine > HHSiD > himbacine>/= 5 pF-HHSiD, respectively. These profiles suggest that muscarinic receptors of the M(1)-subtype mediate the facilitatory effects of acetylcholine and carbachol on neurotransmission to the smooth muscle of the guinea-pig prostate.

  15. Effects of hispidulin, a flavone isolated from Inula viscosa, on isolated guinea-pig smooth muscle.

    Science.gov (United States)

    Abdalla, S; Abu-Zarga, M; Afifi, F; Al-Khalil, S; Sabri, S

    1988-01-01

    1. In small concentrations (10(-7)-3 X 10(-6) M), hispidulin caused concentration-dependent contraction of isolated guinea-pig ileum and only mild relaxation of guinea-pig tracheal rings. 2. Larger concentrations (up to 3 X 10(-4) M) caused concentration-dependent relaxation of the ileum and the trachea. All the effects on the ileum and the trachea are reversible upon removal of the compound. 3. In concentrations from 10(-7) to 3 X 10(-4) M, hispidulin had no effect on the tone of the epinephrine-contracted rings of the guinea-pig main pulmonary artery. 4. Hispidulin caused a shift to the right of the acetylcholine concentration-effect curves on ileum and trachea and significantly inhibited the maximum contractions induced by acetylcholine. 5. In Ca2+-free, depolarizing solution, hispidulin caused both a shift to the right, and an inhibition of the maximum contractions, of the CaCl2 concentration-effect curves on ileum, trachea and pulmonary artery. 6. In Ca2+-free, EGTA-containing solution, hispidulin caused concentration-dependent inhibition of the contractions induced in the pulmonary artery by epinephrine and in the ileum by histamine. 7. These observations suggest that hispidulin may interfere with Ca2+ binding to the Ca2+-receptor protein(s) in the smooth muscle cell and/or with the agonist-induced Ca2+-release from intracellular stores. Less likely, hispidulin may interfere with Ca2+ influx through smooth muscle cell membrane.

  16. Leishmaniose cutânea em cobaias (Cavia porcellus Cutaneous leishmaniasis in guinea pigs (Cavia porcellus

    Directory of Open Access Journals (Sweden)

    Roselene Ecco

    2000-06-01

    Full Text Available São descritos três casos de leishmaniose cutânea em cobaias (Cavia porcellus machos de dois anos de idade que eram criadas como animais de estimação. As lesões macroscópicas eram semelhantes em duas cobaias e consistiam de nódulos cutâneos ulcerados no aspecto dorsal do pavilhão auricular de ambas as orelhas. Na outra cobaia, a lesão consistia de engrossamentos irregulares na pele do escroto que apareceram após uma orquiectomia realizada dois meses antes. A histopatologia era semelhante nos três casos e consistia de acentuada dermatite granulomatosa, com ulceração e numerosas formas protozoárias amastigotas no citoplasma de macrófagos, sugestivas de Leishmania sp. A microscopia eletrônica confirmou o diagnóstico de leishmaniose.Three cases of cutaneous leishmaniasis in three two-year-old male guinea pigs (Cavia porcellus raised as pets are described. Gross lesions were similar in two of the guinea pigs and consisted of raised and ulcerated cutaneous nodules in the dorsal aspect of the pinna of both ears. In another guinea pig the lesion consisted of irregular thickenning in the skin of the scrotum which followed an orchiectomy performed two months before. Histopathology was similar in the three cases and consisted of severe diffuse granulomatous dermatitis with ulceration and numerous intrahistiocytic protozoal amastigotes resembling Leishmania sp. Electron microscopy confirmed the diagnosis of leishmaniasis.

  17. Effect of hydrogen peroxide on persistent sodium current in guinea pig ventricular myocytes

    Institute of Scientific and Technical Information of China (English)

    Ji-hua MA; An-tao LUO; Pei-hua ZHANG

    2005-01-01

    Aim: To study the effect of hydrogen peroxide (H2O2) on persistent sodium current (INa.P) in guinea pig ventricular myocytes.Methods: The whole-cell, cell-attached, and inside-out patch-clamp techniques were applied on isolated ventricular myocytes from guinea pig.Results: H2O2 (0.1 mmol/L, 0.5 mmol/L and 1.0mmol/L) increased the amplitude of whole-cell INa.P in a concentration-dependent mmol/L) increased persistent sodium channel activity in cell-attached and insideout patches.The mean open probability was increased from control values of 0.015±0.004 and 0.012±0.003 to 0.106±0.011 and 0.136±0.010, respectively (P<0.01 vs control).They were then decreased to 0.039±0.024 and 0.027±0.006,respectively, after the addition of 1 mmol/L GSH (P<0.01 vs H2O2).The time when open probability began to increase and reached a maximum was shorter in insideout patches than that in cell-attached patches (4.8± 1.0 min vs 11.5±3.9 min, P<0.01;9.6±1.6 min vs 18.7±4.7 min, P<0.01).Conclusion: H2O2 increased the INa.P of guinea pig ventricular myocytes in a concentration-dependent manner, possibly by directly oxidating the cell membrane.

  18. Nongenomic bronchodilating action elicited by dehydroepiandrosterone (DHEA) in a guinea pig asthma model.

    Science.gov (United States)

    Espinoza, Julia; Montaño, Luis M; Perusquía, Mercedes

    2013-11-01

    Primates secrete large amounts of the precursor steroid dehydroepiandrosterone (DHEA); in humans, its levels are low during childhood and start declining after the fourth decade. It has been postulated that the progressive decline in DHEA levels may be related with the severity of asthma associated with age. To determine whether DHEA may regulate the airway smooth muscle (ASM) activity, isolated tracheal rings with and without epithelium from male guinea pigs were isometrically recorded to characterize the response of ASM to DHEA at different concentrations on KCl- and carbachol (CCh)-induced contraction as well as on ovalbumin (OVA)-induced contraction in sensitized guinea pigs. Additionally, we used barometric plethysmography in sensitized guinea pigs in order to compare changes of the lung resistance increased by the antigen challenge to OVA in the absence and presence of different doses of DHEA. DHEA concentration-dependently abolished the contraction to KCl, CCh and OVA, and no differences were found in preparations with and without epithelium. DHEA-induced relaxation was not modified by the suppression of protein synthesis or transcription, pharmacological inhibition of nitric oxide (NO) synthase, nor by antagonist of β2-adrenergic receptors or an inhibitor of the 3β-HSD enzyme. Likewise, Ca(2+)-induced contraction in Ca(2+)-free depolarized tissues was antagonized by DHEA, and the contraction to the L-type voltage-dependent calcium channel activator (Bay K 8644) was inhibited by DHEA. Furthermore, DHEA prevented OVA-induced increases in lung resistance. These results indicate that DHEA-induced relaxation in ASM is a nongenomic (membrane) action and is not produced after its bioconversion. The data suggest that DHEA-induced relaxation is an epithelium- and NO-independent mechanism that involves a blockade of voltage-dependent calcium channels and possible non-selective cation channels. Copyright © 2013 Elsevier Ltd. All rights reserved.

  19. Acrylamide-induced prenatal programming of intestine structure in guinea pig.

    Science.gov (United States)

    Tomaszewska, E; Dobrowolski, P; Puzio, I; Prost, L; Kurlak, P; Sawczuk, P; Badzian, B; Hulas-Stasiak, M; Kostro, K

    2014-02-01

    Potential effects of prenatal administration of acrylamide (ACR) on postnatal development of the small intestine were not examined experimentally yet. The aim of this study was to establish changes of morphological parameters of the small intestine damaged by prenatal action of ACR in guinea pigs. The 3 mg/kg body weight of ACR was given in drinking water every day during the last 35 days of the pregnancy in guinea pigs. The histomorphometry of the duodenum and jejunum was determined. Immunohistochemical staining with anti cadherin antibody was performed. Maternal treatment with ACR led to the decrease of the expression of cadherin in the epithelium. Maternal ACR treatment increased the number of total, divided and inactive crypt, and the number of damaged villi in the duodenum and jejunum of newborn guinea pigs. The thickness of myenteron and submucosa, mucosa fractal dimension and the depth of crypts in the duodenum were increased by ACR. Additionally, in offspring born by mothers administered with ACR the decrease of villi epithelium thickness and active crypt number was observed. Moreover, ACR decreased goblet cells and inact villi number in the duodenum, mucosa thickness and crypts width in the jejunum. Intestine absorptive surface was affected by ACR in the jejunum as well. Results of measurements showed that maternal ACR treatment had negative influence on small intestine histomorphometry. ACR acting prenatally influenced small intestine nervous plexuses that became enlarged by 2.5 times compared with the control group. In conclusion, our results showed the negative impact of maternal ACR treatment on histological structure, integrity and innervation of small intestine wall as well as on absorptive function of small intestine mucosa.

  20. Kisspeptin Expression in Guinea Pig Hypothalamus: Effects of 17β-Estradiol

    Science.gov (United States)

    Bosch, Martha A.; Xue, Changhui; Rønnekleiv, Oline K.

    2013-01-01

    Kisspeptin is essential for reproductive functions in humans. As a model for the human we have used the female guinea pig, which has a long ovulatory cycle similar to that of primates. Initially, we cloned a guinea pig kisspeptin cDNA sequence and subsequently explored the distribution and 17β-estradiol (E2) regulation of kisspeptin mRNA (Kiss1) and protein (kisspeptin) by using in situ hybridization, real-time PCR and immunocytochemistry. In ovariectomized females, Kiss1 neurons were scattered throughout the preoptic periventricular areas (PV), but the vast majority of Kiss1 neurons were localized in the arcuate nucleus (Arc). An E2 treatment that first inhibits (negative feedback) and then augments (positive feedback) serum luteinizing hormone (LH) increased Kiss1 mRNA density and number of cells expressing Kiss1 in the PV at both time points. Within the Arc, Kiss1 mRNA density was reduced at both time points. Quantitative real-time PCR confirmed the in situ hybridization results during positive feedback. E2 reduced the number of immunoreactive kisspeptin cells in the PV at both time points, perhaps an indication of increased release. Within the Arc, the kisspeptin immunoreactivity was decreased during negative feedback but increased during positive feedback. Therefore, it appears that in guinea pig both the PV and the Arc kisspeptin neurons act cooperatively to excite gonadotropin-releasing hormone (GnRH) neurons during positive feedback. We conclude that E2 regulation of negative and positive feedback may reflect a complex interaction of the kisspeptin circuitry, and both the PV and the Arc respond to hormone signals to encode excitation of GnRH neurons during the ovulatory cycle. PMID:22173890

  1. The metabolism and disposition of fenofibrate in rat, guinea pig, and dog.

    Science.gov (United States)

    Weil, A; Caldwell, J; Strolin-Benedetti, M

    1988-01-01

    The metabolism and disposition of orally administered single doses of [14C]fenofibrate (isopropyl 2-[4-(4-chlorobenzoyl)phenoxy]-2- methylpropionate) have been studied in rat, guinea pig, and dog. In rats, the urinary excretion of 14C in 5 days varied from 11 to 51% of the dose and was markedly dependent upon the dose form given. The interpretation of these data in terms of factors affecting the absorption of fenofibrate from the gut is complicated by the enterohepatic recirculation of metabolites. The tissue distribution of 14C after oral administration of an ethanolic solution of fenofibrate has been studied in the rat. The only tissues in which the concentration of 14C exceeded that in the blood were the organs of absorption and elimination, the gut, liver, and kidneys. Guinea pigs excreted 53% of the dose in the urine in 5 days, with a further 34% in the feces, while in dogs the corresponding figures were 9% and 81%, respectively. In all three species, all the urinary metabolites were products of ester hydrolysis, and the principal excretion product was "reduced fenofibric acid" which arose by subsequent carbonyl reduction. Glucuronidation of fenofibric acid and "reduced fenofibric acid" was a very minor reaction in the rat and guinea pig and was not detected in the dog. In addition, polar unknown metabolite(s) were detected in all three species, but were not investigated further. The results are discussed in terms of the comparative disposition of fenofibrate and other hypolipidemic agents and the contribution of these findings to the safety assessment of such drugs.

  2. Vigilance states, EEG spectra, and cortical temperature in the guinea pig.

    Science.gov (United States)

    Tobler, I; Franken, P; Jaggi, K

    1993-06-01

    Vigilance states, electroencephalogram (EEG) power spectra (0.25-25.0 Hz), and cortical temperature (TCRT) were obtained in nine guinea pigs for 24 h in a 12:12-h light-dark (LD 12:12) schedule. Sleep was markedly polyphasic and fragmented and amounted to 32% of recording time, which is a low value compared with sleep in other rodents. There was 6.8% more sleep in the light period than in the dark period. EEG power density in non-rapid eye movement (NREM) sleep showed no significant temporal trend within the light or the dark period. The homeostatic aspects of sleep regulation, as proposed in the two-process model, can account for the slow-wave activity (SWA) pattern also in the guinea pig: The small 24-h amplitude of the sleep-wakefulness pattern resulted in a small, 12% decline of SWA within the light period. In contrast to more distinctly nocturnal rodents, SWA in the dark period was not higher than in the light period. TCRT showed no difference between the light and the dark period. TCRT in REM sleep and waking was higher than TCRT in NREM sleep. TCRT increased after the transition from NREM sleep to either REM sleep or waking, and decreased in the last minute before the transition and after the transition from waking to NREM sleep. Motor activity measured in six animals for 11 days in constant darkness showed no apparent rhythm in three animals and a significant circadian rhythm in three others. Our data support the notion that guinea pigs exhibit only a weak circadian rest-activity rhythm.

  3. The effect of N6-Cyclopentyladenosine on ouabain-Induced toxicity: isolated guinea pig atria

    Directory of Open Access Journals (Sweden)

    Bakhtiarian A

    2009-04-01

    Full Text Available "nBackground: Adenosine receptors play an important role in the treatment of paroxysmal supraventricular tachycardia in cardiovascular system. This effect is through interaction with A1 type of G-protein-coupled adenosine receptors. The effect of N6-cyclopentyladenosine (CPA, an A1-selective adenosine agonist, was studied on ouabain-induced toxicity in spontaneously beating isolated guinea pig atria. "nMethods: In the beginning the isolated guinea pig atria were mounted on the organ bath containing modified krebs and contractile responses in the four groups (shame, CPA, ouabain, CPA- ouabain were measured. "nResults: CPA (2-16nM produced a dose-dependent decrease in the force of contractions (34%-51% and in the rate of contractions (22%-48%. CPA significantly increased the time of onset of arrhythmia (toxicity induced by ouabain (1.2µM when it was administered 10 min before ouabain was added in organ bath. Ouabain (1.2µM alone produced arrhythmia at 7 min and either asystole or standstill at 22 min. CPA (8nM increased the time required to produce arrhythmia to 27.5 min and prolonged beating atria to more than 63 min and prevented the occurrence of asystole. "nConclusion: CPA produces direct cardiac action, probably due the inhibition of cardiac Ca2+ channel and membrane hyperpolarization of atrium cells in guinea pig atria. Moreover, our results suggest that CPA may reduce the membrane conduction through inhibition of ionic channels, which decrease ouabain- induced toxicity.

  4. Maternal vitamin C deficiency during pregnancy persistently impairs hippocampal neurogenesis in offspring of guinea pigs.

    Directory of Open Access Journals (Sweden)

    Pernille Tveden-Nyborg

    Full Text Available While having the highest vitamin C (VitC concentrations in the body, specific functions of VitC in the brain have only recently been acknowledged. We have shown that postnatal VitC deficiency in guinea pigs causes impairment of hippocampal memory function and leads to 30% less neurons. This study investigates how prenatal VitC deficiency affects postnatal hippocampal development and if any such effect can be reversed by postnatal VitC repletion. Eighty pregnant Dunkin Hartley guinea pig dams were randomized into weight stratified groups receiving High (900 mg or Low (100 mg VitC per kg diet. Newborn pups (n = 157 were randomized into a total of four postnatal feeding regimens: High/High (Control; High/Low (Depleted, Low/Low (Deficient; and Low/High (Repleted. Proliferation and migration of newborn cells in the dentate gyrus was assessed by BrdU labeling and hippocampal volumes were determined by stereology. Prenatal VitC deficiency resulted in a significant reduction in postnatal hippocampal volume (P<0.001 which was not reversed by postnatal repletion. There was no difference in postnatal cellular proliferation and survival rates in the hippocampus between dietary groups, however, migration of newborn cells into the granular layer of the hippocampus dentate gyrus was significantly reduced in prenatally deficient animals (P<0.01. We conclude that a prenatal VitC deficiency in guinea pigs leads to persistent impairment of postnatal hippocampal development which is not alleviated by postnatal repletion. Our findings place attention on a yet unrecognized consequence of marginal VitC deficiency during pregnancy.

  5. Noise-induced nitrotyrosine increase and outer hair cell death in guinea pig cochlea

    Institute of Scientific and Technical Information of China (English)

    HAN Wei-ju; SHI Xiao-rui; Alfred Nuttall

    2013-01-01

    Background Modern research has provided new insights into the biological mechanisms of noise-induced hearing loss,and a number of studies showed the appearance of increased reactive oxygen species (ROS) and reactive nitrogen species (RNS) during and after noise exposure.This study was designed to investigate the noise exposure induced nitrotyrosine change and the mechanism of outer hair cells death in guinea pig cochlea.Method Thirty guinea pigs were used in this study.The experimental animals were either exposed for 4 hours per day to broadband noise at 122 dB SPL (A-weighted) for 2 consecutive days or perfused cochleae with 5 mg/ml of the SIN1 solutions,an exogenous NO and superoxide donor,for 30 minutes.Then the cochleae of the animals were dissected.Propidium iodide (PI),a DNA intercalating fluorescent probe,was used to trace morphological changes in OHC nuclei.The distribution of nitrotyrosine (NT) in the organ of Corti and the cochlear lateral wall tissue from the guinea pigs were examined using fluorescence immunohistochemistry method.Whole mounts of organ of Corti were prepared.Morphological and fluorescent changes were examined under a confocal microscope.Results Either after noise exposure or after SIN1 perfusion,outer hair cells (OHCs) death with characteristics of both apoptotic and necrotic degradation appeared.Nitrotyrosine immunolabeling could be observed in the OHCs from the control animals.After noise exposure,NT immunostaining became much greater than the control animals in OHCs.The apoptotic OHC has significant increase of nitrotyrosine in and around the nucleus following noise exposure.In the normal later wall of cochleae,relatively weak nitrotyrosine immunolabeling could be observed.After noise exposure,nitrotyrosine immunoactivity became stronger in stria vascularis.Conclusion Noise exposure induced increase of nitrotyrosine production is associated with OHCs death suggesting reactive nitrogen species participation in the cochlear

  6. Organophosphorus pesticides decrease M2 muscarinic receptor function in guinea pig airway nerves via indirect mechanisms.

    Directory of Open Access Journals (Sweden)

    Becky J Proskocil

    Full Text Available BACKGROUND: Epidemiological studies link organophosphorus pesticide (OP exposures to asthma, and we have shown that the OPs chlorpyrifos, diazinon and parathion cause airway hyperreactivity in guinea pigs 24 hr after a single subcutaneous injection. OP-induced airway hyperreactivity involves M2 muscarinic receptor dysfunction on airway nerves independent of acetylcholinesterase (AChE inhibition, but how OPs inhibit neuronal M2 receptors in airways is not known. In the central nervous system, OPs interact directly with neurons to alter muscarinic receptor function or expression; therefore, in this study we tested whether the OP parathion or its oxon metabolite, paraoxon, might decrease M2 receptor function on peripheral neurons via similar direct mechanisms. METHODOLOGY/PRINCIPAL FINDINGS: Intravenous administration of paraoxon, but not parathion, caused acute frequency-dependent potentiation of vagally-induced bronchoconstriction and increased electrical field stimulation (EFS-induced contractions in isolated trachea independent of AChE inhibition. However, paraoxon had no effect on vagally-induced bradycardia in intact guinea pigs or EFS-induced contractions in isolated ileum, suggesting mechanisms other than pharmacologic antagonism of M2 receptors. Paraoxon did not alter M2 receptor expression in cultured cells at the mRNA or protein level as determined by quantitative RT-PCR and radio-ligand binding assays, respectively. Additionally, a biotin-labeled fluorophosphonate, which was used as a probe to identify molecular targets phosphorylated by OPs, did not phosphorylate proteins in guinea pig cardiac membranes that were recognized by M2 receptor antibodies. CONCLUSIONS/SIGNIFICANCE: These data indicate that neither direct pharmacologic antagonism nor downregulated expression of M2 receptors contributes to OP inhibition of M2 function in airway nerves, adding to the growing evidence of non-cholinergic mechanisms of OP neurotoxicity.

  7. Repeated low-dose exposures to sarin, soman, or VX affect acoustic startle in guinea pigs.

    Science.gov (United States)

    Smith, C D; Lee, R B; Moran, A V; Sipos, M L

    2016-01-01

    Chemical warfare nerve agents (CWNAs) are known to cause behavioral abnormalities in cases of human exposures and in animal models. The behavioral consequences of single exposures to CWNAs that cause observable toxic signs are particularly well characterized in animals; however, less is known regarding repeated smaller exposures that may or may not cause observable toxic signs. In the current study, guinea pigs were exposed to fractions (0.1, 0.2, or 0.4) of a medial lethal dose (LD50) of sarin, soman, or VX for two weeks. On each exposure day, and for a post-exposure period, acoustic startle response (ASR) was measured in each animal. Although relatively few studies use guinea pigs to measure behavior, this species is ideal for CWNA-related experiments because their levels of carboxylesterases closely mimic those of humans, unlike rats or mice. Results showed that the 0.4 LD50 doses of soman and VX transiently increased peak startle amplitude by the second week of injections, with amplitude returning to baseline by the second week post-exposure. Sarin also increased peak startle amplitude independent of week. Latencies to peak startle and PPI were affected by agent exposure but not consistently among the three agents. Most of the changes in startle responses returned to baseline following the cessation of exposures. These data suggest that doses of CWNAs not known to produce observable toxic signs in guinea pigs can affect behavior in the ASR paradigm. Further, these deficits are transient and usually return to baseline shortly after the end of a two-week exposure period.

  8. Relaxant effects of Ocimum basilicum on guinea pig tracheal chains and its possible mechanism(s

    Directory of Open Access Journals (Sweden)

    Mohammad Hossein Boskabady

    2005-01-01

    Full Text Available Therapeutic effects of Ocimum basilicum on respiratory diseases especially dyspnea have been reported in Iranian ancient medical books. In the present study, the relaxant effects of macerated and soxhlet extracts of this plant on tracheal chains of guinea pigs were evaluated. The relaxant effects of 4 cumulative concentrations of macerated and soxhlet extracts (0.25, 0.5, 0.75 and 1.0 W/V in comparison with saline as negative control and 4 cumulative concentrations of theophylline (0.25, 0.5, 0.75, and 1.0 mM as positive control were examined on precontracted tracheal chains of two groups of 6 guinea pig by 60 mM KCl (group 1 and 10 µM methacholine (group 2. Decrease in contractile tone of tracheal chains was considered as relaxant effect. In group 1 experiments only the last two higher concentrations of theophylline showed significant relaxant effect compared to that of saline (p<0.001 for both concentrations, which were significantly greater than those of macerated and soxhlet extracts (p<0.001 for all cases and in group 2 experiments both macerated and soxhlet extracts showed concentrationdependent relaxant effects compared to that of saline (p<0.05 to p<0.001 for both extracts. There were significant differences between the relaxant effects of both extracts with those of theophylline in group 2 experiments (p<0.01 to p<0.001. The relaxant effects of macerated and soxhlet extracts in group 1 were significantly lower than those of groups 2. These results showed a potent relaxant effect of Ocimum basilicum on tracheal chains of guinea pigs which were lower than theophylline at concentrations used.

  9. Cholinergic-opioidergic interaction in the central amygdala induces antinociception in the guinea pig

    Directory of Open Access Journals (Sweden)

    Leite-Panissi C.R.A.

    2004-01-01

    Full Text Available Several studies have demonstrated the involvement of the central nucleus of the amygdala (CEA in the modulation of defensive behavior and in antinociceptive regulation. In a previous study, we demonstrated the existence of a cholinergic-opioidergic interaction in the CEA, modulating the defensive response of tonic immobility in guinea pigs. In the present study, we investigated a similar interaction in the CEA, but now involved in the regulation of the nociceptive response. Microinjection of carbachol (2.7 nmol and morphine (2.2 nmol into the CEA promoted antinociception up to 45 min after microinjection in guinea pigs as determined by a decrease in the vocalization index in the vocalization test. This test consists of the application of a peripheral noxious stimulus (electric shock into the subcutaneous region of the thigh that provokes the emission of a vocalization response by the animal. Furthermore, the present results demonstrated that the antinociceptive effect of carbachol (2.7 nmol; N = 10 was blocked by previous administration of atropine (0.7 nmol; N = 7 or naloxone (1.3 nmol; N = 7 into the same site. In addition, the decrease in the vocalization index induced by the microinjection of morphine (2.2 nmol; N = 9 into the CEA was prevented by pretreatment with naloxone (1.3 nmol; N = 11. All sites of injection were confirmed by histology. These results indicate the involvement of the cholinergic and opioidergic systems of the CEA in the modulation of antinociception in guinea pigs. In addition, the present study suggests that cholinergic transmission may activate the release of endorphins/enkephalins from interneurons of the CEA, resulting in antinociception.

  10. The actions of isoprenaline and mirabegron in the isolated whole rat and guinea pig bladder.

    Science.gov (United States)

    Persyn, Sara; De Wachter, Stefan; Wyndaele, Jean-Jacques; Eastham, Jane; Gillespie, James

    2016-07-01

    β3-adrenoceptor agonists influence overactive bladder in humans and animal models. However, data is emerging that the mode of action of these drugs is complex. The present study explored the actions of the β3-adrenergic agonist mirabegron and the non-selective agonist isoprenaline on the contractile systems in the rat and guinea pig bladder. Intravesical pressure was measured in isolated whole bladders from female adult animals. In both species spontaneous contractile activity was observed. The muscarinic agonist arecaidine produced complex responses consisting of an initial transient pressure rise followed by complex phasic activity. Three contractile elements were identified: intrinsic micro-contractile activity, initial transient response and steady state phasic activity. The intrinsic and steady state activity could be further divided into a baseline pressure with superimposed phasic activity. The effects of isoprenaline and mirabegron were investigated on these elements. In the rat, the micro-contractile activity could be completely inhibited by isoprenaline (full agonist). The arecaidine-induced initial and steady state baseline pressures were partially reduced, while the phasic activity was little affected. In the guinea pig, both the arecaidine-induced baseline pressure and the phasic activity were affected by isoprenaline. Mirabegron didn't produce significant inhibitory effects in any of the contractile elements in either species. These results show that complex contractile systems operate in the rat and guinea pig bladder that can be modulated by β1/β2-adrenoceptor mechanisms. No evidence was obtained for any β3-dependent regulation of contraction. These data support similar data in humans. Therefore the primary site of therapeutic action of β3-adrenergic agonists remains unknown.

  11. Spontaneous osteoarthritis in Dunkin Hartley guinea pigs: histologic, radiologic, and biochemical changes.

    Science.gov (United States)

    Jimenez, P A; Glasson, S S; Trubetskoy, O V; Haimes, H B

    1997-12-01

    Dunkin Hartley guinea pigs develop spontaneous, age-related osteoarthritis (OA) of the knee and other joints. Histologic changes are observed beginning at 3 months of age. Disease severity increases with age, and at 18 months moderate to severe OA is observed. A study was undertaken to assess the morphologic and biochemical changes of 22-month-old animals, and to compare them with values in 2-month-old guinea pigs. Biochemical indices characteristic of OA, from tibial cartilage, indicated an increase in proteoglycan content from 233 +/- 2 micrograms/mg (mean +/- SEM) at 2 months of age to 365 +/- 6 micrograms/mg at 22 months. Collagen concentration in cartilage decreased from 364 +/- 2 micrograms/mg at 2 months to 223 +/- 3 micrograms/mg at 22 months. Proteoglycan fragments found in synovial fluid measured 4.6 +/- 1 micrograms/ml at 2 months and increased to 37 +/- 2 micrograms/ml at 22 months. Radiographic changes observed at 22 months included marginal osteophytes of the tibia and femur, sclerosis of the subchondral bone of the tibial plateau, femoral condyle cysts, and calcification of the collateral ligaments. Histologic evaluation revealed severe OA, with a Mankin score of 10.7 +/- 0.5 in 22-month-old animals. In contrast, 2-month-old animals had no histologic or radiographically detectable lesions. The results of the study reported here indicate that the lesions observed in this model are similar to those of human OA. Spontaneous development of OA in guinea pigs is amenable to the study of the pathogenesis of OA and to the evaluation of potential disease-modifying agents.

  12. VX Penetration Following Percutaneous Poisoning: A Dermal Microdialysis Study in the Guinea Pig.

    Science.gov (United States)

    Wetherell, Janet R; Armstrong, Stuart J; Read, Robert W; Clough, Geraldine F

    2008-01-01

    ABSTRACT VX, a potent organophosphorus compound, acts primarily by irreversibly inhibiting acetylcholinesterase resulting in an accumulation of acetylcholine, which produces the characteristic signs of nerve agent poisoning. VX is a low-volatility agent, and therefore the most likely route of absorption into the body is via the skin. This study demonstrates for the first time that it is possible to follow the time course of percutaneous VX penetration using the technique of dermal microdialysis and that VX is absorbed through the skin of the anesthetized guinea pig in a concentration-dependent manner. A linear microdialysis probe (5-kDa cut-off) was implanted in the dermis of the back of the guinea pig and perfused (5 muL/min) with physiological Ringer's solution. VX (296 or 592 mug/kg) was applied (33 muL/kg) over the site of the microdialysis probe and dialysate samples collected for up to 6 h. The VX dialysate concentration was measured by liquid chromatography-tandem mass spectrometry (LC-MS-MS). Quantitation was performed over the range 0.1 to 100 ng/mL and the calibration was linear. VX was detected within 15 min, reaching a peak at 30 min following both VX doses. After this time the VX concentration decreased. There was a clear dose-dependent recovery of VX in the dialysate and the total amount recovered was statistically significant between the two doses. This study has clearly shown that microdialysis can be used to follow the time course of the percutaneous absorption of VX in the anesthetized guinea pig and will be used in future studies to develop improved medical countermeasures. Crown Copyright (c) 2007 Dstl.

  13. Experimental intoxication of guinea pigs with Ipomoea carnea: behavioural and neuropathological alterations.

    Science.gov (United States)

    Cholich, Luciana A; Márquez, Mercedes; Pumarola i Batlle, Martí; Gimeno, Eduardo J; Teibler, Gladys P; Rios, Elvio E; Acosta, Ofelia C

    2013-12-15

    Ipomoea carnea is a toxic plant that affects goats, with symptoms being characterised by nervous disorders and death. Swainsonine and calystegines are the principal toxic components isolated from I. carnea, which also yields lysergic acid derivatives. The aim of this study was to improve the clinical characterisation of experimental intoxication by I. carnea in guinea pigs through the evaluation of behavioural changes and to perform a thorough histopathological analysis of the affected CNS. Leaves of I. carnea were administered to guinea pigs. Open-field gait analysis and monoamine levels were measured. The poisoned animals exhibited increased vocalisation, lethargy, and a reduction in the locomotion frequency after the fourth week of intoxication, as demonstrated in the open-field test. Significant differences were observed in hind-limb gait width by the last week of intoxication. After 65 days, the guinea pigs were euthanised, necropsied, and examined using light and electron microscopy. At the end of the experiment, plasma serotonin decreased. In contrast, dopamine decreased, and noradrenaline increased in urine. Brain sections were evaluated with conventional histological methods and immunohistochemistry (IHC), as well as by transmission electron microscopy (TEM). Vacuoles were observed throughout the brain, but they were particularly prominent in the brainstem. In addition, there were PAS-negative regions, and the Nissl substance was dispersed or absent, which was confirmed with the Kluver-Barreda stain. Moderate microgliosis was observed by immunohistochemistry. In the medulla oblongata, numerous ubiquitin-positive spheroids together with neuronal degeneration were observed in the nucleus gracilis/cuneatus. Furthermore, vacuoles were observed in astrocytes, oligodendrocytes, and endothelial cells by TEM. Our results showed that the behavioural effects may have been caused by alterations in the brain in conjunction with changes in monoamine levels. This

  14. The effects of ascorbic acid on cartilage metabolism in guinea pig articular cartilage explants.

    Science.gov (United States)

    Clark, Amy G; Rohrbaugh, Amy L; Otterness, Ivan; Kraus, Virginia B

    2002-03-01

    Ascorbic acid has been associated with the slowing of osteoarthritis progression in guinea pig and man. The goal of this study was to evaluate transcriptional and translational regulation of cartilage matrix components by ascorbic acid. Guinea pig articular cartilage explants were grown in the presence of L-ascorbic acid (L-Asc), D-isoascorbic acid (D-Asc), sodium L-ascorbate (Na L-Asc), sodium D-isoascorbate (Na D-Asc), or ascorbyl-2-phosphate (A2P) to isolate and analyze the acidic and nutrient effects of ascorbic acid. Transcription of type II collagen, prolyl 4-hydroxylase (alpha subunit), and aggrecan increased in response to the antiscorbutic forms of ascorbic acid (L-Asc, Na L-Asc, and A2P) and was stereospecific to the L-forms. Collagen and aggrecan synthesis also increased in response to the antiscorbutic forms but only in the absence of acidity. All ascorbic acid forms tended to increase oxidative damage over control. This was especially true for the non-nutrient D-forms and the high dose L-Asc. Finally, we investigated the ability of chondrocytes to express the newly described sodium-dependent vitamin C transporters (SVCTs). We identified transcripts for SVCT2 but not SVCT1 in guinea pig cartilage explants. This represents the first characterization of SVCTs in chondrocytes. This study confirms that ascorbic acid stimulates collagen synthesis and in addition modestly stimulates aggrecan synthesis. These effects are exerted at both transcriptional and post-transcriptional levels. The stereospecificity of these effects is consistent with chondrocyte expression of SVCT2, shown previously to transport L-Asc more efficiently than D-Asc. Therefore, this transporter may be the primary mechanism by which the L-forms of ascorbic acid enter the chondrocyte to control matrix gene activity.

  15. Non-diabetic hyperglycemia exacerbates disease severity in Mycobacterium tuberculosis infected guinea pigs.

    Science.gov (United States)

    Podell, Brendan K; Ackart, David F; Kirk, Natalie M; Eck, Sarah P; Bell, Christopher; Basaraba, Randall J

    2012-01-01

    Hyperglycemia, the diagnostic feature of diabetes also occurs in non-diabetics associated with chronic inflammation and systemic insulin resistance. Since the increased risk of active TB in diabetics has been linked to the severity and duration of hyperglycemia, we investigated what effect diet-induced hyperglycemia had on the severity of Mycobacterium tuberculosis (Mtb) infection in non-diabetic guinea pigs. Post-prandial hyperglycemia was induced in guinea pigs on normal chow by feeding a 40% sucrose solution daily or water as a carrier control. Sucrose feeding was initiated on the day of aerosol exposure to the H37Rv strain of Mtb and continued for 30 or 60 days of infection. Despite more severe hyperglycemia in sucrose-fed animals on day 30, there was no significant difference in lung bacterial or lesion burden until day 60. However the higher spleen and lymph node bacterial and lesion burden at day 30 indicated earlier and more severe extrapulmonary TB in sucrose-fed animals. In both sucrose- and water-fed animals, serum free fatty acids, important mediators of insulin resistance, were increased by day 30 and remained elevated until day 60 of infection. Hyperglycemia mediated by Mtb infection resulted in accumulation of advanced glycation end products (AGEs) in lung granulomas, which was exacerbated by sucrose feeding. However, tissue and serum AGEs were elevated in both sucrose and water-fed guinea pigs by day 60. These data indicate that Mtb infection alone induces insulin resistance and chronic hyperglycemia, which is exacerbated by sucrose feeding. Moreover, Mtb infection alone resulted in the accumulation tissue and serum AGEs, which are also central to the pathogenesis of diabetes and diabetic complications. The exacerbation of insulin resistance and hyperglycemia by Mtb infection alone may explain why TB is more severe in diabetics with poorly controlled hyperglycemia compared to non-diabetics and patients with properly controlled blood glucose levels.

  16. A Study on the Traditional Chinese Medicine Jinyebaidu for Prevention and Treatment of Intrauterine Infection with Guinea Pigs Cytomegalovirus

    Institute of Scientific and Technical Information of China (English)

    CHEN Suhua; XIONG Jinwen; XING Wei; WEN Liangzhen; LIU Haizhi; WANG Xinrong

    2005-01-01

    The purpose is to study the prophylactic and therapeutic effect of the traditional Chinese Medicine (TCM)-Jinyebaidu (JYBD) to guinea pig cytomegalovirus (GPCMV) intrauterine infec tion. The virus-free female and male guinea pigs were screened with nest-polymerase chain reaction (N-PCR). After inbred, pregnant guinea pigs were selected and divided into 3 groups randomly: 5guniea pigs of the blank control group were not given either GPCMV or JYBD. 31 guniea pigs of the positive control group were inoculated 1 mL (107 TCID50 ) suspension of GPCMV intraperitoneal. 10 guniea pigs of the experimental group were inoculated GPCMV firstly and then perfused stomach with JYBD for 14 days (Dosage in accordance with the modulus of the weight ratio of human to guniea pig). The effects of JYBD on the intrauterine infection of GPCMV were observed.The results showed that JYBD could decrease the maternal infection rate from 100 % (31/31) to 50% (5/10) (P<0. 001), the intrauterine infection rate from 100 % (72/72) to 75 % (21/28) (P<0. 001), and the rate of abnormal outcome of pregnancy from 64.4 % (29/45) to 25.0 % (7/28)(P<0. 001), the infective symptoms being relieved. It can be concluded that traditional Chinese medicine JYBD can prevent and treat GPCMV intrauterine infection, and can be expected a prophy lactic drug for HCMV intrauterine infection.

  17. Comparison of fibre digestion and digesta retention time between nutrias (Myocaster coypus) and guinea-pigs (Cavia porcellus).

    Science.gov (United States)

    Sakaguchi, E; Nabata, A

    1992-11-01

    1. Digestibilities of feed, and transit and retention time of fluid and particle digesta marker measured in nutrias (Myocaster coypus) and guinea-pigs (Cavia porcellus) fed on a diet containing 50% alfalfa. 2. The digestibility of fibre was higher in the nutria, along with the longer retention time of digesta. 3. The liquid and particle marker were similarly excreted, suggesting no separation mechanism in the gastrointestinal tract of both the animals. 4. The apparent digestibility of protein in the nutria was superior to the guinea-pig and other small hindgut fermenters, suggesting that the contribution of coprophagy on protein nutrition of nutrias is significant.

  18. A processing plant persistent strain of Listeria monocytogenes crosses the fetoplacental barrier in a pregnant guinea pig model

    DEFF Research Database (Denmark)

    Jensen, Anne; Williams, D.; Irving, E. A.;

    2008-01-01

    independent fish processing plants. The purpose of the present study was to determine the virulence potential of one RAPD type 9 strain (La111), one human clinical strain (Scott A), and one monkey clinical strain (12443) in a pregnant guinea pig model. Animals were orally exposed to 10(8) CFU of L...... was isolated from 16 and 20% of placentas for 12443 and La111, respectively. The study demonstrates that a food processing plant persistent strain of L. monocytogenes is able to cross the fetoplacental barrier in pregnant guinea pigs. Furthermore, we demonstrate that although information can be gained from...

  19. Quantitation of contact allergy in guinea pigs by measuring changes in skin blood flow and skin fold thickness

    DEFF Research Database (Denmark)

    Andersen, Klaus Ejner; Staberg, B

    1985-01-01

    Skin blood flow determined by laser Doppler flowmetry (LDF) and skin fold thickness (SFT) have been used to quantitate allergic contact dermatitis in the guinea pig maximization test (GPMT) using chlorocresol as the allergen. The closed patch test procedure itself influenced both LDF and SFT...... measurements when determined in 12 sham-treated guinea pigs. The LDF was maximal at 24 hours and the SFT at 48 hours. Before correlating the quantitative measurements with the conventional visual scoring in test and control animals the value from a nearby control site was subtracted from the test site values...

  20. Use of saprophytic leptospira strains in the serodiagnosis of experimental leptospirosis in guinea-pigs (Cavia sp

    Directory of Open Access Journals (Sweden)

    Raul J. S. Girio

    1988-04-01

    Full Text Available The efficiency of four Leptospira biflexa strains (Buenos Aires, Patoc 1, Rufino and São Paulo as single antigen in the serodiagnosis in guinea-pigs experimentally infected with seven Leptospira interrogans serovars (canicola, grippotyphosa, hardjo, icterohaemorrhagiae, pomona, tarassovi and wolffi was evaluated by the microscopic agglutination test. The four saprophytic strains were not able to reveal antibody titres in sera of guinea-pigs experimentally infected with Leptospira interrogans. Serological cross-reactions were observed between strains Patoc 1 and São Paulo and between serovars wolffi and hardjo.

  1. INFLUENCE OF ANTIBIOTICS ON THE MECHANICAL RESPONSES OF GUINEA-PIG ILEUM TO ACETYLCHOLINE AND HISTAMINE

    Directory of Open Access Journals (Sweden)

    Petroianu Andy

    1998-01-01

    Full Text Available The side effects of antibiotics have been extensively described during the last decades, however, their role on digestive motility must be better investigated. Following a line of research, the influence of penicillin, chloranfenicol tetracycline and gentamicine on longitudinal smooth muscle responses to acetylcholine and histamine were studied on guinea-pig ileum. There were no differences between the responses before and after the addition of each antibiotic. Further investigations must be performed in order to find a possible influence of antibiotics on digestive motility.

  2. Sensitization capacity of acrylated prepolymers in ultraviolet curing inks tested in the guinea pig.

    Science.gov (United States)

    Björkner, B

    1981-01-01

    One commonly used prepolymer in ultraviolet (UV) curing inks is epoxy acrylate. Of 6 men with dermatitis contracted from UV-curing inks, 2 had positive patch test reaction to epoxy acrylate. None reacted to the chemically related bisphenol A dimethacrylate. The sensitization capacity of epoxy acrylate and bisphenol A dimethacrylate performed with the "Guinea pig maximization test" (GPM) shows epoxy acrylate to be an extreme sensitizer and bisphenol A dimethacrylate a moderate sensitizer. Cross-reaction between the two substances occurs. The epoxy resin oligomer MW 340 present in the epoxy acrylate also sensitized some animals.

  3. Calcitonin gene-related peptide (CGRP) regulates excitability and refractory period of the guinea pig ureter.

    Science.gov (United States)

    Maggi, C A; Giuliani, S

    1994-08-01

    Previous studies have indicated that calcitonin gene-related peptide (CGRP), released from the peripheral endings of capsaicin-sensitive primary afferent neurons, may play a role as an inhibitory transmitter in the guinea pig ureter. The aim of this study was to compare the effect of capsaicin desensitization and administration of a CGRP receptor antagonist on the excitability and refractory period of the guinea pig ureter to electrical field stimulation. Electrical field stimulation using a long (5 msec.) pulse width produced phasic contractions of the ureter which were unaffected by tetrodotoxin, that is, were produced through direct excitation of ureteral smooth muscle. Human alpha CGRP (1 to 10 nM.) produced a concentration-dependent transient suppression of the evoked contractions, and its effect was prevented by the CGRP receptor antagonist human alpha CGRP(8-37) (1 microM.). In vitro capsaicin pretreatment (10 microM. for 15 minutes) to block neuropeptide release from peripheral endings of sensory nerves or administration of the CGRP receptor antagonist enhanced the responsiveness of the guinea pig ureter to electrical stimulation. In control ureters, the application of two trains of electrical stimuli failed to produce a second contraction at intertrain intervals greater than 20 seconds. The intertrain interval required to obtain a second contraction averaging 50% of the amplitude of the first response (ITI50) of control ureters was about 50 seconds. In vitro capsaicin pretreatment or administration of the CGRP receptor antagonist reduced the refractory period of the ureter to electrical field stimulation: ITI50 averaged 8.8 and 9.1 seconds after capsaicin or CGRP antagonist pretreatment, respectively. These findings demonstrate that capsaicin pretreatment or blockade of CGRP receptors produced qualitatively and quantitatively similar excitatory effects on ureteral excitability and refractory period and are in general agreement with the idea that CGRP is a

  4. Studies on the stereoselectivity of the P2-purinoceptor on the guinea-pig vas deferens.

    OpenAIRE

    Burnstock, G.; Cusack, N. J.; Meldrum, L. A.

    1985-01-01

    ATP, 2-chloro-ATP, 2-methylthio-ATP and their unnatural L-enantiomers, Rp and Sp diastereoisomers of the ATP phosphorothioate analogues, ATP alpha S and ATP beta S, were tested on the guinea-pig vas deferens. The 2-substituted analogues of ATP were no more effective than ATP in causing contraction of the vas deferens. However, stereoselectivity was observed with each pair of enantiomers of ATP, 2-chloro-ATP and 2-methylthio-ATP. No stereoselectivity was observed for the phosphorothioate analo...

  5. Glutamate-induced production of nitric oxide in guinea pig vestibular sensory cells.

    Science.gov (United States)

    Takumida, M; Anniko, M

    2000-06-01

    Glutamate-induced production of nitric oxide (NO) in the vestibular organ of the guinea pig was investigated using the new fluorescence indicator, DAF-2DA, for direct detection of NO. Utricular maculae and isolated vestibular sensory cells were examined to locate NO production sites. The fluorescence intensity of the sensory cells was augmented by stimulation with glutamate, NMDA and AMPA. This is the first direct evidence of NO production in the vestibular end organs. NO may play an important role in the glutamate-induced ototoxicity and also be involved in disease of the inner ear.

  6. [Palaeoparasitological analysis of guinea pig mummies of the Chiribaya culture, Moquegua Valley, Peru].

    Science.gov (United States)

    Dittmar de la Cruz, Katharina; Ribbeck, Regine; Daugschies, Arwid

    2003-01-01

    During several excavations of archeological sites in the Moquegua Valley, Southern Peru, various guinea pig mummies (Cavia aperea f. porcellus) have been discovered. They belong to the Chiribaya Culture (900-1100 AD). The outstanding preservation of the mummified animals gave rise to the idea of a paleoparasitological analysis. In the fur, numerous well preserved ectoparasites (lice, fleas, mites) could be recovered. Generally, ectoparasite remains are rarely found among archeological material. This is the first account of an extensive ectoparasitological analysis of animal mummies in Peru. A modified technique for recovery and preservation of the ectoparasites has been developed.

  7. Experimental joint immobilization in guinea pigs. Effects on the knee joint

    Science.gov (United States)

    Marcondesdesouza, J. P.; Machado, F. F.; Sesso, A.; Valeri, V.

    1980-01-01

    In young and adult guinea pigs, the aftermath experimentally induced by the immobilization of the knee joint in hyperextended forced position was studied. Joint immobilization which varied from one to nine weeks was attained by plaster. Eighty knee joints were examined macro and microscopically. Findings included: (1) muscular hypotrophy and joint stiffness in all animals, directly proportional to the length of immobilization; (2) haemoarthrosis in the first week; (3) intra-articular fibrous tissue proliferation ending up with fibrous ankylosis; (4) hyaline articular cartilage erosions; (5) various degrees of destructive menisci changes. A tentative explanation of the fibrous tissue proliferation and of the cartilage changes is offered.

  8. Placental transfer of a large angiotensin fragment in the guinea pig.

    Science.gov (United States)

    Broughton Pipkin, F; Benjamin, N; Macallan, C

    1977-08-15

    Angiotensin II (AII) levels are usually higher in the fetal than in the maternal circulations. Radioiodinated AII has been used to establish whether or not this hormone crosses the placenta from the fetus to the mother in the pregnant guinea pig. No intact radioiodinated AII was found to have crossed in any of 13 experiments. A single radioiodinated AII fragment was found in 10 of these experiments. This ran as (des-(Asp1 Arg2 Val3)) in one solvent, but this could not be confirmed when a different solvent was used. The results support the hypothesis, previously based on indirect evidence, that AII does not cross the placenta.

  9. In Vitro Response of Guinea Pig Peritoneal Macrophages to Legionella pneumophila

    Science.gov (United States)

    1981-03-01

    In Vitro Responlse of Guinea Pig Peritoneal Macrophages to Legionella pneumophila It. A. KISIIIMi~O~’ .1. Ii.,W11ITE, F. G. SIREY, V. (U.1 Mc(GANN, R...Polaroid film (55 N/P) at a scan speed of 50 RESULTS Phagocytosis of L pneumophila . The vir- ulent and avirulent Philadelphia- I and Washing- ., 2 I...organisms which appeared within a mem- pneumophila . Ingested organisms are in cytoplasmic brane-bound cytoplasmic vesicle (Fig. I). Mac- iesices. rophages

  10. The hairless guinea-pig as a model for treatment of acute irritation in humans

    DEFF Research Database (Denmark)

    Andersen, F; Hedegaard, K; Fullerton, A

    2006-01-01

    BACKGROUND: The effect of six skin care formulations on experimentally induced acute irritation was studied in hairless guinea-pigs (HLGP) and in human volunteers (HV). The formulations were a basic cream, a carbomer cream and four modifications of the carbomer cream, containing either 10......-propanol (NON) 20%. The irritant reactions were treated twice daily with the formulations from the time of removal of the patches. Evaluation of skin irritation and efficacy of treatments was performed daily for 4 days using clinical scoring, evaporimetry (transepidermal water loss), hydration measurement...

  11. Comparison of form-deprived myopia and lens-induced myopia in guinea pigs

    Directory of Open Access Journals (Sweden)

    Hui Xiao

    2014-04-01

    Full Text Available AIM: To study the efficacy difference between form-deprived myopia (FDM and lens-induced myopia (LIM, the degree of myopia, axial length and pathological changes of the posterior sclera from guinea pigs were evaluated.METHODS: Four-week pigmented guinea pigs were randomly assigned into 3 groups, including normal control (n=6, FDM group with monocular cover (n=11 and LIM group with monocular -7D lens treatment (n=11. FDM group was form-deprived while LIM group was lens-induced for 14 d. Refractive error and axial length were measured prior to and post treatment, respectively. Morphological changes of sclera were examined using both light and electronic microscopes.RESULTS: After 14d treatment, refractive errors for FDM group and LIM group were -3.05±0.71D and -2.12±1.29D, respectively, which were significantly more myopic than that of normal controls and fellow control eyes (P<0.01. As for axial length, it was 7.93±0.03 mm for FDM group and 7.89±0.06 mm for LIM group, which were significantly longer than both normal and fellow controls (P<0.01. With respect to both refractory error and axial length, the differences between FDM group and LIM group were not significant (P>0.05. Under light microscope, both FDM group and LIM group showed thinned sclera, disarrangement of fibrosis and enlarged disassociation between fibers. Consistently, ultrastructural examination showed degenerated fibroblasts and thinned fibers in posterior sclera.CONCLUSION:Following two weeks of myopia induction in guinea pigs, with regard to the degree of myopia, axial length and pathological alterations, there was no significant difference between FDM and LIM models. Therefore, FDM and LIM are equally effective and useful as a model of experimental myopia and guinea pigs are ideal animals for induction of experimental myopia because their high sensitivity to both form-deprivation and lens-induction.

  12. Effects of pirenzepine ophthalmic solution on form-deprivation myopia in the guinea pigs

    Institute of Scientific and Technical Information of China (English)

    LE Qi-hua; CHENG Neng-neng; WU Wei; CHU Ren-yuan

    2005-01-01

    Background Nonselective muscarinic receptor antagonist, atropine, was believed to inhibit myopic progression. The purpose of this study was to determine the efficacy, through topical administration, of the M1-selective muscarinic antagonist pirenzepine in preventing experimentally induced form-deprivation myopia in guinea pigs.Methods Fifty-three guinea pigs, which underwent monocular deprivation with their eyelids sutured, were divided into 6 groups. Three groups were treated with 1%, 2% or 4% pirenzepine ophthalmic solutions; the fourth group with atropine; the fifth with saline and the last group left untreated. Ocular refraction, in vivo biometric measurements and wet eye weight were collected before and after the experiment. All the eyes were finally enucleated for histopathological examination to evaluate the possible toxic effects on ocular structures.Results Animals untreated or treated with saline produced (-2.31±1.47) D and (-2.25±0.88) D of axial myopia respectively. Those treated with 1% pirenzepine ophthalmic solution produced relative myopia of (-1.63±0.48) D, and those under the treatment of 2% and 4% pirenzepine ophthalmic solution only developed a relative myopia of (-0.89±0.42) D and (-0.70±0.41) D (F=9.56, P<0.05). The significant reduction in myopia in 2% and 4% pirenzepine treated animals was caused by significantly less vitreous chamber elongation and axial elongation of the deprived eyes [2% group: (0.009±0.052) mm, 4% group: (0.006±0.078) mm] when compared with untreated, saline treated or 1% pirenzepine treated guinea pigs [(0.057±0.056) mm, (0.064±0.053) mm and (0.033±0.035) mm, respectively]. Histological examinations revealed no obviously toxic effects on the eyes treated with pirenzepine.Conclusion Topical administration of the M1-selective muscarinic antagonist, pirenzepine, can prevent induced form-deprivation myopia in guinea pigs by inhibiting axial elongation without obvious damage to ocular tissues.

  13. Effects of Glucose on Transmembrane Ionic Current of Ventricular Myocytes in Guinea Pig

    Institute of Scientific and Technical Information of China (English)

    AIJing; JIAOJun-dong; WANGHe; DUZhi-min; YANGBao-feng

    2004-01-01

    Aim To determine the effects of glucose oi1APD, IK1, IK, ICa-L of ventricular myocytes in guinea pigs. Methods Whole-cell patch-clamp technique was used to record the changed action potential ionic current induced by glucose of single cell in guinea pig ventricular myocytes, to compare the action of 0, 10 and 20 mmol·L-1 glucoses on transmembrane ionic current. Results (1) Compared with 10 mmol·L-1 glucose concentrations, 0 and 20 mmol·L-1 glucose both shortened APD of ventricular myocytes (P<0.05). (2) The inward components of IK1 density were maximal when the glucose concentration was at 10 mmol·L-1. Normalized 1-V relationships showed that both 0 and 20 mmol·L-1 glucose produced a left-shift of I-V curve. The reverse potential changed from-72.4 mV to-64.6 mV. (3) Compared with 10 mmol·L-1, both 0 and 20 mmol·L-1 glucose markedly increased the ICa-L amplitude and density. The ICa-L current density was (-8.0350.82) pA/pF (n=8) at a test potential of 10 mV when the glucose concentration was 10 mmol·L-1. But its current density decreased to (-5.45±0.67) pA/pF and (-6.50±0.56) pA/pF when glucose concentrations were 0 and 20 mmol·L-1, respectively. (4) The current densities of IK were (18.96±2.86) pA/pF, (8.66±1.87) pA/pF, and(15.32:1:3.12) pA/pF, at ±70mV for 0, 10 and 20 mmol·L-1 glucoses, respectively. Conclusion Glucose in different concentrations has different effects on APD, IK1, IK, and ICa-L of single ventricular myocyte in guinea pigs. There are similar actions of 0 and 20 mmol·L-1 glucoses on the transmembrane ionic current of ventricular myocytes in guinea pigs.

  14. Effect of rhubarb on contractile response of gallbladder smooth muscle strips isolated from guinea pigs

    Institute of Scientific and Technical Information of China (English)

    Ya-Li Luo; Jun-Wei Zeng; Mei Yu; Yu-Ling Wei; Song-Yi Qu; Wei Li; Tian Zhen Zheng

    2005-01-01

    AIM: To investigate the effect of rhubarb on contractile response of isolated gallbladder muscle strips from guinea pigs and its mechanism.METHODS: Guinea pigs were killed to remove the whole gallbladder. Two or three smooth muscle strips (8 mm×3mm) were cut along the longitudinal direction. The mucosa on each strip was carefully removed. Each longitudinal muscle strip was suspended in a tissue chamber containing 5 mL Krebs solution (37 ℃), bubbled continuously with 950 mL/L O2 and 50 mL/L CO2. The resting tension (g), mean contractile amplitude (mm),and contractile frequency (waves/min) were simultaneously recorded on recorders. After 2-h equilibration, rhubarb (10, 20, 70, 200, 700, 1 000 g/L) was added cumulatively to the tissue chamber in turns every 2 min to observe their effects on gallbladder.Antagonists were given 3 min before administration of rhubarb to investigate the possible mechanism.RESULTS: Rhubarb increased the resting tension (from 0 to 0.40±0.02, P<0.001), and decreased the mean contractile amplitude (from 5.22±0.71 to 2.73±0.41,P<0.001). It also increased the contractile frequency of the gallbladder muscle strips in guinea pigs (from 4.09±0.46to 6.08±0.35, P<0.001). The stimulation of rhubarb on the resting tension decreased from 3.98±0.22 to 1.58±0.12by atropine (P<0.001), from3.98±0.22 to 2.09±0.19 by verapamil (P<0.001) and from 3.98±0.22 to 2.67±0.43by phentolamine (P<0.005). But the effect was not inhibited by hexamethonium (P>0.05). In addition, the action of mean amplitude and frequency was not inhibited by the above antagonists.CONCLUSION: Rhubarb can stimulate the motility of isolated gallbladder muscle strips from guinea pigs. The stimulation of rhubarb might be relevant with M receptor,Ca2+ channel and α receptor partly.

  15. Guinea pig-adapted foot-and-mouth disease virus with altered receptor recognition can productively infect a natural host.

    Science.gov (United States)

    Núñez, José I; Molina, Nicolas; Baranowski, Eric; Domingo, Esteban; Clark, Stuart; Burman, Alison; Berryman, Stephen; Jackson, Terry; Sobrino, Francisco

    2007-08-01

    We report that adaptation to infect the guinea pig did not modify the capacity of foot-and-mouth disease virus (FMDV) to kill suckling mice and to cause an acute and transmissible disease in the pig, an important natural host for this pathogen. Adaptive amino acid replacements (I(248)-->T in 2C, Q(44)-->R in 3A, and L(147)-->P in VP1), selected upon serial passages of a type C FMDV isolated from swine (biological clone C-S8c1) in the guinea pig, were maintained after virus multiplication in swine and suckling mice. However, the adaptive replacement L(147)-->P, next to the integrin-binding RGD motif at the GH loop in VP1, abolished growth of the virus in different established cell lines and modified its antigenicity. In contrast, primary bovine thyroid cell cultures could be productively infected by viruses with replacement L(147)-->P, and this infection was inhibited by antibodies to alphavbeta6 and by an FMDV-derived RGD-containing peptide, suggesting that integrin alphavbeta6 may be used as a receptor for these mutants in the animal (porcine, guinea pig, and suckling mice) host. Substitution T(248)-->N in 2C was not detectable in C-S8c1 but was present in a low proportion of the guinea pig-adapted virus. This substitution became rapidly dominant in the viral population after the reintroduction of the guinea pig-adapted virus into pigs. These observations illustrate how the appearance of minority variant viruses in an unnatural host can result in the dominance of these viruses on reinfection of the original host species.

  16. Evaluating the clinical and physiological effects of long term ultraviolet B radiation on guinea pigs (Cavia porcellus).

    Science.gov (United States)

    Watson, Megan K; Stern, Adam W; Labelle, Amber L; Joslyn, Stephen; Fan, Timothy M; Leister, Katie; Kohles, Micah; Marshall, Kemba; Mitchell, Mark A

    2014-01-01

    Vitamin D is an important hormone in vertebrates. Most animals acquire this hormone through their diet, secondary to exposure to ultraviolet B (UVB) radiation, or a combination thereof. The objectives for this research were to evaluate the clinical and physiologic effects of artificial UVB light supplementation on guinea pigs (Cavia porcellus) and to evaluate the long-term safety of artificial UVB light supplementation over the course of six months. Twelve juvenile acromelanic Hartley guinea pigs were randomly assigned to one of two treatment groups: Group A was exposed to 12 hours of artificial UVB radiation daily and Group B received only ambient fluorescent light for 12 hours daily. Animals in both groups were offered the same diet and housed under the same conditions. Blood samples were collected every three weeks to measure blood chemistry values, parathyroid hormone, ionized calcium, and serum 25-hydroxyvitamin D3 (25-OHD3) levels. Serial ophthalmologic examinations, computed tomography scans, and dual energy x-ray absorptiometry scans were performed during the course of the study. At the end of the study the animals were euthanized and necropsied. Mean ± SD serum 25-OHD3 concentrations differed significantly in the guinea pigs (pguinea pigs to UVB radiation long term significantly increased their circulating serum 25-OHD3 levels, and that this increase was sustainable over time. Providing guinea pigs exposure to UVB may be an important husbandry consideration that is not currently recommended.

  17. l-dehydroascorbic acid can substitute l-ascorbic acid as dietary vitamin C source in guinea pigs

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    Henriette Frikke-Schmidt

    2016-04-01

    Full Text Available Vitamin C deficiency globally affects several hundred million people and has been associated with increased morbidity and mortality in numerous studies. In this study, bioavailability of the oxidized form of vitamin C (l-dehydroascorbic acid or DHA—commonly found in vitamin C containing food products prone to oxidation—was studied. Our aim was to compare tissue accumulation of vitamin C in guinea pigs receiving different oral doses of either ascorbate or DHA. In all tissues tested (plasma, liver, spleen, lung, adrenal glands, kidney, muscle, heart, and brain, only sporadic differences in vitamin C accumulation from ascorbate or DHA were observed except for the lowest dose of DHA (0.25 mg/ml in the drinking water, where approximately half of the tissues had slightly yet significantly less vitamin C accumulation than from the ascorbate source. As these results contradicted data from rats, we continued to explore the ability to recycle DHA in blood, liver and intestine in guinea pigs, rats and mice. These investigations revealed that guinea pigs have similar recycling capacity in red blood cells as observed in humans, while rats and mice do not have near the same ability to reduce DHA in erythrocytes. In liver and intestinal homogenates, guinea pigs also showed a significantly higher ability to recycle DHA compared to rats and mice. These data demonstrate that DHA in guinea pigs—as in humans—is almost as effective as ascorbate as vitamin C source when it comes to taking up and storing vitamin C and further suggest that the guinea pig is superior to other rodents in modeling human vitamin C homeostasis.

  18. Development of the central nervous system in guinea pig (Cavia porcellus, Rodentia, Caviidae

    Directory of Open Access Journals (Sweden)

    Fernanda Menezes de Oliveira e Silva

    Full Text Available Abstract: This study describes the development of the central nervous system in guinea pigs from 12th day post conception (dpc until birth. Totally, 41 embryos and fetuses were analyzed macroscopically and by means of light and electron microscopy. The neural tube closure was observed at day 14 and the development of the spinal cord and differentiation of the primitive central nervous system vesicles was on 20th dpc. Histologically, undifferentiated brain tissue was observed as a mass of mesenchymal tissue between 18th and 20th dpc, and at 25th dpc the tissue within the medullary canal had higher density. On day 30 the brain tissue was differentiated on day 30 and the spinal cord filling throughout the spinal canal, period from which it was possible to observe cerebral and cerebellar stratums. At day 45 intumescences were visualized and cerebral hemispheres were divided, with a clear division between white and gray matter in brain and cerebellum. Median sulcus of the dorsal spinal cord and the cauda equina were only evident on day 50. There were no significant structural differences in fetuses of 50 and 60 dpc, and animals at term were all lissencephalic. In conclusion, morphological studies of the nervous system in guinea pig can provide important information for clinical studies in humans, due to its high degree of neurological maturity in relation to its short gestation period, what can provide a good tool for neurological studies.

  19. The Effect of Paroxetine on Ouabain-Induced Toxicity in Isolated Guinea Pig Atria

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    Farzaneh Najar

    2011-04-01

    Full Text Available It has been reported that selective serotonin reuptake inhibitors (SSRIs possess some cardiac effects. In the present study we have investigated the effect of paroxetine (PX, a potent SSRI agent, on spontaneously as well as ouabain-induced arrhythmia beating isolated guinea-pig atria. The Guinea-pig heart was rapidly removed; the auricles were dissected out in oxygenated modified Krebs solution. The rate and force of spontaneous contractions were recorded isometrically with a photosensitive transducer. PX (1-16 µg/ml caused a dose-dependent decrease in the rate of contractions (14-70% and contractile force (8-16%. Ouabain alone (1.2 µg/ml produced arrhythmia at 7.2 ± 1.5 min and asystole at 20.1 ± 3.1 min. Pretreatment with PX (4 µg/ml significantly increased the time of arrhythmia onset to 19.8 min. In addition, PX prolonged the duration of action beating from 20.1 ± 3.1 min to 43.1± 2.6 and delayed the occurrence of asystole. The pattern of contractile force by PX + ouabain treatment was more regular than that observed after administration of ouabain alone. The above findings may the probably be due to the inhibition of cardiac Na+ and Ca2+ channels or autonomic nervous system. Results also suggest that PX may reduce the membrane conductance through inhibition of ionic channels to prevent ouabain-induced arrhythmia.

  20. Inhibitory Effect of Sihuangxiechai Decoction on Ovalbumin-Induced Airway Inflammation in Guinea Pigs

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    Xue Ping Huang

    2014-01-01

    Full Text Available The aim of this study was to investigate the effect of sihuangxiechai decoction on asthmatic Guinea pig model which was sensitized by intraperitoneal (i.p. injection of ovalbumin (OVA and challenged by OVA inhalation to induce chronic airway inflammation. Differential cell counts of cytospins were performed after staining with Giemsa solution. The quantity of leukocytes and its classification in bronchoalveolar lavage fluid (BALF and blood were evaluated by blood cell analyzer and microscope. Histological analysis of the lung was performed by hematoxylin and eosin (H&E staining. The levels of interleukin-4 (IL-4 and tumor necrosis factor-alpha (TNF-α in BALF and serum were detected by radioimmunoassay (RIA. The total number of leukocytes in BALF and blood has no significant difference between Sihuangxiechaitang decoction treated group and dexamethasone (DXM treated group but was significantly lower than those of asthma group. The percentage of eosinophils in lung tissues of sihuangxiechai decoction treated group was significantly lower than that of asthma group. The results demonstrated that the levels of IL-4 and TNF-α in the sihuangxiechai decoction treated group were significantly reduced compared with the asthma group. In conclusion, these findings demonstrate that sihuangxiechai decoction has a protective effect on OVA-induced asthma in reducing airway inflammation and airway hyperresponsiveness (AHR in a Guinea pig model and may be useful as an adjuvant therapy for the treatment of bronchial asthma.

  1. Effects of Animal-Assisted Activities with Guinea Pigs in the Primary School Classroom.

    Science.gov (United States)

    O'Haire, Marguerite E; McKenzie, Samantha J; McCune, Sandra; Slaughter, Virginia

    2013-01-01

    This study investigated the effects of a classroom-based animal-assisted activities (AAA) program with guinea pigs on the social functioning of primary school children. We hypothesized that participants in the experimental condition (n = 64), compared with a waitlist control group (n = 64), would demonstrate improvements in social functioning following the program. Parents and teachers used the Social Skills Rating System (SSRS) to evaluate the social skills and problem behaviors of 128 participating children (age range = 4.8 to 12.7 years) before and after an 8-week period. Teachers also rated academic competence at both time points. Children who participated in the AAA program demonstrated significantly greater improvements in social functioning than their control group peers, as defined by greater increases in social skills (teacher SSRS) and decreases in problem behaviors (parent and teacher SSRS). There were no significant differences between the groups in academic competence. AAA participants demonstrated significant increases in social skills and decreases in problem behaviors from pre- to post-program on the teacher version of the SSRS. Control group participants did not show significant changes on these measures. These findings suggest that an AAA program with guinea pigs may be a feasible addition to the primary school classroom in order to improve social functioning. Further component analysis will be necessary to determine whether the animal is the active ingredient in AAA programs of this nature.

  2. Genetic diversity and population structure of the Guinea pig (Cavia porcellus, Rodentia, caviidae in Colombia

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    William Burgos-Paz

    2011-01-01

    Full Text Available The aim was to establish the genetic diversity and population structure of three guinea pig lines, from seven production zones located in Nariño, southwest Colombia. A total of 384 individuals were genotyped with six microsatellite markers. The measurement of intrapopulation diversity revealed allelic richness ranging from 3.0 to 6.56, and observed heterozygosity (Ho from 0.33 to 0.60, with a deficit in heterozygous individuals. Although statistically significant (p < 0.05, genetic differentiation between population pairs was found to be low. Genetic distance, as well as clustering of guinea-pig lines and populations, coincided with the historical and geographical distribution of the populations. Likewise, high genetic identity between improved and native lines was established. An analysis of group probabilistic assignment revealed that each line should not be considered as a genetically homogeneous group. The findings corroborate the absorption of native genetic material into the improved line introduced into Colombia from Peru. It is necessary to establish conservation programs for native-line individuals in Nariño, and control genealogical and production records in order to reduce the inbreeding values in the populations.

  3. The effect of vitamin E on lung pathology in sulfur mustard-exposed guinea pigs.

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    Gholamnezhad, Zahra; Boskabady, Mohammad Hossein; Amery, Sediqa; Vahedi, Nassim; Tabatabaei, Abass; Boskabady, Morteza; Shahriary, Alireza

    2016-12-01

    Pulmonary complications of exposure to sulfur mustard (SM) gas range from no effect or mild symptoms to severe bronchial stenosis. In the present study, the protective effect of vitamin E on the lung inflammation of SM-exposed guinea pigs was examined. Guinea pigs (n = 5 for each group) were exposed to ethanol (control group), 40 mg/m(3) inhaled SM (SME group), SME treated with vitamin E (SME + E), SME treated with dexamethasone (SME + D), and SME treated with both treatments (SME + E + D). Pathological evaluation of the lung was done 14 days postexposure. The epithelial desquamation of trachea and other pathologic changes in the lung of the SME group were significantly higher than those in the control group. Furthermore, the pathological changes of trachea and lung in the SME + E and SME + E + D groups were significantly improved compared with those of SME group. In addition, the pathological changes of trachea and lung of SME + E and SME + E + D animals were significantly less than those of SME + D group.

  4. Immunoreactivity of neurogenic factor in the guinea pig brain after prenatal hypoxia.

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    Chung, Yoonyoung; So, Keumyoung; Kim, Eunyoung; Kim, Seokwon; Jeon, Yonghyun

    2015-07-01

    Chronic prenatal hypoxia is considered to cause perinatal brain injury. It can result in neurological disorders such as cerebral palsy or learning disabilities. These neurological problems are related to chronic placental insufficiency (CPI), which leads to chronic hypoxemia and hypoglycemia. The effects of hypoxia on neurogenesis during development have been a matter of controversy. We therefore investigated the effect of chronic prenatal hypoxia in the brain of the fetal guinea pig using the guinea pig CPI model. Chronic placental insufficiency was induced by unilateral uterine artery ligation at 30-32 days of gestation (dg: with term defined as ∼67dg). At 50 and 60dg, fetuses were sacrificed and assigned to either the growth-restricted (GR) or control (no ligation) group. Immunohistochemistry was performed with HIF-1α, PCNA, NeuN and BDNF antibodies in the cerebral cortex and dentate gyrus. The number of NeuN-IR and BDNF-IR cells was lesser in GR fetuses than in controls in the cerebral cortex and dentate gyrus at 60dg (pcerebral cortex is decreased by chronic prenatal hypoxia at 60dg.

  5. Antitussive effect of naringin on experimentally induced cough in Guinea pigs.

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    Gao, Sen; Li, Peibo; Yang, Hongliang; Fang, Siqi; Su, Weiwei

    2011-01-01

    The mechanism of action of naringin has been investigated in different models of experimentally induced cough in guinea pigs. In contrast to codeine phosphate (6 mg/kg, intravenous administration [i. v.]), naringin (15, 30, and 60 mg/kg, i. v.) had no central antitussive effect on cough elicited by electrical stimulation of the superior laryngeal nerve. Naringin (0.5, 1.0, and 2.0 µmol) could not prevent the cough reflex induced by stimulation of the trachea after intracerebroventricular injection (i. c. v.), while codeine phosphate (0.5 µmol) was highly effective. Further characterizing the peripheral mechanism of naringin, we found that its effect (50 mg/kg, i. v.) was not affected by the depletion of sensory neuropeptides, whereas levodropropizine (10 mg/kg, i. v.) lost its capacity to prevent cough in the capsaicin-desensitized guinea pig. Furthermore, pretreatment with glibenclamide (10 mg/kg, intraperitoneal [i. p.]) significantly reduced the antitussive effect of pinacidil (5 mg/kg, subcutaneous [s. c.]), but could not antagonize the antitussive effect of naringin (30 mg/kg, s. c.). Our present results suggest that naringin is not a central antitussive drug. And naringin does not exert its peripheral antitussive effect through either the sensory neuropeptides system or the modulation of ATP-sensitive K (+) channels.

  6. In vivo MRI evaluation of anabolic steroid precursor growth effects in a guinea pig model.

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    Tang, Haiying; Vasselli, Joseph R; Tong, Christopher; Heymsfield, Steven B; Wu, Ed X

    2009-08-01

    Anabolic steroids are widely used to increase skeletal muscle (SM) mass and improve physical performance. Some dietary supplements also include potent steroid precursors or active steroid analogs such as nandrolone. Our previous study reported the anabolic steroid effects on SM in a castrated guinea pig model with SM measured using a highly quantitative magnetic resonance imaging (MRI) protocol. The aim of the current study was to apply this animal model and in vivo MRI protocol to evaluate the growth effects of four widely used over-the-counter testosterone and nandrolone precursors: 4-androstene-3 17-dione (androstenedione), 4-androstene-3beta 17beta-diol (4-androsdiol), 19-nor-4-androstene-3beta-17beta-diol (bolandiol) and 19-nor-4-androstene-3 17-dione (19-norandrostenedione). The results showed that providing precursor to castrated male guinea pigs led to plasma steroid levels sufficient to maintain normal SM growth. The anabolic growth effects of these specific precursors on individual and total muscle volumes, sexual organs, and total adipose tissue over a 10-week treatment period, in comparison with those in the respective positive control testosterone and nandrolone groups, were documented quantitatively by MRI.

  7. Regulation of (/sup 3/H)GABA release from strips of guinea pig urinary bladder

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    Shirakawa, J.; Taniyama, K.; Iwai, S.; Tanaka, C.

    1988-12-01

    The presence of receptors that regulate the release of gamma-aminobutyric acid (GABA) was studied in strips of the guinea pig urinary bladder. GABA (10(-8)-10(-5) M) and muscimol (10(-8)-10(-5) M), but not baclofen (10(-5) M), reduced the Ca2+-dependent, tetrodotoxin-resistant release of (/sup 3/H)GABA evoked by high K+ from the urinary bladder strips preloaded with (/sup 3/H)GABA. The inhibitory effect of muscimol was antagonized by bicuculline and potentiated by diazepam, clonazepam, and pentobarbital sodium. The potentiating effect of clonazepam was antagonized by Ro 15-1788. Acetylcholine (ACh) inhibited the high K+-evoked release of (/sup 3/H)GABA. The inhibitory effect of ACh was antagonized by atropine sulfate and pirenzepine but not by hexamethonium. Norepinephrine (NE) inhibited the evoked release of (/sup 3/H)GABA. The inhibitory effect of NE was mimicked by clonidine, but not by phenylephrine, and was antagonized by yohimbine but not by prazosin. These results provide evidence that the release of GABA from strips of guinea pig urinary bladder is regulated via the bicuculline-sensitive GABAA receptor, M1-muscarinic, and alpha 2-adrenergic receptors.

  8. Stress and strain analysis of contractions during ramp distension in partially obstructed guinea pig jejunal segments.

    Science.gov (United States)

    Zhao, Jingbo; Liao, Donghua; Yang, Jian; Gregersen, Hans

    2011-07-28

    Previous studies have demonstrated morphological and biomechanical remodeling in the intestine proximal to an obstruction. The present study aimed to obtain stress and strain thresholds to initiate contraction and the maximal contraction stress and strain in partially obstructed guinea pig jejunal segments. Partial obstruction and sham operations were surgically created in mid-jejunum of male guinea pigs. The animals survived 2, 4, 7 and 14 days. Animals not being operated on served as normal controls. The segments were used for no-load state, zero-stress state and distension analyses. The segment was inflated to 10 cmH(2)O pressure in an organ bath containing 37°C Krebs solution and the outer diameter change was monitored. The stress and strain at the contraction threshold and at maximum contraction were computed from the diameter, pressure and the zero-stress state data. Young's modulus was determined at the contraction threshold. The muscle layer thickness in obstructed intestinal segments increased up to 300%. Compared with sham-obstructed and normal groups, the contraction stress threshold, the maximum contraction stress and the Young's modulus at the contraction threshold increased whereas the strain threshold and maximum contraction strain decreased after 7 days obstruction (P<0.05 and 0.01). In conclusion, in the partially obstructed intestinal segments, a larger distension force was needed to evoke contraction likely due to tissue remodeling. Higher contraction stresses were produced and the contraction deformation (strain) became smaller. Copyright © 2011 Elsevier Ltd. All rights reserved.

  9. Post-natal development of the median eminence of the guinea pig.

    Science.gov (United States)

    Silverman, A J; Desnoyers, P

    1975-11-01

    The ultrastructure of the median eminence of neonatal (newborn) 1-, 3-, 5-, and 10-day old) and adult guinea pigs was studied to determine the dynamic changes occurring in this structure during early life. At birth the portal vasculature consists of the Mantelplexus and a few, non-fenestrated capillary loops. The number of ansae and the degree of fenestration increase rapidly after birth. The abundance of cytoplasmic and ciliary projections into the ventricular recess and the large numbers of organelles indicate that the ependymal cells are more active in the neonatal period than in the adult male. Moreover, the ependymal endfeet cover most of the surface area of the primary portal plexus during this time. The neuronal layers of the median eminence are difficult to distinguish at birth due to the lack of myelinated fibers in the zona interna. Significant myelination appears on day 3 but is not complete until day 10. There is a progressive increase in the numbers of Herring bodies and large neuro-secretory granules (1,500-1,700 A) during this same time period. In the zona externa, few nerve terminals abut on the perivascular space until day 3. Increases in numbers of granules per axon profile were noted for each day after birth. Despite the relatively long gestation period of the guinea pig (68-72 days), the morphologic appearance of the median eminence at birth suggests that the neurovascular link controlling anterior pituitary function is not yet complete.

  10. Intraperitoneal insemination of the guinea pig with synchronized estrus induced by progesterone implant.

    Science.gov (United States)

    Ueda, H; Kosaka, T; Takahashi, K W

    1998-10-01

    Female guinea pigs with synchronized ovulation by means of implantation of progesterone-filled tubing (P-tube) followed by a progesterone injection, were inseminated by intraperitoneal injection with sperm suspension. First, to obtain the optimum conditions for insemination, the females were inseminated singly over the range of 1-10 x 10(7) spermatozoa before and after the synchronized ovulation. The incidence of conception and implantation was 100% in the females given more than 5 x 10(7)/animal at 9:00 h on the 5th day after removal of the P-tube. Second, the reproductive ability of the inseminated females under this optimal condition was observed throughout the pregnancy to delivery. Inseminated females had a mean +/- S.D. gestation period of 68.7 +/- 0.5 days, a litter size of 2.8 +/- 0.6 pups and body weight of 110 +/- 14 g. These data were comparable to those of naturally-mated females. Our findings suggest that the artificial insemination by intraperitoneal injection in combination with the synchronized estrus technique is very useful for production control in a small colony of guinea pigs.

  11. [Conception rate and embryo development in guinea pigs with synchronized estrus induced by progesterone implant].

    Science.gov (United States)

    Ueda, H; Kosaka, T; Takahashi, K W

    1994-01-01

    Observations were made on the timing of mating and the pre-implantation development of fertilized eggs in guinea pigs synchronized by long-term progesterone treatment. Females received a subcutaneous implant of progesterone-filled silastic tubing for 14 days. Copulation was observed from the evening of day 4 to the morning of day 6 in 53 of 54 females (98%). Most of them (47/53, 89%) copulated on day 5 after removal of the tubing. Designating the day of copulation (day 5 after removal of the tubing) as day 0 of gestation, embryos collected from the genital tract were at the 4-cell, 8-cell, morula, and blastocyst stages on days 1, 3, 4 and 5 of gestation, respectively. Eggs were recovered at high incidence (85-100%) from days 1 to 5 of gestation. On day 6 gestation, no eggs were recovered from the genital tract, suggesting that implantation had occurred. The mean litter size (+/- S. D.) was 4.0 +/- 0.8 pups, which were born normally after a mean gestation period of 67 +/- 1 days in 7 synchronized females. Since the female guinea pigs synchronized by the long-term progesterone treatment had normal reproductive ability similar to that of cyclic females, this technique would make it possible to obtain animals at a scheduled time even in smaller-sized colonies. In addition, observations on the pre-implantation development of embryos in females with synchronized estrus might be a useful aid in the field of reproductive research.

  12. Beijing sublineages of Mycobacterium tuberculosis differ in pathogenicity in the guinea pig.

    Science.gov (United States)

    Kato-Maeda, Midori; Shanley, Crystal A; Ackart, David; Jarlsberg, Leah G; Shang, Shaobin; Obregon-Henao, Andres; Harton, Marisabel; Basaraba, Randall J; Henao-Tamayo, Marcela; Barrozo, Joyce C; Rose, Jordan; Kawamura, L Masae; Coscolla, Mireia; Fofanov, Viacheslav Y; Koshinsky, Heather; Gagneux, Sebastien; Hopewell, Philip C; Ordway, Diane J; Orme, Ian M

    2012-08-01

    The Beijing family of Mycobacterium tuberculosis strains is part of lineage 2 (also known as the East Asian lineage). In clinical studies, we have observed that isolates from the sublineage RD207 of lineage 2 were more readily transmitted among humans. To investigate the basis for this difference, we tested representative strains with the characteristic Beijing spoligotype from four of the five sublineages of lineage 2 in the guinea pig model and subjected these strains to comparative whole-genome sequencing. The results of these studies showed that all of the clinical strains were capable of growing and causing lung pathology in guinea pigs after low-dose aerosol exposure. Differences between the abilities of the four sublineages to grow in the lungs of these animals were not overt, but members of RD207 were significantly more pathogenic, resulting in severe lung damage. The RD207 strains also induced much higher levels of markers associated with regulatory T cells and showed a significant loss of activated T cells in the lungs over the course of the infections. Whole-genome sequencing of the strains revealed mutations specific for RD207 which may explain this difference. Based on these data, we hypothesize that the sublineages of M. tuberculosis are associated with distinct pathological and clinical phenotypes and that these differences influence the transmissibility of particular M. tuberculosis strains in human populations.

  13. Comparative analysis of the nuclear basic proteins in rat, human, guinea pig, mouse and rabbit spermatozoa.

    Science.gov (United States)

    Calvin, H I

    1976-06-15

    Cysteine-rich protamines (Arg = 47-61%, Cys = 8-16%) were isolated from the sperm of an individual guinea pig, human and rabbit and from pooled samples of mouse and rat sperm. Appreciable concentrations of histones were not found in the sperm nuclei of these species. In addition to the protamines, a substance of relatively low molecular weight, which reacted with the Lowry reagent, appeared in crude acid-soluble extracts of sperm nucleoprotein. This unidentified contaminent was resolved from the protamines by chromatography on Bio-Rex 70. Heterogeneity of human and mouse protamines was revealed by electrophoresis at pH 2.7, in the presence of 2.5 M urea, and confirmed by amino acid analysis, which also suggested the presence of 2 or more species of protamine in the rabbit. By contrast, the guinea pig and rat preparations displayed nearly stoichiometric ratios of amino acid residues, approaching homogeneity by this criterion. The functional consequences of crosslinks between cysteine residues of these proteins and the possible species-specific significance of their differing percentages of histidine are discussed. Potentially analogous functions are suggested for phosphorylated serine and threonine, and for ionized cysteine and tyrosine, within the protamines of developing spermatids. Their amino acid compositions indicate that the protamines of eutherian mammals are coded by a C.G-rich genome which has been unusually susceptible to genetic drift. An especially high rate of G leads to A transitions seems to have occurred in the human protamine genes.

  14. Efficacy comparison of scopolamine and diazepam against soman-induced debilitation in guinea pigs

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    Anderson, D.R.; Gennings, C.; Carter, W.H.; Harris, L.W.; Lennox, W.J.

    1994-12-31

    The efficacy of diazepam (DZ) and scopolamine (SCP), in combination with atropine (ATR) + oxime therapy, against soman-induced seizure/convulsive activity and associated brain damage has been demonstrated, but the efficacy of each against the incapacitating effects of soman has not been addressed. Thus, the therapeutic efficacies of SCP (5 doses; 0-0.86 mg/kg) and DZ (5 doses; 0-5 mg/kg), when each was used in conjunction with ATR (3 doses; 0.5-8 mg/kg) + 2-PAM (25 mg/kg) therapy, were compared in groups of pyridostigmine pretreated guinea pigs exposed to 1.6, 2.0, 2.5, or 3.2 LD5Os of soman. Response surface methodology was employed to describe the relationship between soman-induced incapacitation and the ATR/DZ or ATRISCP dosages. Incapacitation was measured by toxicity scores assigned by three graders to test animals at 60 min postsoman. Results show that as the dosage of SCP increased, the mean toxicity scores decreased. Also, within the indicated dose ranges used, the efficacy of SCP was not dependent on the presence of ATR. In contrast, ATR alone was found to be more effective than when combined with DZ at any dose, and indicates that DZ might be temporarily contributing to soman-induced incapacitation. These findings suggest that in guinea pigs, SCP could replace ATR or DZ, or both, as therapy against soman-induced incapacitation.

  15. Lysine adducts between methyltetrahydrophthalic anhydride and collagen in guinea pig lung.

    Science.gov (United States)

    Jönsson, B A; Wishnok, J S; Skipper, P L; Stillwell, W G; Tannenbaum, S R

    1995-11-01

    The formation of adducts between methyltetrahydrophthalic anhydride (MTHPA), an important industrial chemical and potent allergen, and collagen from guinea pig lung tissue was investigated. Collagen peptides were obtained from the lung tissue by homogenization, defatting, washing, and digestion with collagenase. In experiments in vitro, lung tissue was exposed to 8.4 mumol (50 microCi) of 14C MTHPA. The amount of adducts was 97 nmol MTHPA/g of wet tissue as determined from the bound radioactivity. In a study in vivo, four guinea pigs were injected intratracheally with 8.4 mumol of 14C MTHPA each. The amount of adducts was 0-1.2 nmol MTHPA/g of wet tissue (determined by bound radioactivity). N epsilon-methyltetrahydrophthaloyl-L-lysine (MTHPL) was synthesized and characterized by NMR, UV, and mass spectrometry (MS). A method to analyze MTHPL, after derivatization with methanol and pentafluorobenzoyl chloride, using gas chromatography-MS was developed. Analysis of Pronase-digested MTHPA-exposed lung tissue showed a concentration of 19 nmol MTHPL/g wet lung in vitro and between 0 and 0.15 nmol MTHPL/g wet lung in vivo. Thus, 20% in vitro and 12-15% in vivo of the bound radioactivity was found as adducts with lysine. These results are a first step toward studies of allergenic epitopes in proteins and methods for biological monitoring of exposure to acid anhydrides.

  16. Gastrointestinal migrating motor complex during early stage of cholesterol gallstone formation in guinea pigs

    Institute of Scientific and Technical Information of China (English)

    Wang Ling; Bai Wenyuan; Ma Yongzhi; Gu Yong

    2008-01-01

    Objective: To determine the changes of gastrointestinal migrating motor complex (MMC) during the early stage of cholesterol gallstone formation. Methods: Totally 45 healthy adult guinea pigs were randomly and equally divided into 3 groups, that is, normal control, group B (1% cholesterol diet for 2 weeks) and group C (1% cholesterol diet for 4 weeks). Three pairs of silver electrodes were inserted into the gastric antrum, duodenum and jejunum of every animal respectively. Record of gastrointestinal MMC of these guinea pigs were recorded and analyzed.Gallbladder bile was taken to detect the formation of cholesterol gallstone. Results: There were only 29 guineapigs living. The MMC cycle time and the duration of phase Ⅱ were prolonged significantly and gradually compared with the control group (P<0.01), but the duration of phase Ⅲ became significantly and gradually shorter. Conclusion:During the early stage of cholesterol gallstone formation, the MMC cycle time and the duration of phase Ⅱ are prolonged and the duration of phase Ⅲ is shortened

  17. Radioprotective Effect of Aminothiol PrC-210 on Irradiated Inner Ear of Guinea Pig.

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    Arnaud P J Giese

    Full Text Available Radiotherapy of individuals suffering with head & neck or brain tumors subserve the risk of sensorineural hearing loss. Here, we evaluated the protective effect of Aminothiol PrC-210 (3-(methyl-amino-2-((methylaminomethylpropane-1-thiol on the irradiated inner ear of guinea pigs. An intra-peritoneal or intra-tympanic dose of PrC-210 was administered prior to receiving a dose of gamma radiation (3000 cGy to each ear. Auditory Brainstem Responses (ABRs were recorded one week and two weeks after the radiation and compared with the sham animal group. ABR thresholds of guinea pigs that received an intra-peritoneal dose of PrC-210 were significantly better compared to the non-treated, control animals at one week post-radiation. Morphologic analysis of the inner ear revealed significant inflammation and degeneration of the spiral ganglion in the irradiated animals not treated with PrC-210. In contrast, when treated with PrC-210 the radiation effect and injury to the spiral ganglion was significantly alleviated. PrC-210 had no apparent cytotoxic effect in vivo and did not affect the morphology or count of cochlear hair cells. These findings suggest that aminothiol PrC-210 attenuated radiation-induced cochlea damage for at least one week and protected hearing.

  18. Effects of various doses of estradiol on chlamydial genital infection in ovariectomized guinea pigs.

    Science.gov (United States)

    Pasley, J N; Rank, R G; Hough, A J; Cohen, C; Barron, A L

    1985-01-01

    The effect of various doses of estradiol on genital tract infection by the chlamydial agent of guinea pig inclusion conjunctivitis (GPIC) was investigated in ovariectomized guinea pigs. Prolongation of infection, as determined by chlamydial inclusion counts of cells in Giemsa-stained smears of vaginal scrapings, was observed in animals receiving daily doses of 1.0, 10.0, 100.0, or 1000 micrograms of estradiol. In contrast to controls, ascending infection resulting in endometritis was found in animals receiving doses of greater than or equal to 1.0 microgram of estradiol per day. Response to estradiol treatment was reflected in an increase in cervical-uterine wet weight and uterine wall thickness. No differences were observed in time of appearance of antibody titers to GPIC in serum, but a delay in appearance of IgA antibody to GPIC in genital secretions was found in estradiol-treated animals receiving doses of greater than or equal to 1.0 microgram per day.

  19. Anatomy of the heart of Guinea pig fetuses in late gestation (Cavia porcellus [Linnaeus, 1758

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    Mariangela de Toledo Barbino

    2011-09-01

    Full Text Available This study has been developed in order to describe the anatomy of the heart of Guinea pig (Cavia porcellus [Linnaeu,1758] fetuses in late gestation and to obtain anatomical characteristics that can support and help the understanding of the physiology of fetal circulation. Fetuses have been collected from three female in late gestation, which were described and photographed macroscopically, trhough light microscopy in HE and scanning electronic microscopy. The fetal heart is divided into four cavities, it is surrounded by the pericardium, and it has three layers: epicardium, myocardium, and endocardium. Foramen ovale has a great importance in the fetal circulation, but it could not be visualized in sections carried out in this study. Through these results we conclude that the hearts of Guinea pig fetuses differ from those of other species in structures such as the cranial vena cava, which is not divided into left and right, and that the walls thickness of left and right ventricles does not differ significantly.

  20. The effects of hyperbaric oxygen therapy upon ototoxic injuries produced by amikacin in guinea pigs.

    Science.gov (United States)

    Amora, Luciana de Albuquerque Salviano; Murashima, Adriana de Andrade Batista; Rossato, Maria; Moreira, Márcia Bento; Hyppolito, Miguel Ângelo; Fagundes, Djalma José

    2013-01-01

    Hyperbaric oxygen therapy (HBOT) has enhanced the prevention and treatment of auditory ailments such as ototoxicity. To study the effects of HBOT upon ototoxic injuries produced by amikacin. This experimental study included 12 albino guinea pigs, whose auditory function was assessed through distortion product otoacoustic emissions (DPOAEs) and brainstem auditory evoked potentials (BAEPs) before and after the administration of amikacin (600 mg/kg/day) and HBOT sessions (2 ATA, 60 minutes). Morphological features were analyzed through scanning electron microscopy. Subjects were divided into four groups, as follows: group 1 - saline solution + HBOT; group 2 - amikacin for 8 days; group 3 - amikacin + seven days of rest; and group 4 - amikacin + HBOT. Group 1 subjects had preserved function and morphology throughout the experiment; Group 2 subjects had statistically significant levels of hair cell injury and functional impairment; Subjects on groups 3 and 4 had statistically significant functional and morphological impairment after the administration of amikacin, which were still present after the proposed procedures had been carried out. Hyperbaric oxygen therapy did not change the cochlear hair cell morphology or the electro-physiological thresholds of the guinea pigs given amikacin.

  1. Effects of Diazoxide Treatments on Electrophysiologyic Properties in Guinea Pig Papillary Muscles Undergoing Ischemia/Reperfusion

    Institute of Scientific and Technical Information of China (English)

    YANG Yunhai; HAN Zhaomin; HU Zhiwei; ZHANG Kailun

    2005-01-01

    Summary: The effects of diazoxide treatments on electrophysiologyic properties in guinea pig papillary muscles undergoing ischemia/reperfusion was studied using intracellular microelectrode technique. Twenty-four guinea pigs were randomly divided into three groups (n=8 in each group). In control group, St.Thomas solution was given. In experimental group, St.Thomas solution with diazoxide (100 mol/L) was given. In pretreatment group, the muscle was treated with diazoxide 20 min before arrested with St.Thomas cardioplegia. The results showed that the APD50 and APD90 in experimental and pretreatment groups were significantly shorter after 5 and 10 min reperfusion (P<0.01, P<0.05), but longer after 30 min reperfusion (P<0.01, P<0.05) than in control group. In experimental and pretreatment groups, APA, OS, Vmax recovered more quickly than those in control group. The time to re-systole after reperfusion in control group was longer than that in experimental and pretreatment groups. There was no significant difference in RP among three groups. The time of arrest in pretreatment group was longer than that in experimental and pretreatment group (P<0.05). This study indicates that protective effects of St.Thomas solution with diazoxide is better than that of pretreatment with diazoxide or St.Thomas solution alone.

  2. ESAT-6/CFP10 skin test predicts disease in M. tuberculosis-infected guinea pigs.

    Science.gov (United States)

    Weldingh, Karin; Andersen, Peter

    2008-04-23

    Targeted preventive chemotherapy of individuals with progressive subclinical (incipient) disease before it becomes contagious would break the chain of tuberculosis transmission in high endemic regions. We have studied the ability of a skin test response to ESAT-6 and CFP10 (E6/C10) to predict later development of tuberculosis disease in the guinea pig model. Guinea pigs, either vaccinated with BCG or unvaccinated, were infected with a low dose of Mycobacterium tuberculosis by the aerosol route and the development of delayed type hypersensitivity responses to E6/C10 and to purified protein derivative (PPD) were followed until the onset of clinical disease. We demonstrated a negative correlation between the size of the skin test response and the time to the onset of clinical disease; a large E6/C10 skin test response correlated to a shorter survival time post skin testing, while a small E6/C10 skin test reaction correlated with a longer survival time (r = -0.6 and Pskin test based on E6/C10 that will allow the identification of individuals with incipient disease, who have the highest risk of developing active tuberculosis in the near future.

  3. Relaxant Effects of Matrine on Aortic Smooth Muscles of Guinea Pigs

    Institute of Scientific and Technical Information of China (English)

    JIE ZHENG; PING ZHENG; XU ZHOU; LIN YAN; RU ZHOU; XUE-YAN FU; GUI-DONG DAI

    2009-01-01

    Objectives To determine whether matrine, a kind of traditional Chinese medicinal alkaloid, can relax the aortic smooth muscles isolated from guinea pigs and to investigate the mechanism of its relaxant effects. Methods Phenylephrine or potassium chloride concentration-dependent relaxation response of aortic smooth muscles to matrine was studied in the precontracted guinea pigs. Results Matrine (lx104 mol/L-3.3x10-3mol/L) relaxed the endothelium-denuded aortic rings pre-contracted sub-maximally with phenylephrine, in a concentration-dependent manner, and its pre-incubation (3.3x10-3mol/L) produced a significant rightward shift in the phenylephrine dose-response curve, but had no effects on the potassium chloride-induced contraction. The anti-contractile effect of matrine was not reduced by the highly selective ATP-dependent K+ channel blocker glibenclamide (10-5mol/L), either by the non-selective K+channel blocker tetraethylammonium (103mol/L), or by theβ-antagonist propranolol (105 mol/L). In either "normal" or "Ca2+-free'' bathing medium, the phenylephrine-induced contraction was attenuated by matrine (3.3x103 mol/L), indicating that the vasorelaxation was due to inhibition of intracellular and extracellular Ca2+ mobilization. Conclusion Matrine inhibits phenylephrine-induced contractions by inhibiting activation of a-adrenoceptor and interfering with the release of intracellular Ca2+ and the influx of extracellular Ca2+.

  4. Relaxation effects of matrine on guinea-pig aortic smooth muscles

    Institute of Scientific and Technical Information of China (English)

    ZHENG Jie; ZHENG Ping; ZHOU Xu; YAN Lin; ZHOU Ru; FU Xue-yan; DAI Gui-dong

    2008-01-01

    Objective The present in vivo study was undertaken to determine whether matrine, a kind of traditional Chinese medicinal alkaloid, would relax the isolated guinea pig aortic smooth muscles, if so, to investigate the mechanism involved. Methods The concentration-dependent relaxation response to matrine was studied in phenylephrine or potassium chloride precontracted guinea pig aortic rings. Results Matrine (1× 10-4M- 3.3×10-3 M) relaxed the endothelium denuded aortic rings precontracted submaximally with phenylephrine, in a concentration-dependent manner, and it's preincubation (3.3×10-3 M) produced a significant rightward shift in the phenylephrine dose-response curve, but had no effects on the potassium chloride-induced contraction. The anticontractile effect of matrine was not reduced by the highly selective ATP-dependent K+ channel blocker glibenclamide (10-5 M), the non-selective K+ channel blocker tetraethylammonium (10-3 M), as well as the β-antagonist propranolol (10-5 M). In either "normal" or "Ca2+ -free" bathing medium, the phenylephrine-induced contraction was attenuated by matrine (3.3×10-3 M), indieating the vasorelaxation was due to inhibit of intracellular and extracellular Ca2+ mobilization. Conclusions The results obtained clearly demonstrated that matrine inhibits phenylephrine-induced contractions by inhibiting activation of α-adrenoceptor and interfering with both the release of intracellular Ca2+ and the influx of extracellular Ca2+.

  5. Intratracheal dosing with disodium cromoglycate inhibits late asthmatic response by attenuating eicosanoid production in guinea pigs.

    Science.gov (United States)

    Nabe, Takeshi; Yamamoto, Maki; Suga, Mikiko; Kohno, Shigekatsu

    2004-08-16

    Disodium cromoglycate is an anti-asthmatic drug that has mast cell-stabilizing effects and other anti-inflammatory effects. However, the mechanisms of its anti-inflammatory effects are unclear. In this study, we evaluated effects of disodium cromoglycate on eosinophilia, early and late asthmatic responses, and production of arachidonic acid metabolites in guinea pig lungs. Guinea pigs were alternately sensitized and challenged by exposure to mists of ovalbumin+Al(OH)(3) and ovalbumin, respectively. Disodium cromoglycate (0.5-2 mg/0.1 ml/animal) administered intratracheally before the fifth challenge dose-dependently inhibited asthmatic response, but early asthmatic response was not affected. Disodium cromoglycate at 2 mg/animal potently suppressed increases in cysteinyl leukotrienes (CysLTs) and thromboxane A(2) in the lung during late asthmatic response. Eosinophilia was slightly reduced by disodium cromoglycate. The inhibitory effect of disodium cromoglycate on late asthmatic response is apparently due to inhibition of the release of arachidonic acid metabolites, some of which may be derived from eosinophils that infiltrate the lung.

  6. Evidence for an A1-adenosine receptor in the guinea-pig atrium.

    Science.gov (United States)

    Collis, M. G.

    1983-01-01

    1 The purpose of this study was to determine whether the adenosine receptor that mediates a decrease in the force of contraction of the guinea-pig atrium is of the A1- or A2-sub-type. 2 Concentration-response curves to adenosine and a number of 5'- and N6-substituted analogues were constructed and the order of potency of the purines was: 5'-N-cyclopropylcarboxamide adenosine (NCPCA) = 5'-N-ethylcarboxamide adenosine (NECA) greater than N6cyclohexyladenosine (CHA) greater than L-N6-phenylisopropyl adenosine (L-PIA) = 2-chloroadenosine- greater than adenosine greater than D-N6-phenylisopropyl adenosine (D-PIA). 3 The difference in potency between the stereoisomers D- and L-PIA was over 100 fold. 4 The adenosine transport inhibitor, dipyridamole, potentiated submaximal responses to adenosine but had no significant effect on those evoked by the other purines. 5 Theophylline antagonized responses evoked by all purines, and with D-PIA revealed a positive inotropic effect that was abolished by atenolol. 6 The results indicate the existence of an adenosine A1-receptor in the guinea-pig atrium. PMID:6297647

  7. Acetylcholine-induced calcium oscillation in isolated outer hair cells in guinea pig

    Institute of Scientific and Technical Information of China (English)

    XIE Ding-hua; XIAO Zi-an; YANG Shu

    2006-01-01

    Abstract Objective This study is to explore the relationship between acetylcholine (ACh)-induced calcium release from intracellular Ca2+ stores and function of outer hair cell (OHC) motors, in an attempt to elucidate the mechanism of OHC electromotility at resting state. Methods OHCs were isolated from adult guinea pig (200-300 g) cochlea and loaded with Fluo-3/AM. The cells were treated with ACh/dHBSS, ACh/HBSS, dHBSS only or HBSS only. Intracellular [Ca2+]i variations in cells under the four treatments were observed using an Ar-Kr laser scan confocal microscope. Results [Ca2+]i oscillations were recorded in five OHCs treated with ACh/dHBSS but not in other cells. This is the first time that Ach-excited [Ca2+]i oscillations are reported in guinea pig OHCs independent of extracellular calcium. Conclusions ACh-excited [Ca2+]i oscillations in OHCs originates from intracellular calcium release and may play a crucial role in maintaining active mechanical motility of the OHC at resting and modulating OHC electromotility.

  8. Application of synchrotron source based DEI method in guinea pig cochleae imaging

    Institute of Scientific and Technical Information of China (English)

    YIN Hongxia; LIU Bo; GAO Xin; GAO Xiulai; LUO Shuqian

    2007-01-01

    Hard X-ray diffraction enhanced imaging (DEI), which is based on a synchrotron source and monochromator-analyzercrystal system, is an effective method for imaging X-ray phase shift. Utilizing an analyzer crystal with high angular sensitivity of micro-radian, DEI can measure the transmitted, refracted and scattered X-rays when projecting onto a sample. It dramatically improves the contrast and spatial resolution of the resultant images. At the topography station of Beijing Synchrotron Radiation Facilities (BSRF), we implemented DEI method in guinea pig cochleae imaging and acquired a series of DEI images. Based on these images, the apparent absorption and refraction images were calculated. The DEI images revealed the holistic spiral structures and inner details of guinea pig cochleae clearly, even including the structures at the cellular level, such as the static cilia of hairy cells and the limbus of Hansen cell. Due to the advanrages of high contrast, high spatial resolution and distinct edge-enhanced effect, DEI method promises extensive applications in biology,medicine and clinic in the near future.

  9. Opposing actions of dibutyryl cyclic AMP and GMP on temperature in conscious guinea-pigs

    Science.gov (United States)

    Kandasamy, S. B.; Williaes, B. A.

    1983-01-01

    It is shown that the intracerebroventricular administration of dibutyryl cyclic AMP (Db-cAMP) induced hyperthermia in guinea pigs which was not mediated through prostaglandins or norepinephrine since a prostaglandin synthesis inhibitor and an alpha-adrenergic receptor blocking agent did not antagonize the hyperthermia. However, the hyperthermic response to Db-cAMP was attenuated by the central administration of a beta-adrenergic receptor antagonist, which indicates that cAMP may be involved, through beta-adrenergic receptors, in the central regulation of heat production and conservation. The central administration of Db-cGMP produced hypothermia which was not mediated via histamine H1 or H2 receptors and serotonin. The antagonism of hypothermia induced by Db-cGMP and acetylcholine + physostigmine by central administration of a cholinergic muscarine receptor antagonist and not by a cholinergic nicotinic receptor antagonist suggests that cholinoceptive neurons and endogenous cGMP may regulate heat loss through cholinergic muscarine receptors. It is concluded that these results indicate a regulatory role in thermoregulation provided by a balance between opposing actions of cAMP and cGMP in guinea pigs.

  10. Tetrahydroacridine inhibits voltage-dependent Na+ current in guinea-pig ventricular myocytes

    Institute of Scientific and Technical Information of China (English)

    Wei WANG; Yi-ping WANG; Guo-yuan HU

    2004-01-01

    AIM: To study the effects of tetrahydroacridine (tacrine) on voltage-gated Na+ channels in cardiac tissues.METHODS: Single ventricular myocytes were enzymatically dissociated from adult guinea-pig heart. Voltagedependent Na+ current was recorded using whole cell voltage-clamp technique. RESULTS: (1) Tacrine reversibly inhibited Na+ current with an IC50 value of 120 μmol/L (95 % confidence range: 108-133 μmol/L). (2) The inhibitory effects of tacrine on Na+ current exhibited both a tonic nature and use-dependence. (3) Tacrine at 100 μmol/L caused a negative shift (about 10 mV) in the voltage-dependence of steady-state inactivation of Na+ current, and retarded its recovery from inactivation, but did not affect its activation curve. (4) Intracellular application of tacrine significantly inhibited Na+ current. CONCLUSION: In addition to blocking other voltage-gated ion channels,tacrine blocked Na+ channels in guinea-pig ventricular myocytes. Tactine acted as inactivation stabilizer of Na+channels in cardiac tissues.

  11. Relaxing action of adrenergic β2-agonists on guinea-pig skinned tracheal muscle

    Directory of Open Access Journals (Sweden)

    Kayo Nemoto

    1999-01-01

    Full Text Available Although adrenergic β2-agonist-induced smooth muscle relaxation has been attributed to increased intracellular cyclic AMP (cAMP, a relaxation response has been observed at low β2-agonist concentrations that do not cause increased cAMP To elucidate the mechanism of tracheal muscle relaxation induced by low concentrations of β2-agonists, we used a guinea-pig skinned tracheal smooth muscle preparation to examine the effects on the contractile protein system. The isotonic contraction of β-escin-treated skinned tracheal muscle from guinea-pig was measured. When the intracellular Ca2+ concentration was maintained at 1 μmol/L in the presence of guanosine 5′-triphosphate (GTP; 100 μmol/L, neither isoproterenol (10nmol/L nor salbutamol (60 nmol/L affected Ca2+ sensitivity, but a significant decrease in Ca2+ sensitivity was observed in the presence of okadaic acid (1 μmol/L. The decrease in Ca2+ sensitivity was a slow response and was blocked by pretreatment with propranolol (1 μmol/L. Forskolin (1 μmol/L did not affect Ca2+ sensitivity. These results suggest that adrenergic b 2-agonists may activate protein phosphatase through an unknown pathway involving the β2-receptor, which enhances dephosphorylation of the myosin light chain and/or thin filament proteins, resulting in relaxation of the tracheal smooth muscle.

  12. Pharmacokinetics of niacinamide in blood and skin of hairless guinea pigs

    Energy Technology Data Exchange (ETDEWEB)

    Bongiovannieier, R.; Koplovitz, I.; Shulz, S.; Lieb, J.; Railer, R.

    1993-05-13

    Niacinamide (NA) has been reported to be effective in reducing the development of microblisters caused by sulfur mustard (HD) vapor exposure in the Hairless guinea pig when given as a single bolus pretreatment 30 min prior to HD vapor exposure (Yourick et al.). The purpose of these experiments was to establish the pharmacokinetics of NA in the hairless guinea pig to optimize the evaluation of NA against HD cutaneous injury. A high performance liquid chromatography (HPLC) method was developed for the quantitation of NA in blood and skin. The method was linear (corr coeff r = 0.998) and sensitive with a working range from 50 microns/ml to 2000 microns/ml. The NA Tl/2 was measured after a bolus injection of 750 and 375 mg/kg via IP and IV routes, respectively. The Tl/2 was 2.8 + or - 0.3 hr for both routes. Drug concentrations in blood, during multiple dosing (5 IP) of a fixed dose (375 mg/kg, i.p.) given every 2.8 hr, were within 15% of the theoretical values calculated using a computer model (Principle of Superposition). NA serum levels ranged from 325 microns/mL to 1404 microns/mL (n = 12). The corresponding skin levels were within 93% of the blood levels. The elimination of NA from the skin paralleled its elimination from the blood. The results of these studies will aid in the future evaluation of NA as a pretreatment/treatment for HD injury.

  13. Molecular and Biological Characterization of a New Isolate of Guinea Pig Cytomegalovirus

    Directory of Open Access Journals (Sweden)

    Mark R. Schleiss

    2014-01-01

    Full Text Available Development of a vaccine against congenital infection with human cytomegalovirus is complicated by the issue of re-infection, with subsequent vertical transmission, in women with pre-conception immunity to the virus. The study of experimental therapeutic prevention of re-infection would ideally be undertaken in a small animal model, such as the guinea pig cytomegalovirus (GPCMV model, prior to human clinical trials. However, the ability to model re-infection in the GPCMV model has been limited by availability of only one strain of virus, the 22122 strain, isolated in 1957. In this report, we describe the isolation of a new GPCMV strain, the CIDMTR strain. This strain demonstrated morphological characteristics of a typical Herpesvirinae by electron microscopy. Illumina and PacBio sequencing demonstrated a genome of 232,778 nt. Novel open reading frames ORFs not found in reference strain 22122 included an additional MHC Class I homolog near the right genome terminus. The CIDMTR strain was capable of dissemination in immune compromised guinea pigs, and was found to be capable of congenital transmission in GPCMV-immune dams previously infected with salivary gland‑adapted strain 22122 virus. The availability of a new GPCMV strain should facilitate study of re-infection in this small animal model.

  14. Effect of Binghuang ear drop treatment on otitis externa in guinea pigs.

    Science.gov (United States)

    Zhai, Suo-qiang; Yu, Ning; Guo, Wei-Wei; Zhang, Yue

    2014-12-01

    To investigate the pharmacodynamic effects of Binghuang ear drop on acute suppurative otitis externa in guinea pig model. Thirty guinea pigs were randomly divided into three groups, with ten animals in each group. Group A animals had normal ear canal and Binghuang ear drops (two drops, B.I.D) were applied in both ears for 7 days; Group B animals had induced otitis externa and received identical prescription as group A; Group C had normal ear canal and were treated with normal saline (two drops, B.I.D) for 7 days. After the treatments, the external morphology of ear canals was observed and the paraffin sections of external auditory canal were prepared and examined under the microscope. The inflammatory manifestation and cell infiltration into the skin of group B was significantly attenuated after the Binghuang ear drops treatment. In contrast, no allergy or side effects were produced by Binghuang ear drops application in the animals with normal ear canals. Binghuang ear drops could be used to treat acute otitis externa by eliciting anti-bacterial effects.

  15. Adaptation of H9N2 AIV in guinea pigs enables efficient transmission by direct contact and inefficient transmission by respiratory droplets.

    Science.gov (United States)

    Sang, Xiaoyu; Wang, Airong; Ding, Jie; Kong, Huihui; Gao, Xiaolong; Li, Lin; Chai, Tongjie; Li, Yuanguo; Zhang, Kun; Wang, Chengyu; Wan, Zhonghai; Huang, Geng; Wang, Tiecheng; Feng, Na; Zheng, Xuexing; Wang, Hualei; Zhao, Yongkun; Yang, Songtao; Qian, Jun; Hu, Guixue; Gao, Yuwei; Xia, Xianzhu

    2015-11-10

    H9N2 avian influenza viruses circulate worldwide in poultry and have sporadically infected humans, raising concern whether H9N2 viruses have pandemic potential. Here, we use a guinea pig model to examine whether serial passage results in adaptive viral changes that confer a transmissible phenotype to a wild-type H9N2 virus. After nine serial passages of an H9N2 virus through guinea pigs, productive transmission by direct contact occurred in 2/3 guinea pig pairs. The efficiency of transmission by direct contact increased following the fifteenth passage and occurred in 3/3 guinea pig pairs. In contrast, airborne transmission of the passaged virus was less efficient and occurred in 1/6 guinea pig pairs and 0/6 ferret pairs after the fifteenth passage. Three amino acid substitutions, HA1-Q227P, HA2-D46E, and NP-E434K, were sufficient for contact transmission in guinea pigs (2/3 pairs). The two HA amino acid substitutions enhanced receptor binding to α2,3-linked sialic acid receptors. Additionally, the HA2-D46E substitution increased virus thermostability whereas the NP-E434K mutation enhanced viral RNA polymerase activity in vitro. Our findings suggest that adaptive changes that enhance viral receptor binding, thermostability, and replicative capacity in mammalian cells can collectively enhance the transmissibility of H9N2 AIVs by direct contact in the guinea pig model.

  16. A pro-inflammatory effect of foot and mouth disease vírus on immune and non immune guinea pigs

    Directory of Open Access Journals (Sweden)

    Helio José Montassier

    1992-12-01

    Full Text Available The O1Campos strain of foot and mouth disease virus (FMDV used as inducing agent in the pleurisy model was able to trigger a pro-inflammatory effect on normal and immune guinea pigs. The proinflammatory activity which was detected at two times of the pleurisy (24 and 48 hours on normal guinea pigs was characterized only by mononuclear (MN cell influx, during the first interval of the reaction and by edematogenic effect, MN and polimorphonuclcar (PMN leucocyte migration, at the last time of the reaction. The inflammatory reaction profiles recorded on immune guinea pigs (vaccinated with anti-O1Campos oil adjuvanted vaccine, both after 7 and 30 days post vaccination (pv have showed, in both interval, lower intensities than that observed in normal guinea pigs, although in the 7 days PV guinea pigs the accumulations of total leucocytes and PMN were similar to that displayed by normal animals, after 48 hours of the reaction. Besides, on thirty days PV guinea pigs the FMDV induced a significant increase in volume of exudate and MN cell infiltration, after 24 hours, and all of the inflammatory parameters values dropped to normal levels, during the second interval of the reaction. It was found a negative association between the increase in serum neutralizing antibody titer, from 7 to 30 days PV and the intensities of pleural inflammatory parameters on the immune guinea pigs. The pleurisy test revealed itself feasible to evaluate the pro-inflammatory activity of FMDV.

  17. L-dehydroascorbic acid can substitute L-ascorbic acid as dietary vitamin C source in guinea pigs

    DEFF Research Database (Denmark)

    Frikke-Schmidt, Henriette Rønne; Tveden-Nyborg, Pernille; Lykkesfeldt, Jens

    2016-01-01

    products prone to oxidation-was studied. Our aim was to compare tissue accumulation of vitamin C in guinea pigs receiving different oral doses of either ascorbate or DHA. In all tissues tested (plasma, liver, spleen, lung, adrenal glands, kidney, muscle, heart, and brain), only sporadic differences...

  18. Intravenous toxicokinetics of sulfur mustard and its DNA-adducts in the hairless guinea pig and marmoset

    NARCIS (Netherlands)

    Langenberg, J.P.; Spruit, W.E.T.; Kuijpers, W.C.; Mars, R.H.; Helden, H.P.M. van; Schans, G.P. van der; Benschop, H.P.

    2009-01-01

    ln order to provide a quantitative basis for pretreatment and therapy of intoxications with sulfur mustard the toxicokinetics of this agent as well as its major DNA-adducts are being studied in male hairless guinea pigs for the intravenous, respiratory and percutaneous routes. A highly sensitive met

  19. Dysfunctional muscarinic M(2) autoreceptors in vagally induced bronchoconstriction of conscious guinea pigs after the early allergic reaction

    NARCIS (Netherlands)

    TenBerge, REJ; Krikke, M; Teisman, ACH; Roffel, AF; Zaagsma, J

    1996-01-01

    We studied the function of autoinhibitory muscarinic M(2) receptors on vagal nerve endings in the airways of conscious, unrestrained, ovalbumin-sensitized guinea pigs after the early and late allergic reaction. For this purpose, the effects of the selective muscarinic M(2) receptor antagonist gallam

  20. Pharmacological activation of rapid delayed rectifier potassium current suppresses bradycardia-induced triggered activity in the isolated guinea pig heart

    DEFF Research Database (Denmark)

    Hansen, Rie Schultz; Olesen, Søren-Peter; Grunnet, Morten

    2007-01-01

    arrhythmias. We present here data that support that NS3623 affects native I(Kr) and report the effects that activating this potassium current have in the intact guinea pig heart. In Langendorff-perfused hearts, the compound showed a concentration-dependent shortening of action potential duration, which...

  1. Implementation of depolarization due to beam-beam effects in the beam-beam interaction simulation tool GUINEA-PIG++

    Science.gov (United States)

    Rimbault, C.; Le Meur, G.; Blampuy, F.; Bambade, P.; Schulte, D.

    2009-12-01

    Depolarization is a new feature in the beam-beam simulation tool GUINEA-PIG++ (GP++). The results of this simulation are studied and compared with another beam-beam simulation tool, CAIN, considering different beam parameters for the International Linear Collider (ILC) with a centre-of-mass energy of 500 GeV.

  2. REAL-TIME MEASUREMENT OF AIRWAY RESPONSES TO SULOFUR DIOXIDE (SO2) IN AN INTACT, AWAKE GUINEA PIG MODEL

    Science.gov (United States)

    Real-time measurment of airway responses to Sulfur Dioxide (SO2) in an intact, awake guinea pig model. J Stanek1,2, Q Krantz2, J Nolan2, D Winsett2, W Watkinson2, and D Costa2. 1College of Veterinary Medicine, NCSU, Raleigh, NC, USA; 2Pulmonary Toxicology Branch, ETD, NHEERL, US...

  3. Comparison of three Listeria monocytogenes strains in a guinea-pig model simulating food-borne exposure

    DEFF Research Database (Denmark)

    Roldgaard, Bent; Andersen, Jens Bo; Hansen, Tina Beck

    2009-01-01

    Three different Listeria monocytogenes strains, LO28 (a laboratory strain with truncated InlA), 4446 (a clinical isolate) and 7291 (a food isolate), were compared in a guinea-pig model designed to mimic food-borne exposure. The objectives were (1) to verify the applicability of the animal model f...

  4. Cholesterol-induced inflammation and macrophage accumulation in adipose tissue is reduced by a low carbohydrate diet in guinea pigs.

    Science.gov (United States)

    Aguilar, David; deOgburn, Ryan C; Volek, Jeff S; Fernandez, Maria Luz

    2014-12-01

    The main objective of this study was to evaluate the effects of a high cholesterol (HC) dietary challenge on cholesterol tissue accumulation, inflammation, adipocyte differentiation, and macrophage infiltration in guinea pigs. A second objective was to assess whether macronutrient manipulation would reverse these metabolic alterations. Male Hartley guinea pigs (10/group) were assigned to either low cholesterol (LC) (0.04g/100g) or high cholesterol (HC) (0.25g/100g) diets for six weeks. For the second experiment, 20 guinea pigs were fed the HC diet for six weeks and then assigned to either a low carbohydrate (CHO) diet (L-CHO) (10% energy from CHO) or a high CHO diet (H-CHO) (54% CHO) for an additional six weeks. Higher concentrations of total (P adipose tissue and aortas of guinea pigs fed the HC compared to those in the LC group. In addition, higher concentrations of pro-inflammatory cytokines in the adipose tissue (P adipocytes in the HC group were smaller in size (P adipose and aortas as well as lower concentrations of inflammatory cytokines in adipose tissue were observed in the L-CHO group (P adipose cells and lower macrophage infiltration compared to the H-CHO group. The results of this study strongly suggest that HC induces metabolic dysregulation associated with inflammation in adipose tissue and that L-CHO is more effective than H-CHO in attenuating these detrimental effects.

  5. Quantitation of contact allergy in guinea pigs by measuring changes in skin blood flow and skin fold thickness

    DEFF Research Database (Denmark)

    Andersen, Klaus Ejner; Staberg, B

    1985-01-01

    Skin blood flow determined by laser Doppler flowmetry (LDF) and skin fold thickness (SFT) have been used to quantitate allergic contact dermatitis in the guinea pig maximization test (GPMT) using chlorocresol as the allergen. The closed patch test procedure itself influenced both LDF and SFT meas...

  6. Transcriptional profiling of TLR-4/7/8-stimulated guinea pig splenocytes and whole blood by bDNA assay.

    Science.gov (United States)

    Ching, Lance K; Mompoint, Farah; Guderian, Jeffrey A; Picone, Alex; Orme, Ian M; Coler, Rhea N; Reed, Steven G; Baldwin, Susan L

    2011-10-28

    Toll-like receptor (TLR) agonists are currently being examined as adjuvants for vaccines, with several lead candidates now in licensed products or in late-stage clinical development. Guinea pigs are widely used for preclinical testing of drugs and vaccines; however, evaluation of TLR agonists in this model is hindered by the limited availability of immunological tools and reagents. In this study, we validated the use of a branched-chain DNA (bDNA) assay known as the QuantiGene Plex 2.0 Reagent System for measuring innate cytokine and chemokine mRNA levels following TLR stimulation of guinea pig cells. Gene expression for T-helper-1 (Th1) polarizing cytokines (TNF-α, IL-1β, IL-12) and chemokines (CXCL1, CCL2) was upregulated following ex vivo stimulation of guinea pig splenocytes and whole blood with TLR-4 or TLR-7/8 agonists. These data confirm the utility of the QuantiGene system both as an alternative to RT-PCR for measuring transcript levels and as a high-throughput screening tool for dissecting the immunological response to TLR stimulation in guinea pigs. Overall, the QuantiGene platform is reliable, reproducible, and sensitive. These agonists have the potential to be used as adjuvant components in vaccines against various pathogens. Copyright © 2011 Elsevier B.V. All rights reserved.

  7. [The role of pro- and antioxidant processes in the liver tissue of guinea pigs in pathogenesis of allergic alveolitis].

    Science.gov (United States)

    Shchepans'kyĭ, F I; Reheda, M S

    2005-01-01

    It was shown that allergic alveolitis development is accompanied by increase of superoxyddismutase and catalase activity as well as an increase of dien conjugates and malonic dialdehyde content in Guinea pig liver. The administration of alfa-tokoferol acetate, an antioxidant resulted in decrease of these indices in the liver tissue that testifies its correcting influence upon PLO and antioxidant system processes.

  8. THE INTERACTION OF SELECTIVE AND NONSELECTIVE ANTAGONISTS WITH PREJUNCTIONAL AND POSTJUNCTIONAL MUSCARINIC RECEPTOR SUBTYPES IN THE GUINEA-PIG TRACHEA

    NARCIS (Netherlands)

    TENBERGE, REJ; ROFFEL, AF; ZAAGSMA, J

    1993-01-01

    Muscarinic receptor antagonists were used to study prejunctional M2 and postjunctional M3 receptors in the isolated guinea pig trachea. The effects of four M2-selective muscarinic receptor antagonists (gallamine, methoctramine, AQ-RA 741 and AF-DX 116) were studied on twitch contractions, elicited

  9. Hyperendemic Campylobacter jejuni in guinea pigs (Cavia porcellus) raised for food in a semi-rural community of Quito, Ecuador.

    Science.gov (United States)

    Graham, Jay P; Vasco, Karla; Trueba, Gabriel

    2016-06-01

    Domestic animals and animal products are the source of pathogenic Campylobacter jejuni and C. coli in industrialized countries, yet little is known about the transmission of these bacteria in developing countries. Guinea pigs (Cavia porcellus) are commonly raised for food in the Andean region of South America, however, limited research has characterized this rodent as a reservoir of zoonotic enteric pathogens. In this study, we examined the prevalence of Campylobacter spp. in 203 fecal samples from domestic animals of 59 households in a semi-rural parish of Quito, Ecuador. Of the twelve animal species studied, guinea pigs showed the highest prevalence of C. jejuni (n = 39/40; 97.5%). Multilocus sequence typing (MLST) was used to characterize the genetic relationship of C. jejuni from domestic animals and 21 sequence types (STs) were identified. The majority of STs from guinea pigs appeared to form new clonal complexes that were not related to STs of C. jejuni isolated from other animal species and shared only a few alleles with other C. jejuni previously characterized. The study identifies guinea pigs as a major reservoir of C. jejuni and suggests that some C. jejuni strains are adapted to this animal species. © 2016 Society for Applied Microbiology and John Wiley & Sons Ltd.

  10. Evaluation of vaccines in the EU TB Vaccine Cluster using a guinea pig aerosol infection model of tuberculosis.

    Science.gov (United States)

    Williams, Ann; Hatch, Graham J; Clark, Simon O; Gooch, Karen E; Hatch, Kim A; Hall, Graham A; Huygen, Kris; Ottenhoff, Tom H M; Franken, Kees L M C; Andersen, Peter; Doherty, T Mark; Kaufmann, Stefan H E; Grode, Leander; Seiler, Peter; Martin, Carlos; Gicquel, Brigitte; Cole, Stewart T; Brodin, Priscille; Pym, Alexander S; Dalemans, Wilfried; Cohen, Joe; Lobet, Yves; Goonetilleke, Nilu; McShane, Helen; Hill, Adrian; Parish, Tanya; Smith, Debbie; Stoker, Neil G; Lowrie, Douglas B; Källenius, Gunilla; Svenson, Stefan; Pawlowski, Andrzej; Blake, Karen; Marsh, Philip D

    2005-01-01

    The TB Vaccine Cluster project funded by the EU Fifth Framework programme aims to provide novel vaccines against tuberculosis that are suitable for evaluation in humans. This paper describes the studies of the protective efficacy of vaccines in a guinea pig aerosol-infection model of primary tuberculosis. The objective was to conduct comparative evaluations of vaccines that had previously demonstrated efficacy in other animal models. Groups of 6 guinea pigs were immunized with vaccines provided by the relevant EU Vaccine Cluster partners. Survival over 17 or 26 weeks was used as the principal measure of vaccine efficacy following aerosol challenge with H37Rv. Counts of mycobacteria in lungs and spleens, and histopathological changes in the lungs, were also used to provide evidence of protection. A total of 24 vaccines were evaluated in 4 experiments each of a different design. A heterologous prime-boost strategy of DNA and MVA, each expressing Ag85A and a fusion protein of ESAT-6 and Ag85B in adjuvant, protected the guinea pigs to the same extent as BCG. Genetically modified BCG vaccines and boosted BCG strategies also protected guinea pigs to the same extent as BCG but not statistically significantly better. A relatively high aerosol-challenge dose and evaluation over a protracted time post-challenge allowed superior protection over BCG to be demonstrated by BCG boosted with MVA and fowl pox vectors expressing Ag85A.

  11. THE INTERACTION OF SELECTIVE AND NONSELECTIVE ANTAGONISTS WITH PREJUNCTIONAL AND POSTJUNCTIONAL MUSCARINIC RECEPTOR SUBTYPES IN THE GUINEA-PIG TRACHEA

    NARCIS (Netherlands)

    TENBERGE, REJ; ROFFEL, AF; ZAAGSMA, J

    1993-01-01

    Muscarinic receptor antagonists were used to study prejunctional M2 and postjunctional M3 receptors in the isolated guinea pig trachea. The effects of four M2-selective muscarinic receptor antagonists (gallamine, methoctramine, AQ-RA 741 and AF-DX 116) were studied on twitch contractions, elicited b

  12. Comparative physical and immunological aspects of the chimpanzee and guinea-pig subcutaneous chamber models of Neisseria gonorrhoeae infection.

    Science.gov (United States)

    Arko, R J; Wong, K H

    1977-01-01

    Physical and immunological characteristics of the chimpanzee and guinea-pig subcutaneous chamber models for Neisseria gonorrhoeae infection were compared to evaluate their usefulness for gonococcal research. Urethral infection in chimpanzees anatomically resembled the human infection; however, individual variation in response, limited availability, and the presence of interfering micro-organisms in the urethra were found to limit the usefulness of the chimpanzee in immunological research. Although the guinea-pig subcutaneous chamber model may not be suitable for studying the attachment of gonococci to host cells or for the local production of IgA, it does have the immunological advantages of being more sensitive to infection, less variable in response, free of interfering micro-organisms, and is readily available to investigators. Except for differences in sensitivity and variability, results with the guinea-pig model paralleled results obtained in experiments with chimpanzees. Unlike chimpanzees, guinea-pigs are a comparatively inexpensive, rapidly replenishable animal, which after subcutaneous implantation with small porous chambers provide a convenient model for studying most immunological aspects of gonococcal infections. PMID:403994

  13. Inner ear pressure changes following square wave intracranial or ear canal pressure manipulation in the same guinea pig

    NARCIS (Netherlands)

    Thalen, E; Wit, H; Segenhout, H; Albers, F

    Inner ear pressure was measured in scala tympani with a micropipette during square wave pressure manipulation of the intracranial compartment and, subsequently, of the external ear canal (EEC) in the same guinea pig. As expected, the combination of the cochlear aqueduct and the inner ear behaves as

  14. Vitamin C deficiency in weanling guinea pigs: differential expression of oxidative stress and DNA repair in liver and brain

    DEFF Research Database (Denmark)

    Lykkesfeldt, Jens; Trueba, Gilberto Perez; Poulsen, Henrik E;

    2007-01-01

    Neonates are particularly susceptible to malnutrition due to their limited reserves of micronutrients and their rapid growth. In the present study, we examined the effect of vitamin C deficiency on markers of oxidative stress in plasma, liver and brain of weanling guinea pigs. Vitamin C deficiency...

  15. The effects of cannabidiol on the antigen-induced contraction of airways smooth muscle in the guinea-pig.

    Science.gov (United States)

    Dudášová, A; Keir, S D; Parsons, M E; Molleman, A; Page, C P

    2013-06-01

    (-)-Δ(9)-Tetrahydrocannabinol has been demonstrated to have beneficial effects in the airways, but its psychoactive effects preclude its therapeutic use for the treatment of airways diseases. In the present study we have investigated the effects of (-)-cannabidiol, a non-psychoactive component of cannabis for its actions on bronchial smooth muscle in vitro and in vivo. Guinea-pig bronchial smooth muscle contractions induced by exogenously applied spasmogens were measured isometrically. In addition, contractile responses of bronchial smooth muscle from ovalbumin-sensitized guinea-pigs were investigated in the absence or presence of (-)-cannabidiol. Furthermore, the effect of (-)-cannabidiol against ovalbumin-induced airway obstruction was investigated in vivo in ovalbumin-sensitized guinea-pigs. (-)-Cannabidiol did not influence the bronchial smooth muscle contraction induced by carbachol, histamine or neurokinin A. In contrast, (-)-cannabidiol inhibited anandamide- and virodhamine-induced responses of isolated bronchi. A fatty acid amide hydrolase inhibitor, phenylmethanesulfonyl fluoride reversed the inhibitory effect of (-)-cannabidiol on anandamide-induced contractions. In addition, (-)-cannabidiol inhibited the contractile response of bronchi obtained from allergic guinea-pigs induced by ovalbumin. In vivo, (-)-cannabidiol reduced ovalbumin-induced airway obstruction. In conclusion, our results suggest that cannabidiol can influence antigen-induced airway smooth muscle tone suggesting that this molecule may have beneficial effects in the treatment of obstructive airway disorders.

  16. Comparison of dose-responses of contact allergens using the guinea pig maximization test and the local lymph node assay

    NARCIS (Netherlands)

    Och, F.M.M. van; Vandebriel, R.J.; Prinsen, M.K.; Jong, W.H. de; Slob, W.; Loveren, H. van

    2001-01-01

    The guinea pig maximization test (GPMT) has been used as a method for the prediction of skin sensitizing potential for over 30 years. Besides hazard identification, risk assessment of sensitizing chemicals requires the assessment of potency. For the determination of potency based on lowest effective

  17. Transmission electron microscopy findings in the respiratory epithelium of guinea pigs exposed to the polluted air of southwest Mexico City.

    Science.gov (United States)

    Villegas-Castrejon, H; Villalba-Caloca, J; Meneses-Flores, M; Haselbarth-Lopez, M M; Flores-Rivera, E; Perez-Neria, J

    1999-01-01

    We evaluated the nature and the extent of the damage to the respiratory epithelium of guinea pigs after a 4-month exposure to the mixture of air pollutants in southwest Mexico City. Guinea pigs were placed outdoors on the roof of our facility, 8 hours daily, from February to May 1995. At the same time, control guinea pigs were kept indoors breathing filtered air. Air pollutants, temperature, and humidity data were obtained from the nearest station of the Environmental Monitoring Net. The airways and lung parenchyma were analyzed after 120 days using transmission electron microscopy (TEM). During the 4-month exposure period, ozone (O3) exceeded the norm during 511 hours, and suspended particles less than 10 microm in diameter (PM10) during 52 hours. Both pollutants reached peak levels of more than twice the norm. TEM revealed no important abnormalities in the control group. In the exposed group, there was loss of cilia, detachment of epithelial cells, and eosinophil and macrophage migration toward alveolar spaces through type I pneumocytes with destruction of their basal membranes. In six guinea pigs in the exposed group, we noted bacteria along the airways, with associated inflammatory response. We explain the colonization of the respiratory epithelium by bacteria as the result of the impairment on the defense mechanism caused by the exposure to environmental O3 and PM10.

  18. Effect of anti-IL-5 and IL-5 on airway hyperreactivity and eosinophils in guinea pigs

    NARCIS (Netherlands)

    Oosterhout, A.J.M.; Ladenius, A.R.C.; Savelkoul, H.F.J.; Ark, van I.; Delsman, K.C.; Nijkamp, F.P.

    1993-01-01

    Chronic ovalbumin challenge of sensitized guinea pigs induces bronchoalveolar lavage (BAL) eosinophilia, neutrophilia, and tracheal hyperreactivity. In the present study, the influence of monoclonal antibody to murine interleukin-5 (anti-IL-5) on these phenomena is examined. In ovalbumin-sensitized

  19. The effect of vitamin E on tracheal responsiveness and lung inflammation in sulfur mustard exposed guinea pigs.

    Science.gov (United States)

    Boskabady, Mohammad Hossein; Amery, Sediqa; Vahedi, Nassim; Khakzad, Mohammad Reza

    2011-02-01

    Pulmonary complications of sulfur mustard (SM) range from mild respiratory symptoms to even severe bronchial stenosis. In the present study, the protective effect of vitamin E on tracheal responsiveness (TR) and lung inflammation of SM-exposed guinea pigs were examined. Guinea pigs were exposed to ethanol (control group), 40 mg/m(3) inhaled SM and ethanol vehicle (sulfur mustard exposed (SME) group), SME treated with vitamin E (SME + E), SME with dexamethasone (SME + D) and both drugs (SME + E + D), (n = 8 for each group). TR to methacholine, total and differential white blood cell (WBC) count of lung lavage and serum cytokines were evaluated 14 days post-exposure. TR, WBC, interleukin 4 (IL-4), interferon gamma (INF-γ), eosinophil, and monocyte levels in SME guinea pigs were significantly higher, but lymphocyte was lower than those of controls (P SME + E, SME + D and SME + E + D, INF-γ in SME + E and SME + E + D and WBC in SME + E were significantly decreased compared to that of the SME group (P SME + D + E was significantly higher than that of SME + E (P SME + D (P SME guinea pigs.

  20. LOW-VOLTAGE FIELD-EMISSION SCANNING ELECTRON-MICROSCOPY OF NON-COATED GUINEA-PIG HAIR CELL STEREOCILIA

    NARCIS (Netherlands)

    DUNNEBIER, EA; SEGENHOUT, JM; KALICHARAN, D; JONGEBLOED, WL; WIT, HP; ALBERS, FWJ

    1995-01-01

    The stereociliar structures of the guinea-pig cochlear organ of Corti were studied at low-voltage (1-5 kV) with field-emission scanning electron microscope (SEM) using various pre- and post-fixation methods, such as OTOTO (OsO4/thiocarbohydrazide/OsO4/thiocarbohydrazide/OsO4) and TAO (tannic acid/ar