Rat placental hormones: attempts for identification of rat chorionic gonadotrophin and rat placental lactogen by in vivo experiments

1982 ◽  
Vol 99 (2) ◽  
pp. 288-294 ◽  
Author(s):  
Marco Tabarelli ◽  
R. Kofler ◽  
S. Schwarz ◽  
G. Wick
Keyword(s):  
Limit Of Detection ◽  
Chorionic Gonadotrophin ◽  
Placental Lactogen ◽  
Female Rat ◽  
Immature Female ◽  
Pregnant Rats ◽  
In Vivo Experiments ◽  
Rat Pituitary ◽  
Dose Dependent

Abstract. Rat placental extracts (rPE) were investigated in bioassays for their possible content of rat placental lactogen (rPL) and rat chorionic gonadotrophin (rCG). Luteotrophic and lactogenic activity of rPL was assessed by substitution of rats depleted of endogenous prolactin (Prl) by means of bromoergocryptine (BEC) in early pregnancy and the period of lactation, respectively. The abortifacient effect of a single dose of BEC on day 6 of pregnancy was abolished by rPE equivalent to 1 g rat placenta corresponding to 5 IU bovine Prl (NIH-P-B 2). Substitution was necessary until the evening of day 7 indicating that rPL does not take over the function of Prl before day 8. During lactation rPE reversed the lactation inhibiting effect of daily BEC treatment. In this assay rPL activity corresponded to 1.25–2.5 IU bPrl/g placenta. In order to test for the possible existence of rCG the gonadotrophic activity of rPE was assessed in immature female mice. No gonadotrophic activity was found when rPE equivalent to 1 g rat placenta was administered, whereas equivalents of 3 mg human placenta and 12 mg rat pituitary entailed a dose-dependent response. In this system 0.12 IU human chorionic gonadotrophin (hCG), which served as standard, was the minimal dose (MD) resulting in increased uterine weight. In addition rPE was tested in the immature female rat, where the limit of detection was found to be 0.5 IU hCG. Again no gonadotrophic activity was found in rPE. As the effects of rCG might have been restricted to its presumed target, the corpus luteum of pregnancy, rPE was also tested in pregnant rats depleted of endogenous luteinizing hormone (LH) by a single injection of anti-LH antibodies on day 10 of pregnancy. A MDof 0.5 IU hCG, which served as standard, prevented resorption of foetuses in all animals tested. rPE equivalent to 3.5 g rat placenta, rat pregnancy serum of day 18 and placental transplants could not substitute for endogenous LH.

ANTERIOR PITUITARY SENSITIVITY IN IMMATURE FEMALE RATS STIMULATED WITH GONADOTROPHIN RELEASING HORMONE IN VIVO: EFFECT OF PRIMING WITH OESTROGEN, PREGNANT MARE SERUM GONADOTROPHIN OR BRAIN LESION

1977 ◽  
Vol 74 (1) ◽  
pp. 99-109 ◽  
Author(s):  
D. DE ZIEGLER ◽  
M. WILKINSON ◽  
DANIELLE CASSARD ◽  
K. B. RUF
Keyword(s):  
Brain Lesion ◽  
Treated Group ◽  
Female Rats ◽  
Similar Degree ◽  
Female Rat ◽  
Immature Female ◽  
Releasing Hormone ◽  
Gonadotrophin Releasing Hormone ◽  
Pregnant Mare Serum Gonadotrophin

An investigation of pituitary sensitivity, assessed in terms of increments in plasma LH and FSH concentrations, to stimulation with one or two injections of gonadotrophin releasing hormone (GnRH) was carried out on 26-day-old immature female rats which had received one of the following priming treatments: 10 μg oestradiol benzoate (OB) as a single injection on day 23 or day 25, or on both days; 10 i.u. pregnant mare serum gonadotrophin (PMSG) on day 24; an electrochemical brain lesion placed in the mediobasal hypothalamus on day 23; control animals received either vehicle alone or a sham lesion. Pituitary sensitivity assessed at 10.00 h on day 26, after one or two injections of GnRH (100 ng/100 g body weight, s.c.), was enhanced to a similar degree in the three groups treated with OB in terms of LH (P < 0-01). The FSH response also increased after OB treatment but was not statistically significant. In contrast, 48 h after the injection of PMSG (i.e. when the rats were in a 'pro-oestrous-like' condition) pituitary sensitivity in terms of both LH and FSH dropped sharply (P < 0·001). In lesioned animals, pituitary sensitivity to one injection of GnRH was unchanged. A second GnRH injection administered after a 60 min interval induced a slightly larger LH response in control animals. In contrast, the ratio of the second response to the first increased in animals treated with PMSG, despite the state of overall decrease in sensitivity, being 4·5:1 in PMSG-treated rats versus 1·4:1 in controls. In a second set of experiments, we investigated the variation of pituitary sensitivity in conjunction with an experimentally induced gonadotrophin surge. In animals treated with OB on day 23 and with 1 mg progesterone at 12·00 h on day 26, pituitary sensitivity was increased at both 14.00 and 17.00 h as compared with that in the day 23 OB-treated group at 10.00 h. The PMSG-treated animals maintained their state of decreased responsiveness at 14.00 h, but exhibited increased pituitary sensitivity at the time of the gonadotrophin surge (17.00 h). These results show that OB increases pituitary sensitivity to GnRH in 26-day-old female rats and that the induction of a gonadotrophin surge further increases this sensitivity. In contrast, PMSG-treated rats displayed a state of decreased responsiveness 48 and 52 h, but not 55 h, after the injection. Pituitary sensitivity on the second day after PMSG treatment thus clearly differs from that observed during pro-oestrus in the adult cyclic female rat.

Association between beta2-glycoprotein I plasma levels and the risk of myocardial infarction in older men

Blood ◽  
2009 ◽  
Vol 114 (17) ◽  
pp. 3656-3661 ◽  
Author(s):  
Bas de Laat ◽  
Philip G. de Groot ◽  
Ronald H. W. M. Derksen ◽  
Rolf T. Urbanus ◽  
Koen Mertens ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
Plasma Levels ◽  
High Plasma ◽  
In Vivo Experiments ◽  
Glycoprotein I ◽  
Adhesive Surface ◽  
Von Willebrand ◽  
Willebrand Factor ◽  
Dose Dependent

Abstract von Willebrand factor (VWF) serves as adhesive surface for platelets to adhere to the vessel wall. We have recently found that beta2-glycoprotein I is able to inhibit platelet binding to VWF, indicating a role in the pathophysiology of arterial thrombosis. In the present study, we investigated whether differences in beta2-glycoprotein I plasma levels influence the risk of myocardial infarction. We have measured beta2-glycoprotein I and VWF antigen levels in 539 men with a first myocardial infarction and in 611 control subjects. Although we did not find a profound effect of beta2-glycoprotein I plasma levels on myocardial infarction in the overall population, we found a dose-dependent protective effect of increasing beta2-glycoprotein I plasma levels on myocardial infarction in men 60 years and older. In this age group, we found an odds ratio of 0.41 (95% confidence interval, 0.22-0.74) for high beta2-glycoprotein I levels compared with low levels. High plasma levels of beta2-glycoprotein I remained protective for myocardial infarction despite high levels of VWF. To conclude, high circulating levels of beta2-glycoprotein I appeared to be associated with a reduced risk of myocardial infarction in elderly men. In vivo experiments are needed to investigate the exact contribution of beta2-glycoprotein I on the pathophysiology of myocardial infarction.

Oxytocin has a role in gonadotrophin regulation in rats

1990 ◽  
Vol 125 (3) ◽  
pp. 425-432 ◽  
Author(s):  
G. Robinson ◽  
J. J. Evans
Keyword(s):  
Follicular Development ◽  
Pituitary Cells ◽  
Lh Surge ◽  
Rat Pituitary ◽  
Lh Release ◽  
Rat Pituitary Cells ◽  
Dose Dependent ◽  
In Vivo Administration

ABSTRACT We previously demonstrated that oxytocin stimulates LH release from rat pituitary cells in vitro and advances follicular development and ovulation in mice in vivo. This study reports an investigation of rat LH levels following in-vivo administration of oxytocin. Injection of oxytocin (10 mIU/g, i.p.) to rats at 07.00, 08.00 and 09.00 h of pro-oestrus or at 09.00, 10.00 and 11.00 h of pro-oestrus advanced the onset of the LH surge (P<0.005) and attainment of peak concentrations of LH (P<0.02) in peripheral blood. On the other hand, the descending phase of the LH surge and the surge amplitude were not altered by oxytocin. Treatment at 05.00, 06.00 and 07.00 h of pro-oestrus or at 11.00, 12.00 and 13.00 h of pro-oestrus had no effect on the LH profile. A higher oxytocin dose (20 mIU/g) inhibited LH release when treatment was begun at 05.00, 07.00 or 09.00 h of pro-oestrus. A lower dose (5 mIU/g) was ineffective in altering LH concentrations. In addition, injections of oxytocin (10 mIU/g) at oestrus, metoestrus or dioestrus had no effect on the release of LH. Thus the efficacy of oxytocin in altering concentrations of LH was dose dependent and also critically affected by the day of the oestrous cycle and the time of pro-oestrus. Removal of endogenous oxytocin activity by the use of an oxytocin receptor antagonist abolished the pro-oestrous LH surge, indicating that oxytocin is a vital physiological component of the LH-releasing mechanism in rats. The study provides unequivocal evidence that oxytocin induces LH release in vivo, but the manifestation of oxytocin activity is dependent upon conditions of exposure. Journal of Endocrinology (1990) 125, 425–432

105 DETECTION OF PLACENTAL LACTOGENS IN SWAMP BUFFALO BY RADIOIMMUNOASSAY TECHNIQUE

2009 ◽  
Vol 21 (1) ◽  
pp. 152
Author(s):  
N. V. Hanh ◽  
Q. X. Huu ◽  
N. T. Uoc ◽  
J. Sulon ◽  
N. M. Sausa ◽  
...  
Keyword(s):  
Placental Lactogen ◽  
Blood Collection ◽  
Fetal Plasma ◽  
Placental Lactogens ◽  
In Vivo Experiments ◽  
Domestic Ruminants ◽  
Pregnant Sheep ◽  
Heart Blood ◽  
Swamp Buffalo

Ruminant placental lactogens (PL) are members of the growth factor/prolactin (GH/PRL) family. They are synthesized by trophectodermal binucleate cells. There is evidence to suggest that PL is involved in control of fetal growth, through actions in both the maternal and fetal compartments, as well as in influencing mammary growth during pregnancy (Byatt JC et al. 1992 J. Anim. Sci. 70, 2911–2923). The structure and biology of PL have been studied in the cow, sheep, goat, human, and mice. The maternal concentration of PL is 100- to 1 000-fold greater in pregnant sheep and goats than in cows but no information exists about PL concentration in buffalo. The aim of the present study was to evaluate the ability to detect PL in buffalo fluids by using bovine PL antibody. Samples were collected in the slaughterhouse immediately after animal slaughter. The fetuses were measured after heart blood collection. A bPL RIA system was used to determine the bPL concentrations in the buffalo samples (Alvarez-Oxiley AV et al. 2007 Reprod. Fertil. Dev. 19, 877–885). The rbPL molecules were radio-iodinated with [125]I-Na by using the lactoperoxidase method (Thorell JI and Johansson BG 1971 Biochim. Biophys. Acta 251, 363–369). Concentrations of buffalo PL are presented in Table 1. In this RIA system, the minimum detected value was 0.068 ng mL–1, and the binding competition curves of bovine PL standard and buffalo fluids dilution using bovine PL antibody were paralleled in all kinds of samples. The lowest concentration was detected in allantoid fluid and the greatest concentration in fetal plasma (P < 0.05). Study of the biology of PL in buffalo has proved difficult because the concentration of PL in all buffalo fluids is very low. Furthermore, the research concerning buffalo PL function required in vivo experiments. Existing data suggest that at least the concentration of buffalo PL is different from cattle and other smaller domestic ruminants. In conclusion, our results provide preliminary information about concentrations of PL in buffalo fluids. Table 1.Concentration of placental lactogen in buffalo fluids This work was supported by a grant from the Belgian Technical Cooperation.

scholarly journals In vivo oestrogenic modulation of Egr1 and Pitx1 gene expression in female rat pituitary gland

2014 ◽  
Vol 53 (3) ◽  
pp. 355-366 ◽  
Author(s):  
Alina Gajewska ◽  
Andrzej P Herman ◽  
Ewa Wolińska-Witort ◽  
Kazimierz Kochman ◽  
Lech Zwierzchowski
Keyword(s):  
Pituitary Gland ◽  
Mrna Expression ◽  
Gnrh Agonist ◽  
Gene Promoter ◽  
Specific Response ◽  
Mrna Levels ◽  
Female Rat ◽  
Promoter Activation ◽  
Rat Pituitary

EGR1 and PITX1 are transcription factors required for gonadotroph cell Lhb promoter activation. To determine changes in Egr1 and Pitx1 mRNA levels in central and peripheral pituitary stimulations, an in vivo model based on i.c.v. pulsatile (1 pulse/0.5 h over 2 h) GnRH agonist (1.5 nM buserelin) or antagonist (2 nM antide) microinjections was used. The microinjections were given to ovariectomised and 17β-oestradiol (E2) (3×20 μg), ERA (ESR1) agonist propyl pyrazole triol (PPT) (3×0.5 mg), ERB (ESR2) agonist diarylpropionitrile (DPN) (3×0.5 mg) s.c. pre-treated rats 30 min after last pulse anterior pituitaries were excised. Relative mRNA expression was determined by quantitative RT-PCR (qRT-PCR). Results revealed a gene-specific response for GnRH and/or oestrogenic stimulations in vivo. Buserelin pulses enhanced Egr1 expression by 66% in ovariectomised rats, whereas the oestradiol-supplemented+i.c.v. NaCl-microinjected group showed a 50% increase in Egr1 mRNA expression. The oestrogenic signal was transmitted via ERA (ESR1) and ERB (ESR2) activation as administration of PPT and DPN resulted in 97 and 62%, respectively, elevation in Egr1 mRNA expression. A synergistic action of GnRH agonist and 17β-oestradiol (E2) stimulation of the Egr1 gene transcription in vivo were found. GnRHR activity did not affect Pitx1 mRNA expression; regardless of NaCl, buserelin or antide i.c.v. pulses, s.c. oestrogenic supplementation (with E2, PPT or DPN) consistently decreased (by −46, −48 and −41% respectively) the Pitx1 mRNA in the anterior pituitary gland. Orchestrated Egr1 and Pitx1 activities depending on specific central and peripheral regulatory inputs could be responsible for physiologically variable Lhb gene promoter activation in vivo.

242 POTENTIAL ESTROGENIC EFFECT(S) OF PARABENS AT THE NEONATAL STAGE OF AN IMMATURE FEMALE RAT MODEL

2010 ◽  
Vol 22 (1) ◽  
pp. 279
Author(s):  
S. H. Hyun ◽  
E. B. Jeung
Keyword(s):  
Body Weight ◽  
Rat Model ◽  
Estrogenic Activity ◽  
Female Rats ◽  
Female Rat ◽  
Dependent Manner ◽  
Methyl Ethyl ◽  
Immature Female ◽  
Immature Rats ◽  
Dose Dependent

In this study, to examine the estrogenic activity effects of parabens on hormonal responsiveness and on change in the morphology of reproductive target tissues during a critical development stage in female rats, analyses for parabens including methyl-, ethyl-, propyl-, isopropyl-, butyl-, and isobutylparaben were performed in an immature female Sprague-Dawley rat model. Two hundred female immature rats (n = 10/group) were orally treated with these parabens from postnatal day 21 to 40 in a dose-dependent manner based on our previous study [62.5, 250, and 1000 mg/kg of body weight (BW) per day]. 17α-ethinylestradiol (EE;1 mg/kg of BWper day) was used as a positive control and corn oil as a vehicle.A high doseofmethyl- and isopropylparaben (1000 mg/kg of BW per day) resulted in a significant delay in the date of vaginal opening and a decrease in length of the estrous cycle (P < 0.05). In measurements of organ weight and body weight, we observed significant weight changes in ovaries, adrenal glands, thyroid glands, liver, and kidneys(P < 0.05); conversely, body weight was not altered following paraben treatment. In all groups exposedto paraben treatment, histological analysis of the ovaries from the immature rats revealed interstitial cell disorders, a lack of corpora lutea, an increase in the number of cystic follicles, and thinning of the follicular epithelium, which occurred in a dose-dependent manner. In addition, morphological studies of the uterus revealed the myometrial dysplasia suchas myometrial hyperplasia inthe high-doseofpropyl- and isopropylparaben (1000 mg/kgof BWper day) group and in all dose of butyl- and isobutylparabens groups. We also observed a significant decrease in serum estradiol and T4 concentrations in methyl-, ethyl-, propyl-, isopropyl-, and isobutylparaben-treated groups (P < 0.01 and 0.05).A receptor-binding assay indicated that the relative binding affini- ties of parabens to estrogen receptors occurred in the order: isobutylparaben > butylparaben > isopropylparaben = propylparaben > ethylparaben. These values were much less than the binding affinity for 17?-estradiol. Taken together, long-term exposure to parabens, which show less estrogenic activity than EEl, can produce suppressive effects on hormonal responsiveness and can disrupt the morphology of reproductive target tissues during this critical stage of development in immature female rats.

512. COMMERCIAL EQUINE CHORIONIC GONADOTROPHIN ISOFORM COMPOSITION, IMMUNOACTIVITY, AND BIOACTIVITY IN A MURINE MODEL USING OVARIAN AUGMENTATION AND TESTICULAR INTERSTITIAL CELL BIOASSAYS

2009 ◽  
Vol 21 (9) ◽  
pp. 111 ◽  
Author(s):  
U. A. Ciller ◽  
J. D. McFarlane ◽  
J. R. McFarlane
Keyword(s):  
Interstitial Cell ◽  
Chorionic Gonadotrophin ◽  
In Vitro Bioassay ◽  
Glycoprotein Hormone ◽  
Immature Female ◽  
Future Studies ◽  
In Vivo Bioassay

Equine chorionic gonadotrophin (eCG) is a placental glycoprotein hormone that is harvested from the plasma of pregnant mares for the formulation of commercial products which are used in a variety of assisted reproductive procedures in livestock. It is well documented that the bioactivity of gonadotrophin products is highly variable. The aim of this study was therefore to determine how different eCG products affected target tissues and cells. Isoforms of eCG were separated with iso-electric focusing and immunoactivity measured with RIA. For in vivo bioassay, dose-response eCG treatments were administered subcutaneously to immature female mice with follow-up treatment on day 2. On day 3 the mice were asphyxiated and ovaries dissected and weighed relative to standard. For in vitro bioassay, adult male mice were asphyxiated, testes removed, decapsulated, dispersed, strained and washed with DMEM:F12 0.1% BSA. The cell stock was counted and diluted for culture at 20,000 cells/well. Cell viability was determined using trypan blue. Five doses were tested for each eCG product. The cells were incubated at 32ºC for 3 hours in 5.0% CO2 in humidified conditions. Media was collected after 3 hours and immediately assayed for testosterone with RIA. Product eCG with ~90% isoforms with pH 3.0–3.7 and ~10% with pH 3.8–4.4, showed 29% greater biologically activity in the ovarian augmentation assay and 44.8% more immunoactivity then stated product bioactivity. Product eCG with ~70% isoforms with pH 3.0–3.7 and ~30% with pH 3.8–7.4 was 3.0% less effective in vivo and had 7.9% less immunoactivity then stated bioactivity, however, in vitro testosterone production was more effectively stimulated then with the previous more acidic eCG product. Our study shows a selective difference in commercial eCG biological activity that appears to depend on subtle isoform heterogeneity. Future studies aim to determine the specific actions of eCG isoforms in target tissues.

Vitamin D as a Regulator of Adipocyte Differentiation Effects in vivo and in vitro

2018 ◽  
Vol 69 (3) ◽  
pp. 731-734
Author(s):  
Alin Constantin Pinzariu ◽  
Teodor Oboroceanu ◽  
Florin Zugun Eloae ◽  
Ioana Hristov ◽  
Victor Vlad Costan ◽  
...  
Keyword(s):  
Vitamin D ◽  
Adipocyte Differentiation ◽  
Dependent Manner ◽  
Omental Adipose Tissue ◽  
In Vivo Experiments ◽  
Dose Dependent ◽  
Stromal Stem Cells

The age-associated adiposity and the effect of long-term vitamin D was studied in vitamin D deficient rats. In in vivo experiments, the influence of a 9 months of vitamin D treatment (weekly oral gavage with 0.125 mg vitamin D3 (5000 IU)/100g body weight) on the adipocyte precursors from the omental adipose tissue was examinated. In in vitro experiment, rat adipose-derived mesenchymal stromal/stem cells (ASCs) were induced to differentiate into adipocytes in the presence or absence of 25(OH)D3 (0.25, 25, and 2500 nmol/L). ASCs derived from vitamin D-treated animals showed an increase adipogenic potential as compared to vitamin D-deficient rats. The addition of 25(OH)D3 inhibits the adipocyte differentiation and lipid deposition in a dose dependent manner.

A specific population of gonadotrophs purified from immature female rat pituitary

Science ◽  
1976 ◽  
Vol 194 (4267) ◽  
pp. 848-851 ◽  
Author(s):  
C Denef ◽  
E Hautekeete ◽  
L Rubin
Keyword(s):  
Female Rat ◽  
Immature Female ◽  
Specific Population ◽  
Rat Pituitary
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