scholarly journals Stimulative effects of dexamethasone on serum levels of inhibin and estradiol in eCG-treated immature female rats.

1994 ◽  
Vol 64 ◽  
pp. 111
Author(s):  
Hajime Sakamoto ◽  
Hirosi Kogo
1995 ◽  
Vol 147 (2) ◽  
pp. 271-283 ◽  
Author(s):  
P A Fahy ◽  
C A Wilson ◽  
A J Beard ◽  
N P Groome ◽  
P G Knight

Abstract Recent modifications to a previously reported two-site IRMA have permitted the measurement of serum/plasma concentrations and ovarian contents of inhibin-A (α-βA dimer) in pregnant mare serum gonadotrophin (PMSG)treated immature female rats and adult rats throughout the 4-day oestrous cycle. For comparison, total α inhibin levels were also measured by α subunit-directed inhibin RIA and found to be at least tenfold higher (relative to the same 32 kDa bovine inhibin standard used to calibrate both assays). In immature female rats, serum levels of inhibin-A dimer and total α inhibin increased within 3 h of PMSG injection and rose in parallel over the next 48 h to values four- to fivefold higher than pretreatment levels. Ovariectomy led to a rapid and parallel fall in both inhibin-A dimer and total α inhibin; initial half-lives (±95% confidence intervals) were 22 ± 4 and 20 ± 5 min respectively. In adult rats, marked fluctuations in plasma concentrations and ovarian contents of inhibin-A dimer and total α inhibin occurred during the 4-day oestrous cycle, most notably between the morning of pro-oestrus and the morning of oestrus. Plasma levels of inhibin-A dimer and total α inhibin peaked on the afternoon of pro-oestrus just before the preovulatory gonadotrophin surge. After ovulation, both inhibin-A dimer and total α inhibin fell abruptly (two- to threefold by 0200 h on oestrus; P<0·001), while FSH showed a secondary rise which peaked at 0700 h on oestrus. Although IRMA- and RIA-derived inhibin values generally followed a similar pattern across the 4-day cycle (plasma: r=0·52, P<0·001; ovary: r=0·41, P<0·001), a transient rise in plasma and ovarian inhibin-A dimer was detected at 0700 h on oestrus (P<0·01) which was unaccompanied by a rise in total α inhibin. This rise in plasma inhibin-A dimer was probably responsible for terminating the post-ovulatory FSH surge since FSH levels declined steadily over the next 15 h. Overall, plasma inhibin-A dimer and FSH concentrations across the whole cycle were negatively correlated (r= −0·22, P<0·01) whereas no correlation existed between total α inhibin and FSH (r= −0·11, P=0·12). Journal of Endocrinology (1995) 147, 271–283


1991 ◽  
Vol 69 (2) ◽  
pp. 185-190 ◽  
Author(s):  
Frank H. Yu ◽  
Young W. Yun ◽  
Basil Ho Yuen ◽  
Young S. Moon

Immature female rats treated with superovulatory doses of pregnant mare serum gonadotropin (PMSG) were used to study the effects of the antiandrogen hydroxyflutamide on steroid production, particularly the biologically active androgens, in two experiments. In the first experiment, animals were given either 5 mg hydroxyflutamide or vehicle alone at 30 and 36 h following 40 IU PMSG. Compared with the vehicle group, hydroxyflutamide treatment significantly reduced the percentage of degenerate oocytes recovered from oviducts (p < 0.05). Serum levels of testosterone and androstenedione, and their aromatized product 17β-estradiol, significantly decreased (p < 0.05) in the hydroxyflutamide-treated group; however, nonaromatizable androgen, 5α-dihydrotestosterone, was not affected. In the second experiment, ovaries obtained 48 h after stimulation with 4 or 40 IU PMSG were incubated with and without hydroxyflutamide (10−5 M) and (or) testosterone (10−7 M) to study [4-14C]pregnenolone metabolism to major steroids. In 40 IU stimulated ovaries, hydroxyflutamide significantly decreased the metabolism of pregnenolone to progesterone (p < 0.01) and androstenedione (p < 0.01), while the production of 17β-estradiol increased significantly (p < 0.05); however, pregnenolone conversions to testosterone and 5α-dihydrotestosterone were not affected. Testosterone completely reversed the hydroxyflutamide-induced alteration of pregnenolone metabolism. In contrast, there was no difference in the pregnenolone conversion patterns between untreated and hydroxyflutamide or hydroxyflutamide plus testosterone groups in 4 IU stimulated ovaries. Present results confirm our previous finding that hydroxyflutamide decreases the percentage of abnormal oocytes recovered from superovulating rats and indicates that this hydroxyflutamide effect may be partly mediated by altered ovarian steroidogenesis following inhibition of androgen binding in the ovary.Key words: superovulation, pregnant mare serum gonadotropin, antiandrogen, hydroxyflutamide, androgen.


1973 ◽  
Vol 59 (2) ◽  
pp. 295-304 ◽  
Author(s):  
H. M. A. MEIJS-ROELOFS ◽  
J. Th. J. UILENBROEK ◽  
F. H. de JONG ◽  
R. WELSCHEN

SUMMARY Oestradiol-17β (E2) was measured by radioimmunoassay in the plasma of immature female rats. Maximal E2 levels of 55–60 pg/ml were found at 10–15 days of age; from day 25 to day 35 E2 levels were low to undetectable. The E2 measured appeared to be of ovarian origin: ovariectomy performed on day 13 resulted in a decreased E2 level 2 days later (13 pg/ml) as compared with the value from the control litter mates (46 pg/ml); after adrenalectomy the level of circulating E2 remained normal (54 pg/ml). The effects of ovariectomy and adrenalectomy on uterine weights followed a similar pattern: ovariectomy resulted in a decrease and adrenalectomy in no change in uterine weight. In the strain of rat used, levels of follicle-stimulating hormone (FSH) in the serum (measured by radioimmunoassay) were high from day 10 to day 20 and showed a steep decrease on day 21. After ovariectomy on day 15 this decrease in serum FSH was not observed. The influence of circulating E2 on serum levels of FSH was studied after ovariectomy followed by treatment with varying doses of oestradiol benzoate. Ovariectomy on day 13 resulted in a significantly increased FSH level 2 days later (1770 ng NIAMD-rat-FSH RP-1/ml) as compared with the value obtained from control animals (1033 ng/ml). This increase was not observed after daily injections of 0·1 μg oestradiol benzoate/100 g body weight. The results indicate that E2 and FSH concentrations show a similar pattern between 5 and 35 days of age. Furthermore, an inhibitory feedback mechanism between oestrogens and FSH concentrations was found to be operative. The implications of these findings are discussed.


2018 ◽  
Vol 29 (5) ◽  
pp. 473-481
Author(s):  
Marie Stéphanie Chekem Goka ◽  
Maurice Ducret Awouafack ◽  
Marc Lamshöft ◽  
Landry Lienou Lienou ◽  
Gildas Tetaping Mbemya ◽  
...  

Abstract Background Aloe buettneri, Dicliptera verticillata, Hibiscus macranthus and Justicia insularis are medicinal plants used in the western region of Cameroon to cure infertility among women. This experiment was designed to compare the effect of the aqueous extracts of A. buettneri (AAB), D. verticillata (ADV), H. macranthus (AHM), J. insularis (AJI), their mixture (AME) and the extract obtained from the mixture of their powders (AMP) on some parameters of reproduction. Materials and methods High-performance liquid chromatography coupled with the mass spectrometry (HPLC-MS) was used to detect the constituents of different extracts. The extracts (50 mg/kg) were administered to PMSG-primed immature rats (10 rats/group) for 5 days. At the end of the treatment, five animals of each group were sacrificed and various biological markers of reproduction were recorded. The remaining animals were injected with 10 IU of human chorionic gonadotropin (hCG) sacrificed 48 h later and the number of ovarian hemorrhagic points counted. Results Fifty-four compounds were found in the various extracts with 37 individually distributed among them and the remaining found in at least two extracts. As compared with the control, the AMP and AJI increased serum estradiol level by 2.36 and 2.23 times, respectively. The AMP was the only extract whose administration resulted in a significant increase (p<0.001) in the serum levels of follicle stimulating hormone (FSH) and luteinizing hormone (LH). Compared with the other extract-treated rats, the AMP-treated rats showed the highest number of hemorrhagic points. Conclusions These findings provided evidence on the synergistic effect of compounds present in these plant extracts and supported the usage of the mixture in traditional medicine.


Author(s):  
T. M. Crisp ◽  
F.R. Denys

The purpose of this paper is to present observations on the fine structure of rat granulosa cell cultures grown in the presence of an adenohypophyseal explant and to correlate the morphology of these cells with progestin secretion. Twenty-six day old immature female rats were given a single injection of 5 IU pregnant mares serum gonadotropin (PMS) in order to obtain ovaries with large vesicular follicles. At 66 hrs. post-PMS administration (estrus indicated by vaginal smear cytology), the ovaries were removed and placed in a petri dish containing medium 199 and 100 U penicillin/streptomycin (P/S)/ml. Under a 20X magnification dissecting microscope, some 5-8 vesicular follicles/ovary were punctured and the granulosa cells were expressed into the surrounding medium. The cells were transferred to centrifuge tubes and spun down at 1000 rpm for 5 mins.


1979 ◽  
Vol 90 (3) ◽  
pp. 385-393 ◽  
Author(s):  
José Borrell ◽  
Flavio Piva ◽  
Luciano Martini

ABSTRACT Drugs able to mimic or to antagonize the action of catecholamines have been implanted bilaterally into the basomedial region of the amygdala of adult castrated female rats. The animals were killed at different intervals after the implantation of the different drugs, and serum levels of LH and FSH were measured by radioimmunoassay. The results have shown that the intra-amygdalar implantation of the alpha-adrenergic blocker phenoxybenzamine induces a significant increase of the release both of LH and FSH. The implantation of the beta-adrenergic blocker propranolol brings about a rise of LH only. The dopamine receptor blocker pimozide stimulates the release of LH and exerts a biphasic effect (stimulation followed by inhibition) of FSH secretion. The alpha-receptor stimulant clonidine and the dopaminergic drug 2-Br-alpha-ergocryptine were without significant effects. From these observations it is suggested that the adrenergic signals reaching the basomedial area of the amygdala (possibly from the brain stem) may be involved in the modulation of gonadotrophin secretion.


Zygote ◽  
2021 ◽  
pp. 1-7
Author(s):  
Stéphanie Ouabo Meguem ◽  
Landry Lienou Lienou ◽  
Marie Stéphanie Chekem Goka ◽  
Richard Simo Tagne ◽  
Didiane Mefokou Yemele ◽  
...  

Summary Dicliptera verticillata is a medicinal plant traditionally used in western Cameroon to cure female infertility. This experiment was designed to assess the effects of the aqueous extract of Dicliptera verticillata (AEDv) on fertility and gestation in female rats. Oral increasing doses of AEDv were administered to immature female rats over 20 d. After this time, some animals were mated with fertile males and some fertility parameters were assayed; the other animals were euthanized for preliminary toxicity parameters analysis. The effects of AEDv on the different stages of gestation were assayed on selected animals previously controlled for estrous cycle regularity and mated. AEDv led to an increase in serum, uterine and ovarian proteins as well as in ovarian and uterine weights (P < 0.05) in immature female rats. Hepatic proteins significantly decreased (P < 0.01) in high dose-treated animals (50 and 100 mg/kg) compared with controls. The number of implantation sites and the fertility rate were significantly lower (P < 0.05), while the antifertility activity increased significantly (P < 0.05) in treated rats compared with controls. When administered from the 1st to the 5th day of pregnancy, AEDv led to a decrease of more than 60% in the implantation rate in high dose-treated rats (50, 100, and 400 mg/kg). From the 6th to the 9th day, the implantation, gestation rates and the number of fetuses decreased significantly in all treated groups. From the 11th to the 20th day, a 50% resorption and decrease in gestation rate were reported in 50 mg/kg dose-treated animals. AEDv possesses weak contraceptive and abortifacient effects during pregnancy.


1967 ◽  
Vol 39 (1) ◽  
pp. 53-60 ◽  
Author(s):  
W. C. ADAMS ◽  
J. H. LEATHEM

SUMMARY Immature female rats were fed thiouracil for 30 days and injected with 10 i.u. human chorionic gonadotrophin (HCG) for the last 20 days. In thiouracil-fed animals, HCG produced large ovaries containing follicular cysts. These ovaries showed a subnormal concentration of cholesterol but both a normal total content and normal incorporation of [1-14C]acetate into digitonin-precipitable-sterols. Liver and serum cholesterol concentrations were reduced, but in vivo, 4 hr. incorporation of acetate into sterols was doubled suggesting either an acceleration of cholesterol turnover or delayed utilization of sterol precursors of cholesterol. HCG also reduced ovarian cholesterol concentration in euthyroid animals but total organ content and incorporation of [14C]acetate were not altered, nor were liver and serum cholesterol affected. Since the effect of induced ovarian cysts on sterol metabolism cannot be accounted for by known effects of thyroid or gonadal hormones it is suggested that influences of steroid hormones on lipid metabolism may be greatly modified in thyroid deficiency.


1981 ◽  
Vol 96 (4) ◽  
pp. 470-474 ◽  
Author(s):  
Peter Ball ◽  
Günter Emons ◽  
Ulrich Gethmann

Abstract. Osmotic minipumps containing low doses of either 4-hydroxyoestradiol or 2-hydroxyoestradiol2) were sc implanted for 152 h (6⅓ day) into immature male and female rats. At the end of the test period the animals were killed and the uterine weight, the vaginal opening, the gonadotrophin serum levels and the gonadal weight monitored. The following results were obtained: 1) a significant increase in the uterine weight and a consistent vaginal opening were observed after 4-hydroxyoestradiol but not after 2-hydroxyoestradiol treatment, 2) LH-levels increased after 2-hydroxyoestradiol but not after 4-hydroxyoestradiol; the increase was, however, not significant, 3) FSH-levels and gonadal weights were lowered by 4-hydroxyoestradiol treatment in male animals only; 2-hydroxyoestradiol had no effect on FSH-levels in both sexes, 4) in no instance an antioestrogenic effect of either catecholoestrogen was observed. It is concluded that 4-hydroxyoestrogens — using the above paradigm — have a significant importance on uterine growth and vaginal opening but (on day 6) no role on LH-release, whereas 2-hydroxyoestrogens may increase LH levels (on day 6) but are nearly ineffective with respect to peripheral parameters.


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