scholarly journals Effect of leptin on LH and FSH release in ovariectomized rats

2002 ◽  
Vol 08 (01) ◽  
pp. 105-113
Author(s):  
M. M. Shebl
Keyword(s):  
Luteinizing Hormone ◽  
Follicle Stimulating Hormone ◽  
Female Rats ◽  
Ovariectomized Rats ◽  
Significant Recovery ◽  
Hormonal Release ◽  
Stimulating Hormone

We compared the estradiol/progesterone-induced luteinizing hormone [LH] and follicle-stimulating hormone [FSH] release between normally fed and leptin-supplemented starved ovariectomized female rats and studied also the effect of hyper-leptinaemia on the steroid-induced hormonal release in normally fed ovariectomized rats. Three days’ starvation completely abolished steroid-induced LH and FSH release. Significant recovery of the hormonal release was shown in the leptin-supplemented starved group. The magnitudes of LH and FSH release in the normally fed animals with a higher dose of leptin were statistically the same as those in the normally fed group without leptin. These observations indicate that physiological concentrations of circulating leptin exert a stimulatory effect on steroid-induced LH and FSH release.

Effect of Starvation on Pituitary and Serum Follicle-Stimulating Hormone and Luteinizing Hormone Following Ovariectomy in the Rat

1972 ◽  
Vol 50 (8) ◽  
pp. 768-773 ◽  
Author(s):  
E. A. Ibrahim ◽  
B. E. Howland
Keyword(s):  
Luteinizing Hormone ◽  
Pituitary Gland ◽  
Follicle Stimulating Hormone ◽  
Female Rats ◽  
Intact Female ◽  
Pituitary Glands ◽  
Ad Libitum ◽  
Stimulating Hormone

The concentration of follicle-stimulating hormone (FSH) and luteinizing hormone (LH) in serum and pituitary glands was studied in intact female rats and rats that were ovariectomized on day 0 of the experiment and then starved or fed for 2, 4, 7, or 9 days. Ovariectomy resulted in enhanced rates of synthesis and release of FSH and LH as indicated by the significant (P < 0.01) rises in the concentration of both hormones in the pituitary gland and serum.Starvation resulted in a decrease in body and pituitary weight. The concentration of FSH and LH in pituitary glands of starved rats was higher (P < 0.05) than that in fed rats on days 7 and 9. The concentration of FSH and LH in serum of starved rats was increased after ovariectomy but the levels on days 7 and 9 were lower than those of fed rats.These results suggest that the synthesis of FSH and LH was enhanced in both starved and fed rats following ovariectomy while the rate of release of both hormones was decreased at 7 and 9 days of starvation in comparison with rats fed ad libitum.

THE EFFECT OF PINEAL METHOXYINDOLES ON RAT VAGINAL OPENING TIME

1971 ◽  
Vol 50 (4) ◽  
pp. 679-683 ◽  
Author(s):  
R. COLLU ◽  
F. FRASCHINI ◽  
L. MARTINI
Keyword(s):  
Luteinizing Hormone ◽  
Sexual Maturation ◽  
Lateral Ventricle ◽  
Follicle Stimulating Hormone ◽  
Female Rats ◽  
Vaginal Opening ◽  
Significant Delay ◽  
Immature Female ◽  
The Brain ◽  
Stimulating Hormone

SUMMARY Melatonin and 5-methoxytryptophol, the two methoxyindoles of pineal origin, were injected into a lateral ventricle of the brain of immature female rats. Treatment was started on the 25th day of age and terminated when the vagina opened. The injection of both methoxyindoles resulted in a statistically significant delay in vaginal opening. Since previous experiments had shown that melatonin specifically inhibits secretion of luteinizing hormone and that 5-methoxytryptophol specifically blocks release of follicle-stimulating hormone, the present results support the hypothesis that the onset of sexual maturation needs a balanced secretion of both gonadotrophins.

Modulation of pituitary responsiveness to LHRH by androgens in ovariectomized female rats

1977 ◽  
Vol 55 (2) ◽  
pp. 188-192
Author(s):  
Padmaja N. Kulkarni ◽  
Alan A. Simpson ◽  
William H. Moger
Keyword(s):  
Luteinizing Hormone ◽  
Follicle Stimulating Hormone ◽  
Estradiol Benzoate ◽  
Female Rats ◽  
Ovariectomized Rats ◽  
Luteinizing Hormone Releasing Hormone ◽  
Daily Dose ◽  
17Β Estradiol ◽  
High Doses ◽  
Pronounced Inhibition

The effect of androgens on pituitary response to luteinizing-hormone-releasing hormone (LHRH) and their ability to modify effects of 17β-estradiol (E2) on pituitary responsiveness to LHRH were tested in ovariectomized rats maintained on a daily dose of 0.25 μg estradiol benzoate per rat for 6 d before androgen administration.Testosterone propionate (TP) (4, 40, 400, or 4000 μg per rat), administered 24 h before LHRH (500 ng per rat), had no significant effect on luteinizing hormone (LH) or follicle-stimulating hormone (FSH) response. Similar doses of dihydrotestosterone (DHT) did not significantly alter the LH response but significantly suppressed the FSH response. Even the lowest dose completely blocked the FSH response to LHRH. TP in combination with 4 or 400 μg of E2 suppressed the stimulatory effect of E2 on both LH and FSH response to LHRH in a dose-related manner. DHT and E2 in combination affected LH response inconsistently, whereas their ratio determined FSH response; there was pronounced inhibition of FSH response in rats given high doses of DHT combined with low doses of E2; DHT inhibition of FSH response in animals receiving 4 μg of DHT with 400 μg E2 was partially overcome by the stimulatory effect of E2. Our results indicate that TP and DHT affect LH and FSH response to LHRH differently. The ratio of androgen to estrogen is important in determining the response to LHRH.

COMPARISON OF FOLLICLE-STIMULATING HORMONE AND LUTEINIZING HORMONE SECRETION AFTER ELECTRICAL STIMULATION OF THE PREOPTIC PART OF THE HYPOTHALAMUS IN FEMALE RATS ANAESTHETIZED WITH ETHYL CARBAMATE OR SODIUM PENTOBARBITONE

1978 ◽  
Vol 78 (1) ◽  
pp. 151-152 ◽  
Author(s):  
R. G. DYER ◽  
M. B. TER HAAR ◽  
LINDA C. MAYES
Keyword(s):  
Electrical Stimulation ◽  
Luteinizing Hormone ◽  
Follicle Stimulating Hormone ◽  
Hormone Secretion ◽  
Control Process ◽  
Female Rats ◽  
Female Rat ◽  
Luteinizing Hormone Secretion ◽  
Stimulation Of ◽  
Stimulating Hormone

A.R.C. Institute of Animal Physiology, Babraham, Cambridge, CB2 4AT (Received 17 January 1978) For over 30 years, the method by which the brain regulates the secretion of gonadotrophic hormones has been studied by electrical stimulation of those parts of the central nervous system thought to be implicated in the control process. Much of the work has been performed on the female rat. In this species, anaesthetic doses of sodium pentobarbitone, administered immediately before the pro-oestrous 'critical period', block the preovulatory surge of luteinizing hormone (LH) for 24 h. The same treatment also reduces the early phase of the pro-oestrous secretion of follicle-stimulating hormone (FSH; Daane & Parlow, 1971). Electrical stimulation of the preoptic part of the hypothalamus can overcome this blocking effect and analysis of the optimum parameters required to restore normal secretion of gonadotrophins may give some insight into the endogenous process (e.g. Everett, 1965; Fink & Aiyer, 1974;

scholarly journals Comparison of inhibitory effect of ibuprofen with Piper guineense Schumach and Thonn. on some reproductive hormones in female rats

2017 ◽  
Vol 6 (4) ◽  
pp. 205-209
Author(s):  
Emmanuel Onuka Agbai ◽  
◽  
Chisomaga Chiwuikem Eke ◽  
Collins Okechukwu Nwanegwo ◽  
Ugochukwu Bond Anyaehie ◽  
...  
Keyword(s):  
Luteinizing Hormone ◽  
Follicle Stimulating Hormone ◽  
Inhibitory Effect ◽  
Female Rats ◽  
Assay Method ◽  
Piper Guineense ◽  
Serum Luteinizing Hormone ◽  
Group B ◽  
Group D ◽  
Stimulating Hormone

The aim of the present study was to compare the inhibitory effect of ibuprofen with oral administration of Piper guineense leaf extract on follicle-stimulating hormone, luteinizing hormone, progesterone and estrogen in female rats irrespective of the estrous cycle. The animals were randomly assigned to four groups (n = 7): group A (control), Group B, 180 mg-kg of ibuprofen, Group C, 200 mg-kg of Piper guineense extract, Group D, 180 mg-kg of ibuprofen and 200 mg-kg of Piper guineense extract. At the end of two weeks administration, rats were sacrificed under urethane anesthesia and hormones measured using enzyme-linked immunosorbent assay method. Results showed significant reduction in serum follicle-stimulating hormone and luteinizing hormone following ibuprofen administration in Group B rats at P < 0.05. Piper guineense extract treated Group C rats caused significant reduction in serum luteinizing hormone and progesterone at P < 0.05. In contrast, serum follicle stimulating hormone significantly increased in Group D rats at P < 0.05 whereas serum luteinizing hormone and progesterone were markedly reduced at P < 0.05. Serum estrogen level remained unchanged among groups. In conclusion, results obtained suggested that extract inhibited luteinization of follicles thus could impair ovulation, therefore the extract can be used as oral contraceptive in family planning.

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