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

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.

1971 ◽  
Vol 50 (4) ◽  
pp. 679-683 ◽  
Author(s):  
R. COLLU ◽  
F. FRASCHINI ◽  
L. MARTINI

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.


1978 ◽  
Vol 78 (1) ◽  
pp. 151-152 ◽  
Author(s):  
R. G. DYER ◽  
M. B. TER HAAR ◽  
LINDA C. MAYES

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;


1968 ◽  
Vol 57 (2) ◽  
pp. 289-295 ◽  
Author(s):  
E. Steinberger ◽  
G. Duckett

ABSTRACT On the basis of a study of changes in follicle stimulating hormone (FSH) levels in rat pituitary glands, obtained at various times after orchiectomy, it has been previously suggested that the Leydig cell secretions may regulate the release of FSH from the pituitary gland (Steinberger & Duckett 1966). This hypothesis was put to test in the present study. FSH levels have been determined in the pituitary gland and plasma of normal, testosterone-treated, orchiectomized, and orchiectomized testosteronetreated rats. A marked drop of pituitary FSH levels, associated with an elevation of plasma FSH levels, was observed in orchiectomized rats. Administration of testosterone to orchiectomized rats prevented the drop in pituitary FSH levels and rendered the blood levels undetectable. These results are interpreted as supporting the hypothesis that testosterone has an inhibitory effect on the release of FSH from the pituitary gland.


2017 ◽  
Vol 6 (4) ◽  
pp. 205-209
Author(s):  
Emmanuel Onuka Agbai ◽  
◽  
Chisomaga Chiwuikem Eke ◽  
Collins Okechukwu Nwanegwo ◽  
Ugochukwu Bond Anyaehie ◽  
...  

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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