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.

RETARDATION OF FIRST OVULATION IN PUBERTAL RATS AFTER TREATMENT WITH 5α-ANDROSTANE-3α,17β-DIOL OR ITS 3β-EPIMER

1982 ◽  
Vol 92 (1) ◽  
pp. 31-35 ◽  
Author(s):  
P. KRAMER ◽  
H. M. A. MEIJS-ROELOFS
Keyword(s):  
Body Weight ◽  
Precocious Puberty ◽  
Sexual Maturation ◽  
Female Rats ◽  
Female Rat ◽  
Vaginal Opening ◽  
Significant Delay ◽  
Vaginal Smears ◽  
Immature Female ◽  
High Doses

The effect was studied of five daily injections of 50 μg of either 5α-androstane-3α,17β-diol (3α-androstanediol) or its 3β-epimer (3β-androstanediol), starting on day 22 of life, on sexual maturation in female rats. No difference was found in the age and body weight at first oestrus between oil-treated rats and rats treated with either 3α- or 3β-androstanediol. The only difference observed between these groups consisted of the occurrence of a 'pinhole' vaginal opening a few days before oestrus in 50% of the steroid-treated rats; in oil-treated rats immediate full vaginal opening and first oestrus coincided in ten out of 12 rats. Different effects were obtained when the higher dose of 100 μg daily was used; effects were dissimilar in rats treated with 3α- and 3β-androstanediol. If administration of the higher dose of 3β-androstanediol was started on day 22 and continued until the day of full vaginal opening and first oestrus, a significant delay of this first oestrus, preceded by a few days of a 'pinhole' type of vaginal opening, was observed. After administration of the higher dose of 3α-androstanediol a 'pinhole' type of vaginal opening, accompanied by dioestrous-like vaginal smears, was also found, but oestrus did not occur during the period when injections were given. After the injections were stopped on day 45, first oestrus developed within 6 days in all rats. The previous findings of others that administration of 3β-androstanediol to the immature female rat may induce precocious puberty (i.e. precocious vaginal opening and first ovulation) were not confirmed in the present study. Our results indicate that high doses of free 3α-androstanediol, and to a lesser degree 3β-androstanediol, may even delay first ovulation in the rat. A possible interference of 3α-androstanediol with the triggering of the first ovulatory gonadotrophin peaks is discussed.

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.

Effect of anterior and posterior hypothalamic lesions on precocious sexual maturation

1964 ◽  
Vol 206 (4) ◽  
pp. 805-810 ◽  
Author(s):  
Raul C. Schiavi
Keyword(s):  
Sexual Maturation ◽  
Female Rats ◽  
Vaginal Opening ◽  
Uterine Weight ◽  
Comparative Effect ◽  
Hypothalamic Lesions ◽  
Medial Hypothalamus ◽  
Show Evidence ◽  
The Brain ◽  
Made In

The comparative effect of anterior and posterior hypothalamic lesions on the development of sexual maturation of prepubertal female rats was investigated. Lesions by electrocoagulation were made in the medial hypothalamus of 45 rats at 25–26 days of age. Thirty-nine animals of the same age constituted the sham-operated and nonoperated controls. A hastened appearance of vaginal opening and first estrus, a significant increase in uterine weight, precocious ovarian luteinization, and premature sexual cycles were observed following both types of lesions. Sham-operated rats and animals with lesions in other parts of the brain did not show evidence of precocious sexual maturation.

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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