Precocious puberty and synaptogenesis in the hypothalamic arcuate nucleus in pregnant mare serum gonadotropin (PMSG) treated immature female rats

SummaryThe present study evaluated the effect of the aqueous extract from leaves of E. speciosa on some physiological and biochemical parameters of reproduction and the onset of puberty in pregnant mare serum gonadotropin (PMSG)-primed immature female rats. High pressure liquid chromatography (HPLC) was used to quantify the phenolic compounds in the methanol/methylene chloride (1:1) extract, the ethanolic and ethyl acetate fractions and the aqueous residue of E. speciosa. E. speciosa (0, 8, 32 or 64 mg/kg) were administered for 15 days to 24 non-PMSG-primed and 24 primed rats with 0.01 IU of PMSG. At the end of the treatment period, animal were sacrificed and their body, ovarian, uterine weight, ovarian protein or cholesterol level, as well as data on puberty onset were recorded. Of the 16 polyphenolic compounds quantitatively revealed in the extracts and fractions of E. speciosa after HPLC analysis, quercetin, rutin, apigenin and eugenol were the most abundant. Non-primed rats showed a significant increase (P < 0.05) in the uterine relative weight at the dose of 8 mg/kg when compared with the other treatments. The uterine proteins and the ovarian cholesterol (P < 0.05), respectively, showed a reduction at doses of 64 mg/kg and 32 mg/kg in non-primed rats. However in PMSG-primed rats, a significant decrease (P < 0.05) was observed in ovarian cholesterol at 64 mg/kg. In conclusion, E. speciosa potentializes the PMSG-inducing effect on folliculogenesis in PMSG-primed rats.

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PRECOCIOUS PUBERTY IN RATS WITH HYPOTHALAMIC LESIONS

Acta Endocrinologica ◽

10.1530/acta.0.xxxiii0569 ◽

1960 ◽

Vol XXXIII (IV) ◽

pp. 569-576 ◽

Cited By ~ 31

Author(s):

Ronald J. Gellert ◽

William F. Ganong

Keyword(s):

Precocious Puberty ◽

Arcuate Nucleus ◽

Anterior Hypothalamus ◽

Female Rats ◽

Vaginal Opening ◽

Mammillary Body ◽

Immature Female ◽

Hypothalamic Lesions ◽

Electrolytic Lesions

ABSTRACT Eight female rats with electrolytic lesions involving the arcuate nucleus in the posterior tuberal region of the hypothalamus matured significantly earlier than unoperated controls. Lesions placed in the anterior hypothalamus, mammillary body, hippocampus, cortex and thalamus of immature female rats had no effect on the age at which vaginal opening and first oestrus occurred.

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EFFECT OF ELECTRICAL STIMULATION OF THE HYPOTHALAMUS ON GONADOTROPHIN RELEASE AND THE ONSET OF PUBERTY

Journal of Endocrinology ◽

10.1677/joe.0.0540277 ◽

1972 ◽

Vol 54 (2) ◽

pp. 277-284 ◽

Cited By ~ 8

Author(s):

H. M. A. MEIJS-ROELOFS

Keyword(s):

Electrical Stimulation ◽

Precocious Puberty ◽

Arcuate Nucleus ◽

Follicle Stimulating Hormone ◽

Anterior Hypothalamus ◽

Female Rats ◽

Immature Female ◽

Ovarian Weight ◽

Stimulation Of ◽

Stimulating Hormone

SUMMARY Electrical stimulation of the hypothalamus with biphasic pulses was performed in immature female rats. When performed at 27 days of age or later, electrical stimulation in the arcuate nucleus region advanced puberty in all animals, as did stimulation of the anterior hypothalamus at 29 days of age or later. Stimulation in younger rats did not uniformly advance puberty. The responsiveness to electrical stimulation thus seems to develop a few days earlier in the arcuate nucleus region than in the anterior hypothalamus. In a second experiment the possible involvement of follicle-stimulating hormone (FSH) in the advancement of puberty was investigated: the simplified augmented ovarian weight assay for endogenous FSH was performed in rats stimulated in the arcuate nucleus region as well as in controls. A marked increase in ovarian weight, indicating increased FSH levels, was demonstrated in all animals stimulated on day 27 or later; at earlier ages only a percentage of the stimulated animals responded. This percentage paralleled the percentage of animals that showed advancement of puberty. It is concluded that electrical stimulation in both the arcuate nucleus region and the anterior hypothalamus advances the onset of puberty. It is suggested that electrical stimulation causes increased plasma FSH levels and, in consequence, precocious puberty.

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Effects of hydroxyflutamide on rats treated with a superovulatory dose of pregnant mare serum gonadotropin

Canadian Journal of Physiology and Pharmacology ◽

10.1139/y91-027 ◽

1991 ◽

Vol 69 (2) ◽

pp. 185-190 ◽

Cited By ~ 1

Author(s):

Frank H. Yu ◽

Young W. Yun ◽

Basil Ho Yuen ◽

Young S. Moon

Keyword(s):

Serum Levels ◽

Treated Group ◽

Biologically Active ◽

Female Rats ◽

Vehicle Group ◽

Immature Female ◽

Pregnant Mare Serum Gonadotropin ◽

Serum Gonadotropin ◽

17Β Estradiol ◽

Androgen Binding

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.

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The Fine Structure of Rat Granulosa Cell Cultures Correlated with Progestin Secretion

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100073209 ◽

1973 ◽

Vol 31 ◽

pp. 552-553

Author(s):

T. M. Crisp ◽

F.R. Denys

Keyword(s):

Fine Structure ◽

Granulosa Cell ◽

Cell Cultures ◽

Single Injection ◽

Surrounding Medium ◽

Petri Dish ◽

Female Rats ◽

Vaginal Smear ◽

Immature Female ◽

Serum Gonadotropin

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.

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Ontogeny of sex differences in LH and FSH levels 48 h after castration in the rat

AJP Endocrinology and Metabolism ◽

10.1152/ajpendo.1981.241.6.e460 ◽

1981 ◽

Vol 241 (6) ◽

pp. E460-E464

Author(s):

J. R. Lorenzen ◽

J. A. Ramaley

Keyword(s):

Follicle Stimulating Hormone ◽

Female Rats ◽

Hormonal Changes ◽

Vaginal Opening ◽

Immature Female ◽

Immature Male ◽

Male And Female Rats ◽

Serum Lh ◽

Pituitary Secretion ◽

Serum Gonadotropin

Serum gonadotropin levels were measured 12, 24, and 48 h after gonadectomy in male and female rats (ages, 22--60 days) to assess when during development the rate of rise of luteinizing hormone (LH) and follicle-stimulating hormone (FSH) after castration approximates that seen in the gonadectomized adult. In females serum LH levels 48 h after ovariectomy were increased above sham levels only when the ovaries were removed prior to vaginal opening. Ovariectomy on the day of vaginal opening or at older ages resulted in no increase in LH levels by 48 h after surgery. Serum FSH levels at 24 and 48 h after ovariectomy declined with increasing age at the time of ovariectomy. In males serum LH levels at 48 h after castration increased with increasing age at the time of gonadectomy. Serum FSH levels at either 12, 24, or 48 h after orchidectomy did not change appreciably with age at the time of surgery. It is concluded that the acute pituitary secretion of gonadotropins after removal of testes in the immature male resembles that seen in the mature male early in the course of the development of sexual maturity. In contrast, the acute pituitary secretion of gonadotropins after removal of the ovaries in the immature female does not resemble that seen in the ovariectomized adult until she is mature and capable of ovulating. Thus, the observed delay in the rise of LH seen in ovariectomized adults may be a function of some aspect of the hormonal changes associated with the estrous cycle.

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