Effect of exercise on the onset of puberty, gonadotropins, and ovarian inhibin

1987 ◽  
Vol 63 (3) ◽  
pp. 1165-1173 ◽  
Author(s):  
J. Pellerin-Massicotte ◽  
G. R. Brisson ◽  
C. St-Pierre ◽  
P. Rioux ◽  
D. Rajotte

Swimming 6 h/day from 11 days of age led to a significant delay of the onset of puberty of female rats compared with the sedentary group. Rats who were in contact with water but without the energy expenditure due to exercise (paddlers) had their vaginal opening in a middle point between control and exercising rats. Vaginal opening occurred at different ages but at a same body weight. Exercise and stress led to a marked decrease of the body weights between 19 and 40 days of age. Serum luteinizing hormone and follicle-stimulating hormone were increased with the exercise program at 30 days of age, whereas no significant differences between groups in serum gonadotropins were observed at 50 days of age. Only the anterior pituitary luteinizing hormone content was increased by exercise in adult rats. Total ovarian proteins were significantly reduced by stress and to a greater degree by exercise. Ovarian inhibin activity is not modified by exercise at 30 days of age, whereas it increased significantly in the exercising group at 50 days of age and to a lesser degree in paddlers. It is therefore suggested that the onset of puberty in rats is dependent on a critical weight and that exercise and stress can delay the onset of puberty. This delay could be explained by a deficiency of hormonal maturational process while exercising until sexual maturity alters the inhibin activity, which suggests that inhibin could play a major role for the normal reproductive function and this could possibly explain the menstrual disturbances in the female athlete.

Animals ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 567
Author(s):  
Wenyu Si ◽  
Hailing Li ◽  
Tiezhu Kang ◽  
Jing Ye ◽  
Zhiqiu Yao ◽  
...  

This study explored the role of γ-aminobutyric acid transaminase (GABA-T) in the puberty and reproductive performance of female rats. Immunofluorescence technique, quantitative real-time PCR (RT-qPCR) and enzyme-linked immunosorbent assay (ELISA) were used to detect the distribution of GABA-T and the expression of genes and hormones in female rats, respectively. The results showed that GABA-T was mainly distributed in the arcuate nucleus (ARC), paraventricular nucleus (PVN) and periventricular nucleus (PeN) of the hypothalamus, and in the adenohypophysis, ovarian granulosa cells and oocytes. Abat mRNA level at 28 d was lowest in the hypothalamus and the pituitary; at puberty, it was lowest in the ovary. Abat mRNA level was highest in adults in the hypothalamus; at infancy and puberty, it was highest in the pituitary; and at 21 d it was highest in the ovary. After vigabatrin (GABA-T irreversible inhibitor) was added to hypothalamus cells, the levels of Abat mRNA and Rfrp-3 mRNA were significantly reduced, but Gnrh mRNA increased at the dose of 25 and 50 μg/mL; Kiss1 mRNA was significantly increased but Gabbr1 mRNA was reduced at the 50 μg/mL dose. In prepubertal rats injected with vigabatrin, puberty onset was delayed. Abat mRNA, Kiss1 mRNA and Gnrh mRNA levels were significantly reduced, but Rfrp-3 mRNA level increased in the hypothalamus. Vigabatrin reduced the concentrations of GABA-T, luteinizing hormone (LH) and progesterone (P4), and the ovarian index. Lactation performance was reduced in adult rats with vigabatrin treatment. Four hours after vigabatrin injection, the concentrations of GABA-T and LH were significantly reduced in adult and 25 d rats, but follicle-stimulating hormone (FSH) increased in 25 d rats. In conclusion, GABA-T affects the reproductive function of female rats by regulating the levels of Gnrh, Kiss1 and Rfrp-3 in the hypothalamus as well as the concentrations of LH and P4.


2002 ◽  
Vol 172 (3) ◽  
pp. 441-448 ◽  
Author(s):  
L Pinilla ◽  
ML Barreiro ◽  
LC Gonzalez ◽  
M Tena-Sempere ◽  
E Aguilar

Hypothalamic differentiation in the female rat during the neonatal period is critically dependent on the steroid milieu, as permanent changes in reproductive function are observed after administration of oestradiol and testosterone during such a critical stage. Selective oestrogen modulators (SERMs) constitute a family of drugs that, depending on the tissue, are able to exert oestrogenic or antioestrogenic actions. The present experiments were conducted to analyse whether the SERMs, tamoxifen and raloxifene, can cause oestrogenic actions during the hypothalamic differentiation period. Postnatal female rats were injected between days 1 and 5 with 100 microg/day tamoxifen, raloxifene or ICI 182,780 (a pure antioestrogen). Other groups of animals were injected on day 1 of age with 100 microg oestradiol benzoate (OeB) or 1.25 mg testosterone propionate (TP) alone or in combination with raloxifene (500 microg/day between days 1 and 5). In all experimental groups, the age, body weight and concentrations of serum gonadotrophins at vaginal opening were recorded, whereas vaginal cyclicity and the negative and positive feedback between oestradiol and LH were monitored in adulthood. The results obtained confirmed the ability of high doses of OeB or TP to alter the normal differentiation of the brain permanently. They also reinforced the hypothesis that oestrogens are also necessary for normal brain differentiation in female rats because administration of a pure antioestrogen, such as ICI 182,780 permanently altered the function of the reproductive axis. In addition, our data provided evidence for different actions of the two SERMs under analysis (raloxifene and tamoxifen) upon peripheral targets, as raloxifene advanced vaginal opening whereas tamoxifen did not. In contrast, their actions on brain differentiation appeared similar and analogous to those obtained after neonatal administration of oestradiol, as evidenced by vaginal acyclicity, ovarian atrophy, sterility and abolition of negative and positive feedback between oestradiol and LH, thus suggesting an oestrogenic action of these SERMs on hypothalamic differentiation. Moreover, the oestrogenic activity of raloxifene was supported by its inability to block the effects of OeB and TP administered neonatally. In conclusion, the present results indicated that the SERMs, tamoxifen and raloxifene, exert an oestrogen-like effect upon hypothalamic differentiation of the neonatal female rat.


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.


1977 ◽  
Vol 75 (3) ◽  
pp. 419-426 ◽  
Author(s):  
H. M. A. MEIJS-ROELOFS ◽  
P. KRAMER

The involvement of the adrenal gland in the release of gonadotrophins and the onset of puberty in female rats was studied. Two and four days after adrenalectomy (ADX) on either day 5 or 10 after birth, a significant decrease in the concentration of FSH was found; 4 days after ADX on either day 15 or 20, FSH concentrations had increased significantly compared with sham-operated and/or intact controls. However, in the rats adrenalectomized on day 15 or 20, the body weights were lower than in control rats. Relative uterine weights (mg/100 g body wt) in adrenalectomized rats never differed from those of control rats. A delay in the time at which vaginal opening and the first oestrus occurred was found in rats adrenalectomized at 20 or 25 days of age; however this delay was accompanied in these rats by a retardation in the gain in body weight. It is argued that the effects of ADX on both the release of gonadotrophins and the onset of puberty are primarily, and presumably exclusively, due to the effects on general bodily development (expressed in body weight). The lack of effect of ADX on uterine weight supports the hypothesis that 'oestrogen-like' products from the adrenal gland are not biologically active as oestrogens.


1970 ◽  
Vol 42 (2) ◽  
pp. 137-145
Author(s):  
Vappu Kossila ◽  
Ritva Myllymaa

The experimental period was apparently too short and the number of rats too small to demonstrate a significant effect of iodine deficiency on some indices of reproduction of the females and the growth rate of their progeny. It was found, however, that iodine deficiency: a) delayed significantly the conception of the second generation females (C2) (Table 3) but was quite ineffective in the first generation females (B1, C1) (Tables 2 & 4), b) did not significantly affect the number of pups dropped or their birth weight, c) increased pup mortality during suckling period, d) tended to decrease the weight of the female sex organs of adult rats (Table 5), e) increased the absolute thyroid weight more rapidly in young growing rats than in old fullgrown rats (Tables 3, 4 & 5), and more rapidly in growing males than females, f) decreased significantly and progressively the PBI level in the serum of adult females which had pregnancies and lactations, g) obviously adversely affected the milk secretion of C1 rats during their second lactation on iodine deficient diet (Experiment II) as judged from the growth rate of their pups during 0—15 days after birth, h) did not adversely affect the growth rate of the suckling offspring of the dams during their first lactation on iodine deficient diet (Tables 3 & 4), i) did not significantly affect the rate of gain of the young rats from weaning up to 60-days of age. The rats transferred from iodine deficient to commercial diet at weaning had larger body weights and smaller thyroids at the age of 60 days than their litter mates remaining on an iodine deficient diet (Table 4). There is of course a possibility that the commercial diet was more palatable than the semisynthetic diet. It is also possible that the iodine deficiency activated the thyroid during the preweaning period and that after the transfer to iodine containing commercial diet at weaning, more thyroxine was secreted from preactivated glands compared to thyroids of the controls or thyroids of the rats kept on an iodine deficident diet throughout the growth period. Thyroid hormones are required for normal growth. A hypothyroid condition favours the accumulation of water and fat into the body tissues and may by this way result in an increase of the body weight. ln this study, however, no attempt was made to estimate the fat content of the body of the experimental rats.


Reproduction ◽  
2012 ◽  
Vol 143 (1) ◽  
pp. 21-33 ◽  
Author(s):  
Victoria Tyndall ◽  
Marie Broyde ◽  
Richard Sharpe ◽  
Michelle Welsh ◽  
Amanda J Drake ◽  
...  

We investigated the effects of different windows of testosterone propionate (TP) treatment during foetal and neonatal life in female rats to determine whether and when excess androgen exposure would cause disruption of adult reproductive function. Animals were killed prepubertally at d25 and as adults at d90. Plasma samples were taken for hormone analysis and ovaries serial sectioned for morphometric analyses. In prepubertal animals, only foetal+postnatal and late postnatal TP resulted in increased body weights, and an increase in transitory, but reduced antral follicle numbers without affecting total follicle populations. Treatment with TP during both foetal+postnatal life resulted in the development of streak ovaries with activated follicles containing oocytes that only progressed to a small antral (smA) stage and inactive uteri. TP exposure during foetal or late postnatal life had no effect upon adult reproductive function or the total follicle population, although there was a reduction in the primordial follicle pool. In contrast, TP treatment during full postnatal life (d1–25) resulted in anovulation in adults (d90). These animals were heavier, had a greater ovarian stromal compartment, no differences in follicle thecal cell area, but reduced numbers of anti-Mullerian hormone-positive smA follicles when compared with controls. Significantly reduced uterine weights lead reduced follicle oestradiol production. These results support the concept that androgen programming of adult female reproductive function occurs only during specific time windows in foetal and neonatal life with implications for the development of polycystic ovary syndrome in women.


1993 ◽  
Vol 129 (3) ◽  
pp. 251-259 ◽  
Author(s):  
E Trimiño ◽  
L Pinilla ◽  
E Aguilar

We have analyzed the mechanisms involved in ovarian failure after administration of gonadotropin hormone-releasing hormone agonists (GnRH-A) or antagonists (GnRH-ANT). Ovarian and uterine weights, serum concentrations of follicle-stimulating hormone (FSH), luteinizing hormone (LH) and estradiol and pituitary FSH and LH contents were measured in Wistar female rats injected from 1–15 or 90–104 days of age with the agonist d-Ala6-d-Gly10-GnRH or the GnRH-ANT Org. 30276. Vaginal opening, first estrous presentation, vaginal smears and reproductive capacity were also analyzed. In both neonatal and adult females GnRH-A induced pituitary desensitization and reduced ovarian and uterine weights and estradiol serum concentrations. Therefore, serum gonadotropin concentrations were increased in adults and decreased in neonatal females. Puberty occurrence and reproductive function remain unaltered after neonatal treatment with GnRH-A. In neonatal females, FSH and LH pituitary content and FSH serum concentrations decreased at the end of treatment with GnRH-ANT. The effects on LH and estradiol secretion depended on the pattern of treatment. Interestingly enough, both vaginal opening and first estrous presentation were precipitated by GnRH-ANT administration. Normal reproductive function was observed in adults. We conclude that: (i) pituitary desensitization of receptors occurred in both neonatal and adult females after chronic administration of GnRH-A; (ii) the ovarian failure observed in adults that is accompanied by increased serum concentrations of gonadotropins was probably due to an inhibitory effect of GnRH-A directly on the ovaries; (iii) the blockade of GnRH action shortly after birth with GnRH-ANT precipitated the onset of puberty; possibly the antagonist blocks some suppressive effects of endogenous LHRH; (iv) the effects of neonatal administration of GnRH-A or GnRH-ANT were transitory.


2021 ◽  
Vol 20 (1) ◽  
pp. 87-96
Author(s):  
T. G. Borovskaya ◽  
V. E. Goldberg ◽  
M. E. Poluektova ◽  
A. V. Vychuzhanina ◽  
Yu. A. Shchemerovа ◽  
...  

The purpose of the study was a comparative experimental assessment of long-term toxic effects of cytostatic drugs (epirubicin, etoposide, platidiam, carboplatin, paclitaxel) on the female reproductive function and search for pharmacological ways to reduce them.Material and Methods. Experiments were carried out on 200 outbred male rats, Wistar stock, 2.5 months old. Antitumor drugs were administered once, intravenously, in maximum tolerated dose. The reproductive status in rats was assessed 90 and 180 days after injection of cytostatic drugs. Correction of ovariotoxicity of cytostatic drugs was carried out using a recombinant human granulocyte colony stimulating factor (rhG-CS F, Neupomax, FARMSTA NDA RT-UfaVITA OJSC , Russia) and liquid extract of Scutellaria Baikalsky («GNTsLS », Kharkov). The mating and fertility ability of female rats as well as pre- and post-implantation fetal mortality were determined. Ovarian reserve was evaluated using morphological analysis of the ovaries using quantitative assessments of structural damage. Concentration of anti-Muller hormone in the blood of adult rats-females receiving etoposide and rhG-CS F were evaluated by enzyme immunoassay (IFA, ELISA , Cloud clone, Corp. Wuhan). Statistical processing of obtained experimental data was performed using Mann-Whitney U-test and Fisher angular transformation.Results. The mating and fertility ability of animals was found to be persisted. However, signs of early depletion of the ovarian reserve and a decrease in reproductive potential were observed. The risk of early menopause was increased to a greater extent after using epirubicin, etoposide and paclitaxel, and to a lesser extent after platidiam and carboplatin. The reproductive potential of animals was reduced due to increased fetal death. Platinum-containing drugs were found to be the most toxic. G-CS F was the effective drug for protecting the ovarian reserve from cytostatic effects. The use of Scutellaria baicalensis extract increased the reproductive potential of animals by reducing the rate of embryonic death. 


1980 ◽  
Vol 85 (1) ◽  
pp. 69-74 ◽  
Author(s):  
F. GOGAN ◽  
I. A. BEATTIE ◽  
M. HERY ◽  
E. LAPLANTE ◽  
C. KORDON

SUMMARY Implantation of oestradiol into adult rats of both sexes induced different patterns of LH secretion depending on the time at which gonadectomy or testosterone injection were performed. Castration 2 h after birth allowed an LH peak to occur daily at 18.00 h, but its amplitude was lower than that of adult gonadectomized female rats treated with oestradiol. Castration 24 h after birth elicited two kinds of response; a circadian discharge of LH lower than that of male rats gonadectomized 2 h after birth or a steady low level of LH. The LH rhythmicity induced by implantation of oestradiol was not seen after castration at 8 weeks of age. Neonatal administration of testosterone to female rats prevented the LH peak induced by oestradiol that was seen in adult ovariectomized rats. Neonatal or adult ovariectomy did not interfere with the rhythmical response of LH after implantation of oestradiol. Thus, it is concluded that sexual differentiation of the hypothalamus is primarily of masculine origin.


1983 ◽  
Vol 103 (2) ◽  
pp. 172-179 ◽  
Author(s):  
J. Bíró ◽  
E. M. Ritzén ◽  
K. Hall ◽  
P. Eneroth

Abstract. Plasma concentrations and anterior pituitary content of growth hormone (rGH), thyroid stimulating hormone (rTSH), and rat prolactin (rPrl) as well as the plasma concentrations of triiodothyronine (T3), thyroxine (T4) and somatomedin A (SM-A) have been determined in intact, castrated or hysterectomized adult rats with and without treatment with steroid-free, crude uterine extracts. Hysterectomy caused a significant increase in the plasma GH but decrease in the plasma TSH concentrations. Injection of crude, steroid-free uterine extracts for 14 days had the following effects: decreased plasma GH concentration of intact rat and anterior pituitary GH content of both intact and castrated animals; increased plasma TSH and T3 concentrations above the ovariectomized control; decreased pituitary content of prolactin in castrated rats. The plasma levels of immunoreactive somatomedins A were negatively correlated to the plasma GH concentrations but positively correlated to the body weight. It was concluded that the uterus is not only a target for different endocrine influences but contains biologically active, non-steroidal substances which have a complex effect on the endocrine system of adult, female rats.


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