Effects of Neonatal Androgenization on Serum Gonadotropin Levels of Prepubertal and Adult Male and Female Rats

Moguilevsky, Jaime A.; Scacchi, Pablo; Epstein, Yoram; Lunenfeld, Bruno

doi:10.1159/000122770

Cited by 11 publications

(8 citation statements)

References 6 publications

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“…2B), rather than more rapidly as one would expect if this trait was masculinized. Similar results have been reported by Moguilevskiet al [28]. This defect in LH responsiveness is not due to an inability of the pituitary to respond to GnRH (fig.…”

Section: Discussionsupporting

confidence: 90%

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Effect of Neonatal Treatment with the Sex-Opposite Steroid on Gonadotropin Responsiveness in Rats

Grady¹

1986

Neuroendocrinology

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This study was performed to determine if two sex differences in gonadotropin responses to negative feedback, the acute postcastration rise and the effect of follicular fluid (FF) in the acute castrate, could be reversed by neonatal treatment with sex-opposite steroids. Female rats that received testosterone propionate (TP-females) and male rats that received estradiol benzoate (EB-males) neonatally were studied as adults. EB-males showed an LH response to gonadecto-my which was much less than control males, and did not differ from control females, which could suggest the hypothesis that neonatal estrogen ‘feminizes’ the male response to gonadectomy. However, as the postgonadectomy response in both LH and FSH was depressed in both TP-females and EB-males in comparison to their respective matched sex controls, neonatal steroid treatment appears simply to impair hypothalamic-pituitary function. This is not a result of decreased pituitary responsiveness to GnRH in TP-females and EB-males. On the other hand, neonatal steroid treatment does not change the sex-specific response to imposition of peptide negative feedback (i.e., FF administration). In control and TP-females, FF significantly suppressed serum FSH levels, both in intact animals and 9 h after gonadectomy. In both control and EB-males, FF suppressed FSH in intact animals, but failed to do so in acute castrates. Thus, neonatal steroid treatment does not reverse the sex differences in gonadal-gonadotropin interrelations, but rather causes an impairment in the acute recognition of loss of negative feedback at the hypothalamic level.

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Section: Discussionsupporting

confidence: 90%

“…This notion is supported by the finding that neo natal treatment of male rats with testosterone [28,32] and female rats with estradiol [16] also impairs hypothalamic pi tuitary function and results in sterility.…”

Section: Discussionmentioning

confidence: 86%

Effect of Neonatal Treatment with the Sex-Opposite Steroid on Gonadotropin Responsiveness in Rats

Grady¹

1986

Neuroendocrinology

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“…In previous papers [8,9] it has been dem onstrated that neonatal androgenization in creases FSH in both male and females rats; these results are confirmed again in this paper. Nevertheless, not only such differences dis appear after castration but also androgenized rats showed lower levels of FSH than the controls in the first few days after gonadectomy.…”

Section: Discussionsupporting

confidence: 90%

“…The tonic or male Gn pattern characteristically shows higher levels of plas ma and pituitary follicle-stimulating hormone (FSH) and serum prolactin [4,5,10]. In pre vious papers [8,9] we demonstrated that the administration of testosterone to male and female rats during the first days of life pro duces an increase in the FSH and prolactin levels in the adult as compared with untreated rats.…”

mentioning

confidence: 96%

Effect of Castration on Serum Gonadotropin Levels in Androgenized Male and Female Rats

Moguilevsky¹,

Faigón²,

Scacchi³

et al. 1979

Neuroendocrinology

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The changes in LH and FSH secretion 12, 18 h and 1, 3, 5, 20 and 30 days following castration in adult rats of both sexes neonatally androgenized were studied. After castration, serum LH concentration rose slowly in the female and rapidly in male rats. Orchidectomy induced an increase of LH that was significantly slower in the androgenized rats than in the controls until 20 days after the postcastration period, reaching similar values at 30 days. In the female rats the increase in the LH levels from 48 h to 30 days after castration was significantly lower in the androgenized than in the control rats. Basal levels of FSH were higher in the androgenized males than in the controls. The concentration of the hormone increased in both groups 12 h after orchidectomy, the basal differences disappearing. These groups of rats showed similar values from 48 h up to 30 days after castration. As in the males, FSH basal levels were higher in androgenized rats than in control female rats and the difference disappeared 12 h after castration. The increase in the FSH concentration postgonadectomy was significantly lower in androgenized rats than in the control rats from 48 h to 20 days. At this time, both groups reach a plateau with similar values. These results indicate that androgenized male and female rats showed, at different times of the postcastration period, lower levels of FSH and LH than the controls and that these differences disappear after 30 days of castration. On the other hand, the differences in the basal levels of FSH concentration between controls and androgenized male and female rats also disappear in the first few hours postgonadectomy.

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“…Neonatal treatment with es tradiol [Aguilar, 1979] or testosterone [Mennin and Gorski, 1975] blocks cyclic LH secre tion in the adult female rat. In both sexes, treatment with androgens shortly after birth leads to an increase in adult basal FSH levels without altering LH secretion [Moguilevski et al, 1978]. The gonadotrophic response to castration is attenuated in neonatally estrogenized female rats [Aguilar, 1979;Vaticdn et al, 1980], Together with disturbances in go nadotrophin secretion, gonadal function changes: in adult females an anovulatory syn drome can be seen after neonatal androgen or estrogen treatment [Barraclough, 1961;Gors ki, 1963] while in neonatally estrogenized males testicular atrophy has been reported [Kind et al, 1963].…”

Section: Introductionmentioning

confidence: 99%

Dissociation of Luteinizing Hormone and Follicle-Stimulating Hormone Control Mechanisms in Male and Female Rats by Neonatal Administration of Estradiol Benzoate or Testosterone Propionate

et al. 1984

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Testicular atrophy (TA) and decreased plasma luteinizing hormone (LH) levels were observed in the adult male rat after treatment with 500 µg of estradiol benzoate (EB) on the first day of life, while administration of 1 mg of testosterone propionate (TP) on the same day was also associated with TA but increased LH levels. TA and no changes in plasma LH levels were seen when the treatment was performed with similar doses of both steroids on day 5 of life. In no case were plasma follicle-stimulating hormone (FSH) levels altered by these treatments. No differences in basal LH and FSH levels were found in adult females after treatment with 100 µg of EB or 1 mg of TP on day 5. LH response to castration was lower in neonatally androgenized and estrogenized adult male and female rats than in their respective controls, while FSH response was scarcely modified. In conclusion, neonatal treatment with EB or TP in both sexes induced alterations in LH control mechanisms without changing those of FSH.

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Effects of Neonatal Androgenization on Serum Gonadotropin Levels of Prepubertal and Adult Male and Female Rats

Cited by 11 publications

References 6 publications

Effect of Neonatal Treatment with the Sex-Opposite Steroid on Gonadotropin Responsiveness in Rats

Effect of Neonatal Treatment with the Sex-Opposite Steroid on Gonadotropin Responsiveness in Rats

Effect of Castration on Serum Gonadotropin Levels in Androgenized Male and Female Rats

Dissociation of Luteinizing Hormone and Follicle-Stimulating Hormone Control Mechanisms in Male and Female Rats by Neonatal Administration of Estradiol Benzoate or Testosterone Propionate

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