A Positive Feedback Action of Androgen on Pituitary Follicle Stimulating Hormone: Induction of a Cyclic Phenomenon
1969; Oxford University Press; Volume: 85; Issue: 5 Linguagem: Inglês
10.1210/endo-85-5-881
ISSN1945-7170
AutoresDonald C. Johnson, REHAN H. NAQVP,
Tópico(s)Stress Responses and Cortisol
ResumoTemporal changes in endogenous follicle stimulating hormone (FSH) following a single injection of testosterone propionate (TP) or estradiol benzoate were investigated in immature female rats. Circulating FSH level was evaluated directly in the experimental animals by a modified augmented ovarian weight method. Human chorionic gonadotropin was administered at various times after the steroid injection at 22 days of age, and the resulting ovarian weight recorded as an index of their endogenous FSH. The 2 doses of TP used (25 and 100 μg) induced cyclic increases in FSH whichwere spaced approximately 24 hr apart. Alternating with the peaks in FSH activity were troughs with no more FSH than in oil-treated controls. The low dose induced 3 distinct cycles, while the larger dose induced 4. On the basis of this and previous studies, we conclude that TP induced an increased synthesis and matched release of FSH, both occurring at regular intervals. Estradiol benzoate (1 μg) caused one large and extended increase in endogenous FSH which could be accounted for largely on the basis of a depletion of pituitary stores. (Endocrinology85: 881, 1969)
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