Abstract
The effect of exogenous follicle stimulating hormone (FSH) on testicular function was studied in twenty 4‐month‐old Holstein bulls during two seasons (ten in late winter and ten in summer). Five mg FSH or saline were given subcutaneously at 12‐hour intervals (10 mg/day) for ten days, after which time the testes were removed, weighed, and incubated in vitro with 0,15, or 150 ng luteinizing hormone (LH) for 3 hours. FSH treatment resulted in significantly heavier testes (38%) in the summer (39.3 ± 1.6 vs 28.5 ± 1.5 g) but not in late winter. Epididymal weight was not affected. Across seasons, serum LH concentrations were higher (P = 0.06) in FSH‐treated bulls (2.39 ± 0.13 vs 1.80 ± 0.13 ng/ml); the largest increase occurred in the summer. FSH treatment did not change serum testosterone levels in late winter, whereas in the summer serum testosterone concentrations were threefold higher (0.90 ± 0.06 vs 0.29 ± 0.02 ng/ml; P < 0.05) in the FSH‐treated bulls. In addition, serum testosterone concentrations increased with time of FSH treatment. FSH treatment stimulated a 2.4‐fold increase (P < 0.05) in testosterone content of the testes across seasons and a threefold increase (P < 0.05) in testosterone synthesis in vitro in the summer. There was no dose effect of LH on in vitro testosterone synthesis. We conclude that administration of exogenous FSH to intact prepubertal bulls is capable of altering testicular function, but that seasonal influences can modify this function. 1983 American Society of Andrology
Original language | English (US) |
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Pages (from-to) | 371-377 |
Number of pages | 7 |
Journal | Journal of Andrology |
Volume | 4 |
Issue number | 6 |
DOIs | |
State | Published - 1983 |
Externally published | Yes |
Keywords
- bull
- follicle stimulating hormone
- luteinizing hormone
- prepubertal
- testosterone
ASJC Scopus subject areas
- Endocrinology, Diabetes and Metabolism
- Reproductive Medicine
- Endocrinology
- Urology