Biology of Reproduction, Vol 50, 44-48, Copyright © 1994 by Society for the Study of Reproduction

ARTICLES

Follicular fluid administration delayed, but did not prevent, the hemicastration-induced increase in follicle-stimulating hormone secretion and compensatory testicular hypertrophy in ram lambs

JL Brown, HM Schoenemann and PK Chakraborty
Department of Obstetrics and Gynecology, Uniformed Services University of the Health Sciences Bethesda, Maryland 20814.

To determine whether the post-hemicastration rise in serum FSH is related to compensatory testicular hypertrophy, 4-mo-old ram lambs were hemicastrated and injected s.c. with 5 ml of saline (HC; n = 5) or steroid-free follicular fluid (HC + FF; n = 5) twice daily for 28 days. Sham-operated intact lambs, injected with saline, served as controls (INT; n = 5). Blood samples were collected frequently during the first 48 h, daily for the remainder of the first week, and then three times/wk for the next 11 wk. Serum FSH concentrations in HC lambs increased above presurgery levels by 9 h, peaked at 13 days, and returned to baseline as compared to INT controls by 5 wk. Follicular fluid administration delayed (p < 0.05) the hemicastration-induced rise in FSH, but only for 14 of the 28 days of treatment; after this time, concentrations increased to the levels observed in HC rams. Within 2 days after the last follicular fluid injection (Day 30), FSH concentrations increased again to levels greater (p < 0.05) than those observed in HC animals. FSH secretion in HC + FF rams then declined to basal values by 7 wk, 2 wk later than in HC rams. Although the time course differed, the duration of elevated FSH did not differ between HC and HC + FF rams (36.4 +/- 2.0 vs. 37.8 +/- 4.7 days, respectively; p > 0.05). Testicular volume, determined on the last day of treatment (Day 28), was 70% greater (p < 0.05) in HC than in INT or HC + FF lambs; volume did not differ (p > 0.05) between INT and HC + FF rams.(ABSTRACT TRUNCATED AT 250 WORDS)