AJP - Endocrinology and Metabolism, Vol 262, Issue 2 E179-E184, Copyright © 1992 by American Physiological Society
Termination of the peripubertal FSH increase in male rats
S. J. Nazian and D. F. Cameron
Department of Physiology and Biophysics, College of Medicine, University of South Florida, Tampa 33612.
To determine if the pubertal testosterone rise plays a role in the
termination of the peripubertal follicle-stimulating hormone (FSH)
increase, male rats were injected with ethylene dimethanesulfonate (EDS) at
40 days of age to eradicate the Leydig cells just before the onset of the
testosterone rise. Rats were decapitated at weekly intervals from age 26 to
96 days. Compared with vehicle-injected controls, EDS treatment resulted in
a delay in the peripubertal increase in the relative weights of prostates
and seminal vesicles of approximately 2 wk. Serum testosterone remained at
pretreatment levels for 1 wk postinjection. Testicular interstitial fluid
testosterone remained at pretreatment concentrations for considerably
longer and was significantly lower than controls for 2 wk postinjection.
EDS treatment resulted in serum FSH levels that were elevated by 1 wk
postinjection. They remained significantly higher than controls until 96
days of age. Compared with controls, serum alpha-inhibin was elevated after
EDS as was serum luteinizing hormone. These results suggest that the
pubertal testosterone increase plays an important role in terminating the
peripubertal FSH rise.
