Evidence that in a physiological setting Sertoli cell number is the major determinant of circulating concentrations of inhibin B in the adult male rhesus monkey (Macaca mulatta).
The relationship between changes in Sertoli cell number and function and changes in circulating inhibin B concentrations was investigated following unilateral orchidectomy (UO) in the adult rhesus monkey. As expected, the 50% loss in Sertoli cells resulting from UO on day 0 was associated with a rapid and corresponding decline in plasma concentrations of inhibin B. The decrease in inhibin B levels was sustained until the remaining testis was removed on day 44, at which time a compensatory 50% increase (P < 0.05) in the number of round spermatids was evident in the absence of a change in Sertoli cell number. Moreover, Sertoli cell number and inhibin B levels among individual monkeys were highly correlated (r2 = 0.65, P < 0.002). Round spermatid number and inhibin B, however, were poorly correlated (r2 = 0.37, P < 0.04). These findings indicate that, in a physiological setting where the negative feedback control system governing the adult primate testis is operational, Sertoli cell number, rather than function, is the primary determinant of circulating inhibin B levels.
Ramaswamy
S
S
Department of Cell Biology and Physiology, University of Pittsburgh School of Medicine, Pennsylvania 15261, USA.
Marshall
G R
GR
McNeilly
A S
AS
Plant
T M
TM
D000818:Animals; D002452:Cell Count; D005640:Follicle Stimulating Hormone / Q000097:blood; D007265:Inhibins / Q000097:blood*; D008253:Macaca mulatta; D008297:Male; D009919:Orchiectomy; D009929:Organ Size / Q000502:physiology; D012708:Sertoli Cells / Q000166:cytology* / Q000378:metabolism*
D007265:Inhibins; D005640:Follicle Stimulating Hormone