Stage-specific inhibin secretion by rat seminiferous tubules

Abstract

The endogenous inhibin content was measured by radioimmunoassay in segments of seminiferous tubules at specific stages of the spermatogenic cycle isolated by transillumination-assisted dissection as described by Parvinen (1982). In addition, the immunoactive inhibin production in response to FSH stimulation was investigated. The inhibin content was greatest in tubules at stages II-VI of the cycle and was lowest at stages VII-VIII. Over 48 h of culture, the secretion of inhibin into the medium was greatest at stages XIII-VI and lowest at stages VII-VIII. The inhibin response to FSH stimulation was greatest at stages IX-XIII and least at stages VII-VIII. The results demonstrate that the secretion of inhibin by adult tubules in vitro varies according to the stage of the seminiferous cycle.