Sertoli cells are the site of interleukin-1 alpha synthesis in rat testis

To elucidate the cellular origin of interleukin-1 (IL-1) in the mammalian testis, we assayed IL-1 activity in culture media of Sertoli cells collected from rats at 20, 35 and 45 days of age as well as in culture media of interstitial, peritubular and germ cells from adult rats. IL-1 was detected in Sertoli cell culture media isolated from 35- and 45-day-old rats. At 45 days approximately twice as much IL-1 was produced than at 35 days. In contrast, IL-1 activity was not detected in 20-day-old rat Sertoli cell culture media nor in interstitial, peritubular and germ cell culture media. The Sertoli cell IL-1 activity was specifically neutralized by an IL-1 alpha antiserum. It is concluded that Sertoli cells produce IL-1 alpha and that this production increases during sexual maturation.