Immunohistochemical localization of cyclic AMP and ultrastructural demonstration of adenylate cyclase activity in the testis of Esox lucius at time of spermiation.

In the testis of Esox lucius at the time of spermiation, activity of cyclic adenosine 3',5'-monophosphate (cAMP) was immunocytochemically localized at the level of the Sertoli cells. In these cells adenylate cyclase activity was also ultracytochemically demonstrated by using adenylyl imidodiphosphate as a substrate. Reaction products of adenylate cyclase were primarily detectable on the basal and adluminal plasma membranes and on the surface of protrusions of the cell body into the lumen.