Adenylate cyclase activity in axon terminals of ovulation-hormone producing neuroendocrine cells of Lymnaea stagnalis (L.).

Adenylate cyclase activity was demonstrated ultracytochemically in the neurohaemal area of the ovulation-neurohormone producing Caudo-Dorsal Cells (CDC) of the freshwater snail L. stagnalis. During electrical activity the axon terminals of the CDC release the hormone by exocytosis and show high adenylate cyclase activity on their plasma membranes. Electrically inactive terminals hardly show exocytosis and exhibit only little reaction product of adenylate cyclase. This result indicates that cAMP plays a role in the control of release of the CDC hormone.