Role of phosphatidylinositol-3-kinase and protein kinase Cζ in the adenylate cyclase signal mechanism of action of relaxin in muscle tissues of rats and mollusks

We showed that phosphatidylinositol-3-kinase and protein kinase Cζ are involved in the adenylate cyclase signal mechanism of relaxin action. A selective inhibitor of phosphatidylinositol-3-kinase wortmannin blocked the stimulatory effect of relaxin on adenylate cyclase in rat skeletal muscles and Anodonta cygnea smooth muscles. Antibodies against protein kinase Cζ abolished the relaxin-induced stimulation of adenylate cyclase in rat muscles, but not in mollusk muscles. Our results indicate that phosphatidylinositol-3-kinase and protein kinase Cζ play a role in the adenylate cyclase signal mechanism of relaxin action.