Involvement of adenylyl cyclase signaling mechanism in insulin and IGF-I coregulation of fundamental cell processes.

The discovery of the adenylyl cyclase signaling mechanism (ACSM) of insulin and related peptides allows for advancing the hypothesis of its participation in regulatory action on cell growth, apoptosis, and metabolism. The following evidences were obtained: (1) The order of efficiency of insulin and IGF-I growth-promoting action and their antiapoptotic effect coincides with that of the peptide-activating action on AC. (2) The growth-promoting and antiapoptotic effects of insulin and IGF-I are distinctly reproduced by cAMP. (3) The anabolic effects of insulin and IGF-I activation on glycogen synthesis and the pentosophosphate pathway are inhibited by cAMP.