Changes in Hormone Sensitivity of the Adenylate Cyclase Signaling System in the Testicular Tissue of Rats with Neonatal Streptozotocin-Induced Diabetes

Abstract

Activity of the adenylate cyclase signaling system was evaluated in the testicular tissue of rats with neonatal streptozotocin-induced diabetes (120 and 180 days duration). This state is similar to type 2 diabetes in humans. The regulation of this system by polypeptide hormones and biogenic amines was studied. Sensitivity of the adenylate cyclase signaling system to the regulatory effect of human chorionic gonadotropin and PACAP (pituitary adenylyl cyclase-activating polypeptide) was significantly reduced. The effects of these agents are realized via stimulatory G proteins. Somatostatin, acting through inhibitory G proteins, produced less pronounced effect on the adenylate cyclase signaling system. The increase in the duration of diabetes was accompanied by a decrease in the stimulatory effects of human chorionic gonadotropin and PACAP on adenylate cyclase. Sensitivity of the adenylate cyclase signaling system to biogenic amines remained unchanged (serotonin) or increased under these conditions (epinephrine). Our results indicate that changes in hormonal regulation of the adenylate cyclase signaling system and functional activity of cAMP-dependent signaling cascades are important factors for dysfunction of spermatogenesis and steroidogenesis during insulin-independent diabetes.