The investigation results of hormones content in α- and β-cells of healthy rats and rats with streptozotocyne induced diabetes pancreatic island and also when injecting them cholecystokinin octapeptide (26–33) by different ways are shown in this work. CCK8 influenced mainly β-cells, that resulted in insulin content increase in them and the most marked effect was in intraperitoneal way of injection and in its conjunctival instillations, the least effect was in intracerebroventricular one. Such results can be indicative of cholecystokinin effects’ realization not only in the periphery, but also at the structure’s level of the central nervous system and is favorable to diabetes course in rats.
