[Insulin in mollusks and its role in regulating carbohydrate metabolism]

Some experiments including glucose loading, insulin or antiinsulin serum injection and in vitro investigations on bivalve freshwater molluscs Anodonta cygnea and Unio pectorum were carried out. All the treatments used were found to cause shifts in glycaemic level, glycogen content in muscles and glycogen-synthetase activity in the same organ, glucose uptake by muscle slices, IRI content in the haemolymph and in gut extracts and PAF-positivity in the gut cells. It was demonstrated earlier that PAF-positive cells located in the gut epithelium of the same molluscs show immunostaining with mammalian anti-insulin serum which indicates the production of insulin or insulin-like substance. The above data prove the important role of insulin or insulin-like substance produced by molluscs in regulation of carbohydrate metabolism in these animals.