Glycogen metabolism in the capillary endothelium. Electron histochemical study of glycogen synthetase and phosphorylase in the pecten capillary of the chick.

Glycogen synthetase and phosphorylase activities in the pecten capillary of the chick were studied electron histochemically. Polyglucose particles synthesized by glycogen synthetase or phosphorylase in the pecten capillary were demonstrated to be amorphous. They were located in the cytoplasmic matrix of the endothelium and expanded it widely. The endothelial cell of the pecten capillary plays a role in glycogenesis as well as glycogenolysis and may require substantial energy to its important transport functions.