HISTOLOGICAL LOCALIZATION OF GLYCOGEN IN THE URINARY TRACT AND LUNG

Abstract

Glycogen in normal rabbit kidney is confined to the collecting tubule epithelium. The amount present increases from infrequent particles in the cortex to heavy deposits at the papilla. Only Bouin's fluid adequately preserves this glycogen, but that in the epithelium and smooth muscle of the renal pelvis and ureter and the bronchiolar epithelium of rabbits may be demonstrated after a variety of fixatives. Monkey kidney reveals glycogen also in the distal straight tubules. Rats and hamsters show little glycogen in renal tubules and mice and dogs none. 24 hours fasting had no effect on the bronchiolar or the collecting tubule glycogen of rabbits but alloxan hypoglycemia depleted the latter completely. Rabbits with alloxan hyperglycemia showed abnormal deposits in the epithelium of the distal straight and convoluted tubules. From available histochemical knowledge, the enzyme structure of the collecting duct is compatible with glycogen accumulation in that part of the duct where energy requirements are low. Glycogen deposition in the proximal and distal tubules in diabetes appears incompatible with the enzyme structure normally present in these segments.