Ultrastructural localization of glucose-6-phosphatase in renal glomerulus of the adult dog.

The ultrastructural distribution of glucose-6-phosphatase activity was investigated in renal glomeruli of adult dogs by electron-microscopic cytochemistry. The enzymatic activity was found mainly in the parietal epithelial cells of Bowman's capsule. Weaker activity occurred in visceral epithelial cells. No activity was found in either the endothelial or the mesangial cells. Strong activity of glucose-6-phosphatase was commonly found in the nuclear envelope, and occasionally in the rough endoplasmic reticulum. The distribution of the enzyme and its functional significance are discussed in relation to previously reported data.