Ultracytochemichal Study of Glucose-6-Phosphate Dehydrogenase Activity

Abstract

The ultrastructural localization of glucose-6 dehydrogenase (G6PD) activity has been investigated using a copper ferrocyanide method in the rat liver cells by immersion fixation and freeze substitution fixation by using glutaraldehyde. After immersion in 2% glutaraldehyde fixative for 30min at 4•Ž, the site of reaction products, copper ferrocyanide, were on the cytoplasm close to the r-ER in hepatic parenchymal cells of rat. These findings were ascertained by several control experiments and X-ray microanalysis. After the metal contact quenching at-196•Ž, freeze substitution fixation, 2% glutaraldehyde in aceton for 3 days at-80•Ž, was performed. The reaction products were not observed on the cytoplasm close to the r-ER, but also on the cytoplasm near the r-ER. It is suggested that freeze substitution fixation were useful to elucidate the ultrastructural sites of soluble enzyme. study of basic FGF related to the development of capillaries in the bovine retina. Hitoshi ISHIGOOKA (1) and Takashi KITAOKA (2)