Distribution of Glucose-6-phosphate Metabolizing Enzymes in Fish

Abstract

Distribution of hexokinase, glucose-6-phosphate dehydrogenase (G6PD), 6-phosphogluconate dehydrogenase (6PGD), phosphoglucomutase (PGM), phosphoglucose isomerase (PGI), and glucose-6-phosphatase (G6Pase) in fiish tissue was investigated to estimate the latent activity of glucose metabolism.
The hepatic hexokinase activity of fish, which is regarded as an activity of glucose uptake into the metabolic pathway, is 1/3-1/7 that of the reported value for rat liver, and there are no extreme differences among the activities of the four species investigated.
From the activities of hepatic enzymes relating to the Embden-Meyerhoff pathway (PGM and PGI) and to the hexosemonophosphate shunt (G6PD and 6PGD), grass carp is considered to posssess the strongest latent activity of glucose metabolism, being followed by eel, carp, and rainbow trout.