Lactate dehydrogenase activity and isoenzyme patterns in skeletal muscle, fat, exocrine pancreas and isolated pancreatic islets of normal and obese-Hyperglycaemic mice.

Abstract

The total lactate dehydrogenase (LDH) activity and LDH isoenzyme patterns of isolated pancreatic islets, acinar pancreas, fat tissue and skeletal muscle from mice with obese-hyperglycaemic syndrome were compared with those of corresponding tissues from lean littermates. The pancreatic tissues of obesehyperglycaemic animals exhibited higher LDH activity than corresponding tissues of normal animals. This increase in LDH activity was not parallel in islets and acinar tissue. No significant difference in the LDH activity of either skeletal muscle or fat tissue between the two groups of animals was found. In animals with obese-hyperglycaemic syndrome, LDH isoenzyme patterns of pancreatic islets, acinar pancreas and fat showed LDH 5 increase and LDH 4 decrease. LDH isoenzyme patterns of skeletal muscle showed the decrease of LDH 5 percentage. The LDH 1, LDH 2 and LDH 3 percentages of the fat tissue were lower in animals with obese-hyperglycaemic syndrome, but those of the skeletal muscle were lower in normal animals. Results presented are consistent with the opinion that in obese-hyperglycaemic mice both endocrine and exocrine pancreatic tissues as well as fat tend to have an increase in the proportion of glycolysis in their intermediary metabolism, whereas the reverse tendency — towards an increase in the proportion of oxidative pathways — is valid for skeletal muscle.