Activities of skeletal muscle enzymes in hereditary obese-hyperglycemic mice (genotype obob)

Abstract 1. 1. The activities of some enzymes involved in carbohydrate metabolism have been studied in skeletal muscles obtained from 4-month-old obese-hyperglycemic mice ( obob ) and their lean litter mates. The obese animals were in a dynamic phase of the syndrome and displayed high serum levels of glucose and insulin. 2. 2. The muscles from the obese mice had a lower water and higher glycogen content compared to those from lean controls. 3. 3. The activities of glycogen synthetase, phosphofructokinase, pyruvate kinase and lactate dehydrogenase were about 20 to 40 per cent lower in the muscles from obese mice. On the other hand, the activities of hexokinase, enzymes in the hexosemonophosphate shunt and oxidative enzymes did not differ between the two groups of animals. 4. 4. The findings may reflect a decreased glycolytic capacity of the muscles from obese mice.