The influence of insulin on the metabolism of glucosamine in the isolated rat diaphragm muscle.

1. The influence of insulin on the metabolism of [1-(14)C]glucosamine by diaphragm muscle from normal rats and rats rendered diabetic with streptozotocin has been studied. 2. The glucosamine was converted into glucosamine 1-phosphate, glucosamine 6-phosphate, glycogen, lactate and small amounts of other unidentified intermediates. 3. Insulin increased the incorporation of (14)C into glycogen in both the normal and diabetic muscle, but did not increase the formation of the glucosamine phosphate esters. 4. The (14)C content in the glycogen was present partly as glucose and partly as glucosamine; there was significantly more [(14)C]glucose in the glycogen of the diabetic muscle than in that of the normal muscle.