Carbohydrate metabolism in normal and diabetic rats following long-term oral trypsin inhibitor administration.

The effect of long-term oral trypsin inhibitor administration on blood glucose, plasma insulin, liver, and muscle glycogen and glucose utilization in vitro by peripheral tissues in normal and diabetic rats was studied. In normal rats the glycogen levels in liver and muscle were increased after 3 weeks of treatment. Glucose oxidation (14CO2-production) was augmented in muscle after 3 and 8 weeks and in liver after 3 weeks. An increased 14C-incorporation into glycogen from 14C-glucose and increased glycogen concentration after incubation were found in muscle after 3 weeks. In diabetic rats the basal blood glucose was decreased after 3 and 5 weeks of treatment, and the basal plasma insulin:blood glucose ratio increased after 5 weeks. The glycogen levels were increased after 3 and 5 weeks in liver. No effect on glucose oxidation (14CO2-production) in muscle was found. The 14C-incorporation into glycogen and the total glycogen content, however, was increased in muscle after both 3 and 5 weeks. Incubation of muscle tissue with serum from normal or diabetic rats treated with oral trypsin inhibitor for 3 and 5 weeks respectively had no apparent acute effects on the glucose metabolism. It is suggested that the observed action of oral trypsin inhibitors on glucose metabolism in peripheral tissues is mediated by one or more unknown gastrointestinal factor(s).