Abstract
Insulin effects on glucose metabolism were studied in normal and diabetic rat tissues. In the epididymal fat pad, diaphragma, and skeletal muscles, glucose-U-14C up-take from the medium decreases in diabetic rats, and recovers to the normal level with the addition of insulin. Insulin has no significant effect on glucose up-take in both liver and kidney. CO2 production from glucose-U-14C decreased in diabetic tissues and not in heart tissue. Insulin causes a significant increases of CO2 production in the muscles, epididymal fat pad, and diaphragma. The activities of hexokinase and pyruvate kinase decreased in diabetes, and increased with the administration of insulin. In the peripheral tissues, the increase of these enzyme activities via insulin administration would not be caused by the so-called genome units described by Weber et al.(1965), but by a certain factors due to glucose metabolism caused by insulin. Hexokinase and pyruvate kinase exhibit a different pattern of response to insulin according to tissues. These indicates that the presence of multiple enzyme form may be significantly involved.
