The effect of human plasma on the glucose uptake of the rat diaphragm before and after administration of carbutamide.

The glucose uptake of the rat diaphragm has been determined in the presence of the plasma of young volunteers before and after administration of carbutamide without and with added insulin. The increase in the glucose uptake of the rat diaphragm due to the added plasma above that in the medium alone has been termed plasma effect. The increase in the glucose uptake of the rat diaphragm with plasma and added insulin above that with only insulin in the medium has been termed plasma+insulin effect. There was a significant increase in the plasma effect and the plasma+insulin effect after carbutamide administration. The increase in the plasma+insulin effect was significantly greater than the increase in the plasma effect. From these observations it has been suggested that carbutamide potentiates the action of insulin peripherally. Observed facts about carbutamide do not contradict this mechanism of action.