Insulin facilitates transport of macromolecules and nutrients to muscles

We previously showed that intravenous insulin increased plasma noradrenaline during euglycemia and without concomitant changes in plasma adrenaline. Insulin decreased plasma volume and increased the fractional escape rate of albumin from plasma. In normal subjects, oral glucose increased heart rate, systolic blood pressure and plasma noradrenaline. These changes were absent or attenuated in diabetic patients (without neuropathy) after an oral glucose load. These responses were normalized by insulin infusion. Our results suggest that insulin facilitates the transfer of macromolecules and nutrients from the blood to the extracellular space after food intake. This process may be greatly disturbed in insulin-dependent diabetic patients.