Thermogenic and metabolic effects of dopamine in healthy men.

Abstract

To assess the thermogenic response of dopamine at three different infusion rates and to analyze its effects on various biochemical variables. Randomized sequential experimental treatment bracketed by control periods. Eight young healthy male volunteers with normal body weight (51 to 89 kg). Three experimental periods during which dopamine was administered iv in a randomized order at rates of 2.5, 5, or 10 micrograms/kg.min with one preinfusion baseline and two recovery periods in between. A significant (p less than .01) increase in resting energy expenditure was observed in response to the two highest dopamine infusion rates (5 and 10 micrograms/kg.min), corresponding to 6% and 15% median increases, respectively, as compared with preinfusion values. At the lowest dopamine infusion rate, no variation in resting energy expenditure was observed. Dopamine induced a significant (p less than .01) increase in hyperglycemia at all three infusion rates, and, at the highest infusion rate, dopamine induced a significant (p less than .05) increase of plasma free fatty acid concentrations. Insulin plasma concentrations were significantly (p less than .05 to p less than 0.1) increased at the three dopamine infusion rates. Dopamine infusion produces a dose-dependent thermogenic effect and induces various metabolic actions in man.