AJP - Endocrinology and Metabolism, Vol 257, Issue 4 E541-E546, Copyright © 1989 by American Physiological Society
Effects of dopamine on total oxygen consumption and oxygen delivery in healthy men
Y. Ruttimann, R. Chiolero, E. Jequier, E. Breitenstein and Y. Schutz
Institute of Physiology, Faculty of Medicine, University of Lausanne, Switzerland.
The effect of acute intravenous dopamine (DA) administration at three
sequential (but randomized) infusion rates was studied in eight young male
volunteers. DA was infused at 2.5, 5, and 10 micrograms.kg-1.min-1. O2
consumption (VO2) and CO2 production (VCO2) were measured continuously by
means of a computerized indirect calorimeter (blood system). In response to
the 5- and 10-micrograms.kg-1.min-1 DA infusion rates, a significant
increase (P less than 0.01) in VO2 corresponding to a 6% (range, 3-10) and
15% (range, 12-23) increase, respectively, of preinfusion values was
observed. In contrast, at the low dose (2.5 micrograms.kg-1.min-1), DA
induced no significant change in VO2. Cardiac output (Qc) increased
significantly after the three DA administration rates [19% (range, 0-42),
34% (range, 17-71), and 25% (range, -3 to +47)] for the doses 2.5, 5, and
10 micrograms.-kg-1.min-1, respectively. The increase in O2 delivery (QO2)
outweighed VO2 at all administration rates despite the relative drop in QO2
at the maximal DA administration rate. These results indicate that in
humans DA improves net O2 supply to tissues proportionally more than it
increases VO2 at all doses used in the present study.
