Abstract: | Crawford, Paul, Peter A. Good, Eric Gutierrez, Joshua H. Feinberg, John P. Boehmer, David H. Silber, and Lawrence I. Sinoway. Effects of supplemental oxygen on forearm vasodilation in humans.J. Appl. Physiol. 82(5):1601-1606, 1997. Supplemental O2 reduces cardiac output andraises systemic vascular resistance in congestive heart failure. Inthis study, 100% O2 was given tonormal subjects and peak forearm flow was measured. Inexperiment 1, 100%O2 reduced blood flow andincreased resistance after 10 min of forearm ischemia (flow 56.7 ± 7.9 vs. 47.8 ± 6.7 ml · min 1 · 100 ml 1;P < 0.02; vascular resistance 1.7 ± 0.2 vs. 2.4 ± 0.4 mmHg · min · 100 ml · ml 1;P < 0.03). Inexperiment 2, lower body negativepressure (LBNP; 30 mmHg) and venous congestion (VC) simulatedthe high sympathetic tone and edema of congestive heart failure.Postischemic forearm flow and resistance were measured under fourconditions: room air breathing (RA); LBNP+RA; RA+LBNP+VC; and 100%O2+LBNP+VC. LBNP and VC did notlower peak flow. However, O2raised minimal resistance (2.3 ± 0.4 RA; 2.8 ± 0.5 O2+LBNP+VC,P < 0.04). When O2 alone(experiment 1) was compared withO2+LBNP+VC(experiment 2), no effect of LBNP+VCon peak flow or minimum resistance was noted, although the return rateof flow and resistance toward baseline was increased.O2 reduces peak forearm flow evenin the presence of LBNP and VC. |