Figure 2
From: Non-endothelial endothelin counteracts hypoxic vasodilation in porcine large coronary arteries
Effect of the endothelin receptor antagonist SB217242 on hypoxic vasodilation. (A) Effect of the endothelin receptor antagonist SB217242 (10 μM) on concentration-response curves for oxygen (O2) lowering in coronary arterial segments with and without endothelium contracted with PGF2α (10 μM). (B) Tissue ET-1 in arteries exposed to 1 h of hypoxia (5% CO2, 95% N2) compared to normoxic controls. By adding ET-1 (10-7 M) to the organ bath we were able to measure ET-1 (P < 0.001). (C) Concentration-response curves for increasing concentrations of ET-1 in coronary artery segments with and without endothelium and constricted with PGF2α (10 μM) and subsequently exposed to 1% O2 or 95% O2 for 30 min as well as during the rest of the experiments. Results are means ± SEM of 4-9 experiments. Differences were evaluated with two-way ANOVA followed by Bonferroni post-test: * P < 0.05, ** P < 0.01, ***P < 0.001 compared to control.