Figure 9.

Hyperpolarization of smooth muscle cells by 100 nM bradykinin and 50 μM L-SNC in porcine coronary arteries with or without endothelium. (a) resting membrane potential (RMP). (b) change in membrane potential. Experiments were performed in the presence of 300 μM L-NA, 10 μM diclofenac and 1 μM U46619. Data are mean±s.e.mean of five to six separate experiments; ^*P<0.01 vs control. U46619 did not significantly affect RMP (–44.5±1.2 mV vs –42.7±1.7 mV, n=6), and in parallel experiments, using arterial rings from the same pig and following preconstriction with the same U46619 concentration (1 μM), 100 nM bradykinin relaxed the arteries by 89±9% (n=6).