Contractile response property of coronary arteries induced by K+, S6c and ET-1.

The coronary arteries were isolated from rats exposed to fresh air, cigarette smoke and cigarette smoke plus GW5074 (0.5 mg/kg). Emax represents maximal contraction, pEC50 represents the negative logarithm of the agonist concentration that produces 50% of the maximal contractile effect. Coronary artery contractile responses were induced by K+, S6c and ET-1. K+-induced responses were expressed as absolute values of contraction (mN), and S6c and ET-1-elicited responses were expressed as percentage of K+-induced contraction. Statistical analysis was performed with unpaired student's t-test with Welch's correction.**Pvs. fresh air group;##Pvs. smoke group.