Fig. 3. Effects of the protein kinase inhibitors on the resting tension ( A and B ) and ropivacaine (Rop)–induced sustained contraction ( C and D ) of rat aortic smooth muscle. The tension was measured using isometric force transducers. Endothelium-denuded rings were equilibrated for 1 h at a resting tension of 3 g and then exposed to different concentrations of bisindolylmaleimide I (Bis I) for 15 min ( A ). The statistical data for the effects of all of the inhibitors used on resting tension are presented in B . The resting tension (3 g) was considered as 100% (n = 6). A bolus of ropivacaine (3 × 10−4m) was applied to the rings to induce a sustained contraction, and Bis I was then delivered ( C ). The statistical data for the effects of all of the inhibitors used on sustained ropivacaine-induced contraction are presented in D . Ropivacaine-induced contraction was expressed as a percent of the 30 mm potassium chloride–induced contraction. ** P < 0.01 versus control (n = 6). Calp C = calphostin C; PD = PD 098059; Y = Y 27632.