Contractile responses elicited by cumulative application of the endothelin ET
receptor agonist sarafotoxin 6c in segments of human internal mammary arteries. The arterial segments were either not cultured or cultured in the absence or presence of the protein kinase C inhibitors (A) Ro-32-0432 or (B) bisindolylmaleimide I. The results are shown as mean values ± S.E.M of six experiments. Statistical analysis was performed using ANOVA with Dunnett's post-test for multiple comparisons. P < 0.05 (*) and P < 0.01 (**) was considered significant. Comparisons were made between the results from arteries exposed to culture with and without Ro-32-0432 or bisindolylmaleimide I.