Effect of PKC inhibition with calphostin C (1 μM) on clofibrate (10 μM)- and AII (1 μM)-induced regulation of ET-1 production by CMVEC. Cells were preincubated with calphostin C for 15 min and then clofibrate before further incubation with AII for 4 h. Following the incubation, media were collected for ET-1 determination and cells for protein estimation. Results were corrected for proteins, expressed as femtomoles per microgram of protein, and presented as mean ± S.E.M. (*, compared with control; #, compared with clofibrate and calphostin C; p < 0.05, n = 6, ANOVA).