Effect of chronic hypoxia and ET-1 on MLCK and SMαA colocalization. ET-1 significantly decreased the colocalization of MLCK with SMαA in FN but not FH MCAs. In both FN and FH arteries, treatment with ET-1 together with inhibition of PKC (Che), p38 (SB), and CaMKII (KN93) increased MLCK and SMαA colocalization. FN and FH values differed significantly in all treatment groups. Results are presented as means ± SE for n = 6–9 (FN) and n = 11–13 (FH). §P < 0.05, FN vs. FH. *P < 0.05, ET-1 vs. ET-1 with inhibitor treatments.