Fig. 4.
Reduced contraction and regulatory light chain (RLC) phosphorylation in mesenteric arteries from MLCKSMKO mice. Dose-response curves of KCl (A), norepinephrine (NE; D), phenylephrine (PE), ANG II, and endothelin-1 (ET-1; G–I) in fresh mesenteric artery segments from MLCKSMKO (KO) and CTR mice analyzed by wire myography are shown. Bars are means ± SE (N=4); *P < 0.05, **P < 0.01. After stimulation with 124 mM KCl (B, C) or 1 μM NE (E, F), mesenteric arteries were quickly frozen at indicated times for sample preparation. RLC phosphorylation (RLC-p) was measured by Western blots of glycerol/urea PAGE gels (B, E). RLC-p level was expressed as percentage of total RLC (C, F; N=4). All values represent means ± SE; *P < 0.05, **P < 0.01 compared with MLCKSMKO values at the indicated time.