Figure 1.

ACh-induced MLC₂₀ phosphorylation in the GSMCs of male and female rats. Phosphorylation of MLC₂₀ was detected from absorbance at 450 nm. Treatment of GSMCs with ACh significantly increased MLC₂₀ phosphorylation in each sex. The ACh-induced phosphorylation of MLC₂₀ was significantly higher in male cells compared with female cells. ML-7 significantly inhibited ACh-induced MLC₂₀ phosphorylation in the GSMCs of male and female rats. ML-7 abolished the sex differences in phosphorylation. *P<0.05 vs. F/ACh; ^#P<0.05 vs. M/ACh + ML-7; ^$P<0.05 vs. F/ACh + ML-7. MLC₂₀, 20-kDa regulatory myosin light chain; ACh, acetylcholine; ML-7, myosin light chain kinase inhibitor; GSMC, gastric smooth muscle cell; F, female; M, male.