Fig 5.

Effects of inhibition of MLCK alone and combined with inhibition of rho-associated kinase (ROK) on OT-stimulated phosphorylation of regulatory light chain (RLC) in hUM. (A) Inhibition of MLCK using ML7 (25 μM) caused significant reduction in the concentrations of pRLC in response to OT (n = 4; P < 0.01 by two-way anova). Addition of g-H (1 μM) further reduced the basal pRLC level, but the response to OT was not altered compared to ML7 alone (n = 4; P < 0.01 by two-way anova). (B) Treatment with ML7 with or without g-H abolished the OT-stimulated response in ppRLC. (C) The responses assessed using the total p19RLC antibody confirmed the findings in panels A and B, again indicating that the primary effect of inhibition of MLCK is in decreasing phosphorylation at S19.