Fig. 6.

Inhibition of MLC kinase prevents ACh-stimulated MLC phosphorylation and force development but does not affect actin polymerization in tracheal smooth muscle tissues. The F-actin/G-actin ratios and MLC phosphorylation were determined in muscle strips that were treated with 30 μM ML-7 or untreated. A: treatment with ML-7 dramatically depressed ACh-induced MLC phosphorylation (n = 4). B: ML-7 significantly inhibited force development in response to ACh stimulation (n = 8). C: incubation of ML-7 did not affect the increase in F-actin/ G-actin ratio in response to ACh stimulation (n = 6). *Significant difference between ML-7-treated tissues and untreated tissues (P < 0.05). Values are means ± SE.