Figure 6.

Inhibition of carbachol‐induced Rho kinase activity by l‐cysteine and NaHS in colonic muscle cells. (A) Muscle cells isolated from rabbit colon were treated with different concentrations of carbachol (CCh) for 10 min. In some experiments, cells were pretreated with l‐cysteine (10 mmol/L) or NaHS (1 mmol/L) for 10 min and then treated with CCh for 10 min. Rho kinase activity was measured by immunokinase assay using [³²P]ATP. Results are expressed as cpm/mg protein. Values are mean ± SEM of 4–6 experiments. (B) Muscle cells isolated from rabbit colon were treated with CCh (1 μmol/L) for 10 min. In some experiments, cells were pretreated with different concentrations of l‐cysteine (0.01 mmol/L to 100 mmol/L) or NaHS (0.01 mmol/L to 100 mmol/L) for 10 min and then treated with CCh (1 μmol/L) for 10 min. Rho kinase activity was measured by immunokinase assay using [³²P]ATP. Results are expressed as a percent inhibition of CCh‐induced Rho kinase activity. Values are mean ± SEM of 4–6 experiments. **P < 0.01, significant inhibition of CCh‐induced Rho kinase activity.