Figure 4.

Inhibition of carbachol‐induced contraction by l‐cysteine and NaHS in colonic smooth muscle. Muscle cells isolated from circular muscle layer of the mouse (top panel) and human colon (bottom panel) were pretreated with l‐cysteine (10 mmol/L) or NaHS (1 mmol/L) for 10 min and then treated with carbachol (CCh; 1 μmol/L) for 10 min to induce sustained contraction. Muscle cell length was measured by scanning micrometry. Contraction by CCh was calculated as the decrease in muscle cell length from basal cell length (31 ± 3% decrease in cell length from the basal cell length of 115 ± 7 μm in mouse colon and 30 ± 3% decrease in cell length from the basal cell length of 93 ± 6 μm in the human colon). Values are mean ± SEM of 5–7 experiments. **P < 0.01, significant inhibition of CCh‐induced muscle contraction.