Modulation by several inhibitors of the relaxation induced by sinomenine. Symbols used are in the absence (open circles, n = 6), in the presence of 100 μM L-NMMA (open triangles, n = 5), 10 μM indomethacin (open squares, n = 5), 0.1 μM nicardipine (closed circles, n = 5), 0.3 μM propranolol (closed triangles, n = 5), and 30 nM staurosporine (closed squares, n = 5). Values (%) represent mean ± S.E.M. *: P < 0.05, **: P < 0.01, ***: P < 0.001, with respect to control value.