[Effects of isocorydine on contraction of the rabbit oviduct smooth muscle].

On isolated isthmus of oviduct of the rabbit, Isocorydine (Isoc) (3 mu mol/L) decreased significantly the frequency of spontaneous contraction and muscle tension, but not the amplitude of contraction. The tension and frequency of spontaneous contraction can be suppressed by Isoc at concentrations from 3 to 300 mumol/L. The amplitude of contraction was decreased only at 300 mu mol/L. It is suggested that the frequency and tension of spontaneous contraction of isthmic muscle are more sensitive to Isoc than the amplitude. Isoc antagonized the norepinephrine-induced contraction of the oviduct. The transport of ova through the oviduct reduced by hCG could be delayed by Isoc.