[Effects of gossypol acetic acid on the motility of rat oviduct smooth muscle].

The effects of gossypol acetic acid (GAA) on the contractile activity of rat oviduct smooth muscle were studied in vitro with an attempt to clarify its mechanism of action. The result showed that GAA apparently increased the contractile tension of oviduct smooth muscle. This effect was not the result of excitation of the alpha-adrenergic receptor, but due to promotion of PGs biosynthesis and release. It might also be related to an increase in Ca2+ influx in the tissue. The pharmacological effect of GAA was also shown to be relevant to sexual cycle. The action of increasing contractile tension by GAA on the estrus duct was much larger than that on the diestrus duct. In addition, the results indicate that PGE1 and PGE2 increased the contractile activity of oviduct, the action of PGE1 was more potent than that of PGE2, and this effect was found to be increased significantly by GAA.