Gossypol attenuates selectively the blood pressure lowering effect of endothelium-dependent vasodilators in the rabbit in vivo.

The in vivo blood pressure lowering effect of three vasodilators whose in vitro effects are endothelium-dependent (acetylcholine, substance P and adenosine triphosphate) was reduced by 40-60% after systemic treatment of the animals with gossypol. In vitro, gossypol is an inhibitor of the production and/or release of endothelium-derived relaxing factor. Systemically administered gossypol had no effect on blood pressure decreases produced by the endothelium-independent agents prostaglandin E1 (alprostadil) and glyceryl trinitrate. These results suggest that endothelium-mediated vasodilator mechanisms could participate in blood pressure regulation.