Endothelium has the potential to produce and release a diverse group of contracting factors, named endothelium-derived contracting factors (EDCFs). These factors include endothelin, products of cyclooxygenase activity, and reac tive oxygen species. In normal vessels, production of EDCFs appears to be absent or minimal. However, EDCFs may be important mediators of vascular dysfunction in disease states. For example, a cyclooxygenase-derived EDCF produces contraction by activation of PGH2-thromboxane A2 receptors in cerebral arterioles of spontaneously hypertensive rat and in a rat model of type I diabetes. In these arterioles, indomethacin or inhibition of prostaglandin H2/thromboxane A2 receptors restores endothelial function to normal, suggesting that endothelial dysfunction is mediated by a cyclooxygenase-derived EDCF.
Was this article helpful?