Urocortin-induced relaxation in the human internal mammary artery

Abstract

Urocortin produced both endothelium-dependent and -independent relaxation in human IMA rings. The endothelium-dependent component primarily involves the release of endothelial nitric oxide (NO) that in turn stimulates Ca(2+)-activated K(+) channels in vascular smooth muscle via cyclic GMP-dependent mechanisms. CRF-R1, CRF-R2alpha, and CRF-R2beta mRNAs are present in the human IMA.