Comparison of relaxation responses of vascular and non-vascular smooth muscle to endothelium-derived relaxing factor (EDRF), acidified sodium nitrite (NO) and sodium nitroprusside

Abstract

Smooth muscle relaxant activity of endothelium-derived relaxing factor (EDRF) released from columns of cultured bovine endothelial cells by bradykinin (0>1 - 3 nmol/l) was measured in four non-vascular preparations: guinea-pig taenia caeci, guinea-pig trachea, rat stomach (fundus) and rat anococcygeus. Each preparation was contracted to a steady level of force with a variety of agonists such that they relaxed optimally to sodium nitroprusside (SNP). The EDRF-induced relaxations in each preparation were compared with those obtained in de-endothelialized ring preparations of greyhound coronary artery by means of paired bioassays run in parallel. EDRF released from the endothelial cell columns ..