NOVEL VASCULAR RELAXING AGENT, N-(6-AMINOHEXYL)-5-CHLORO-1-NAPHTHALENESULFONAMIDE WHICH AFFECTS VASCULAR SMOOTH-MUSCLE ACTOMYOSIN

Abstract

The relaxing effect and possible mechanism of N-(6-aminohexyl)-5-chloro-l-naphthalenesulfonamide (W-7) on isolated rabbit artery were investigated. The addition of W-7 in concentrations ranging from 1 .times. 10-6-3 .times. 10-4 M caused a significant relaxation of isolated rabbit vascular strips contracted by KCl, prostaglandin F2.alpha., norepinephrine, histamine, CaCl2, serotonin or angiotensin II. W-7 also caused a shift to the right of the dose-response curves for all agonists tested. Propranolol and atropine did not affect W-7 induced relaxation, suggesting that this drug does not act through .beta.- adrenergic or cholinergic receptors. Superprecipitation of actomyosin from bovine aorta smooth muscle was inhibited by the addition of W-7 in a dose-dependent fashion. The concentration of W-7 which inhibited superprecipitation of bovine aorta smooth muscle actomyosin was in good agreement with the dose producing relaxation of isolated vascular strips. Apparently W-7 produces relaxation of isolated vascular strips by inhibiting actin and myosin interaction.