Int J Angiol 2002; 11(1): 23-29
DOI: 10.1007/s00547-001-0049-5
Original Articles

© Georg Thieme Verlag KG Stuttgart · New York

Mechanism of superoxide anion-induced modulation of vascular tone

Lalita A. Bharadwaj, Kailash Prasad
  • Toxicology Group and Department of Physiology, College of Medicine, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
Further Information

Publication History

Publication Date:
25 April 2011 (online)

Abstract

We investigated the effects of superoxide anions (O2−) generated by xanthine (X) plus xanthine oxidase (XO) on isolated rabbit aorta suspended in Krebs-Ringer solution. Xanthine plus xanthine oxidase produced concentration-dependent contractions of rabbit aorta. Superoxide dismutase completely reversed the contractile response observed. Superoxide anion-induced contraction of rabbit aorta was totally abolished in preparations denuded of endothelium. The contractile effect was reduced by 56% by the cyclooxygenase inhibitor, indomethacin. The contractile effect was not affected by the angiotensin converting enzyme inhibitor, captopril. These results indicate that O2 produces a contraction of the isolated rabbit aorta that is endothelium-dependent and is partly mediated by an arachidonic acid metabolite.