Faculty Collaboration Database

Regulation of spontaneous EDRF release in diabetic rat aorta by oxygen free radicals. Am J Physiol 1992 Jul;263(1 Pt 2):H257-65

Date

07/01/1992

Pubmed ID

1636763

DOI

10.1152/ajpheart.1992.263.1.H257

Scopus ID

2-s2.0-0026736722 (requires institutional sign-in at Scopus site)   175 Citations

Abstract

The interaction of endothelium-derived relaxing factor (EDRF) and oxygen-derived free radicals may potentially play an important role in the pathophysiology of complications associated with diabetes. In the present study, we investigated spontaneous EDRF release in diabetic rat aorta that is unmasked by the addition of superoxide dismutase (SOD). SOD produced a significantly greater relaxation in diabetic aorta compared with control aorta using both aortic ring and bioassay preparations. This relaxation was unaltered by pretreatment with catalase or indomethacin. Removal of the endothelium or pretreatment with either NG-monomethyl-L-arginine or methylene blue eliminated SOD-induced relaxation in both control and diabetic rings. Measurement of antioxidant enzymes revealed an elevation in catalase in diabetic aorta, with no difference in the SOD or glutathione peroxidase activity. The increase in catalase activity suggests increased exposure of diabetic aorta to hydrogen peroxide. Pretreatment of rings with the catalase inhibitor, 3-amino-1,2,4-triazole, attenuated the SOD-induced relaxation in diabetic aortic rings but had no effect in control aortic rings. In summary, our observations suggest that the diabetic rat aorta releases more spontaneous EDRF than control aorta; however, the activity of EDRF on vascular smooth muscle tone is masked by increased destruction by oxygen-derived free radicals.

Author List

Langenstroer P, Pieper GM

Author

Peter Langenstroer MD Professor in the Urologic Surgery department at Medical College of Wisconsin

MESH terms used to index this publication - Major topics in bold

Animals
Aorta
Arginine
Biological Assay
Diabetes Mellitus, Experimental
Free Radicals
Male
Nitric Oxide
Oxygen
Rats
Rats, Inbred Strains
Superoxide Dismutase
Vasoconstriction
omega-N-Methylarginine