title: EDRF plays central role in collateral flow after arterial occlusion in rabbit ear.
abstract: An in vitro model has been developed in which the acute development of collateral perfusion of a segment of rabbit central ear artery, isolated between ligatures, is assessed by X-ray microangiography. Collateral perfusion was quantified by normalizing the volume of the segment filled with respect to its preocclusion control. The influence of endothelium-derived relaxing factor (EDRF) activity on perfusion was examined by using 100 microM NG-nitro-L-arginine methyl ester (L-NAME), a potent inhibitor of nitric oxide synthesis. Filling of the isolated segment after occlusion was time dependent, being 21.6 +/- 4.2% after 2 min and 46.6 +/- 5.3% after 90 min. This acute development of collateral flow was reversed by addition of L-NAME 60 min after ligation, after which filling was reduced to 17.8 +/- 3.8%. When L-NAME was added before ligation, filling of the segment was 15.6 +/- 5.9% at 2 min and 14.8 +/- 7.4% at 90 min, so that the time-dependent component of collateral flow development was abolished. The inhibitory effects of L-NAME on collateral perfusion were reversed by an excess of L-arginine. These findings indicate that EDRF plays a central role in the development and maintenance of collateral flow.
authors.affiliation: Department of Diagnostic Radiology, University of Wales College of Medicine, Heath Park, Cardiff, United Kingdom.
authors.forename: M D
authors.initials: MD
authors.lastname: Randall
authors.forename: T M
authors.initials: TM
authors.lastname: Griffith
mesh_terms: D000792:Angiography / Q000379:methods; D000818:Animals; D001120:Arginine / Q000031:analogs & derivatives / Q000494:pharmacology; D001158:Arteries / Q000502:physiology; D003097:Collateral Circulation / Q000187:drug effects / Q000502:physiology*; D004423:Ear / Q000098:blood supply* / Q000000981:diagnostic imaging; D066298:In Vitro Techniques; D008026:Ligation; D008297:Male; D019331:NG-Nitroarginine Methyl Ester; D009569:Nitric Oxide / Q000502:physiology*; D010477:Perfusion; D011817:Rabbits
chemical_list: D009569:Nitric Oxide; D001120:Arginine; D019331:NG-Nitroarginine Methyl Ester