Vascular release of superoxide radicals is enhanced in hypercholesterolemic rabbits.

Production/release of superoxide anions from aortic rings was measured by a modified lucigeninenhanced chemiluminescence (CL) technique. The aortic rings were obtained from control and cholesterol-fed (1% for 12 weeks) rabbits. The CL signal was significantly increased in aortic wall of cholesterol-fed rabbits. Pretreatment with oxypurinol, an inhibitor of xanthine oxidase, had a slight but insignificant effect on the CL response produced by aortic rings from control animals but significantly reduced CL response to aortic rings from cholesterol-fed rabbits. Pretreatment with diethyldithiocarbamate (DETC), an inhibitor of intrinsic superoxide dismutase (SOD), increased the CL signal for both animal groups, but this increase was greatly aggravated in aortic rings from hypercholesterolemic rabbits