Enhancement of endothelium dependent relaxation in the rat aortic ring by selenium supplement

• Published in: Cardiovascular research 1994-03, Vol.28 (3), p.345-348
• Main Authors: Lu, Xiaoyan, Liu, Song-Yan, Man, Ricky Y K
• Format: Article
• Language: English
• Subjects: Acetylcholine - pharmacology; Animals; Aorta; Arginine - analogs & derivatives; Arginine - pharmacology; Benzopyrans - pharmacology; Biological and medical sciences; Cromakalim; Culture Techniques; endothelium dependent relaxation; Endothelium, Vascular - drug effects; Glutathione Peroxidase - pharmacology; Indomethacin - pharmacology; Male; Medical sciences; Miscellaneous; NG-Nitroarginine Methyl Ester; Nitroprusside - pharmacology; Pyrroles - pharmacology; Radiotherapy. Instrumental treatment. Physiotherapy. Reeducation. Rehabilitation, orthophony, crenotherapy. Diet therapy and various other treatments (general aspects); rat aortic ring; Rats; Rats, Sprague-Dawley; Selenium - pharmacology; selenium supplement; Vasoconstriction - drug effects; Vasodilator Agents - pharmacology
• ISSN: 0008-6363; 1755-3245
• DOI: 10.1093/cvr/28.3.345

Objective: The aim was to examine the effect of selenium supplement on endothelium dependent relaxation in rat aortic rings. Methods: Rats were supplemented with selenium for 3 d (intraperitoneal injection of 4.33 μmol sodium selenite·kg−1 body weight·d−1). Saline injections served as controls. Rat aortic ring was precontracted with phenylephrine and endothelium dependent relaxation was produced by the addition of acetylcholine. Results: Acetycholine-induced endothelium dependent relaxation was enhanced in aortic rings from rats after receiving selenium supplement as compared to control rats. For comparison, endothelium independent vasodilators (sodium nitroprusside and cromakalim) were investigated. Selenium supplement did not affect the relaxation produced by these vasodilators. N-nitro-L-arginine methyl ester (L-NAME) abolished acetylcholine induced relaxation in aortic rings from animals with selenium supplement while indomethacin had no effect on the relaxation. Direct addition of selenium or glutathione peroxidase and glutathione into the organ bath had no effect on acetylcholine induced endothelium dependent relaxation. Conclusions: The enhanced relaxation after selenium supplement was due to an increase in the release of nitric oxide since L-NAME was effective in blocking the relaxation. The lack of an effect by indomethacin indicated little role for cyclo- oxygenase products in this system. Our results suggest that the effect of selenium supplement on endothelium dependent relaxation is mediated by cellular changes that cannot be mimicked by the direct addition of selenium or the selenium dependent enzyme glutathione peroxidase. Cardiovascular Research 1994;28:345-348