title: Tetrahydrobiopterin, L-arginine and vitamin C act synergistically to decrease oxidant stress and increase nitric oxide that increases blood flow recovery after hindlimb ischemia in the rat.
abstract: Nitric oxide (NO) derived from endothelial nitric oxide synthase (eNOS) is a potent vasodilator and signaling molecule that plays essential roles in neovascularization. During limb ischemia, decreased NO bioavailability occurs secondary to increased oxidant stress, decreased L-arginine and tetrahydrobiopterin. This study tested the hypothesis that dietary cosupplementation with tetrahydrobiopterin (BH4), L-arginine and vitamin C acts synergistically to decrease oxidant stress, increase NO and thereby increase blood flow recovery after hindlimb ischemia. Rats were fed normal chow, chow supplemented with BH4 or L-arginine (alone or in combination) or chow supplemented with BH4 + L-arginine + vitamin C for 1 wk before induction of hindlimb ischemia. In the is-chemic hindlimb, cosupplementation with BH4 + L-arginine resulted in greater eNOS and phospho-eNOS (P-eNOS) expression, Ca(2+)-dependent NOS activity and NO concentration in the ischemic calf region (gastrocnemius), as well as greater NO concentration in the region of collateral arteries (gracilis). Rats receiving cosupplementation of BH4 + L-arginine led to greater recovery of foot perfusion and greater collateral enlargement than did rats receiving either agent separately. The addition of vitamin C to the BH4 + L-arginine regimen further increased these dependent variables. In addition, rats given all three supplements showed significantly less Ca(2+)-independent activity, less nitrotyrosine accumulation, greater glutathione (GSH)-to-glutathione disulfide (GSSG) ratio and less gastrocnemius muscle necrosis, on both macroscopic and microscopic levels. In conclusion, co-supplementation with BH4 + L-arginine + vitamin C significantly increased blood flow recovery after hindlimb ischemia by reducing oxidant stress, increasing NO bioavailability, enlarging collateral arteries and reducing muscle necrosis. Oral cosupplementation of BH4, L-arginine and vitamin C holds promise as a biological therapy to induce collateral artery enlargement.
authors.affiliation: Department of Surgery, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America.
authors.forename: Jinglian
authors.initials: J
authors.lastname: Yan
authors.forename: Guodong
authors.initials: G
authors.lastname: Tie
authors.forename: Louis M
authors.initials: LM
authors.lastname: Messina
mesh_terms: D000284:Administration, Oral; D000818:Animals; D001120:Arginine / Q000008:administration & dosage / Q000494:pharmacology* / Q000627:therapeutic use; D001205:Ascorbic Acid / Q000008:administration & dosage / Q000494:pharmacology* / Q000627:therapeutic use; D001708:Biopterins / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000494:pharmacology / Q000627:therapeutic use; D002118:Calcium / Q000378:metabolism; D004357:Drug Synergism; D006614:Hindlimb / Q000098:blood supply* / Q000187:drug effects / Q000473:pathology / Q000503:physiopathology; D007511:Ischemia / Q000188:drug therapy / Q000473:pathology* / Q000503:physiopathology; D008297:Male; D008954:Models, Biological; D009132:Muscles / Q000187:drug effects / Q000201:enzymology / Q000473:pathology / Q000503:physiopathology; D009566:Nitrates / Q000378:metabolism; D009569:Nitric Oxide / Q000378:metabolism*; D052250:Nitric Oxide Synthase Type III / Q000378:metabolism; D009573:Nitrites / Q000378:metabolism; D018384:Oxidative Stress / Q000187:drug effects*; D010766:Phosphorylation / Q000187:drug effects; D051381:Rats; D017207:Rats, Sprague-Dawley; D020127:Recovery of Function / Q000187:drug effects; D012039:Regional Blood Flow / Q000187:drug effects
chemical_list: D009566:Nitrates; D009573:Nitrites; D001708:Biopterins; D009569:Nitric Oxide; D001120:Arginine; D052250:Nitric Oxide Synthase Type III; C003402:sapropterin; D001205:Ascorbic Acid; D002118:Calcium