title: Effects of vitamin C treatment on collar-induced intimal thickening.
abstract: Vitamin C has efficient antioxidant properties and is involved in important physiological processes such as collagen synthesis. As such, vitamin C deficiency leads to serious complications, including vascular diseases. The aim of this study was to investigate the effects of vitamin C treatment on collar-induced intimal thickening. Rabbits were fed a normocholesterolemic diet and a non-occlusive silicon collar was placed around the left carotid artery for 3, 7, and 14 days. The rabbits were treated with or without vitamin C (150 mg/kg/day). Collar-induced intimal thickening became apparent at day 7. The effect of the collar on intimal thickening was more prominent at day 14. Vitamin C treatment significantly inhibited collar-induced intimal thickening at day 14. The placement of the collar around the carotid artery decreased maximum contractile responses against contractile agents (KCl, phenylephrine, 5-hydroxytryptamine). The effect of the collar on contractile responses was enhanced as days elapsed. Decreased contractile responses of collared carotid arteries normalized at day 14 in the vitamin C treatment group. Vitamin C treatment also restored sensitivity to phenylephrine. The collar also significantly decreased acetylcholine-induced relaxations at day 3 and day 7. Acetylcholine-induced relaxations normalized in collared-arteries in the placebo group at day 14. Vitamin C treatment significantly increased acetylcholine-induced relaxations of both normal and collared carotid arteries at day 14. MMP-9 expression increased in collared arteries at day 3 and day 7 but did not change at day 14. MMP-2 expression increased in collared arteries at day 14. However, vitamin C treatment reduced collar-stimulated expression of MMP-2 at day 14. These findings indicate that vitamin C may have potentially beneficial effects on the early stages of atherosclerosis. Furthermore these results, for the first time, may indicate that vitamin C can also normalize decreased contractile response through perivascular collar placement.
authors.affiliation: Department of Pharmacology, Faculty of Pharmacy, Ege University, Izmir, Turkey.
authors.forename: Mehmet Zuhuri
authors.initials: MZ
authors.lastname: Arun
authors.affiliation: Department of Pharmacology, Faculty of Pharmacy, Ege University, Izmir, Turkey.
authors.forename: Levent
authors.initials: L
authors.lastname: Üstünes
authors.affiliation: Department of Pharmacology, Faculty of Pharmacy, Ege University, Izmir, Turkey.
authors.forename: Gülnur
authors.initials: G
authors.lastname: Sevin
authors.affiliation: Department of Pathology, School of Medicine, Dokuz Eylül University, Izmir, Turkey.
authors.forename: Erdener
authors.initials: E
authors.lastname: Özer
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000494:pharmacology*; D001205:Ascorbic Acid / Q000494:pharmacology*; D002339:Carotid Arteries / Q000187:drug effects* / Q000201:enzymology / Q000473:pathology / Q000503:physiopathology; D002340:Carotid Artery Diseases / Q000188:drug therapy* / Q000201:enzymology / Q000209:etiology / Q000473:pathology / Q000503:physiopathology; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D008297:Male; D020778:Matrix Metalloproteinase 2 / Q000378:metabolism; D020780:Matrix Metalloproteinase 9 / Q000378:metabolism; D058426:Neointima; D058226:Plaque, Atherosclerotic; D011817:Rabbits; D013997:Time Factors; D066253:Vascular Remodeling / Q000187:drug effects; D014661:Vasoconstriction / Q000187:drug effects; D014662:Vasoconstrictor Agents / Q000494:pharmacology; D014664:Vasodilation / Q000187:drug effects; D014665:Vasodilator Agents / Q000494:pharmacology
chemical_list: D000975:Antioxidants; D014662:Vasoconstrictor Agents; D014665:Vasodilator Agents; D020778:Matrix Metalloproteinase 2; D020780:Matrix Metalloproteinase 9; D001205:Ascorbic Acid
keywords: MMP; collar; intimal thickening; rabbit carotid artery; vascular reactivity; vitamin C