Effects of vitamin C treatment on collar-induced intimal thickening

WOS: 000366530900003PubMed ID: 26719672Vitamin 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.Scientific Research Foundation of Ege University, Izmir, TurkeyEge UniversityThis research was supported by the Scientific Research Foundation of Ege University, Izmir, Turkey

Investigation of changes in vWF expression in rabbit carotid artery collar model

WOS: 000430370600006Objective: Placement of a soft silicone collar around the carotid arteries of rabbits induces intimal thickening which is considered as one of the crucial steps in the development of atherosclerosis. In this study we aimed to investigate vWF expression levels on days 7 and 14 after collar placement.& para;& para;Methods: A soft inert silicon collar was placed around the left carotid artery for 7 and 14 days. vWF expression was investigated by quantitave RT-PCR. In each artery (collar or sham) cross-sectional areas of intima, media were measured and intima/ media ratio was calculated.& para;& para;Results: Intimal thickening was more pronounced on day 14 compared to day 7. However the collar caused increase in vWF expression which was found to be at the same level on days 7 and 14.& para;& para;Conclusion: Our findings emphasize the importance of vWF in collar-induced intimal thickening