Abstract: Objective To investigate the effect of melatonin on intima hyperplasia in rat carotid arteries after balloon injury. Methods Twenty male sprague-dawley rats were randomized into control, melatonin injected, balloon injured, and balloon injured with melatonin injected. An established balloon-induced carotid artery injury was performed. And carotid arteries were harvested 14 days later. The ratio of intima to media (i/m) were measured. And Western blot were used to detected the expression of NF-kB, IL-1β, IL-6 and TNF-α. Results The balloon injury could significantly induce the increasing of i/m and the expression of NF-kB, IL-1β, IL-6 and TNF-α in rat carotid arteries. Melatonin could minimize this effect caused by balloon injury. Conclusions Melatonin could inhibit the intima hyperplasia in rat carotid arteries after balloon injury through alleviating the inflammation mediated by NF-kB.

Key words: melatonin, balloon injury, inflammation, intima hyperplasia