Chronic continuous light exposure leads to melatonin deficiency along with complex neurohumoral activation resulting in hypertension. The aim of this study was to show, whether continuous light induces fibrotic rebuilding of the aorta and whether the treatment with melatonin or captopril can prevent these potential alterations.
In a six-week experiment, Wistar rats were divided into 4 groups: controls, rats exposed to continuous light (LC), LC + captopril (100 mg/kg/24 h) and LC + melatonin (10 mg/kg/24 h). We conclude that in continuous light-induced hypertension, administration of melatonin, along with SBP reduction, decreases collagen I and III concentration in the aorta.
It is suggested that antifibrotic effect of melatonin may reduce the stiffness of the aorta and small arteries and beneficially influence the peripheral vascular resistance.