Impact of selenium on the leukotriene B4 synthesis pathway during isoproterenol-induced myocardial infarction in experimental rats.

Selenium (Se), an essential micronutrient, exerts its biological functions through selenoproteins. There are evidences that show Se to have an impact on the course and outcome of a number of etiologically inflammatory diseases. Leukotriene B(4) (LTB(4)) is an inflammatory mediator, and its production is mediated through two specific enzymes--lipooxygenase (LOX) and leukotriene A(4) hydrolase (LTA(4)H). We examined the effect of Se on LTB(4) synthesis during isoproterenol (ISP)-induced myocardial infarction (MI) in rats. Rats were divided as: control, ISP, Se, and Se + ISP. Sodium selenite was administered at dose of 8 μg/100 g/day. ISP was injected subcutaneously twice (10 mg/100 g body weight). The rats pretreated with Se had increased concentration of phospholipids and enhanced biosynthetic enzymes compared with that of ISP. The activities of phospholipases decreased on Se treatment. The level of calcium was increased in ISP group whereas, on Se treatment, it was near normal levels. Activities of LOX and expression of LTA(4)H were down-regulated in the case of Se-pretreated rats. Our study shows the anti-inflammatory mechanism of selenium during MI.