The effects of high doses of selenium supplementation on mRNA and protein levels of cMLCK levels and total antioxidant capacity in rat heart tissue.

BACKGROUND

High doses of selenium are associated with heart disease prevalence in high-risk areas. Cardiac myosin light chain kinase (cMLCK) is an essential enzyme for normal function of heart tissue. Therefore, we studied the effect of high doses of selenium on the expression of cMLCK gene and its protein in normal heart tissue in rats.

MATERIALS AND METHODS

Twenty male rats were randomly divided into four groups: control, Se 0.3mg/kg, Se 1.5mg/kg, and Se 3mg/kg. Sodium-selenite was administered orally into drinking water for 20 weeks. Se levels of heart tissue were measured by atomic absorption. Serum creatine phosphokinase (CPK) and total serum antioxidant capacity were measured. Moreover, the concentration of MLCK protein and the gene expression level of cMLCK in normal heart tissue were analyzed.

RESULTS

Excess Se in dietary can significantly increase CPK. Se concentration of heart tissue in the Se 3mg/kg group was significantly higher than the control. cMLCK mRNA levels were decreased by 0.3mg/kg and 3mg/kg sodium selenite intake. There was no significant difference between the three groups for total antioxidant capacity and MLCK protein.

CONCLUSION

High concentrations of selenium can probably effect on normal function of the heart tissue by changing the expression levels of cMLCK.