The molecular mechanisms of sodium metabisulfite on the expression of KATP and L-Ca2+ channels in rat hearts

Sodium metabisulfite (SMB) is used as an antioxidant and antimicrobial agent in a variety of drugs and foods. However, there are few reported studies about its side effects. This study is to investigate the SMB effects on the expression of ATP-sensitive K+ (K-ATP) and L-type calcium (L-Ca2+) channels in rat hearts. The results show that the mRNA and protein levels of the K-ATP channel subunits Kir6.2 and SUR2A were increased by SMB; on the contrary, SMB at 520 mg/kg significantly decreased the expression of the L-Ca2+ channel subunits Ca(v)1.2 and Ca(v)1.3. This suggests that SMB can activate the expression of K-ATP channel by increasing the mRNA and protein levels of Kir6.2 and SUR2A, while it inhibits the expression of L-Ca2+ channels by decreasing the mRNA and protein levels of Ca(v)1.2 and Ca(v)1.3 in rat hearts. Therefore, the molecular mechanism of the SMB effect on rat hearts might be related to the increased expression of K-ATP channels and the decreased expression of L-Ca2+ channels. (C) 2015 Elsevier Inc. All rights reserved.