Effect of sulfur dioxide inhalation on the expression of K_(ATP) and L-Ca(2+) channels in rat hearts

摘要

Epidemiological studies have revealed an association between sulfur dioxide (SO_2) exposure and cardiovascular diseases. This study is designed to investigate the SO_2 effect on the expression of ATP-sensitive K~+ (K_(ATP)) channel and L-type calcium (L-Ca~(2+)) channel in rat hearts. The results show that the mRNA and protein levels of the K_(ATP) channel subunits Kir6.2 and SUR2A of rat hearts in SO_2 groups were higher than those in control group. SO_2 at 14 mg/m~3 significantly decreased the expression of the L-Ca~(2+) channel subunits Ca_v1.2 and Ca_v1.3. This suggests that SO_2 can activate the K_(ATP) channels by up-regulating the expression of Kir6.2 and SUR2A, while it inhibits the L-Ca~(2+) channels by down-regulating the expression of Ca_v1.2 and Ca_v1.3 in rat hearts. The molecular mechanism of SO_2-induced negative inotropic effect might be linked to the expression changes of these subunits, which may contribute to the pathogenesis of SO_2-associated cardiovascular diseases.