Hypercholesterolemia alters vascular functions and gene expression of potassium channels in rat aortic smooth muscle cells

AIM: To investigate the effects of hypercholesterolemia on functions of rat aorta and on gene expression of inward rectifier and ATP-sensitive potassi um channels in aortic smooth muscle. METHODS: Rats were treated with high-c holesterol emulsion ig for 2 weeks; the aortic rings with and without endot helium were prepared to examine the aortic contractile and relaxation respo nses; RT-PCR was used to observe the gene expression of inward rectifier an d ATP-sensitive potassium channels. RESULTS: Hypercholesterolemia damaged t he endothelium-dependent vascular functions severely, but did not affect th e endothelium-independent vascular functions; Kir6.2 mRNA expression was up regulated (P < 0.05) and Kir3.1 mRNA expression was downregulated markedly (P < 0.05) in hypercholesterolemic smooth muscle. CONCLUSION: Hypercholeste rolemia altered the vascular functions and regulated gene expression levels of specific inward rectifier and ATP-sensitive potassium channel subtypes.