Effects of ATP-sensitive potassium channels on the expression of P21, P27 and leptin

This study investigated the effects of ATP-sensitive potassium channels on the expression of P21, P27 and leptin. The expression of receptor of ATP-sensitive potassium channels (sulphonylurea receptor, SUR) mRNA in the preadipocytes and leptin mRNA was detected by PCR after rat preadipocytes were treated with the opener (diazoxide) or inhibitor (glibenclamide) of ATP-sensitive potassium channels during the process of inducing differentiation. The expression of P21 and P27 in preadipocytes treated with diazoxide or glibenclamide was assayed by Western blot. The results showed that the expression of SUR2, not SUR1 was detected in adipose tissue, preadipocytes and adipocytes. After treatment of preadipocytes with diazoxide, the expression levels of P21 and P27 were obviously higher than those in control group, but the expression levels of P21 and P27 in glibenclamide-treated group were lower than those in control group. During the process of inducing differentiation, the expression of leptin mRNA in preadipocytes treated with diazoxide was increased greatly, but the expression of leptin mRNA in glibenclamide-treated group decreased obviously. It was concluded that ATP-sensitive potassium channels might be involved in the proliferation and differentiation of rat preadipocytes by changing the expression of P21, P27 and leptin.