Abstract: Objective to study the expression changes and mechanism of large conductance Ca2+-activated K+ channel on aortas between SHR and WKY. Methods the expression of BKα subunit andβ1 subunit on aortas between SHR and WKY by means of real-time quantitative PCR and western blotting.Results In mRNA study,expression ofαandβ1 subunit are higher in SHR than WKY(n=6,p<0.05).In protein expression,αsubunit has no significant difference between SHR and WKY(n=6,p>0.05),butβ1subunit in SHR is more than WKY, and there was significant difference(n=6,p<0.05).Conclusions the expression of BKα subunit andβ1 subunit mRNA and protein in SHR are higher than that in WKY which may be a Negative feedback mechanism to Vascular tone during hypertension.

Key words: hypertension, aortas smooth muscle, large conductance Ca2+-activated K+ channel, α subunit, β1 subunit