Angiotensin II modifies the expression of α1-adrenoceptors in aorta smooth muscle cells of α1D-adrenoceptor knockout mice.

Summary 1 The effect of angiotensin II (Ang II) on α1A-, α1B-, and a1D-adrenoceptors (α1-AR) expression was analyzed in aorta smooth muscle cells obtained from wild-type (WT) and knock out of α1D-AR (α1D-AR KO) mice. 2 The relative abundance of mRNA for the three α1-ARs was determined in WT and α1D-AR KO aortic smooth muscle cells. There were no significant differences between WT and α1D-AR KO cells. 3 As early as 1 h Ang II increased α1B-AR mRNA in WT cells ≈ 2 fold compared with control; in contrast, in α1D-AR KO cells the α1B-AR transcript was ≈ 50% of control. 4 Western blot assays showed that Ang II incremented protein content for α1A-AR, 86% and 107% in WT and α1D-AR KO cells, respectively. 5 Protein for α1B- and α1D-ARs did not change significantly with Ang II in both WT and a1D-AR KO cells. 6 The effect of Ang II on α1B-AR mRNA seems to be influenced by the absence of α1D-AR in aortic smooth muscle cells, which might be important to understand the interactions among α1-ARs. [ABSTRACT FROM AUTHOR]