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

Abstract

1 The effect of angiotensin II (Ang II) on α_1A-, α_1B-, and a_1D-adrenoceptors (α₁-AR) expression was analyzed in aorta smooth muscle cells obtained from wild-type (WT) and knock out of α_1D-AR (α_1D-AR KO) mice.

2 The relative abundance of mRNA for the three α₁-ARs was determined in WT and α_1D-AR KO aortic smooth muscle cells. There were no significant differences between WT and α_1D-AR KO cells.

3 As early as 1 h Ang II increased α_1B-AR mRNA in WT cells ≈ 2 fold compared with control; in contrast, in α_1D-AR KO cells the α_1B-AR transcript was ≈ 50% of control.

4 Western blot assays showed that Ang II incremented protein content for α_1A-AR, 86% and 107% in WT and α_1D-AR KO cells, respectively.

5 Protein for α_1B- and α_1D-ARs did not change significantly with Ang II in both WT and a_1D-AR KO cells.

6 The effect of Ang II on α_1B-AR mRNA seems to be influenced by the absence of α_1D-AR in aortic smooth muscle cells, which might be important to understand the interactions among α₁-ARs.