Effects of the antibodies against α1- adrenergic receptor on the proliferation of vascular smooth muscle cells in rats

AIM: The autoantibodies against α1-adrenergic receptor that was found in patients with malignant hypertension, primary hypertension and refractory hypertension has the agonist activity liked the NE, and may play a role in hypertension. In this paper, the effects of this antibody on vascular smooth muscle cell (VSMC) proliferation and its mechanism were to be studied. METHODS: The cultured rat VSMC proliferation induced by the antibodies against α1- adrenergic receptor that was purified by the immune affinity chromatography, was measured by the BrdU cell proliferation assay and cell cycle distribution. The expression of c-jun and c-fos were determined by RT-PCR and Western blotting. RESULTS: Compared to the normal IgG, the antibodies against α1-adrenergic receptor promoted the VSMC proliferation and increased the mRNA and protein expression of the c-jun significantly. The role was similar to the norepinephrine, and all was blocked by prazosin, while the mRNA and protein expression of c-fos were not affected by the antibodies. CONCLUSION: The antibodies against α1-adrenergic receptor promote the rat VSMC proliferation, and increase the expression of c-jun, which maybe play a role in the vascular remodeling in hypertension.