Abstract 2407: Distribution and Biological Effects of Autoantibody Against α1-Adrenoceptor in Patients with Primary Hypertension
Objective: To observe the distribution and biological effects of the anti-α1-adrenoceptor-autoantibody from the sera of patients with primary hypertension.
Methods: The anti-α1AR-autoantibody was detected by SA-ELISA with the synthetic peptide corresponding to the sequence of the second extracellular loop of human α1AR. The IgGs from the positive sera of patients with primary hypertension were purified by affinity chromagraphy, and the effects of the purified IgGs on the tension of isolated thoracic aortic rings of rats were observed.
Results: The positive rate of the autoantibody against α1AR in patients with primary hypertension was obviously higher than healthy subjects (48.8% n=86 vs. 9.0% n=100, respectively, p<0.05); The autoantibody (10−9~10−5mol/L) increased tension of isolated thoracic aortic ring of rats with concentration-dependent matter (maximal contraction from 19.27±2.18% to 137.51±4.62%, n=12, p<0.01), which is similar to the α1AR agonist phenylephrine (PE) and independent with the endothelial cells. But the effect can not occurrence with IgGs from the negative sera, and can not be modified by pretreating aortic ring with Prasozin (α1AR antagonist) or synthetic peptide corresponding to the sequence of the second extracellular loop of human α1AR in high concentration.
Conclusion: Our results demonstrated for the first time that the anti-α1-adrenoceptor autoantibody in the sera of patients with primary hypertension exhibited remarkable effects of vascular contraction, and suggesting that the involvement of immunologic mechanism by cardiac receptor antibody in the pathogenesis of primary hypertension.