Objective: To determine whether autoantibodies against the cardiac G-protein-coupled beta 2- and alpha 1-adrenergic and AT1 receptors are related to patients with primary hypertension.
Methods: Synthetic peptides corresponding to amino acid sequences of the second extracellular loops of the beta 2- and alpha 1-adrenergic and AT1 receptors were respectively used as antigens to screen sera from patients with hypertensive heart diseases (n = 50) as well as simple hypertension (n = 40) and healthy blood donors (n = 40) using ELISA test.
Results: The positive ratio of autoantibodies against beta 2 and alpha 1 and AT1 receptors in patients with hypertensive heart diseases were significantly higher than patients with simple hypertension and healthy donors. The geometric mean titers of autoantibodies against beta 2- and alpha 1-adrenergic and AT1 receptors had no difference between the patients with hypertensive heart diseases and the patients with simple hypertension, but the geometric mean titers of two groups were higher than healthy donors. In the patients with hypertensive heart diseases, 81.0% of the patients with autoantibodies against beta 2-adrenergic receptor had autoantibodies against alpha 1-adrenergic receptor and 76.2% had autoantibodies against AT1 receptors. The percent of the autoantibodies against three receptors in patients with hypertensive heart diseases were 52.4%.
Conclusions: Autoantibodies against beta 2- and alpha 1-adrenergic and AT1 receptors play an important role in the pathophysiological changes of primary hypertension, and may participate myocardial and vessel remodeling.