Expression and characterization of the human α2B-adrenoceptor in a vascular smooth muscle cell line

A vascular smooth muscle cell line stably expressing the human α2B-adrenoceptor at a density of 1.5 pmol/mg membrane protein was generated by transfection of rat A7r5 cells. [35S]GTPγS binding experiments and [3H]thymidine incorporation experiments indicated that the expressed receptors were functional, had the expected pharmacological characteristics and efficiently stimulated smooth muscle cell proliferation. Confocal fluorescence microscopy was used to visualize α2B-adrenoceptors in A7r5-α2B cells and indicated that the receptors were mainly localized in the plasma membrane. The expression of the smooth muscle-specific marker α-actin was similar in transfected A7r5-α2B cells and in non-transfected A7r5 wild-type cells. The generated A7r5-α2B cell line will be a useful tool for studying the function and regulation of α2B-adrenoceptors in vascular smooth muscle cells.