The beta sympathomimetic group inhibits beta adrenergic receptors, including: beta1, beta2, beta3, in which the most clinically applicable are beta1 and beta 2 receptors. Beta 1 receptors are abundant on the heart and kidneys. Beta 2 receptors are abundant in bronchi, vascular smooth muscle, digestive, musculoskeletal... beta3 is found in fatty tissue, bladder, intestine.