内在拟交感活性,指某些药物与β受体结合后除能阻断β受体外,尚对β受体具有微弱的激动作用,因而表现出拟似交感神经兴奋时的部分效应。这些药物的内在活性不强,与受体结合后只能使其中一部分活化,故引起的生理效应较弱。且一般被其β阻断作用所掩盖而无法表现出来。如果在实验动物预先用利血平耗竭体内儿茶酚胺,使药物的β阻滞作用无从发挥,再用这类药物,其激动β受体的作用便可充分表现出来,从而导致心率加速, Intrinsic sympathomimetic activity, refers to the combination of certain drugs and beta receptors in addition to block the beta receptor, the beta receptor has a slight agitation, which showed similar to the sympathetic part of the effect of excitement. The intrinsic activity of these drugs is not strong, and only a part of the receptor after activation, it caused the physiological effects of weak. And is generally obscured by its beta blockade can not be demonstrated. If the experimental animals in advance with reserpine depletion of catecholamines in vivo, so that the drug can not play the role of β-block, and then use these drugs, the role of agonist β receptors can be fully demonstrated, leading to accelerated heart rate,