Arnett C D, Davis J N
J Pharmacol Exp Ther. 1979 Nov;211(2):394-400.
Denervation resulted in a marked increase in the beta adrenergic response and isoproterenol-stimulated cyclic adenosine 3':5'-monophosphate accumulation of dispersed cells prepared from a rat submandibular gland. This increase in beta adrenergic response was paralleled by an increase in the density of beta adrenergic receptors in membranes prepared from these glands. Denervation also produced a moderate increase in alpha adrenergic receptor density in membranes prepared from whole glands. However, the alpha adrenergic response in cells, epinephrine-induced release of potassium, appeared unaltered by denervation. Furthermore, membranes prepared from denervated dispersed cells did not show the increase in alpha adrenergic receptor density seen in membranes from an intact denervated gland. These data demonstrate that removal of noradrenergic nerve terminals affects alpha and beta adrenergic receptors differently. While it is clear that beta adrenergic membrane receptors participate in denervation-induced supersensitivity, the changes in alpha adrenergic membrane receptors are more complex and may not contribute to the supersensitivity seen after denervation. On the basis of competitive binding studies, the adrenergic receptors in membranes from intact submandibular glands were subclassified as beta-1 and alpha-2. Denervation did not alter the binding characteristics of the alpha-2 receptors in this gland, demonstrating that alpha-2 adrenergic membrane receptors can be postsynaptic in this adrenergically innervated tissue.
去神经支配导致大鼠下颌下腺制备的分散细胞的β肾上腺素能反应以及异丙肾上腺素刺激的环磷酸腺苷3':5'-单磷酸积累显著增加。β肾上腺素能反应的这种增加与这些腺体制备的膜中β肾上腺素能受体密度的增加平行。去神经支配还使全腺体制备的膜中α肾上腺素能受体密度适度增加。然而，细胞中的α肾上腺素能反应，即肾上腺素诱导的钾释放，似乎不受去神经支配的影响。此外，去神经支配的分散细胞制备的膜未显示出完整去神经支配腺体的膜中所见的α肾上腺素能受体密度增加。这些数据表明，去甲肾上腺素能神经末梢的去除对α和β肾上腺素能受体的影响不同。虽然很明显β肾上腺素能膜受体参与去神经支配诱导的超敏反应，但α肾上腺素能膜受体的变化更为复杂，可能与去神经支配后所见的超敏反应无关。基于竞争性结合研究，完整下颌下腺膜中的肾上腺素能受体被分类为β-1和α-2。去神经支配并未改变该腺体中α-2受体的结合特性，表明α-2肾上腺素能膜受体在这个肾上腺素能神经支配的组织中可以是突触后受体。
