Majewski H, Rand M J
Eur J Pharmacol. 1981 Feb 19;69(4):493-8. doi: 10.1016/0014-2999(81)90455-6.
The ability os isoprenaline to enhance transmitter release from sympathetic nerves in rat atria incubated with [3H]noradrenaline was assessed under three conditions of prejunctional alpha-adrenoceptor activation: in the presence of phentolamine, in the presence of noradrenaline, and in the absence of either drug. Isoprenaline-induced enhancement of transmitter release was inversely related to the degree of activation of prejunctional alpha-adrenoceptors. Thus there appears to be an interaction between the prejunctional alpha-adrenoceptor inhibitory mechanism and the prejunctional beta-adrenoceptor facilitatory mechanism. In rabbit ear arteries incubated with [3H]noradrenaline, isoprenaline facilitated transmitter release in the presence but not in the absence of phentolamine. Therefore in some tissues it may be necessary to block prejunctional alpha-adrenoceptors before prejunctional beta-adrenoceptors can be demonstrated.
在三种节前α-肾上腺素能受体激活条件下，评估了异丙肾上腺素增强用[3H]去甲肾上腺素孵育的大鼠心房交感神经递质释放的能力：在酚妥拉明存在下、去甲肾上腺素存在下以及两种药物均不存在时。异丙肾上腺素诱导的递质释放增强与节前α-肾上腺素能受体的激活程度呈负相关。因此，节前α-肾上腺素能受体抑制机制与节前β-肾上腺素能受体促进机制之间似乎存在相互作用。在用[3H]去甲肾上腺素孵育的兔耳动脉中，异丙肾上腺素在酚妥拉明存在时促进递质释放，但在其不存在时则不然。因此，在某些组织中，可能有必要在证明节前β-肾上腺素能受体之前阻断节前α-肾上腺素能受体。
