Institut für Experimentelle und Klinische Pharmakologie und Toxikologie, Albert-Ludwigs-Universität Freiburg, Freiburg, Germany.
Handb Exp Pharmacol. 2024;285:185-245. doi: 10.1007/164_2024_714.
Presynaptic α-adrenoceptors are localized on axon terminals of many noradrenergic and non-noradrenergic neurons in the peripheral and central nervous systems. Their activation by exogenous agonists leads to inhibition of the exocytotic release of noradrenaline and other transmitters from the neurons. Most often, the α-receptor subtype is involved in this inhibition. The chain of molecular events between receptor occupation and inhibition of the exocytotic release of transmitters has been determined. Physiologically released endogenous noradrenaline elicits retrograde autoinhibition of its own release. Some clonidine-like α-receptor agonists have been used to treat hypertension. Dexmedetomidine is used for prolonged sedation in the intensive care; It also has a strong analgesic effect. The α-receptor antagonist mirtazapine increases the noradrenaline concentration in the synaptic cleft by interrupting physiological autoinhibion of release. It belongs to the most effective antidepressive drugs. β-Adrenoceptors are also localized on axon terminals in the peripheral and central nervous systems. Their activation leads to enhanced transmitter release, however, they are not activated by endogenous adrenaline.
突触前 α-肾上腺素受体位于外周和中枢神经系统中许多去甲肾上腺素能和非去甲肾上腺素能神经元的轴突末梢。它们被外源性激动剂激活后，会抑制神经元中去甲肾上腺素和其他递质的胞吐释放。大多数情况下，涉及这种抑制的是 α-受体亚型。已经确定了受体占据和抑制递质胞吐释放之间的分子事件链。生理释放的内源性去甲肾上腺素会引发自身释放的逆行自动抑制。一些可乐定样 α-受体激动剂已被用于治疗高血压。右美托咪定用于重症监护中的长时间镇静；它还具有很强的镇痛作用。α-受体拮抗剂米氮平通过中断生理自动抑制释放来增加突触间隙中的去甲肾上腺素浓度。它属于最有效的抗抑郁药物。β-肾上腺素受体也位于外周和中枢神经系统的轴突末梢。它们的激活会导致递质释放增加，但它们不会被内源性肾上腺素激活。
