Cesselin F
Rev Neurol (Paris). 1986;142(8-9):649-70.
Since the discovery of Met- and Leu-enkephalin (Hughes and Kosterlitz, in 1975) about 20 opioid peptides including beta-endorphin, enkephalins and dynorphins have been identified in the central nervous system. Multiple opiate receptors: mu, delta, kappa, etc, with distinct pharmacological characteristics and regional distributions are present in the CNS, which may correspond to the heterogeneity of opioid peptides. Although both endomorphins and opiate receptors have been found in all areas directly involved in nociception, pharmacological, electrophysiological and most biochemical investigations have not demonstrated so far that endomorphinergic neurones play a role in the control of pain. As emphasized in this review, only the measurement of endomorphin release directly in the CNS has allowed the demonstration that some endomorphinergic neurones, notably those containing Met-enkephalin in the spinal cord, can be activated by noxious stimuli. However, the characteristics of this activation depend on both the nature of the stimulus (chemical, mechanical or thermal) and the body area where it is applied. The functional significance of such "pain"--induced activation of spinal enkephalinergic neurones is still speculative.
自1975年发现甲硫氨酸脑啡肽和亮氨酸脑啡肽（休斯和科斯特利茨）以来，在中枢神经系统中已鉴定出约20种阿片肽，包括β-内啡肽、脑啡肽和强啡肽。中枢神经系统中存在多种具有不同药理学特性和区域分布的阿片受体，如μ、δ、κ等，这可能与阿片肽的异质性相对应。虽然在所有直接参与痛觉感受的区域都发现了内吗啡肽和阿片受体，但迄今为止，药理学、电生理学和大多数生化研究都没有证明内吗啡肽能神经元在疼痛控制中发挥作用。正如本综述所强调的，只有直接在中枢神经系统中测量内吗啡肽的释放，才能证明一些内吗啡肽能神经元，特别是脊髓中含有甲硫氨酸脑啡肽的神经元，可被有害刺激激活。然而，这种激活的特征取决于刺激的性质（化学、机械或热刺激）及其施加的身体部位。脊髓脑啡肽能神经元这种“疼痛”诱导激活的功能意义仍具有推测性。
