Zangen A, Herzberg U, Vogel Z, Yadid G
Department of Life Science, Bar-Ilan University, Ramat-Gan, Israel.
Neuroscience. 1998 Aug;85(3):659-62. doi: 10.1016/s0306-4522(98)00050-5.
The hypothesis that the naturally occurring analgesic peptide, beta-endorphin, is released in the brain in response to pain had never been directly validated. In this study, we applied a brain microdialysis method for monitoring beta-endorphin release in vivo, to test this hypothesis in the brains of conscious, freely moving rats. Herein we first show that endogenous beta-endorphin can be measured in vivo in the brain under physiological conditions. Upon induction of a nociceptive stimulus by injection of formalin into the hind-paws of rats, the extracellular levels of beta-endorphin in their arcuate nucleus increased by 88%, corresponding to their nociceptive response. This direct evidence for the release of endogenous beta-endorphin in the brain in response to nociceptive stimulus indicates a possible mechanism for organisms to cope with pain.
天然存在的镇痛肽β-内啡肽会在大脑中因疼痛而释放，这一假说从未得到过直接验证。在本研究中，我们应用脑微透析方法在体内监测β-内啡肽的释放，以在清醒、自由活动的大鼠大脑中验证这一假说。在此我们首次表明，在生理条件下可在体内测量大脑中的内源性β-内啡肽。通过向大鼠后爪注射福尔马林诱导伤害性刺激后，它们弓状核中β-内啡肽的细胞外水平增加了88%，这与它们的伤害性反应相对应。大脑中内源性β-内啡肽因伤害性刺激而释放的这一直接证据表明了生物体应对疼痛的一种可能机制。
