Facchinetti F, Tassinari G, Porro C A, Galetti A, Genazzani A R
Department of Obstetrics and Gynecology, University of Modena, ModenaItaly Institute of Physiology, University of Modena, ModenaItaly.
Pain. 1992 Apr;49(1):113-116. doi: 10.1016/0304-3959(92)90196-I.
Several studies have described changes in beta-endorphin-like immunoreactivity (beta-ELI) in the rat brain in response to pain and stress stimuli. In order to ascertain the components of beta-ELI, brain samples of rats experiencing acute prolonged (tonic) pain were evaluated for their beta-ELI and later submitted to a chromatographic purification allowing the measurement of beta-endorphin (beta-EP) and acetyl beta-EP. The chromatographic analysis of both ventromedial hypothalamus (VMH) and periaqueductal grey (PAG) homogenates indicates that beta-ELI is distributed in several fractions including shortened forms of beta-EP and their respective acetylated compounds. Quantitatively, while beta-ELI in formalin-injected animals was increased by 48% in VMH and 45% in PAG in respect to controls, the net increase of purified beta-EP was 1100% and 470%, respectively, for VMH and PAG. Moreover, the maximal increase of beta-ELI was evident at 120 min, in both tissues. In contrast, the beta-EP peak was reached at 30 min in VMH and at 60 min in PAG. Acetyl beta-EP was unchanged by treatment in both central areas. No correlation of beta-ELI and beta-EP was found in VMH. These data demonstrate that the evaluation of beta-ELI gives a poor estimate of beta-EP changes, due to several components of the endorphin family.
多项研究描述了大鼠大脑中β-内啡肽样免疫反应性（β-ELI）在疼痛和应激刺激下的变化。为了确定β-ELI的成分，对经历急性长期（紧张性）疼痛的大鼠脑样本进行β-ELI评估，随后进行色谱纯化，以测量β-内啡肽（β-EP）和乙酰化β-EP。腹内侧下丘脑（VMH）和导水管周围灰质（PAG）匀浆的色谱分析表明，β-ELI分布在几个组分中，包括缩短形式的β-EP及其各自的乙酰化化合物。定量分析显示，与对照组相比，注射福尔马林动物的VMH中β-ELI增加了48%，PAG中增加了45%，而VMH和PAG中纯化β-EP的净增加分别为1100%和470%。此外，两种组织中β-ELI的最大增加在120分钟时明显。相比之下，VMH中β-EP峰值在30分钟时达到，PAG中在60分钟时达到。两个中枢区域的乙酰化β-EP在处理后均无变化。在VMH中未发现β-ELI与β-EP之间的相关性。这些数据表明，由于内啡肽家族的多个成分，对β-ELI的评估对β-EP变化的估计较差。
