清醒大鼠垂体前叶中α-新内啡肽的释放。

Release of alpha-neoendorphin from the anterior pituitary gland of conscious rats.

作者信息

Konya H, Masuda H, Nagai K, Kakishita E

机构信息

2nd Department of Internal Medicine, Hyogo College of Medicine, Japan.

出版信息

Brain Res. 1994 Nov 28;665(1):130-4. doi: 10.1016/0006-8993(94)91162-2.

DOI:10.1016/0006-8993(94)91162-2

PMID:7882005

Abstract

alpha-Neoendorphin (alpha-NEO) is a proenkephalin B-derived opioid peptide and kappa type opioid receptor agonist. In the present study, we used a combination of microdialysis and a highly sensitive radioimmunoassay to measure the extracellular levels of immunoreactive (ir)-alpha-NEO from the anterior pituitary gland of conscious free-moving rats. When rats were given water ad libitum under a 12:12 h light-dark cycle with lighting from 06.00 to 18.00 h, ir-alpha-NEO showed circadian rhythmicity that peaked at 00.00-03.00 h and reached a minimum at 12.00-15.00 h. Furthermore, we investigated whether naloxone (10(-6) to 10(-8) M) affected ir-alpha-NEO level. The alpha-NEO release induced by naloxone was optimum at 10(-7) M, and 10(-6) M naloxone seemed to induce alpha-NEO release to a lesser degree. These results suggested that alpha-NEO release by naloxone might be mediated via anterior pituitary cell auto-receptor (kappa type) inhibition.

摘要

α-新内啡肽（α-NEO）是一种源自脑啡肽原B的阿片肽，也是κ型阿片受体激动剂。在本研究中，我们采用微透析和高灵敏度放射免疫测定相结合的方法，来测量清醒自由活动大鼠垂体前叶中免疫反应性（ir）-α-NEO的细胞外水平。当大鼠在12:12小时的明暗周期（6:00至18:00小时光照）下随意饮水时，ir-α-NEO呈现昼夜节律，在0:00至3:00小时达到峰值，在12:00至15:00小时降至最低。此外，我们研究了纳洛酮（10⁻⁶至10⁻⁸M）是否会影响ir-α-NEO水平。纳洛酮诱导α-NEO释放的最佳浓度为10⁻⁷M，10⁻⁶M纳洛酮诱导α-NEO释放的程度似乎较小。这些结果表明，纳洛酮诱导的α-NEO释放可能是通过抑制垂体前叶细胞自身受体（κ型）介导的。