阿片肽对大鼠下丘脑体外释放免疫反应性促肾上腺皮质激素释放因子的影响。

Effects of opioid peptides on immunoreactive corticotropin-releasing factor release from the rat hypothalamus in vitro.

作者信息

Yajima F, Suda T, Tomori N, Sumitomo T, Nakagami Y, Ushiyama T, Demura H, Shizume K

出版信息

Life Sci. 1986 Jul 14;39(2):181-6. doi: 10.1016/0024-3205(86)90453-4.

Abstract

Effects of opioid peptides on immunoreactive corticotropin-releasing factor (I-CRF) release from the rat hypothalamus were examined using a rat hypothalamic perifusion system and a rat CRF RIA in vitro. beta-Endorphin (0.3 - 30 nM), dynorphin (0.3 - 30 nM) and FK 33-824 (1 - 10 microM) suppressed basal I-CRF release in a dose-dependent fashion. At 2.2 nM concentrations of these peptides, mean percent inhibition was 56% for beta-endorphin; less than 5% for alpha-endorphin; 44% for dynorphin; 23% for leucine-enkephalin; 6% for methionine-enkephalin; less than 5% for FK 33-824; and less than 5% for D-ala2, D-leu5-enkephalin. The inhibitory effects of beta-endorphin and enkephalins were completely blocked by naloxone, but those of dynorphin were only partially blocked. These results suggest that opioid peptides act through opioid receptors and inhibit I-CRF release from the hypothalamus under our conditions. Therefore, endogenious opioid peptides may have a physiological role in the CRF-releasing mechanism of the hypothalamus.

摘要

利用大鼠下丘脑灌流系统和大鼠促肾上腺皮质激素释放因子（CRF）放射免疫分析法（RIA）体外检测了阿片肽对大鼠下丘脑免疫反应性促肾上腺皮质激素释放因子（I-CRF）释放的影响。β-内啡肽（0.3 - 30 nM）、强啡肽（0.3 - 30 nM）和FK 33-824（1 - 10 μM）以剂量依赖方式抑制基础I-CRF释放。在这些肽浓度为2.2 nM时，β-内啡肽的平均抑制百分比为56%；α-内啡肽小于5%；强啡肽为44%；亮氨酸脑啡肽为23%；甲硫氨酸脑啡肽为6%；FK 33-824小于5%；D-ala2，D-leu5-脑啡肽小于5%。β-内啡肽和脑啡肽的抑制作用被纳洛酮完全阻断，但强啡肽的抑制作用仅被部分阻断。这些结果表明，在我们的实验条件下，阿片肽通过阿片受体发挥作用并抑制下丘脑I-CRF的释放。因此，内源性阿片肽可能在下丘脑CRF释放机制中具有生理作用。