阿片受体介导大鼠海马内脑啡肽对细胞免疫功能的调节

以刀豆蛋白Ａ（ＣｏｎＡ）刺激的脾淋巴细胞增殖活性及自然杀伤细胞（ＮＫｃｅｌ）活性为细胞免疫功能检测指标,观察了阿片受体阻断剂纳洛酮（Ｎａｌｏｘｏｎｅ,ＮＬＸ）对大鼠海马内微量注射甲硫脑啡肽所致的免疫功能增强作用的影响。结果发现：（１）海马内微量注射白细胞介素１（ＩＬ１）诱导剂（细菌内毒素）脂多糖（ｌｉｐｏｐｏｌｙｓａｃｈａｒｉｄｅ,ＬＰＳ,５０ｎｇ／１μｌ）可降低机体免疫功能。（２）双侧海马内预先注射甲硫脑啡肽（ＭＥＮＫ,浓度：１０μｇ／μｌ）各１μｌ,可阻止脑内ＬＰＳ降低免疫功能的作用。（３）脑啡肽的这种作用可被阿片受体阻断剂纳洛酮（１０μｇ／１μｌ）阻断。（４）海马内单纯注射纳洛酮对机体免疫功能也起抑制作用。上述结果提示,海马内脑啡肽对免疫功能的增强作用是通过阿片受体介导的。

Opioid receptor mediated modulation of intrahippocampal enkephalin induced cellular immune function

In the present work, the effect of intrahippocampal microinjection of opioid receptor antagonist naloxone on the enhancement of cellular immune responses induced by enkephalin was studied in rat. The results showed that (1) the proliferation activity of splenic lymphocytes stimulated by Con A and natural killer (NK) cell activity were decreased with microinjection of 1 microl lipopolysaccharide (LPS,50 ng/microl) into bilateral hippocampus; (2) the decrease of cellular immune responses induced by LPS could be inhibited by a preceding intrahippocampal injection of 1 microl met-enkephalin (10 microg/1 microl); (3) the enhancement of cellular immune responses induced by met-enkephalin could be blocked by an opioid receptor antagonist naloxon (10 microg/microl); and (4) cellular immune responses were also inhibited when naloxon was injected intrahippocampally alone. The above results suggest that the enhancement of cellular immune responses induced by enkephalin was mediated by opioid receptors in hippocampus.