急性低氧下β-内啡肽参与对大鼠体液免疫的抑制性调节

β ENDORPHIN INVOLVED IN THE REGULATION OF HUMORAL IMMUNE FUNCTION OF RATS DURING ACUTE HYPOXIA 

正常大鼠脑室注射β内啡肽（βＥＰ）（１ｎｇ／ｒａｔ）使溶血素生成和鸡卵白蛋白的ＩｇＧ抗体产生受到明显抑制，脾脏单个核细胞ＤＮＡ含量也下降；７ｋｍ４８ｈ低氧同样使溶血素的产生明显下降，大鼠脑室注射阿片受体阻断剂钠屈酮（ｎａｌｔｒｅｘｏｎｅ）可使低氧造成的ＩｇＧ和溶血素生成抑制翻转，低氧抑制的脾脏单个核细胞ＤＮＡ合成得到部分阻断；脑室注射βＥＰ与７ｋｍ低氧１２ｈ一样使脾脏中儿茶酚胺含量增加。因而，本研究认为阿片类物质在急性低氧应激过程中参与了对大鼠体液免疫功能的调节作用。其对低氧体液免疫功能的抑制作用可能与激活交感神经系统有关。

Abstract In order to investigate the role of β endorphin in the regulation of humoral immune function of rats during acute hypoxia, the effects of β endorphin on mitogen induced spleen lymphocyte DNA synthesis and hemolysin formation as well as IgG production to chicken egg albumen were observed. It was found that after rats received icv injection of β endorphin (1 ng/rat), the T lymphocyte DNA content, the hemolysin forming capacity of SRBC sensitized rats and the IgG level were reduced significantly compared with the control (icv normal saline). Similar suppressive effects on immune function could be found after rats were exposed to 7 km altitude in a hypobaric chamber for 48 h. Pretreatment with icv injection of naltrexone, the immunosuppressive effects of acute hypoxia were partially blocked. Icv administration of β endorphin produced an increase in splenic cathcholamines, similar to those of hypoxia treated group (7 km for 12 h). All the above findings suggest that β endorphin may modulate the immune response to hypoxia stress via opioid receptor and its inhibitory action may be mediated by activating sympathetic nervous system.