摘要
白细胞介素-2(IL-2)不仅是重要的免疫调节因子,而且还具有重要的中枢调节作用。本实验以钾离子透入引起大鼠甩尾反应为指标,发现侧脑室注射IL—2能显著提高动物痛阈,并能被纳洛酮所阻断,表示IL-2的中枢镇痛作用可能与阿片受体有关。利用基因定位突变技术获得的无免疫活性IL-2实查体仍具有中枢镇痛作用,表明IL—2分子上发挥镇痛和免疫调节作用的功能位点是相互独立的。纳洛酮能够阻断IL—2的中枢镇痛作用,而不能影响IL—2增殖CTLL-2细胞的作用,提示IL-2发挥镇痛和免疫调节作用可能通过不同的受体途径。IL-2分子中第45位Tyr残基突变为Val后,虽仍保留了免疫活性,但丧失了镇痛功能,表示45位Tyr残基是IL—2发挥中枢镇痛功能的关键残基之一。我们推测IL—2的镇痛功能位点可能在IL—2分子中第45位Tyr残基附近区域。
Interleukin-2 (IL-2) not only possess immunoregulatory activity, but also has important effect on central nervous system. We now report that IL-2 is an analgesic substance after injecting IL-2 into the lateral cerebral ventricle of rats. The pain threshold (PT) was evaluated by the tail-fiick induced by potassium iontophoresis. Naloxone could block the analgesic capability of IL-2, suggesting that analgesic effect of IL-2 be related to opiate receptors. The IL-2 mutant, which was obtained by oligonucleotide-mediated site-directed mutagenesis and had no immune activity, still had the analgesic capability, suggesting that there be different domains of immune and analgesic activity in IL-2 molecule. Since naloxone could block the analgesic effect, but not the proliferating effect on CTLL-2 cells of IL-2,it is suggested that the immune and analgesic effect of IL-2 might be mediated by different receptors. There was no analgesic effect after the 45th residue (Tyr) of IL-2 molecule was mutated to Val, despite that 45Val-IL-2 still had immune activity, suggesting that the 45th residue-Tyr be one of the crucial residues of IL-2 for its analgesic effect. It is suggested that the analgesic functional site(s) of IL-2 may be located at the domain around the 45th Tyr-residue of IL-2 molecule.
出处
《神经科学》
SCIE
CAS
1994年第2期21-26,42,共6页
Chinese Journal of Neuroscience
关键词
白细胞介素-2
中枢神经系统
免疫
镇痛
功能位点
Interleukin-2, Central Nervous System, Immune, Receptors, Analgesia, Naloxone,Mutant