阿片受体拮抗剂对移植排斥反应的作用及机制分析

Effect and Mechanism of Opioid Receptor Antagonist on Allograft Rejection

目的 在以往工作基础上进一步观察选择性δ-阿片受体拮抗剂 naltrindole对移植排斥反应的影响及其作用机制。方法 整体实验以小鼠异体异位心肌组织移植为模型 ,离体实验以体外混合淋巴细胞反应作为观察指标。另外 ,取不同培养时间段的混合淋巴细胞 ,以同位素标记 [α-32 P]-PPE c DNA为探针做 Northern blot分析。结果 naltrindole对移植排斥的抑制作用较纳曲酮更强。δ-阿片受体激动剂 D-Ser2 -Lue-脑啡肽可以促进体外混合淋巴细胞反应 ,该作用能够被 naltrindole拮抗。Northern blot结果提示 ,在混合培养一定时间的淋巴细胞中有脑啡肽前体 PPE m RNA的表达。结论 δ-阿片受体拮抗剂 naltrindole能显著抑制移植排斥反应。移植排斥反应中的免疫细胞激活后可能表达有脑啡肽。 naltrindole抑制移植排斥反应的作用是由 δ-受体介导的 。

Objective In our previous work, naltrexone, a common opioid receptor antagonist was found to be able to inhibit transplantation rejection. Here, we profound this work by using a specific opioid δ receptor antagonist naltrindole to explore the mechanism of the transplantation rejection related to opioid.Methods A transplantation model was used in the in vivo experiments, in which the cardiac tissue of newborn C57 mouse was transplanted into subcutis of the ear of Balb/c mouse. Mixed and cultured together, lymphocytes from two different strains of mice were used in the in vitro experiments. 3H TdR uptake (Bq) was measured to show the mixed lymphocyte reaction. The total RNA of the mixed lymphocytes cultured for certein time was hybridized with [ 32 P] PPE cDNA probe.Results (1)The survival of the transplanted tissues of naltrindole administrated group was significantly longer than that of naltrexone administrated group. (2) Treated with naltrexone or naltrindole, the proliferation of the mixed lymphocytes was inhibited in dose dependent style.And the inhibitory effect of naltrindole was greater than that of naltrexone. (3) It was also found that enkephalin increased the mixed lymphocyte reaction at the early stage of culturing in a concentration dependent biphasic manner, and nal trindole could totally antagonize its effect .(4) There was transcription of PPE mRNA in mixed lymphocytes cultured after certain time (10, 20, 40 and 60 h). Induced immune reaction and its endogenou ligand of this effect was most probably enkephalin.Conclusions (1) The results suggest that δ opioid receptor is involved in the antigen induced immune reaction and its endogenou ligand of this effect is probably enkephalin. (2) The activated immune cells in rejection is likely to produce enkephalin, which works as an stimulating factor for rejecting immune reaction.