福尔马林致痛大鼠背根节内5-HT受体亚型mRNA的表达变化

CHANGES IN 5-HT RECEPTOR SUBTYPES mRNA EXPRESSION IN THE DORSAL ROOT GANGLIA IN RATS WITH FORMALIN-INDUCED INFLAMMATORY PAIN

摘要:

目的:探讨外周5-HT受体亚型在外周伤害性感受中的作用.方法:用反转录PCR技术观察大鼠单侧足底皮下注射福尔马林致痛后背根节内5-HT1～7受体亚型mRNAs的表达变化.结果:在大鼠足底皮下注射福尔马林后1 h,注射侧腰段背根节内5-HT1A、5-HT1B、5-HT2A、5-HT3、5-HT4和5-HT7受体亚型mRNAs的表达水平显著升高,而5-HT1D、5-HT1F、5-HT2C、5-HT5A和5-HT6受体亚型mRNAs的表达在福尔马林致痛后无明显变化.在正常和福尔马林致痛大鼠的背根节内均未检测到5-HT1E、5-HT2B和5-HT5B受体亚型mRNAs的表达.结论:5-HT1A、5-HT1B、5-HT2A、5-HT3、5-HT4和5-HT7受体亚型可能参与了福尔马林诱导的炎性痛,且它们在外周伤害性信息的传递方面可能发挥不同的作用.

Abstract:

Objective: To investigate the involvement of 5-HT receptors in the peripheral nociceptive signaling.Methods: The expression of 5-HT receptor subtype mRNAs was detected in the lumbar dorsal root ganglion (DRG) by reverse transcription-polymerase chain reaction(RT-PCR) following unilateral injection of formalin into the plantar surface of rat hind paw.Results: Formalin administration resulted in a significant increase in the mRNA level of 5-HT_(1A),5-HT_(1B),5-HT_(2A),5-HT_3,5-HT_4 and 5-HT_7 receptor subtypes in the ipsilateral DRG at 1 h,but not at 10 min or 3 h after formalin injection.Expression of 5-HT_(1D),5-HT_(1F),5-HT_(2C),5-HT_(5A) and 5-HT_6 receptor subtype mRNAs remained no remarkable changes at these time points.5-HT_(1E),5-HT_(2B) and 5-HT_(5B) receptor mRNAs were not detectable in the DRG in both normal and formalin rats.Conclusion: The present results suggest that 5-HT_(1A),5-HT_(1B),5-HT_(2A),5-HT_3,5-HT_4 and 5-HT_7 receptor subtypes might be involved in the formalin-induced inflammatory pain.Different change patterns of 5-HT receptor subtypes in rat DRG following inflammatory pain indicate the possible different roles of each 5-HT receptor subtype in the transmission of peripheral nociception.