5-HT_1受体亚型mRNAs在坐骨神经分支选择损伤模型大鼠脊髓背角的表达变化

CHANGES OF THE EXPRESSION OF 5-HT_1 RECEPTOR mRNAs IN THE SPINAL DORSAL HORN BY SPARED SCIATIC NERVE INJURY

为探讨脊髓内5-HT1受体亚型在神经病理性痛信息传递和调控中的作用,本研究利用反转录聚合酶链式反应(RT-PCR)技术观察了坐骨神经分支选择性损伤(SNI)模型大鼠脊髓背角内5-HT1A、5-HT1B、5-HT1D、5-HT1E和5-HT1F受体亚型mR-NAs表达变化。结果表明:损伤侧脊髓背角内5-HT1A受体亚型mRNA的表达水平在术后3d明显增高,7d达到高峰,随后开始下降,术后28d与正常对照相比仍有显著变化;5-HT1B受体亚型mRNA的表达水平也于术后3d开始显著增高,此后持续升高,至21d达到高峰,28d时有轻微下调,但高于对照水平;未观察到损伤侧脊髓背角内5-HT1D受体亚型mRNA表达水平的显著变化。5-HT1F受体亚型mRNA的表达水平于术后4d显著增高,此后一直维持该表达水平至28d。上述受体亚型在非损伤侧脊髓背角内的表达水平均无变化。在脊髓背角内未检测到5-HT1E受体亚型mRNA的表达。上述5-HT1受体亚型mRNA在SNI模型脊髓背角内具有不同的表达变化特点,提示不同的5-HT1各受体亚型在神经病理性痛信息的传递和调节中可能发挥着不同的作用。

To investigate the involvement of 5-HT1 receptor subtypes in the transmission and modulation of the neuropathic pain, the expression of 5-HT1A, 5-HT1B, 5-HT1D, 5-HT1 E and 5-HT1F receptor subtype mRNAs in the spinal dorsal horn of the rat with spared nerve injury （SNI） was detected by reverse transcriptase-polymerase chain reaction （RT-PCR） technique. The results showed that SNI resulted in a significant increase in the expression level of S-HT1A receptor subtype mRNA from 3 day after injury on the ipsilateral side, reached a peak at the 7th day. The mRNA level then decreased but was still higher than normal level at 14, 21 and 28 days. The expression level of 5-HT1B receptor subtype mBNA was observed to significantly increase in the spinal dorsal born from 3 day after injury on the ipsilateral side, reached a peak at the 21 th day, then slightly decreased but was still higher than normal level at 28 days. No significant change in the expression level of 5-HT1D receptor subtype mRNA on the ipsilateral side was observed when compared to that of contralateral side. The expression of the 5-HT1F receptor subtype mRNA increased significantly from 4 day after injury on ipsilateral side, then kept this level till 28 day. No change in the mRNA levels of these receptor subtypes was observed on the contralateral side. We did not detect the expression of 5-HT1 F. receptor subtype mRNA in the spinal dorsal horn. The present results demonstrate the different changing patterns of 5-HT1 receptor subtype mRNAs in the spinal dorsal horn after SNI, suggesting their different roles in the transmission and modulation of neuropathic pain.