5-HT_(2,4,5)受体亚型mRNAs在大鼠不同节段脊髓背、腹角的表达

Expression of 5-HT_(2,4,5) receptor subtype mRNAs in rat spinal dorsal and ventral horns of different segments

目的 :观察 5 HT2 、5 HT4和 5 HT5受体亚型mR NAs在大鼠脊髓不同节段的背角和腹角的表达 .方法 :反转录聚合酶链式反应 (RT PCR)技术 .结果 :5 HT2A受体亚型mRNA在颈、胸、腰段脊髓的腹角 (VH)有强表达 ,高于相应节段的背角 (DH) ;5 HT2C受体亚型mRNA在颈、胸、腰、骶段脊髓的DH和VH均有较强的表达 ,但在DH的表达水平要高于VH ;5 HT4受体亚型mRNA在各节段脊髓DH和VH中的表达水平呈由颈髓到骶髓逐渐增高的趋势 ,而且在VH表达较强 ,在DH则较低 ;5 HT5A在脊髓的表达较弱 ,在各节段的表达水平基本一致 ,DH和VH之间没有差异 .在脊髓内没有检测到 5 HT2B和 5 HT5B受体亚型 .结论 :上述 5 HT受体亚型在脊髓具有不同的表达特点 。

AIM: To examine the expression of mRNAs encoding serotonin (5 HT) 5 HT 2, 5 HT 4 and 5 HT 5 receptor subtypes within different segments of rat spinal cord. METHODS: Reverse transcriptase polymerase chain reaction (RT PCR) technique was used. RESULTS: Strong expression of 5 HT 2A receptor subtype mRNA was present in the ventral horn (VH) of cervical, thoracic and lumbar cord. 5 HT 2C receptor mRNA was predominantly present in both dorsal horn (DH) and VH of the cervical, thoracic, lumbar and sacral segments of the spinal cord with higher expression level in the DH. The expression of 5 HT 4 receptor mRNA in the DH and VH of different segments showed a gradually increasing pattern from cervical cord to sacral cord, with higher expression level in the DH and lower expression level in the VH of all the spinal cord segments. The 5 HT 5A receptor mRNA was found at weak expression level in the spinal cord. No significant difference in its expression was observed between different segments or dorsal and ventral horns. The presence of 5 HT 2B and 5 HT 5B receptor mRNAs was not detected in the present study. CONCLUSION: Our data indicate a distinct expression pattern of 5 HT receptor subtypes in the spinal cord, suggesting their different physiological roles in the nociception and movement at the spinal level.