N型钙通道与疼痛

N型电压依赖性钙通道(VDCCs)在疼痛的传递与调控中具有重要作用。它们密集分布于脊髓背角伤害感受性神经元突触前末梢,参与主要疼痛介质如谷氨酸和P物质等释放的调节。通过阻断上述通道,选择性N型VDCCs阻断剂表现出强效镇痛作用,N型VDCCs Cav2．2亚基基因敲除小鼠也表现为痛阈提高。N型VDCCs还分布于自主神经系统和中枢神经系统突触部位,现有的N型VDCCs阻断剂用于疼痛治疗时出现的各种副作用与这些部位的突触抑制有关。最近发现,背根节伤害感受性神经元上存在一种特异的N型VDCCs亚型,这为疼痛治疗提供了一个非常有意义的新靶标。

Involvement of N-type calcium channels in pain and antinociception

N-type voltage-dependent calcium channels are critical for pain transduction and modulation. These channels are highly present at the presynaptic terminals of nociceptive neurons in dorsal horn of the spinal cord where they regulate the release of the key pro-nociceptive neurotransmitters such as glutamate and substance P. Consistent with this, the selective blockers of the N-type channels are powerful analgesics, and, mice lacking the N-type Ca V2.2 subunit have higher pain thresholds compared to wild-type. The N-type channels are also present at synapses in the autonomic system and the central nervous system, the inhibition of these synapses is the main reason of the side effects in analgesic therapy with current N-type channel blockers. Recently, a unique splice isoform of the N-type channels was found exclusively expressed at the nociceptive neurons in dorsal root ganglia, which may represent a novel target for pain management.