Yoshimoto K, Yayama K, Sorimachi Y, Tani J, Uemara K, Yoshida T, Ogata M, Nishimura A, Ueda S, Komura S
Department of Legal Medicine, Kyoto Prefectural University of Medicine, Japan.
Forensic Sci Int. 1997 Feb 7;85(1):29-39. doi: 10.1016/s0379-0738(96)02077-4.
In the present study, we used in vivo brain microdialysis to examine the effects of ion channel blockers tetrodotoxin (TTX), EGTA-free Ca2+ and verapamil on rapid postmortem changes in extracellular levels of dopamine (DA), serotonin (5-HT) and their metabolites dihydroxyphenylacetic acid (DOPAC) and 5-hydroxyindoleacetic acid (5-HIAA) in the ACC of freely moving rats. Extracellular ACC DA levels decreased following the perfusion of the three ion channel blockers in freely moving rats, and then, at death by cervical dislocation, maximum respective 220-, 60- and 90-fold increases were observed in the extracellular output of DA in animals treated with EGTA, verapamil and TTX, respectively. Also, ACC 5-HT decreased following perfusion with the three blockers in the freely moving rats, and then maximum increases of 80-, 30- and 45-fold in the extracellular output of 5-HT were observed at death in animals treated with EGTA, verapamil and TTX, respectively, compared to the baseline. Cervical dislocation-induced rapid postmortem changes were inhibited markedly by perfusion with CSF containing the CA2+ entry blocker verapamil. These observations suggested that rapid postmortem changes in ACC DA and 5-HT release were associated with the action of calcium ion channels and/or voltage gated channels in the CNS.
在本研究中，我们使用体内脑微透析技术，来检测离子通道阻滞剂河豚毒素（TTX）、无EGTA的Ca2+以及维拉帕米，对自由活动大鼠前扣带回（ACC）中多巴胺（DA）、5-羟色胺（5-HT）及其代谢产物二羟基苯乙酸（DOPAC）和5-羟基吲哚乙酸（5-HIAA）细胞外水平的快速死后变化的影响。在自由活动大鼠中灌注这三种离子通道阻滞剂后，ACC细胞外DA水平下降，然后，在通过颈椎脱臼处死时，在用EGTA、维拉帕米和TTX处理的动物中，分别观察到DA细胞外释放量最大分别增加220倍、60倍和90倍。此外，在自由活动大鼠中灌注这三种阻滞剂后，ACC中的5-HT下降，然后，与基线相比，在用EGTA、维拉帕米和TTX处理的动物处死时，分别观察到5-HT细胞外释放量最大增加80倍、30倍和45倍。用含有Ca2+进入阻滞剂维拉帕米的脑脊液灌注，可显著抑制颈椎脱臼诱导的快速死后变化。这些观察结果表明，ACC中DA和5-HT释放的快速死后变化与中枢神经系统中钙离子通道和/或电压门控通道的作用有关。
