Jakobsen B, Tasker A, Zimmer J
Anatomy and Neurobiology, University of Southern Denmark-Odense, Denmark.
Amino Acids. 2002;23(1-3):37-44. doi: 10.1007/s00726-001-0107-5.
The neurotoxicity of domoic acid was studied in 2-3 week old rat hippocampal slice cultures, derived from 7 day old rat pups. Domoic acid 0.1-100 microM was added to the culture medium for 48 hrs, alone or together with the glutamate receptor antagonists NS-102 (5-Nitro-6,7,8,9-tetrahydrobenzo[G]indole-2,3-dione-3-oxime), NBQX (2,3-dihydroxy-6-nitro-7-sulphamoyl-benzo(F)quinoxaline) or MK-801 ((+)-5-methyl-10,11-dihydro-5H-dibenzo[a,d]-cyclohepten-5,10-imine hydrogen maleate), followed by transfer of the cultures to normal medium for additional 48 hrs. Neuronal degeneration in the fascia dentata (FD), CA3 and CA1 hippocampal subfields was monitored and EC(50) values estimated by densitometric measurements of the cellular uptake of propidium iodide (PI). The CA1 region was most sensitive to domoic acid, with an EC(50) value of 6 microM domoic acid, estimated from the PI-uptake at 72 hrs. Protective effects of 10 microM NBQX against 3 and 10 microM domoic acid were observed for both dentate granule cells and CA1 and CA3c pyramidal cells. NS102 and MK 801 only displayed protective effects when combined with NBQX. MK801 significantly increased the combined neuroprotective effect of NBQX and NS102 against 10 microM domoic acid in both CA1 and FD, but not in CA3. We conclude, that domoic acid neurotoxicity in CA3 and in hippocampal slice cultures in general primarily involves AMPA/kainate receptors. At high concentrations (10 microM domic acid) NMDA receptors are, however, also involved in the toxicity in CA1 and FD.
在源自7日龄幼鼠的2 - 3周龄大鼠海马切片培养物中研究了软骨藻酸的神经毒性。将0.1 - 100微摩尔的软骨藻酸单独或与谷氨酸受体拮抗剂NS - 102（5 - 硝基 - 6,7,8,9 - 四氢苯并[G]吲哚 - 2,3 - 二酮 - 3 - 肟）、NBQX（2,3 - 二羟基 - 6 - 硝基 - 7 - 氨磺酰基 - 苯并[F]喹喔啉）或MK - 801（(+)-5 - 甲基 - 10,11 - 二氢 - 5H - 二苯并[a,d] - 环庚烯 - 5,10 - 亚胺氢马来酸盐）一起添加到培养基中48小时，然后将培养物转移到正常培养基中再培养48小时。监测齿状回（FD）、海马CA3和CA1亚区的神经元变性，并通过对碘化丙啶（PI）细胞摄取的光密度测量估计半数有效浓度（EC(50)）值。CA1区对软骨藻酸最敏感，根据72小时时的PI摄取量估计，软骨藻酸的EC(50)值为6微摩尔。对于齿状颗粒细胞以及CA1和CA3c锥体细胞，观察到10微摩尔的NBQX对3微摩尔和10微摩尔软骨藻酸具有保护作用。NS102和MK801仅在与NBQX联合使用时才显示出保护作用。MK801显著增强了NBQX和NS102对CA1和FD中针对10微摩尔软骨藻酸的联合神经保护作用，但对CA3没有作用。我们得出结论，CA3以及一般海马切片培养物中的软骨藻酸神经毒性主要涉及AMPA/海人藻酸受体。然而，在高浓度（10微摩尔软骨藻酸）下，NMDA受体也参与CA1和FD中的毒性作用。
