Kamiya H, Sawada S, Yamamoto C
Department of Physiology, Faculty of Medicine, Kanazawa University, Japan.
Neurosci Lett. 1988 Aug 15;91(1):84-8. doi: 10.1016/0304-3940(88)90253-4.
The effects of some organic calcium channel blockers and a toxin on synaptic transmission were examined in hippocampal slices from the guinea pig. omega-Conotoxin fraction GVIA, a novel peptide that blocks N and L type voltage-sensitive calcium channels, blocked synaptic transmission from mossy fibers to CA3 neurons at very low concentration (100 nM). However, organic calcium channel blockers such as verapamil (100 microM) and nifedipine (10 microM), which block L type calcium channels, had little effect on the synaptic transmission. Phenytoin (100 microM, T type calcium channel blocker) was also ineffective to block the synaptic transmission. These results suggest that presynaptic calcium channels which cause transmitter release may be N type calcium channel.
在豚鼠海马切片中研究了一些有机钙通道阻滞剂和一种毒素对突触传递的影响。ω-芋螺毒素GVIA是一种新型肽，可阻断N型和L型电压敏感性钙通道，在极低浓度（100 nM）时就能阻断从苔藓纤维到CA3神经元的突触传递。然而，诸如维拉帕米（100 μM）和硝苯地平（10 μM）等阻断L型钙通道的有机钙通道阻滞剂对突触传递几乎没有影响。苯妥英（100 μM，T型钙通道阻滞剂）也无法有效阻断突触传递。这些结果表明，引起递质释放的突触前钙通道可能是N型钙通道。
