蜘蛛神经毒素可阻断β蝎毒素诱导的大鼠脑皮质突触体对钙的摄取。

Spider neurotoxins block the beta scorpion toxin-induced calcium uptake in rat brain cortical synaptosomes.

作者信息

Miranda D M, Romano-Silva M A, Kalapothakis E, Diniz C R, Cordeiro M N, Moraes-Santos T, De Marco L, Prado M A, Gomez M V

机构信息

Laboratírio de Neurofarmacologia, Departamento de Farmacologia, ICB-UFMG, MG, Belo Horizonte, Brazil.

出版信息

Brain Res Bull. 2001 Mar 15;54(5):533-6. doi: 10.1016/s0361-9230(01)00443-9.

DOI:10.1016/s0361-9230(01)00443-9

PMID:11397544

Abstract

In this paper we describe the effects of the beta scorpion toxin Tityus gamma (TiTX gamma) and spider neurotoxins Tx3-3 and Tx3-4 in the (45)Ca(2+) uptake in synaptosomes. The TiTX gamma-stimulatory effect on (45)Ca(2+) uptake in synaptosomes was inhibited omega-Conotoxin MVIIC (omega-CgTX MVIIC) (0.1 microM) and omega-Agatoxin IVA (0.1 microM) by 70% and 41%, respectively. omega-CgTX MVIIC (1.0 microM) almost completely blocked the TiTX gamma-induced (45)Ca(2+) uptake in synaptosomes. Verapamil (1.0 microM) and omega-Conotoxin GVIA (0.1 microM) had no effect in the scorpion toxin-induced (45)Ca(2+) influx. The spider neurotoxins Tx3-3 and Tx3-4 inhibited the TiTX gamma-induced calcium uptake with an IC(50) of 10.0 and 30.0 nM, respectively. It is suggested that spider neurotoxins Tx3-3 and Tx3-4 blocking effect in the TiTX gamma-induced calcium uptake involves P/Q-type calcium channels.

摘要

在本文中，我们描述了β-蝎毒素γ（TiTXγ）以及蜘蛛神经毒素Tx3-3和Tx3-4对突触体中（45）Ca（2+）摄取的影响。TiTXγ对突触体中（45）Ca（2+）摄取的刺激作用分别被ω-芋螺毒素MVIIC（ω-CgTX MVIIC）（0.1微摩尔）和ω-阿加毒素IVA（0.1微摩尔）抑制了70%和41%。ω-CgTX MVIIC（1.0微摩尔）几乎完全阻断了TiTXγ诱导的突触体中（45）Ca（2+）摄取。维拉帕米（1.0微摩尔）和ω-芋螺毒素GVIA（0.1微摩尔）对蝎毒素诱导的（45）Ca（2+）内流没有影响。蜘蛛神经毒素Tx3-3和Tx3-4抑制TiTXγ诱导的钙摄取，其半数抑制浓度（IC50）分别为10.0和30.0纳摩尔。提示蜘蛛神经毒素Tx3-3和Tx3-4对TiTXγ诱导的钙摄取的阻断作用涉及P/Q型钙通道。