Rat epileptic seizures evoked by BmK {alpha}IV and its possible mechanisms involved in sodium channels

Journal Article · Tue May 01 00:00:00 EDT 2007 · Toxicology and Applied Pharmacology

DOI:https://doi.org/10.1016/j.taap.2007.01.006· OSTI ID:20976914

Zhifang, Chai ^[1]; Zhantao, Bai ^[1]; Xuying, Zhang ^[1]; Tong, Liu ^[1]; Xueyan, Pang ^[2]; Yonghua, Ji ^[2]

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1. Graduate School of the Chinese Academy of Sciences, Shanghai Institute of Physiology, Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031 (China)
2. School of Life Sciences of Shanghai University, Shang-Da Road 99, Shanghai 200444 (China)

This study showed that rat unilateral intracerebroventricular injection of BmK {alpha}IV, a sodium channel modulator derived from scorpion Buthus martensi Karsch, induced clusters of spikes, epileptic discharges and convulsion-related behavioral changes. BmK {alpha}IV potently promoted the release of endogenous glutamate from rat cerebrocortical synaptosomes. In vitro examination of the effect of BmK {alpha}IV on intrasynaptosomal free calcium concentration [Ca{sup 2+}]{sub i} and sodium concentration [Na{sup +}]{sub i} revealed that BmK {alpha}IV-evoked glutamate release from synaptosomes was associated with an increase in Ca{sup 2+} and Na{sup +} influx. Moreover, BmK {alpha}IV-mediated glutamate release and ion influx was completely blocked by tetrodotoxin, a blocker of sodium channel. Together, these results suggest that the induction of BmK {alpha}IV-evoked epileptic seizures may be involved in the modulation of BmK {alpha}IV on tetrodotoxin-sensitive sodium channels located on the nerve terminal, which subsequently enhances the Ca{sup 2+} influx to cause an increase of glutamate release. These findings may provide some insight regarding the mechanism of neuronal action of BmK {alpha}IV in the central nervous system for understanding epileptogenesis involved in sodium channels.

• OSTI ID: 20976914
• Journal Information: Toxicology and Applied Pharmacology, Vol. 220, Issue 3; Other Information: DOI: 10.1016/j.taap.2007.01.006; PII: S0041-008X(07)00022-1; Copyright (c) 2007 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved; Country of input: International Atomic Energy Agency (IAEA); ISSN 0041-008X
• Country of Publication: United States
• Language: English

Related Subjects

60 APPLIED LIFE SCIENCES
CALCIUM
CALCIUM IONS
CENTRAL NERVOUS SYSTEM
IN VITRO
INDUCTION
INJECTION
MODULATION
RATS
SCORPIONS
SODIUM
SODIUM IONS