Characterization of Functional Effects of Two New Active Fractions Isolated From Scorpion Venom on Neuronal Ca2+ Spikes: A Possible Action on Ca2+-Dependent Dependent K+ Channels

Basic and Clinical Neuroscience

ARTICLE

Tamadon, Hanieh¹  Ghasemi, Zahra²  Ghasemi, Fatemeh¹  Hosseinmardi, Narges¹  Vatanpour, Hossein³  Janahmadi, Mahyar¹ 

[1] Department of Physiology, Neuroscience Research Center, School of Medicine, Shahid Beheshti University of Medical Sciences;Department of Physiology, School of Medicine, Tarbiat Modares University;Department of Toxicology and Pharmacology, School of Pharmacy, Shahid Beheshti University of Medical Sciences

关键词: Scorpion Venom;    Intracellular recording;    Calcium spike;    Buthotus schach;   

DOI  :  10.32598/bcn.9.10.175

来源: Iran University of Medical Sciences

【 摘 要 】

Introduction: It is a long time that natural toxin research is conducted to unlock the medical potential of toxins. Although venoms-toxins cause pathophysiological conditions, they may be effective to treat several diseases. Since toxins including scorpion toxins target voltagegated ion channels, they may have profound effects on excitable cells. Therefore, elucidating the cellular and electrophysiological impacts of toxins, particularly scorpion toxins would be helpful in future drug development opportunities. Methods: Intracellular recording was made from F1 cells of Helix aspersa in the presence of calcium Ringer solution in which Na+ and K+ channels were blocked. Then, the modulation of channel function in the presence of extracellular application of F4 and F6 toxins and kaliotoxin (KTX; 50 nM and 1 μM) was examined by assessing the electrophysiological characteristics of calcium spikes. Results: The two active toxin fractions, similar to KTX, a known Ca2+-activated K+ channel blocker, reduced the amplitude of AHP, enhanced the firing frequency of calcium spikes and broadened the duration of Ca2+ spikes. Therefore, it might be inferred that these two new fractions induce neuronal hyperexcitability possibly, in part, by blocking calcium-activated potassium channel current. However, this supposition requires further investigation using voltage clamping technique. Conclusion:These toxin fractions may act as blocker of calcium-activated potassium channels.

【 授权许可】

Unknown