[Effect of batroxobin on K+ channel activated by Ca2+ in primary culture rat cortex neurons of rat].
OBJECTIVE
To investigate the effect of batroxobin on K+ channel activated by Ca2+ in primary cultured cortex neurons of fetal SD rat.


METHODS
The patch clamp technique of single channel recordings including cell-attach and inside-out mode was used.


RESULTS
Extracellular batroxobin activated the Kca. In Ca2+ bath solution of cell-attach mode, Vp +30 mV, when the concentrations of batroxobin were 0.15, 0.25, 0.50, 0.75 and 1.0 mmol/L, the open probabilities of the channel were 0.013 +/- 0.002, 0.082 +/- 0.011, 0.131+/- 0.012, 0.211+/- 0.010 and 0.062 +/- 0.009 (P < 0.01), respectively. It appeared concentration-dependent within 0.75 mmol/ L. batroxobin. In Ca2+ free-bath solution of cell-attach mode, Vp+50 mV, when the concentrations of batroxobin were 0.15, 0.40, 0.60 and 1.0 mmol/L, the open probabilities of the channel were 0.013 +/- 0.001, 0.112 +/- 0.007, 0.193 +/- 0.010 and 0.301 +/- 0.009 (P < 0.05), respectively. In the 6 cases of inside-out mode patch clamp, Vp +40 mV, when the concentrations of batroxobin were 0, 0.25 and 0.50 mmol/L, the open probabilities of the channel were 0. 012 +/- 0.007, 0.011 +/- 0.009 and 0.013 +/- 0.008 (P > 0.05), respectively. There was no significant difference in open probabilities, average open/close times and amplitudes at different intracellular batroxobin concentrations.


CONCLUSIONS
Batroxobin can affect the activation of the Kca channel through regulating the concentration of cytoplasmic free Ca2+. It may have a protective effect on neurons.
Lai
Xiao-hui
XH
Department of Neurology, West China Hospital, Sichuan University, Chengdu 610041, China.
Zhu
Wen-mei
WM
Xu
Gang
G
Yuan
Guang-gu
GG
D000818:Animals; D000831:Animals, Newborn; D012103:Batroxobin / Q000494:pharmacology*; D002478:Cells, Cultured; D002540:Cerebral Cortex / Q000166:cytology / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D005260:Female; D008297:Male; D009474:Neurons / Q000166:cytology / Q000378:metabolism*; D018408:Patch-Clamp Techniques; D024681:Potassium Channels, Calcium-Activated / Q000187:drug effects*; D051381:Rats; D017207:Rats, Sprague-Dawley
D024681:Potassium Channels, Calcium-Activated; D012103:Batroxobin