Lamotrigine inhibits depolarization-evoked Ca++ influx in dissociated amygdala neurons.
Spectrophotometry with the Ca(++)-sensitive dye fura-2 was used to study the effect of lamotrigine (LAG) on the depolarization-evoked Ca++ influx in the acutely isolated basolateral amygdala neurons. Depolarization of the neurons with high K+ resulted in the elevation of intracellular Ca++ concentration [Ca++]i in a concentration-dependent manner. The K(+)-induced Ca++ influx was completely blocked in the Ca(++)-free solution or by Cd++, indicating that depolarization-induced increases in [Ca++]i were triggered largely, if not at all, by Ca++ entry from extracellular space and Ca++ entry occurred through voltage-dependent Ca++ channels. Application of LAG reduced the depolarization-evoked Ca++ influx in a concentration-dependent manner. The effect of LAG was markedly reduced in the presence of N-type Ca++ channel blocker omega-conotoxin-GVIA (omega-CgTX). These results suggest that the action of LAG is mediated, at least in part, by the modulation of N-type Ca++ channels.
Wang
S J
SJ
Department of Pharmacology, College of Medicine, National Cheng-Kung University, Tainan City, Taiwan.
Tsai
J J
JJ
Gean
P W
PW
D000679:Amygdala / Q000166:cytology / Q000187:drug effects* / Q000502:physiology*; D000818:Animals; D002118:Calcium / Q000378:metabolism*; D002121:Calcium Channel Blockers / Q000494:pharmacology*; D004594:Electrophysiology; D000077213:Lamotrigine; D008297:Male; D009474:Neurons / Q000187:drug effects* / Q000378:metabolism / Q000502:physiology*; D011188:Potassium / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D014227:Triazines / Q000494:pharmacology*
D002121:Calcium Channel Blockers; D014227:Triazines; D011188:Potassium; D002118:Calcium; D000077213:Lamotrigine