Selective blockade of P-type calcium channels by lead in cultured hippocampal neurons.
The effects of lead ions (Pb2+) on neuronal calcium channels were examined in cultured hippocampal neurons. Pb2+ blocked calcium channels in a concentration-dependent manner. The current-voltage relationship of the inhibition suggested a selective blockade of high-threshold calcium channels by Pb2+ up to a concentration of 3 microM. Pb2+ (3 microM) preferentially suppressed the omega-agatoxin IVA-sensitive components of the calcium channels. These findings suggest that Pb2+ mainly affects the P-type calcium channels at low concentrations.
Ujihara
H
H
Department of Pharmacology, Yamaguchi University School of Medicine, Japan.
Sasa
M
M
Ban
T
T
D000818:Animals; D001464:Barium / Q000378:metabolism; D002121:Calcium Channel Blockers / Q000494:pharmacology*; D002478:Cells, Cultured; D006624:Hippocampus / Q000166:cytology / Q000378:metabolism*; D015640:Ion Channel Gating / Q000187:drug effects; D007854:Lead / Q000494:pharmacology*; D009474:Neurons / Q000187:drug effects / Q000378:metabolism*; D018408:Patch-Clamp Techniques; D051381:Rats; D017208:Rats, Wistar; D013111:Spider Venoms / Q000037:antagonists & inhibitors / Q000494:pharmacology; D020867:omega-Agatoxin IVA
D002121:Calcium Channel Blockers; D013111:Spider Venoms; D020867:omega-Agatoxin IVA; D001464:Barium; D007854:Lead