Alterations of Ca2+ currents and their sensitivities to Ca2+ antagonists during application and after deprivation of nerve growth factor.
The alterations in morphology and Ca2+ currents (ICa) were assessed in PC12 cells, which were (1) control (untreated), (2) treated with nerve growth factor (NGF), and (3) deprived of NGF. NGF treatment induced neuronal differentiation morphologically and increased the current density of ICa, and especially that of the omega-conotoxin (omega-CgTX)-sensitive component. NGF-deprived cells manifested morphological deterioration and did not exhibit remarkable changes in the current density of the total ICa and dihydropyridine components, whereas the omega-CgTX-sensitive ICa component was decreased significantly compared with that in NGF-treated cells. The results suggest that the total function of Ca2+ channels, including the dihydropyridine component, does not seem to be lost at the initial stage of neuronal deterioration, whereas omega-CgTX-sensitive Ca2+ channels lost their function early.
Furukawa
K
K
Department of Neurophysiology, Tohoku University School of Medicine, Sendai, Japan.
Onodera
H
H
Kogure
K
K
Akaike
N
N
D000818:Animals; D002118:Calcium / Q000502:physiology*; D002121:Calcium Channel Blockers / Q000494:pharmacology; D002454:Cell Differentiation / Q000187:drug effects*; D009414:Nerve Growth Factors / Q000494:pharmacology*; D009474:Neurons / Q000166:cytology* / Q000502:physiology; D016716:PC12 Cells; D010455:Peptides / Q000494:pharmacology; D020866:omega-Conotoxin GVIA
D002121:Calcium Channel Blockers; D009414:Nerve Growth Factors; D010455:Peptides; D020866:omega-Conotoxin GVIA; D002118:Calcium