Tetrahydroaminoacridine (THA) reduces voltage-dependent calcium currents in rat sensory neurons.
Tetrahydroaminoacridine (THA) is a centrally active anticholinesterase that also interacts with neuronal K+ and Na+ channels and cardiac Ca2+ channels. The effects of THA on neuronal voltage-dependent Ca2+ channels are not known. We tested the effects of THA (25 nM-250 microM) on the Ca2+ current components of acutely dissociated rat nodose ganglion and dorsal root ganglion (DRG) neurons using the whole cell patch clamp recording technique. THA reduced the low-threshold (T) and high-threshold (N/L) Ca2+ current components in a concentration-dependent manner (IC50 approximately equal to 125 microM for T; approximately equal to 80 microM for N/L). Minimal current reduction was seen below approximately 10 microM. Our results show that THA reduces voltage-dependent Ca2+ currents in rodent sensory neurons suggesting another means by which THA may affect Ca(2+)-dependent physiologic processes.
Kelly
K M
KM
Department of Neurology, University of Michigan Medical Center, Ann Arbor 48109.
Gross
R A
RA
Macdonald
R L
RL
D000818:Animals; D002118:Calcium / Q000502:physiology*; D002800:Cholinesterase Inhibitors / Q000494:pharmacology; D004056:Differential Threshold; D004594:Electrophysiology; D005727:Ganglia, Spinal / Q000166:cytology / Q000502:physiology; D009475:Neurons, Afferent / Q000502:physiology*; D009620:Nodose Ganglion / Q000166:cytology / Q000502:physiology; D051381:Rats; D013619:Tacrine / Q000494:pharmacology*
D002800:Cholinesterase Inhibitors; D013619:Tacrine; D002118:Calcium