An electrophysiological study of 9-amino-1,2,3,4-tetrahydroacridine (THA) on sino-atrial node preparations of rabbits

Tetrahydroaminoacridine (THA) reduces voltage-dependent calcium currents in rat sensory neurons

“…N currents may be primary regulators of the inhibition of release of neurotransmitters [11] and reduction of these currents by THA may contribute to the observed inhibitory effect of THA on depolarizationinduced release of 7-aminobutyric acid (GABA) in rat cerebral cortex [3]. THA's reduction of cardiac slow inward Ca 2+ currents [13,15] is likely mediated by Ltype Ca 2+ channels and Ca 2+ current reduction in those studies may be qualitatively similar to the results found here.…”

“…In addition to its anticholinesterase activity, THA is known to have effects on several types of neuronal voltage-dependent ion channels. THA is structurally related to 4aminopyridine, a K + channel blocker, and has been shown to block K + currents in several studies [1,3,4,7,10,12,13,15,16,18,20]. THA can also block inward Na + currents [16] and inhibit Na + inactivation [18].…”

“…THA can also block inward Na + currents [16] and inhibit Na + inactivation [18]. In studies of guinea pig ventricular myocytes [15] and rabbit sinoatrial node [13], THA reduced slow inward voltage-dependent Ca 2+ currents. The effects of THA on neuronal voltage-dependent Ca 2+ currents are not known.…”