[The effect of amiridin and tacrine on the potassium currents in a nerve fiber].
The experiments on isolated nerve fibers from the frog Rana ridibunda have demonstrated that aminoacridine tacrin and aminocholine amiridine given in a concentration of 1 microM induced a 3-4 mV increase in the resting potential of the intact Ranvier nodal membrane depolarized by several millivolts by external source current, accompanied by a rise in the amplitude and curvature of action potential. With the voltage clamp, the two agents shifted a steady state potassium conductivity vs. the voltage curve measured in the vicinity of the resting potential in isotonic KCl solution. The shift had a hyperpolarizing direction and magnitude of 1-2 mV at the agents' concentrations of 0.01-0.1 microM and 10 mV at concentrations higher than 1 microM. The resting potential change calculated on the basis of conductivity measurements was in agreement with that observed experimentally. It is suggested that the tacrin- and amiridine-induced shift of the voltage sensitivity region of potassium channels near the resting potential might underlie their therapeutic effects in patients with senile dementia of the Alzheimer type.
Burov
Iu V
IuV
Peganov
E M
EM
Shapovalova
L M
LM
D000634:Aminoquinolines / Q000494:pharmacology*; D000818:Animals; D002800:Cholinesterase Inhibitors; D004305:Dose-Response Relationship, Drug; D066298:In Vitro Techniques; D007552:Isotonic Solutions; D008564:Membrane Potentials / Q000187:drug effects / Q000502:physiology; D009412:Nerve Fibers / Q000187:drug effects* / Q000502:physiology; D015221:Potassium Channels / Q000187:drug effects* / Q000502:physiology; D011619:Psychotropic Drugs / Q000494:pharmacology*; D011895:Rana ridibunda; D000077331:Ringer's Solution; D013619:Tacrine / Q000494:pharmacology*
D000634:Aminoquinolines; D002800:Cholinesterase Inhibitors; D007552:Isotonic Solutions; D015221:Potassium Channels; D011619:Psychotropic Drugs; D013619:Tacrine; D000077331:Ringer's Solution; C049860:amiridine
Vliianie amiridina i takrina na kalievye toki v nervnom volokne.