ABSTRACT
In in vitro experiments on isolated rat hippocampal neurons, we studied the electrophysiological mechanisms of the antiarrhythmic effects of N-deacetyllappaconitine monochlorhydrate (DALCh), active metabolite of lappaconitine hydrobromide (allapinin). Electrical activity of neurons was recorded by the patch-clamp method in the whole cell configuration. It was shown that DALCh increased the duration of both slow and fast depolarization phases and decreased the amplitude of the action potential. DALCh effectively inhibited transmembrane currents of Na+ ions and partially K+ ions through the corresponding transmembrane voltage-gated ion channels. Thus, DALCh, in contrast to lappaconitine hydrobromide, belongs not to 1C, but to the 1A class of antiarrhythmics according to the Vaughan-Williams classification.
Subject(s)
Neurons , Potassium Channels , Aconitine/analogs & derivatives , Action Potentials , Animals , Anti-Arrhythmia Agents/pharmacology , Neurons/metabolism , Patch-Clamp Techniques , Potassium Channels/metabolism , RatsABSTRACT
Uraline, a new norditerpenoid alkaloid, was isolated from aerial parts of Delphinium uralense. The structure of 1alpha,7,8-trihydroxy-6beta,14alpha,16beta-trimethoxy-18-N-(2-methyl)succinylanthranoyloxyaconane was ascribed to the new compound on the basis of 1H and 13C NMR, IR, and mass spectra. The known alkaloids methyllycaconitine and delcorine were also isolated from the plant.
