[Neuroreceptor mechanisms of the afobazole effect]

Abstract

The interaction of afobazole (5-ethoxy-2-[2-(morpholino)-ethylthio]benzimidazole dihydrochloride) and its main metabolite M-11 (2-[2-(3-oxomorpholine-4-yl)-ethylthio]-5-ethoxy benzimidazole hydrochloride) with neuroreceptors was studied using the method of radioligand analysis. The binding of afobazole with s1 (Ki =5.9 x 10(-6) M), MTI (Ki =1.6 x 10(-5) M), and MT3 (Ki =9.7 x 10(-7) M) receptors, as well as with a regulatory site of MAO-A (Ki = 3.6 x 10(-6) M) was revealed. The binding of M-11 with MT3 receptors (Ki = 3.9 x 10(-7) M) was demonstrated. The translocation of s1 receptor from endoplasmatic reticulum to the external membrane was revealed by the confocal microscopy technique on the immmortalized hippocampal HT-22 cells under the condition of 30- and 60-min-long afobazole (10(-8) M) application. Afobazole was shown to inhibit MAO-A reversibly. These properties of afobazole are consistent with our previous findings of the anxiolytic and neuroprotective effects of this drug.