Antiviral Drug Ivermectin at Nanomolar Concentrations Inhibits Glycine-Induced Chloride Current in Rat Hippocampal Neurons

Ivermectin (IVM) belongs to the class of macrocyclic lactones, which is used as an antiparasitic agent. At present, the researchers focus on possibility to use IVM in treatment of certain forms of cancer and viral diseases such as COVID-19. The mechanisms of IVM action are not clear. It is assumed that IVM affects chloride channels and increases cytoplasmic concentration of chloride. This study examines the effect of IVM on chloride currents induced by glycine (I(Gly)). Experiments were carried out on isolated pyramidal neurons of the rat hippocampus with whole-cell patch clamp. A short-term (600 msec) application of IVM in a concentration of 10 μM induced a slow inward current, which persisted after washing the neurons. The low concentrations (0.1-1000 nM) of IVM did not induce any novel current, but it rapidly and reversibly reduced the peak amplitude and accelerated desensitization of I(Gly) in a dose-dependent manner. The threshold concentrations of IVM sufficient to reduce peak amplitude of I(Gly) and to accelerate desensitization of I(Gly) were 100 nM and 0.1 nM, respectively. The study revealed a high sensitivity of neuronal glycine receptors to IVM.