Action of furosemide on GABA- and glycine currents in rat septal cholinergic neurons in culture.

The action of furosemide on GABA- and glycine-induced currents in rat septal cholinergic neurons in culture was examined by use of the whole-cell voltage-clamp technique. Furosemide inhibited the peak amplitude of either GABA or glycine current in a dose-dependent manner; its half-maximal concentration for them was some 2 and 1 mM, respectively. Furosemide at a concentration of 1 mM depressed the maximal peak amplitude of the dose-response curve for either GABA or glycine to about 70% of control. These results indicate that furosemide inhibits in a noncompetitive fashion GABA and glycine receptor-channels in septal neurons.