ATTENUATED INHIBITION BY LEVOFLOXACIN, L-ISOMER OF OFLOXACIN, ON GABARESPONSE IN THE DISSOCIATED RAT HIPPOCAMPAL-NEURONS

The effects of ofloxacin (OFLX) and its isomers, levofloxacin (LVFX) a nd DR-3354, on the gamma-aminobutyric acid (GABA)-induced Cl- current in acutely dissociated rat hippocampal CA1 neurons were investigated u sing nystatin perforated patch recording configuration under voltage-c lamp conditions. At 10(-5) M these 3 compounds themselves did not affe ct the GABA response. Biphenylacetic acid (BPA) at 10(-5) M also had n o effect on the GABA response, but BPA greatly suppressed the GABA res ponse in combination with these 3 compounds without affecting the reve rsal potential of GABA response. The inhibitory effects of OFLX and DR -3354 on the GABA response were stronger than that of LVFX. LVFX inhib ited the response in a competitive and voltage-independent manner. The results suggest that LVFX has lower CNS adverse effects, such as conv ulsions, compared to OFLX.