Fig. 6.

Based on the cumulative concentration-response (C-R) curves of gentamicin on ST (A), PTT (B) and ETT (C), the combination of 2 mM MgCl₂ and 0.5 µM ropivacaine shifts to the right the C-R curves of gentamicin, and in other words, antagonizes the effect of gentamicin. The concentration of gentamicin is transformed to log concentration. Data are presented as mean ± SEM. The units of concentrations for Mg and Rv are mM and µM, respectively. n is the number of experiments. Gm: gentamicin, Mg: magnesium chloride, Rv: ropivacaine, ST: single twitch, PTT: peak tetanic tension, ETT: end tetanic tension. ^*P < 0.05, vs. Mg 2 mM + Rv 1 µM by t-test with Bonferroni's correction.