Effects of Various Antiepileptics Used to Alleviate Neuropathic Pain on Compound Action Potential in Frog Sciatic Nerves: Comparison with Those of Local Anesthetics
Figure 5
Effect of a local anesthetic levobupivacaine (LB) on CAPs recorded from frog sciatic nerve fibers. ((a), (b)) LB reduces CAP peak amplitude in a reversible manner. (a) Recordings of CAPs before, at 20 min after exposure to LB, and thereafter 60 min in the absence of LB. (b) Average time courses of changes in CAP peak amplitude following exposure to LB at 0.05–1 mM for 20 min, relative to those before the soaking (each point: –7). Relative CAP amplitude after washout of LB is shown only for data at 0.5 mM. (c) The CAP inhibition produced by LB is concentration dependent. ((c)(A)) Recordings of CAPs before and at 20 min after exposure to LB at 0.1, 0.2, and 1 mM. ((c)(B)) The peak amplitudes of CAPs recorded from sciatic nerve fibers treated with LB at various concentrations for 20 min, relative to control, which were plotted against LB concentration (each point: –7). This concentration-response curve was drawn according to the Hill equation (IC50 = 0.23 mM; ).
