Effects of A-803467 (1, 10, and 100 μM) applied to the pool surrounding the dorsal roots on the compound action potential evoked by single-pulse electrical stimulation of the tibial nerve in 5 rats whose femoral artery was ligated 72 h before the start of the experiment. A and B: individual compound action potential recorded from a filament of the L4 dorsal root. Note that the 1 μM concentration of A-803467 had no effect on the compound action potential evoked by stimulation of group III and IV afferents; in this example, the 100 μM concentration of A-803467 slightly decreased the group III component of the compound action potential but had no effect on the group IV component. C and D: summary data from 6 rats in which the effects of A-803467 (1, 10, and 100 μM) and lidocaine (2%) on the compound action potential evoked by stimulation of the tibial nerve are expressed as a percentage of the control area. †A significant decrease (P < 0.05) in area of the compound action potential from control values.