Fig. 5.

Effects of TTX (1 μM) and lidocaine (2%) applied to the pool surrounding the dorsal roots on the pressor response to electrical stimulation of the tibial nerve at current intensities that recruited group IV afferents. A: temporal plot of the effects of these agents in 7 rats whose hindlimbs were freely perfused. B: temporal plot of the effects of these agents in 7 rats whose femoral arteries were ligated 72 h before the start of the experiment. Open circles, control response; filled circles, response while TTX was applied to the pool; open triangles, response while lidocaine was applied to the pool. Note that the first data point after the start of stimulation (vertical broken line) was taken 2 s after its start, and every point afterward was taken at 5-s intervals from the start of stretch. C: peak responses (open bars) to electrical stimulation of the tibial nerve in 7 rats whose hindlimbs were freely perfused. D: peak pressor responses (filled bars) to electrical stimulation of the tibial nerve in 7 other rats whose femoral arteries were ligated 72 h before the start of the experiment. *The change in mean arterial pressure was greater (P < 0.05) than its corresponding baseline value. †The change in mean arterial pressure was less (P < 0.05) than its corresponding control value.