Effects of intrathecal administration of ALX-1393 on licking and freezing nociceptive behaviors in rats treated with intravesical resiniferatoxin (RTX; 3 µM). (a, b) The number of licking or freezing behaviors counted every minute. Intravesical application of RTX, which stimulates TRPV1 receptor-expressing C-fiber afferent nerves, increased the licking behavior, with a peak in the early phase (0–5 min) as described previously [14]. (c, d) The total number of licking or freezing behaviors for each 5-min period. The glycine transporter type 2 inhibitor significantly suppressed both nociceptive behaviors in a dose-dependent manner. Each point or the bar represents the mean plus or minus the standard error of the mean from five rats.
V1 = vehicle for ALX-1393; V2 = vehicle for RTX; RTX = resiniferatoxin (3 µM, intravesically); ALX = ALX-1393 (in µg, intrathecal); V = vehicle.
# p < 0.05.
## p < 0.01 (unpaired student t test).
* p < 0.05.
** p < 0.01 (compared to the vehicle group).