Fig. 1.

Referred hyperalgesia in the presence of acute and subacute acrolein-induced cystitis. A: acute acrolein-induced cystitis increased mechanical sensitivity 4, 24, and 48 h after intravesical (i.vesc) administration of acrolein. B: subacute acrolein-induced cystitis showed long-lasting referred hyperalgesia that persisted for ≥72 h after the 3rd acrolein instillation. C and D: referred hyperalgesia associated with acute and subacute acrolein-induced cystitis was reversed by administration of intravesical k252a. E: intrathecal (it) administration of k252a did not prevent referred hyperalgesia in rats with acute cystitis. F: intrathecal administration of k252a in rats with subacute cystitis did not prevent referred hyperalgesia 4 h after the 3rd intravesical instillation of acrolein. Values (means ± SE) are presented as latency for withdrawal (n = 6–12). *P < 0.05 (2-way ANOVA followed by Bonferroni's post hoc test).