Effect of ifenprodil on oxaliplatin-induced mechanical and cold hypersensitivity at day 3 in rats fed with a normal diet.

Neuropathic pain was induced in rats fed with normal diet by a single i.p. injection of oxaliplatin (OXA) at 6 mg/kg on day 0. (A) Mechanical hypersensitivity was assessed before and 3 days after oxaliplatin injection, and then at 1, 2, 8 and 24 h after an intrathecal injection of ifenprodil (2.5, 5 and 10 µg), using the electronic von Frey test. (B) Cold hypersensitivity expressed as time spent on the cold plate (%) was assessed before and 3 days after oxaliplatin injection and then at 4, 8 and 24 h after an intrathecal injection of ifenprodil (2.5, 5 and 10 µg) using the thermal place preference test (12°C vs. 25°C). All data are expressed as means ± SEM (n = 6 to 9 per group). Two-way repeated-measures ANOVA followed by a Tukey-Kramer post hoc test. *, p<0.05; **, p<0.01; ***, p<0.001 vs. NaCl 0.9%.