Role of spinal monocarboxylate transporter-2 in development of acute inflammatory pain in mice

Abstract

Objective To investigate the role of spinal monocarboxylate transporter-2 (MCT-2) in the development of acute inflammatory pain in mice. Methods Thirty-two male adult Kunming mice, weighing 20-25 g, were divided into 4 groups (n=8 each) using a random number table: control group (group C), inflammatory pain group (group IP), MCT-2 inhibitor α-cyano-4-hydroxy-cinnamate group (group 4-CIN), and dimethyl sulfoxide group (group D). In IP, 4-CIN and DMSO groups, the inflammatory pain was induced by injection of 5% formalin 10 μl into the plantar surface of the right hindpaw.At 30 min before formalin injection, the artificial cerebrospinal fluid, 4-CIN (100 μmol) and 10% DMSO 5 μl were injected intrathecally over 10 s in IP, 4-CIN and DMSO groups, respectively.Pain behavior was scored within 60 min after establishment of the model.The lumbar segment of the spinal cord was harvested at 60 min after establishment of the model for detection of the expression of MCT-2 by Western blot analysis. Results Compared with group C, the pain behavior score was significantly increased in phaseⅠand phase Ⅱ, and the expression of MCT-2 was up-regulated in IP, 4-CIN and DMSO groups (P 0.05). Conclusion Spinal MCT-2 is involved in the development of acute inflammatory pain in mice. Key words: Monocarboxylic acid transporters; Spinal cord; Inflammation; Pain