The effects of diclofenac sodium on cold water swim induced analgesia (CWSS) in mice

Abstract

It was clearly demonstrated that cold water swimming induces analgesia in mice and rats; via opioid and non-opioid mechanisms. Aim of this study is to determine the effects of diclofenac sodium (DS) on this phenomenon. 60 Swiss Webster strain albino male mice (average weight 25-35 gr) was investigated after ethic committee approval. Animals were separated into four equal groups in a randomised fashion. Normal saline (Control: C) was given to the 1st group, naloxone (NL) 100?g. kg.-1 was given to the 2nd group, diclofenac sodium (DS) 2 mg. kg.-1 was given to the 3rd group and diclofenac sodium 2 mg. kg.-1 with naloxone 100?g. kg.-1(DS+ NL) was given to the 4 th group of animals 7 minutes before CWSS test at same volumes (0.1 ml) by intraperitoneal (IP) route. After about 7 minutes, CWSS was performed at 10°C water for 3 minutes. Animals were taken to the separate chamber and dried gently. Hot plate test (HPT) at 56°C was performed 10 minutes later. Animals were exposed to HPT maximum 20 seconds to prevent tissue injury. Characteristic fore limb licking, hind limb shaking or withdrawal were taken as positive result. Data were expressed as mean ± standard deviation (Mean ± SD). Analyses of variance (ANOVA), student's t test and Mann - Whitney U test were used for statistical analyses. P<0.05 was taken as statistically significant. There were no differences between groups on basal temperature. Also, no difference were found between HPT results of C and DS; NL and DS + NL treated animals. In comparison significant differences were found between C and NL; C and DS + NL given animals (p<0.05). Regarding to these results there were no additional effects of DS on CWSS analgesia at given doses. The analgesia is decreased by NL and is not changed by DS. Study design will be constructed and directed to the tonic pain models.