The effect of naloxone administration on CuCl2 treatment effect on the chemical pain induced by formalin in male Wistar rat

Abstract

Background and Aim : Micronutrients are necessary for human bodies and involved in different<br><br>reaction and biochemistry process. Reduction or increase in the amount of micronutrients can<br><br>disrupt normal function of the body. Different micronutrients such as Mg2, Mn2, Zn2 and Cu2<br><br>affect the central nervous system and may be effective in pain and inflammation. Our previous<br><br>study has shown that effective dose of cucl2 which caused analgesia subsequent to chemical pain<br><br>induced by formalin in rat paw is 10 mg/kg dose. In this study the effect of naloxone on cucl2<br><br>analgesic effects was assessed to find any relenship between cucl2 analgesia and opioid system<br><br>was assed.<br><br>Methods : Adult male Wister rats (200 250 g) were used in this study. Animals were divided into<br><br>4 groups (control, sham (naloxone), cucl2 and cucl2+naloxan treating animals). Drugs all intra<br><br>peritoneal injected and pain behavior was assessed by formalin test and data were analysis<br><br>statistically.<br><br>Results : Pain behaviors in control and sham (naloxone) animals due to formalin paw injection<br><br>were alleviated in cucl2 (10mg/kg, ip) treated animals (p&lt;0.0001, p&lt;0.0001) while naloxone in<br><br>[cucl2 (10mg/kg) +Naloxone (2mg/kg, ip)] animals reversed the cucl2 analgesia (p&lt;0.0001).<br><br>Conclusion : At our previous study it was discussed that copper ions can possibly interfere with<br><br>opioid system. So increasing the sensitivity of opioid receptors to endogenous opioids in the<br><br>presence of cu ion is suggested here to investigate, because, naloxone administration convert the<br><br>cucl2 analgesia.