An investigation on systemic administration of CuCl2 on the thermal pain in male Wistar rat

Abstract

Introduction: Micronutrients are necessary for human bodies. Reduction or increase in the<br><br>amount of micronutrients can disrupt normal function of the body. Different micronutrients such<br><br>as Mg2, Mn2, Zn2 and Cu2 affect the central nervous system and may be effective in pain and<br><br>inflammation. In this study, the effect of CuCl2 on thermal pain was assessed.<br><br>Methods: Adult male Wistar rats (200–250 g) were used in this study. Animals were divided<br><br>into 6 groups (control, sham, CuCl2 (5 mg/kg), CuCl2 (10 mg/kg), CuCl2 (20 mg/kg) and CuCl2<br><br>(100 mg/kg)). Animals received CuCl2 peripherally and pain behavior was assessed by tail flick<br><br>test and data were analysised statistically.<br><br>Results: All doses of CuCl2 (5, 10, and 20 mg/kg) used in this study elevated the pain threshold<br><br>and caused thermal analgesia in tail flick test (p&lt;0.0001, p&lt;0.0001, and p&lt;0.007, respectively).<br><br>Rats that received CuCl2 in 100 mg/kg were died.<br><br>Conclusion: Previous studies have shown that copper ions are involved in strengthening of<br><br>analgesic effects of morphine. It is possible that copper induce thermal analgesia by increasing<br><br>the sensitivity of opioid receptors to endogenous opioids.