The effects of tramadol and nitric oxide on acute inflamatuvar pain in rats

Inflammatory pain begins with the combination of tissue injury and inflammation and it is a kind of pain which responses to non-opioid and opioid drugs. This kind of pain is combined with neuroendocrine stress highly proportionally and must be treated effectively at early stages.In this study, we tried to explore the effects of three different dosages of tramadol and combination of nitric oxide with these dosages of tramadol on acute inflammatory pain in rats. After having the acception of Test Animal Ethical Committee of Adnan Menderes University Medical Faculty, 48 Wistar male rats were used. Rats were seperated to 8 groups randomly and after performing the hot-plate test; serum isotonic (control group, Group K) to first group ; Tramadol 5mg/kg (T-5 group) to second group; tramadol 10 mg/kg (T-10 group) to third group; Tramadol 30 mg/kg (T-30 group) to fourth group; tramadol 5 mg/kg and nitroglycerin 1 mg/kg (T5-N group) to fifth group; tramadol 10 mg/kg and 1 mg/kg nitroglycerin (T10-N group) to sixth group; tramadol 30 mg/kg and 1 mg/kg nitroglycerin (T30-N group) to seventh group; and just 1 mg/kg of nitroglycerin (N group) was introduced to periton of rats in the eighth group. Acute inflammatory pain responses were measured with hot-plate and formalin test. We also measured the diameter of inflamation on the formalin injected area and pathological analysis was done after amputation of the formalin injected foot. According to hot-plate test prolongation was found in Group T-30 and Group T30-N. Also according to formalin test low response was found only at early stages in these two groups. But there was no statistically difference between with or without nitroglycerin added groups. In terms of pathological findings there was only difference of vasodilatation in group N.As a consequence, we believe that high dosages of tramadol effectively decreases the acute inflamatory pain, but also no significant difference was found by adding nitroglycerin in terms of analgesic effect.