Effects of amitriptyline on the experimental acute and chronic inflammation models

Amitriptyline is a tricyclic antidepressant, antagonizes serotonergic, adrenergic, histaminergic and some cholinergic receptors and blocks sodium, calcium and potassium channels which have affects on inflammmation pathophysiology. Aim of our study is to examine the anti-inflammatory effect (AIE) of amitriptyline on acute and chronic inflammation models in rats. In our study acute inflammation was created with carrageenan and histamine. After measuring the basal right hind paw volumes of rats, distilled water for control group, diclofenac sodium and amitriptyline (5-10-20mg/kg carrageenan model, 10mg/kg histamine model) for other groups were injected intraperitoneally. After 30 minutes, inflammation was induced by injection of %1 carrageenan or %0.1 histamine solutions into the same paws. Paw volumes were measured 5 times at 1 hour intervals after carrageenan injection and 6 times at 30 minutes intervals after histamine injection. The AIE of amitriptyline were calculated according to paw volumes of control group. Chronic AIE of amitriptyline was tested with Cotton-Pellet granuloma method. Amitriptyline (10mg/kg) showed AIE at 1 and 2 hours (%52.56 and 46.43) in carrageenan-induced (p<0.05), and at 30, 60, 90, 120 and 150 minutes (%46.23, 40.05, 43.34, 47.67 and 52.94 respectively) in histamine-induced (p<0.05) paw edema models. In Cotton-Pellet granuloma model, amitriptyline showed anti-proliferative effect according to wet (%26.62) and dry (%31.09) cotton pellets weights (p<0.05). Amitriptyline showed both acute ve chronic AIE. Acute AIE of amitriptyline may be due to the inhibition of some neuromediators (especially histamine) on early phase of inflammation. Chronic AIE may be usefull for the treatment of some chronic inflammatory diseases accompanied with depression.