Impaired Peripheral Dopaminergic System in Patients with Ulcerative Colitis

Ulcerative colitis (UC) is the chronic inflammatory disease unknown etiology. Little is known on the role of dopaminergic system in the pathogenesis of UC, despite the evidence that dopaminergic hypoactivity may result in excessive inflammation. We demonstrated a diminished risk for UC in patients with schizophrenia (hyper-dopaminergic system) (Tolstanova G. et al. Gastroenterology 2010;138 (5):S-264). In this study we tested the hypothesize that patients with chronic UC is characterized by the disturbance of peripheral dopaminergic system. Methods. Colonic biopsy samples from 7 patients with chronic UC with recurrence stage and 7 - from healthy colon were included in the study. Expressions and localization of D2, D3 dopamine receptors, DAT (responsible for dopamine re-uptake) and tyrosine hydroxylase (TH, rate-limiting enzyme of dopamine synthesize) were investigated with immunohistochemistry. Results. Profound expression of DАТ, D2R, D3R and ТН was found in apical membrane of colonocytes and basal membr...