RESUMO
Objective To investigate the relationship between the rat depression behaviors induced by chronically unpredicted stress (CUS) with interleukin-1β (IL-1β),interleukin-6 (IL-6) protein expression and indole-2,3-dioxygenase (IDO) mRNA and protein expression.Methods Thirty male Sprague Dawley (SD)rats were divided into the control group (CG) and model group (MG).The solitary raise combined with CUS 28 d continued stimulus was used to establish the rat depression model.The open field test (OFT) and the force swimming test (FST) were used to evaluate the rat depression behaviors;qRT-PCR was used to determine the mRNA expression of IDO in hippocampus and cortex;Western blot was used to determine the protein expressions of IL-1β,IL-6 and IDO in hippocampus and cortex.Results Compared with the CG group,the OFT score in the rats of the MG group was significantly decreased(P＜0.01),the immobility time in FST was significantly extended (P＜0.00),the expression of IDO mRNA in hippocampus and cortex was significantly increased (P＜0.01) and the protein expression of IL-1β,IL-6 and IDO in hippocampus and cortex was significantly increased (P＜0.05).Conclusion The rat depression behaviors induced by CUS may be associated with the increase of intracerebral inflammatory cytokine expression and inducing IDO over-expression.