The Effects of Depression on the Survival of Rats with Carcinoma

Objective: To establish the animal model of depression associated cancer and discuss the effects of depression on neoplasitc cases with depression and their survival rate.Methods:36 SD rats were randomly divided into three groups with 12 rats in each group;group A-blank group;group B-tumor group(tumor cell inoculation without stimulations);group C-tumor depression group.The animal models were developed as stimulations of depression associated with tumor by separation feeding and chronic unpredictable mild stress and/or their receiving tumor-cell-inoculation.Life expectancy and quality of life of rats with inoculated Walker 256 tumor cells were observed.The Inhibitory effect of serum from depressive rats on lymphocyte proliferation introduced by ConA was measured by MTT assay.The serum-cortisol level of each group was detected by radioimmunity essay.Results:After mild stress,all rats were in depression.The life expectancy and quality of life of depression were the worst in group C.The life expectancy of the three groups were(60.00±0.00),(47.67±20.52),(24.83±17.39)d,with significant difference(P0.05).The serum from depressive and/or bearing cancer rats inhibited ConA-induced lymphocyte proliferation(P0.05).The inhibition ratio were group A(11.84±5.38)%,group B(25.61±7.14)% and group C(39.98±8.52)% with statistical difference(P0.01).Compared with group A and B,group C had higher level of serum-cortisol(P0.05).Conclusion:The stress depression might induce immune dysfunction by increasing serum-cortisol level of the neoplasitc rats,which can affect life expectancy of neoplasitc rats.