RESUMEN
Stress gradually suppresses the immune system making the body susceptible to various diseases. The aim of this study was to show the effects of cold and immobilization stress on growth of malignant cells in Balb/c mice. In an experimental study which was carried out in the Molecular and Cellular Research Center of Shahrekord University of Medical Sciences in 2008, 3 groups of 10 Balb/c mice were selected to investigate the effects of cold stress and immobilization stress on growth of WEHI - 164 fibrosarcoma cells in groups of 10, Balb/c mice. Each mouse was injected with tumor cells subcutaneously in the chest; for 2 hours/day mice in group 1 were subjected to cold stress and mice in group 2 were immobilized; the control group received tumor cells with no stresses. Tumor sizes were measured every two days and case groups were compared with the control group. Results showed that the tumor sizes in stressed mice were significantly different from controls. After 14 days of tumor inoculation, mean tumor size in mice subjected to cold stress and immobilization was 31.99 +/- 2.61 and 37.13 +/- 3.51cumm respectively, but in the control group the mean tumor size was 18.15 +/- 3.09 cumm, [p<0.05]. Results in this study showed that cold and immobilization stresses increase the growth of WEHI-164 tumor cells