چكيده لاتين :
In this research the immune system parameters of medical students in stressful and non-stressful conditions were studied. Two groups of male and female medical students (n= 170 in each group) of Tehran and Shahid Beheshti Universities were studied. One group had a stressful pre internship Examination (PIE), but the other group didnʹt have such an examination. Subjects who suffered from disorders that affected the immune system were excluded. Finally, the (PIE) group consisted of 147 subjects, and the non-(PIE) group consisted of 155 subjects. Then 40 subjects were selected randomly from each group. Peripheral blood was obtained at the same time. Number of T-helper cells (CD4), T-suppressor cytotoxic cells (CD8), Natural killer cells (CD56+CD16), complement system (C3, C4, CH50), Immunoglobulin M and G (IgM, IgG), Cortisol hormone, Eosinophils, Neutrophils and Lymphocytes were measured. The results showed that there was a significant difference between the (PIE) group and non-(PIE) group in CD4, CD8, CD4/CD8 , CD16, C4, IgG and Cortisol. Also the level of CD8,C4, IgG and Cortisol of PIE group was significantly more than non-PIE group.