Effects of psychological stress on serum iron and erythropoiesis

There are about one billion patients with iron deficiency anaemia all over the world. Recently, researchers have reported successively that stress can cause decrease of serum iron, in consistent with our studies showing that heat exposure and acceleration stress led to significant decrease of serum iron in rats. However, so far whether pure psychological stress can cause decrease of serum iron and consequently affect erythropoiesis has not been reported. To study the characteristic effects of psychological stress on serum iron and erythropoiesis, and to establish an useful experimental basis for further study involving how sufficient intake of dietary iron causes decrease of serum iron and the consequent effects on physiological function of the human body. Psycological stress was adminstered to 20 rats with Communication Box system. On the 7th and 14th day after administration, 10 rats were executed, respectively, and the rat blood and femoral bone marrow were collected for analysis of serum iron (SI), serum ferritin (SF), serum transferrin receptor (sTfR), haemoglobin (Hb), red blood cell count (RBC), RBC distribution width (RDW), mean corpuscular volume (MCV), serum erythropoietin (EPO) and bone marrow iron. Experimental data were statistically analysed with SPSS 11.0. For rats analysed on the 7th and 14th day in psychological stress group, (1) femoral bone marrow iron was significantly decreased; (2) serum iron was decreased by 28.6% (P < 0.01) and 27.5% (P < 0.01); (3) Hb was decreased by 10.0% (P < 0.01) and 12.8% (P < 0.01), RBC count was decreased by 5.1% (P < 0.05) and 9.8% (P < 0.01), MCV was decreased by 1.7% (P < 0.05) and 7.3% (P < 0.01), RDW was increased by 10.7 and 22.5%; (4) serum ferritin, transferrin receptor and EPO showed no significant changes in comparison with controls after 7-day administration, but serum ferritin and EPO were decreased by 23.8 and 12.3% while transferrin receptor increased by 31.5% after 14-day administration. For rats receiving different period of pure psychological stress: (1) serum iron and bone marrow iron showed significant decrease compared with the controls; (2) erythropoiesis was significantly inhibited; however, (3) how psychological stress affects serum iron and erythropoiesis need to be further investigated.