Study The Effect Of EPO On GH-IGF-1 Axis In Iron Deficiency Anemia Rats

Objective:To find out whether EPO modulate the GH-IGF-1 axis by activating the AKT,a downstream signaling molecule of EPO,to affect body weight and growth in iron deficiency anemia individuals.Methods: 1.Prepared the iron-deficiency anemia rats models: 36 3-week-old female Wistar rats were divided into two groups and fed with low-iron diet or iron-containing diet,and weighed body weight.Anemia models were identified 2 weeks later: blood was collected from the canthus veins,and hemoglobin(Hb),red blood cell distribution width(RDW),Mean corpuscular volume(MCV),Mean corpuscular hemoglobin(MCH),and hematocrit(Hct)were measured by a fully automated hematology analyzer.2.Recombinant human erythropoietin(r Hu EPO)intervention: a dose of 5,000 IU/kg EPO or an equal amount of saline was used to inject into rats' abdominal cavity in experience group and control group.3.HE staining of rats' liver.4.Immunohistochemical was used to detect the expression of IGF-1 in liver after the intervention of r Hu EPO in experience group.5.ELISA assay was used to detect the levels of GH and IGF-1 in serum after r Hu EPO intervention.6.Western blot was used to detect the levels of erythropoietin receptor(EPOR),total protein kinase B(t-AKT)and phosphorylated protein kinase B(p-AKT)protein in rats' liver after intervention.Results: 1.Successfully prepared iron-deficiency anemia rat model: compared with the control group,the values of Hb,MCV,MCH,Hct in experience group significantly decreased(P< 0.01);RDW increased(P< 0.01);Rats in the experience group had lower body weight than those in control group after a two-week feeding(P< 0.05).2.Compared with the control group,hepatic cells became swollen and showed vacuolation in the low-iron group,and partial cell nuclear condensation.3.Immunohistochemical found that quantity of IGF-1 positive in cytoplasm of hepatocytes decreased significantly after intervention of r Hu EPO in rats of the experience group.4.Serum levels of GH decreased after injection of r Hu EPO the experience group(P<0.05),and IGF-1 levels decreased significantly(P<0.01).Serum levels of GH and IGF-1 were found no different after intervention with r Hu EPO in the control group(P> 0.05).5.Westen blot results showed that the expression of EPOR protein in the liver of experience group was higher than that in the control group(P<0.01).After the administration of r Hu EPO,the EPOR increased,but not significant(P> 0.05).There was no difference of t-AKT in liver after r Hu EPO injection(P> 0.05).The level of p-AKT increased(P < 0.05).Conclusion: 1.Iron deficiency can cause damage in liver cell.2.The expression of EPOR increased in iron deficiency anemia rats The EPOR expression did not change after the EPO injection in short-term.3.In iron deficiency anemia individuals,the GH,IGF-1 down,weight loss,slow growth,the EPO may be involved in part of the regulation,activation of AKT signal may be an important molecular mechanism.