BACKGROUND: Current researches on whether the intramuscular injection of heterogeneous umbilical cord mesenchymal stem cells (UC-MSCs) is safe or not lack theoretical basis.
OBJECTIVE: To explore the effects of intramuscular injection of heterogeneous UC-MSCs on expression of myocardial vascular endothelial growth factor (VEGF), cardiac troponin I (cTnI) and serum VEGF, hepatocyte growth factor (HGF), insulin-like growth factor 1 (IGF-1) and granulocyte macrophage colony stimulating factor (GM-CSF) in normal Wistar rats.
METHODS: A total of 60 Wistar rats were divided into six groups randomly. Rats in the six groups were respectively administrated with intramuscular injection of PBS, Dulbecco’s modified Eagle’s medium, hUC-MSC supernatant, 0.25×105, 1.0×105, 4.0×105 hUC-MSCs. Rats received a second intramuscular injection 4 weeks after first injection. Eight weeks later, the blood sample and myocardial tissue were taken. The serum concentration of VEGF, HGF, IGF-1 and GM-CSF were measured with enzyme-linked immunosorbent assay kit. The myocardial VEGF and cTnI expression were detected by immunohistochemical technique.
RESULTS AND CONCLUSION: There was no significant difference in the serum concentration of the VEGF, HGF, IGF-1 and GM-CSF among the groups before and after injection (P > 0.05). In the same group, no statistical significant changes in the serum concentration of the VEGF, HGF, IGF-1 and GM-CSF were found among the rats before and after injection (P > 0.05). Eight weeks after injection, weak positive expression of the VEGF in the cytoplasm of cardiocytes in the six groups was observed, and strong positive expression of the cTnI in the cytoplasm of cardiocytes in the six groups was observed. There was no significant difference in the VEGF and cTnI content in the myocardium among the groups (P > 0.05). Intramuscular injection of hUC-MSCs or the supernatant of hUC-MSCs had no effects on the serum concentration of the VEGF, HGF, IGF-1, GM-CSF and the myocardial VEGF and cTnI expression in normal Wistar rats.