| ObjectiveTo observe the cardiomyocytes regeneration and neovascularization after mobilizing autologus bone marrow stem cells by granulocyte colony stimulating factor (G-CSF) alone or G-CSF combined with human Growth Hormone (rhGH) in Wistar rats with actue myocardial infarctionMethods①Wistar rats with acute myocardial infarction(AMI) was established by liquid nitrogen cryoinjury②The rats was divided into 6 groups: the mobilization group (N,n=8, treated with G-CSF 50μg·kg-1·d-1×5 subcutaneously), the sham operation group (SO,n=6,opening the thorax without cryoinjury), the myocardial infarction group (MI,n=8,with cryoinjury), the G-CSF group (G, n=8, treated with G-CSF 50μg·kg-1·d-1×5 subcutaneously following one day after AMI), the rhGH group (GH,n=8, treated with rhGH 2IU·kg-1·d-1×14 subcutaneously following one day after AMI) and the G-CSF combined with rhGH group (GG, treated with G-CSF50μg ? kg-1·d-1×5 subcutaneously and rhGH 2IU ? kg-1·d-1×14 subcutaneously following one day after AMI). ③ White blood cell and mononuclear cells proportion in peripheral blood were examined by ABX blood cell Analyzer to estimate bone marrow stem cells mobilization.④Except the N group, BrdU, 50mg·kg-1 was given once a day for 10 days before the rats killed at 28 days. The body and heart weight were measured, the ratio was calculated. The hearts were harvested for histopathological examination. The density of capillary was counted and infarct size calculated under light microscope in HE stain slices. ⑤Immunohistochemical double stain of BrdU and cTnI was used to detect the regeneration of myocytes and angiogenesis from bone marrow stem cells in theinfarct zones. Results(l)Animal model: All rats in group N and group SO were survived for 28 days.7 rats in another 4 groups(8 rats in each group of ML G^ GH> GG) died after AMI (the mortality was 21.875%). After the animal model was established successfully the ECG showed ST segment elevation diminished R wave and the existence of Q wave. HE stain showed myocyte coagulative necrosis, inflammatory cells infiltration and fibrotic repairment. (2)stem cell mobilization: ?After 6 days administration of G-CSF the WBC increased to (14.85±2.56)X 109/L, and MNC%(33.19 + 4.52)% significantly in group N(P<0.05). ?After 6 days administration of G-CSF the WBC increased to (16.47±3.00)X 109/L, and MNC%(34.46±4.14)% significantly in group G(P<0.05).(3) After the cryoinjury undergone the WBC increased to (11.49±1.89)X 109/L significantly(P<0.05), and MNC% increased to (18.22 ±2.70)% but no statistical difference was found(.P>0.05) compaired with those before cryoinjury in MI group.?Between group G and MI the significant difference of WBC and MNC% was observed (P<0.05).(3)(DBody and heart weight in GH group(206.10± 13.18, 1.29 + 0.12)g. GG group (209.85+11.24, 1.36 + 0.12)g were higher than those in SO^ MI and G groups respectively (/><0.05).(2)The ratio of heart and body weight was higher in GG group(0.647 +0.026)% than the one in ML G and OP group(/><0.05).(4) body weight difference between the initial and 28 days: in GH 32.47 + 9.32g^ in GG 36.80±4.29g were higher than those in other 3 groups respectively (P<0.05).(5)There were no significant differences in infarct sizes amongML G^ GH , GG(from 18.36 + 1.34 to 20.15 + 1.91). (6)The capillary densities were higher in G(7.60 + 2.04)/0.2mm2^ GH (7.25 + 2.28) /0.2mnA GG (9.20 + 2.28) /0.2mm2 than those in MI (3.60+ 1.39)/0.2mm2 and OP group(1.02 + 0.87)/0.2mm2 (PO.05), and significant difference was also found between... |
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