Granulocyte Colony-Stimulating Factor Facilitates The Angiogenesis Induced By Ultrasound-Targeted Microbubble Destruction To The Infarcted Myocardium In Rats

SECTIONⅠThe selection of the minimal effective dosage and frequency of preadministration of granulocyte colony-stimulating factor which facilitates the myocardial angiogenesis in rats induced by ultrasonic microbubble destructionObjective To determine the minimal effective dosage and frequency of preadministration of granulocyte colony-stimulating factor (G-CSF) which facilitates the myocardial angiogenesis in rats induced by ultrasonic microbubble destruction. Methods A total of 40 normal Wistar rats were randomly divided into 5 groups. The rats of every group were treated with subcutaneous injection of G-CSF respectively at 5ug/kg/d for 4 days;10ug/kg for one day; 15ug/kg for one day; 20ug/kg for one day. All the rats were also treated with ultrasonic microbubble destruction. Two weeks later the rats were killed and the myocardium were harvested for HE staining to observe the tissue microstructure. Immunohistochemistry staining was used to detect the vascularization. Results There was significant CD34 expression in group C and group D ; less expression in group A and group B; little expression in group E. The MVD of group C and group D were higher than other groups, But there was no significant difference between them. Conclusions The minimal effective dose and frequency of preadministration of G-CSF is 15 ug/kg for one day.SECTIONⅡGranulocyte colony-stimulating factor facilitates the myocardial angiogenesis in the normal rats induced by ultrasonic microbubble destructionObjective To investigate whether granulocyte colony-stimulating factor (G-CSF) can facilitate the myocardial angiogenesis in rats induced by ultrasonic microbubble destruction . Methods A total of 40 normal Wistar rats were randomly divided into 4 groups. In group A myocardium in rats were treated with G-CSF pretreatment followed by ultrasonic destruction of microbubbles (US/MB) ; In group B myocardium in rats were treated with US/MB alone and in group C were treated with G-CSF alone;Group D was the control group. Two weeks later the rats were killed and the myocardium were harvested for HE staining to observe the tissue microstructure. Immunohistochemistry staining was used to detect the vascularization and microvessel density (MVD) was counted in high-power field on microscopy . Results There was significant VEGF and CD34 expression in group A; less expression in group B; little expression in group C and the contro1. The MVD of group A were the highest among all the groups(P<0.05). Conclusions Ultrasonic microbubble destruction can facilitate the endogenous secretion of VEGF and accelerate the vascularization to the normal myocardium in rats. Pretreatment with G-CSF can augment the angiogenic effect of US/MB.SECTIONⅢGranulocyte colony-stimulating factor facilitates the angiogenesis induced by ultrasound-targeted microbubble destruction to the infarcted myocardium in ratsObjective To explore whether granulocyte colony-stimulating factor (G-CSF) can facilitate secretion of vascular endothelial growth factor(VEGF) and angiogenesis induced by ultrasound-targeted microbubble destruction to the infarcted myocardium in rats. Methods Forty Wistar rats were randomly divided into 4 groups after the models of myocardial infarction were prepared. In group A myocardium in rats were treated with G-CSF pretreatment followed by ultrasound-targeted microbubble destruction (US/MB); In group B myocardium in rats were treated with US/MB alone and in group C were treated with G-CSF alone;Group D was the surgery alone( SA) . Two weeks later the rats were killed and the myocardium were harvested. The CD34 expression was detected by immunohistochemistry, and microvessel density (MVD) was counted in high-power field on microscopy . The VEGF expression in myocardium was detected by ELISA and Western blot. Results There was significant CD34 expression in the myocardium of group A and the MVD[(231.20±24.48)/HPF] were the highest among all the groups(P<0.05). The contents of VEGF in the myocardium of group A [(3.14±0.21) ng/g] were higher than those of other groups (P<0.05). A protein strap about 21 kD was shown in the group A by Western blot detection. A tenuous protein strap about 21 kD was shown respectively in the other three groups. Conclusions Ultrasound-targeted microbubble destruction can facilitate the endogenous secretion of VEGF and accelerate the vascularization to the infarcted myocardium in rats . Pretreatment with G-CSF can augment the angiogenic effect of US/MB.