胰岛素促进大鼠移植脂肪微血管的形成

背景：细胞培养实验发现胰岛素不但能促进血管内皮细胞的增殖和修复，还能有效促进前脂肪细胞的增殖和分化，体内实验观察胰岛素对移植脂肪新生微血管的影响罕有报道。目的：探讨胰岛素对大鼠移植脂肪内微血管形成的作用。方法：将48只SD大鼠随机分成胰岛素组和对照组，从大鼠输卵管旁取出1mL脂肪组织，制成脂肪颗粒移植到大鼠背部，建立颗粒脂肪移植模型。胰岛素组在移植前将脂肪颗粒放入浓度为300mUlL的胰岛素中预处理；对照组对移植脂肪组织不施加处理因素。在移植后10，20，28d取移植的脂肪组织做苏木精一伊红和CD34血管染色，观测移植脂肪细胞变化和微血管生长隋况。结果与结论：苏木精一伊红染色切片中可见移植体内有成熟脂肪细胞，细胞体积变小，部分脂肪细胞有破裂萎缩现象，细胞间有纤维组织增生，胰岛素组脂肪细胞周围纤维组织少于对照组。在10，20d，胰岛素组微血管密度为（3．92±0．12）个／HP和（6．96±0．42）个／HP，对照组为（2．05±0．21）个／HP和（4．40±0．36）个／HP，胰岛素组微血管密度均高于对照组，两组比较差异有显著性意义（P〈0．01）。提示胰岛素能促进移植脂肪块内微血管生长，提高移植脂肪的存活率。

Insulin promotes the microvessel formation in fat grafts

BACKGROUND： Currently, the in vitro cell culture experiment shows that insulin can not only promote the proliferation and repairing of vascular endothelia cells, but also can increase the proliferation and differentiation of preadipocytes. However, there are a few papers about the effect of insulin on revascularization in fat grafts through in vivo experiment. OBJECTIVE： To investigate the influence of insulin on the microvessel formation in fat grafts of rats. METHODS： Forty-eight Sprague Dawley female rats were used in this study, and then the rats were randomly divided into insulin group and control group. 1 mL fat graft was obtained from the side of fallopian tubes of the rats to make fat particles and then transplanted to the dorsal of the rats to establish the granule fat graft models. In the insulin group, granule fat grafts were pre-treated with insulin with the concentration of 300 mUlL before transplantation; the fat grafts in the control group without any treatment. The samples of fat grafts were harvested at 10, 20 and 28 days after the transplantation and treated with hematoxylin-eosin staining and CD34 vascular staining respectively. The changes of grafted adipocytes and the growth of microvessel were observed. RESULTS AND CONCLUSION： Mature adipocytes could be observed in the hematoxylin-eosin staining sections, the size of adipocytes was smaller than that before transplantation, and part of the adipocytes were ruptured and shrinked. Hyperplasia of fibrous tissue was observed in two groups, and the number of fibrous tissue around the adipocytes in the insulin group was smaller than that in the control group. At 10 and 20 days after transplantation, the microvessel densities were （3.92±0.12） microvessels/high power field and （6.96±0.42） microvessels/high power field in the insulin group, （2.05±0.21） microvessels/high power field and （4.40±0.36） microvessels/high power field in the control grouP, respectively. Microvessel density in insulin group was higher than that in the control group, and there was a significant difference between two groups （P 〈 0.01 ）. The result shows that insulin can improve the survival rate of autogenous fat grafts by promoting the microvessel formation.