高脂血症大鼠心肌中脂滴分布和H-FABP表达变化

目的　观察高脂血症大鼠心肌细胞脂滴含量和心功能，以及心型脂肪酸结合蛋白（heart type fatty acid binding protein，H-FABP）的表达。 方法　高脂饲料喂养SD雄性大鼠，建立高脂血症模型。饲养后4周、8周、12周，分别进行心功能检测后取出心，制作冰冻切片，光学显微镜观察脂滴在心肌的分布（油红O染色），透射电镜观察心肌组织脂滴；采用免疫组织化学、免疫荧光、免疫印迹检测心肌细胞和心肌组织中H-FABP的表达。 结果　与普通饮食大鼠相比，高脂饮食大鼠血清甘油三酯和总胆固醇明显升高，在第12周升高最为明显，并伴有射血分数的明显下降；心肌细胞内脂滴含量增多，第4周增多最为显著，第8周、第12周逐渐减少；心肌细胞和心肌组织中H-FABP在第8周、第12周表达明显增加。 结论　高脂血症大鼠心肌发生脂肪变性，随着血脂浓度升高脂肪变性减轻，心功能降低，这一变化可能与H-FABP表达增多，增加心肌细胞内脂肪酸氧化有关。

The lipid droplet distribution and expression of heart type fatty acid binding protein in the myocardium of hyperlipidemic rat heart

Objective　To observe the changes of lipid droplet in cardiomyocytes and cardiac function of hyperlipidemia rats, and the expression changes of heart type fatty acid binding protein (H-FABP). Methods　High fat diet SD male rats was established hyperlipidemia rat model. After feeding for 4 weeks, 8 weeks and 12 weeks, the cardiac function of the rats was detected and the heart was removed. Frozen sections were stained with oil red O, and the distribution of lipid droplets in the myocardium was observed under light microscope. The changes of lipid droplets in myocardium were observed by transmission electron microscope. The expression of H-FABP in cardiomyocytes and myocardium was detected by immunohistochemistry, immunofluorescence and Western blotting.　Results　Compared with the normal diet rats, the serum triglyceride and total cholesterol increased significantly in the high-fat diet rats, the most obvious was in the 12 week, accompanied by a significant reduction in ejection fraction, increasing of lipid droplets in myocardial cells. The number of H-FABP in myocardium and myocardium increased significantly at the 8th week and the 12th week.　Conclusions　The myocardium of hyperlipidemia rats occurs fatty degeneration. With the increasing concentration of blood lipid, the fatty degeneration and the heart function decrease, which may be related to the increasing of H-FABP expression and the increasing of fatty acid oxidation in cardiac myocytes.