OBJECTIVETo investigate the effects of Ginkgo biloba extract (GbE) on the glucose uptake rate and gene expression of glucose transporter 4 (GLUT4) in diaphragm of diabetic rats.

METHODForty SD male rats were randomly divided into normal control group (n=10) and model group (n=30). Diabetic models were induced by feeding with high-sucrose-high-fat diet and intraperitoneal injecting 25 mg X kg(-1) streptozotocin. 20 successful models were rearranged to two groups: diabetic group and GbE treatment group, 10 rats in each. Then the saline and 8 mg X kg(-1) x d(-1) of GbE were respectively intraperitoneal injected, once a day continuously for 8 weeks. The contents of fasting blood glucose (FBG), fasting insulin (FINS) were detected, respectively. The glucose uptake rate and gene expression of GLUT4 in diaphragm were determinated and the varieties of diaphragm ultrastructure were observed.

RESULTCompared with control group, levels of FBG and FINS obviously increased in diabetic rats (P < 0.01), but the glucose uptake rate and expression of GLUT4 mRNA in diaphragm decreased significantly (P < 0.05, P < 0.01). The ultrastructure in diabetic group under electron microscope indicated that diaphragm mitochondrion swelled and degenerated. The above changes were inhibited by GbE.

CONCLUSIONGbE can improve the glucose metabolism in diabetic rats and reduce the diabetes-induced diaphragm damage. The action mechanism of the drug may be related to promote the mRNA expression of GLUT4 in diaphragm and improve the uptake and metabolism of blood glucose.