Protective effect of ginkgo biloba extract on pancreas transplantation in type 2 diabetic rats / 中国组织工程研究

ABSTRACT

BACKGROUND: Ginkgo biloba extract (GBE) has the pharmacological actions of antioxidation, eliminating free radicals and anti-platelet activating factors, it also can relieve the ischemia/reperfusion injury of various organs.OBJECTIVE: Toobserve whether GBE can relieve the ischemia/reperfusion injury of transplanted pancreas in diabetic rats or not.DESIGN: A complete randomized grouping design, controlled study.SETTINGS Department of Gastrointestinal Surgery and Department of Anesthesiology, Xijing Hospital, Fourth Military Medical University of Chinese PLA Hospital.MATERIALS Totally 128 male SD rats of clean grade, aged 3-6 months,weighing 250-320 g, were used. GBE was produced by Dr. Willmar Schwabe Pharmaceuti - cals (Ginaton parenteral solution, 5 mL/piece, containing 17.5 mg GBE, including 4.2 mg ginkgo flavone glycosides, batch number 1511102).METHODS: The experiments were carried out in the laboratory of Department of Gastrointestinal Surgery from September 2001 to April 2004.① Eighty rats were injected with STZ (65 mg/kg) via penile vein, and 60 of them with fasting blood glucose exceeding 17.4 mmol/L for 2weeks were taken as the diabetic rats, and the other 48 normal rats were taken as donors. ② The 60 diabetic rats were randomly divided into two groups ischemia/reperfusion group (n=30) and GBE group (n=30), and pancreas transplantation was performed in both groups. In the ischemia/reperfusion group, the rats were douched with 4 ℃ iced balanced salt solution containing heparin (1.5×105 U/L) for 20 minutes. In the GBE group, the recipients were given intravenous injection of GBE (1.5 mL/kg) at 1 day and 30 minutes before transplantation, and those in the ischemia/reperfusion group were intravenously injected with saline of the same volume. The donor pancreases were all reserved in 4 ℃ iced balanced salt solution containing heparin (1.5×105 U/L), the cold and hot ischemia times were kept for 180 and 15 minutes in each group to induce ischemia/reperfusion injury of transplanted pancreas. ③ Six randomly selected rats were killed at 2 days before transplantation and at 3 and 7days after transplantation respectively to detect fasting blood glucose; The activity of amylase was determined with corresponding kit provided by Nanjing Jiancheng Bioengineering Institute; Pancreas tissues were removed for hematoxylin and eosin (HE) staining; Six rats were used to observe the metabolic indexes; The other 6 rats were used to observe the survival rate within 1 month. ④ The differences of the measurement data were compared with the paired t test.MAIN OUTCOME MEASURES: ① Changes of fasting blood glucose level, metabolic indexes and activity of amylase before and after pancreas transplantation in the rat recipients of both groups; ② Pathological changes at 3 and 7 days after transplantation in the rat recipients of both groups.RESULTS: All the 60 rat as recipients finished the detections of blood glucose, food intake, water intake, urinary output and blood amylase. ①The survival rate within 1 month after transplantation was obviously higher in the GBE group than in the ischemia/reperfusion group (83%, 33%, P＜ 0.01). ② The blood glucose, water intake, food intake and the urinary output at 3 and 7 days after transplantation were obviously decreased as compared with those at 2 days before transplantation in both theischemia/reperfusion group and GBE group (P ＜ 0.05-0.01), and those at 3 and 7days after transplantation were obviously lower in the GBE group than in the ischemia/reperfusion group (P ＜ 0.05-0.01). ③ The activity of blood amylase at 3 days after transplantation was obviously increased as compared with that before transplantation in both the ischemia/reperfusion group and the GBE group (P ＜ 0.01, 0.05), it was still obviously higher at 7 days after transplantation than at 2 days before transplantation in the ischemia/reperfusion group (P ＜ 0.01), and it had almost recovered to normal in the GBE group. The activities of blood amylase at 3 and 7 days after transplantation were obviously lower in the GBE group than in the ischemia/reperfusion group (P ＜ 0.01). ④ The results of the pathological observation showed that the damaged severity of the transplanted pancreas was greater in the ischemia/reperfusion group than in the GEB group.CONCLUSION: GBE pretreatment can improve the survival rate of pancreas transplantation in rats, reduce the activity of blood amylase, ameliorate the metabolism, relieve the severity of reperfusion injury of pancreas,and plays a protective role in the pancreas transplantation.