低分子右旋糖酐在小血管外科的应用机制

The mechanism of the low molecular dextran in microvascular surgery

目的 研究低分子右旋糖酐对凝血功能和小血管吻合口血小板沉积的影响。方法 (1 )SD大鼠 32只。股静脉插管 ,实验组 (2 4只鼠 )注射低分子右旋糖酐葡萄糖液 (8 5ml/kg) ,对照组 (8只鼠 )等体积 5%葡萄糖液。用药后 1、3、6、1 2h ,测血小板最大聚集率、PT和KPTT。 (2 )兔 1 6只 ,实验和对照组各 8只。切断并吻合双侧股动脉 ,血流重建前 0 .5h ,耳缘静脉注射低分子右旋糖酐葡萄糖液 (8.5ml/kg) ,血流重建后 1 5min、1 2 0min,用1 2 5I SZ 2 1 (抗GPⅡb/Ⅲa单克隆抗体 )处理双侧吻合口后 ,测定放射活性。结果 实验组大鼠术后 1、3、6、1 2h组 ,血小板最大聚集率较对照组平均降低 43 44% (P <0 .0 1 )。给药后 1、3、6h组 ,KPTT均延长 ;1h组平均延长 74.31 % (P <0 0 5)。兔血流重建后 1 5min、1 2 0min ,实验组所有吻合口均通畅。吻合口标记抗体的放射活性 ,比对照组增加 1 2 1 .80 % (P <0 0 5)和 47.82 % (P <0 0 5)。结论 低分子右旋糖酐可抑制血小板聚集 ,抑制内源性凝血系统的功能 ;

Objective To assess the effects of dextran on the function of coagulative system and the platelet deposition at the anastomotic sites. Methods 32 SD rat were randomly divided into the experimental (24) and the control (8) groups. Dextran 40 (8.5 ml/kg) was administered through a catheter placed in a femoral vein at experimental group and the same volume of 5% Glucose solution at control group. Blood samples were taken and the platelet aggregation, PT and KPTT were tested. 16 New Zealand White rabbits were divided into experimental and control groups, with 8 in each. The bilateral femoral arteries were transected and anastomosed in an end to end way. 30 minutes before surgery, dextrans 40 was given via ear marginal vein (8.5ml/kg).15 and 120 minutes after the re establishment of blood flow, the bilateral anastomotic sites were given with 125 I labeled anti GPⅡb/Ⅲa antibody(SZ 21). Then the radioactivities were measured. Results Compared with the control group, the maximal aggregation rates of platelet in experimental groups decreased 43.44%(on average) at postoperative 1,3,6 and 12 hours. KPTT was longer in experimental group than that in the control group at postoperative 1,3,6 hours, with 74.31% longer at 1h point(on average). 15 and 120 minutes after the re establishment, all of the artery were patent. The radioactivities at the anastomotic site in experimental groups increased 121.80% and 47.82% when compared with the control group.Conclusions The low molecular dextran can inhibit the platelet aggregation and intrinsic coagulation system, but it has no significant influence on the platelet deposition at the anastomotic sites.