Studies on antithrombogenic and thrombolytic effect of combined use of low molecular weight dextran and urokinase

Abstract

The purpose of this study is to elucidate whether LMWD and combined use with UK have the prophylactic effect of thrombus formation and thrombolytic enhacement or not. This study was carried out by Chandler's loop method.One hundred thirty ml of blood sample were respectively taken from two healthy young volunteers at the rate of one volume of 3.8% citrate and nine of blood. One ml of citrated blood was poured into each Chandler's loop and then 0.1ml of 0.25M calcium chloride was added. An artificial clot was formed after 30 minutes rotation of a loop equipped to a cylinder which rotates 12 times per minute, holding 80 degree of angle upwards from the horizontal surface. After a clot formation, various concentration of LMWD and UK was added into each Chandler's loop. Each clot was weighed after four hours rotation. Experiments were performed in 5 groups. In each group, ten loops were used and the weight of a clot was statistically evaluated. The following items were investigated: 1) effect of LMWD on artificial clot formation, 2) effect of LMWD on thrombolysis of artificial thrombi, 3) effect of LMWD and combined use of UK on thrombolysis of artificial thrombi. It was varified that the blood containing 4.2mg of LMWD per ml is more significantly prophylactic for clot formation as compared with control (p<0.001, N=9). More 16.7mg of LMWD per ml showed significant thrombolytic activity compared with control (p<0.05, N=8). On thrombolytic activity, combined use of 15.4mg of LMWD per ml and 50 I. U. of UK per ml showed enhancement of 3.5 times over than control (p<0.01, N=8). Concomitant use of 3.8mg of LMWD per ml and 1, 000 I. U. per ml enhanced fibrinolytic activity 1.9 times than control (p<0.01, N=8).The simultaneous combined administration of LMWD and UK will be more effective for thrombolytic treatment than UK only.