Effect of lymph on acute microcirculatory disturbance of rats induced by dextran 500

Objective To study the interference effect of lymph on acute disturbance of microcirculation in rats induced by dextran 500.Methods Twenty male Wistar rats were anesthetized by intramuscular injection of pentobarbital sodium(50 mg/kg·bw),and administrated intravenously dextran 500 (1 g/kg·bw)within 1 min,then we duplicate the acute disturbance of microcirculation animal models.Lymph was infused through cervical vein with one fifteenth of body blood volume in a constant speed after 6 min of making model in lymph treatment group,and the lymph was replaced by the equivalent volume of normal saline (NS)in model group.The mesentery near the lower ileum was spread on the observed window to investigate the internal diameter of mesenteric micro-vessels(A 1,A 2,V 1,V 2)and micro-blood flow condition by using a vital microscope with TV recorder before and after making model and after lymph or NS treatment.The analysis of blood flow condition by Tian’s multiple score method was used.The rats were connected the right common carotid artery with pressure transducer. Blood pressure was monitored continuously, and the survival time was recorded.Results ①Dextran 500 could lead to acute disturbance of microcirculation in rats.The diameter of mesenteric micro-vessels contracted(P005～001),the micro-blood flow speed slowed(P005)and the red cell aggregated(P0.05～0.01)after making model in the two groups,but the two groups had no statistical difference before and after making model(P005).②Lymph can markedly improved disturbance of microcirculation.The abnormality of the diameter of mesenteric micro-vessels, the micro-blood flow speed and the condition of the red cell aggregation in lymph treatment group was significantly slighter than those of control group(P005～001).③Lymph can improve blood pressure.The blood pressure droped continuously in control group after making model,but it can be kept in a higher level in lymph treatment group(P005).④The survival time of the rats in lymph treatment group was significantly longer than the control group(P005).Conclusion Lymph could markedly improve the acute disturbance of microcirculation induced by dextran 500 ,maintain the blood pressure and lengthen the survival time in rats.