Effects of ethanol extract from Mrrubium Incisum(夏至草醇提物) on acute microcirculatory disturbance in rats

Objective To observe the effects of ethanol extract from Mrrubium Incisum(EEMI,夏至草醇提物) on mesenteric blood and lymphatic microcirculation in rats with acute microcirculatory disturbance(AMD) induced by Dextran 500.Methods Twenty male Wistar rats were randomly divided into two groups: EEMI group(n=10) and model group(n=10).The AMD model was established by intravenously administrating Dextran 500(10 ml/kg) via left carotid vein.Six minutes later,EEMI(6 g/kg) was slowly infused into the carotid vein in EEMI group,while in the model group,similar amount of normal saline was injected.The mesenteric blood and lymphatic microcirculations were observed by intravital microscope with TV recorder.Results In the model group,the comparisons between the various items of manifestations before and after the experiment showed that after the experiment the caliber of mesenteric micro-vessels were contracted,the speed of blood flow in the vessels was slowed down,the red blood cell(RBC) aggregated,and the liquid state integral value was increased markedly;at the same time,the frequency of spontaneous contraction of mesenteric lymphatic vessels(ML),lymphatic contractive activity(IndexⅠ),total lymphatic contractive activity(IndexⅡ) and the lymphatic dynamics(LD-Index) of mesenteric micro-lymphatic vessels were reduced significantly(all P0.05).After EEMI injection,the caliber of mesenteric micro-vessels was expanded,the speed of blood flow in the vessels was increased and the liquid state integral value was lower,and the spontaneous contraction frequency,IndexⅠ,IndexⅡ and LD-Index of ML were markedly increased in EEMI group than those in the model group(all P0.05).Conclusion EEMI can ameliorate obviously the acute blood and lymphatic microcirculatory disturbance induced by Dextran 500 in rats.