The Influence Of Acute Regional Contusion And Lace-ration Of The Brain On Cerebral Microcirculation And Ultrastructure Of Nervous Tissue In Rats

Background and Purpose: Disturbance of cerebral microcirculation after brain injury are significant pathological and pathophysiological changes and it would worsen the secondery brain cell injury and infect the prognosis of the patients.The perfusion method has been used to study brain injury changes of cerebral circulation in the past, which could stimulate the blood vessels, make microvasculature dilatation and disruption, and only display the alteration of shape microcirculation. With the Endogenous peroxidase (EGPO) histochemical method to display the alteration of cerebral microcirculation not only can avoid the artifical changes on blood vessels but also determine the vivid microcirculation by the number of the vessels and the color depth of the material which in the vessels. To explore the alteration law of cerebral microcirculation after brain injury and cerebral ischemia and the ultrastructure of nervous tissue, we use EGPO histochemical method to display the alteration of micrangium shape and microcirculation after brain injury and systemic analysis the changes of altrastructure of micrangium endotheliocyte and nervous tissue. Our purpose is to furnish evidence for improve the disturbance of cerebral microcirculation after brain injury and treat the cerebral ischemia and promote the resume of nervous function.Methods: Acute regional brain trauma was applied according to Feeney's apparatus. Eighty-one rats were randomly divided into control group and traumatic group. The traumatic group were divided into 30min, 2h, 6h, 12h, 24h, 48h, 72h, 168h group according to the observation point. Each grouphas nine rats. The animals of the traumatic group were injuried by 750g cm collisional force after craniotomy of the right parietal.Six of it were performed EGPO histochemical staining, HE staining, water content of the brain and the charts were analysised by CMIAS system.Three of it were observed on the alteration of micrangium endotheliocyte and nervous tissue altrastructure. The brain of the control group animals were were not injuried its observing target equals to traumatic group.Results: (1)The hemorrhage were observed at the traumatic area and the blood vessel did not staining, arouding where "non"microvessels area was showed and it continuing 72h. (2)The density of microvasculature volume fraction declined at 30min. It reached peak at 48h and resumed at 168h. (3)The MOD declined at 30min, raised again at 48h and 72h, declined again at 168h. (4)HE staining show the obliteration and flexion and stricture and fragmentation of microvasculature, disorder of endotheliocyte, aggregation of red cell, and edema which surronding the microvasculature. (5)The micrangium endotheliocyte was damaged at 30min, the microvilli was formed at 2h and 6h, the cavum of micrangium was narrowed at 12-72h. (6)The ultrastructure of nervous tissue gradually worsen after brain injury.Conclusion: (1)Feeney's method is pefect one to study acute regional contusion and laceration of the brain. (2)The microvasculature disappeared at traumatic area and a few microvasculature but non microvasculature area around it. (3)The blood of microcirculation was declined during 30min-12h, and hyperaemia during 24-48h and declined again during 72-168h. (4)The micrangium endotheliocyte was were gradually damaged and the the cavum of microvasculature was narrowed and the microvilli was formed at 2h and 6h. (5)The ultrastructure of nervous tissue gradually worsen after brain injury. (6) The damage of nervous cell and micrangium endotheliocyte subsequent thebrain ischemia, which subsequent the disrupt of microvascular structure and hypoperfusion of microcirculation.