The Study Of Cerebral Tissue Channel In Normal,Acute And Chronic Hypertensive Rats

Objective Tissue channel is the most basic and direct pathway for the transmission of substances, energy, and information. Cerebral tissue channel and the cerebral interstitial fluid have not been fully understood. The first aim of this study is to investigate the following questions in normal rats: â‘ Characteristics of the cerebral interstitial fluid formation. â‘¡The configuration of cerebral tissue channel and properties of substance transmission. â‘¢Characteristics of cerebral interstitial fluid movement. â‘£The structure of cerebral tissue channel; On the bases of knowing the normal configuration, structure, and function of cerebral tissue channel of normal rats, the influence of hypertension both in acute and chronic hypertensive rats on cerebral tissue channel was studied. Methods Multiple practical methods were used to study the cerebral tissue channel in rats: â‘ Intravenous injection of Evan's blue and lanthanum perfusion were used to observe the permeability of blood-brain barrier to macro-molecules. â‘¡Fluorescence labeled markers of different molecule weight were injected into different part of rat brain, sequencing cryoultramicrotomy and image analysis were used to observe the distribution of labeled markers of different molecule weight in different parts of rat brain. â‘¢Fluorescence labeling marks were injected in vivo and fresh tissue sections were prepared, to observe relation of the distribution of markers with the tissuesmicthe.@Microdialysis were used to measure the velocity of interstitial nuidmovement in cerebral tissue channel, in order to analyses the fimctional conditionof the cerebral tissue channels.@Ruthenum red-staining section were observed under electron microscopeto analyse the diffetal distribulion of proteoglyCan, one of the strucforalsubstances of tissue channel, in normal and hrpedensive rats.Results:O Evan's blue (combined with athumin) and lanthanum are confined in thecerebra blood vessles in normal rats after indavenous injection of Evan's blueand perfusion of lanthanum opolyTnerista fixation fluid. The permeability ofbloodthrain bAner in acule hyPertensive rats increase and macro-moleculeseffoses into cerebral interstitial fluid.@ The distribution of same substances injected into differot pwts ofcerebral tissue is different Which diffeses around the injection site, diffeses alongthe nerve fibers and drains along the vascular sPace.@ The distribation of diffeeni substances injected illto saxne parts ofcerebral tissue is differen. Micro-mo1ecules are easy to diffuse, whilemacro-molecules can diffuse along both nerve fiber and vascular sPace and aredrained oul of the brain. In the cerebral edema induced by acllte hyPertension, thedrainage effect increases.@ The results of microdialysis in rat brain show that the velocity ofifiterstitial fluid in adult rats is slower than that in yOunger ones, so does in thechronic hyPertension than in the normal ones. In the cerebral edema induced byacute hyPertension, substances "lose" more in the cerebral tissue channel ofcorpus callosum.@ The quatity of Ruthenium red--stained particles of proteoglycan is muchmore in adult fats, acllte and chronic hrpedensive fats than that in younger andnormal rats, resPechvelyConclusionO Normal cerebral interstitial nuid is mainly comPosed ofmcro-moleculesbecause the exist of blood-bran bAneL Macro-molecules leaked into interstitialfluid from blood in acute hyPertension.@ There are 3 tyPes of cerebral tissue channels in rat: intercellular tyPe,perinerve fiber trpe, and perivascular troe. Periner...