Significance of fluid flow for morphology of acute hypoxic-ischaemic brain cell injury.
It has been suggested that the presence or absence of hypoxic fluid flow during ischaemia determines the structural character of the ischaemic nerve cell injury. It is hypothesised that if a flow of fluid irrigates the injured neurons, there will be major shifts of ions and water, with consequent volumetric changes in the tissue and the 'dark' type of neuronal injury will result; otherwise, the structural changes are less striking and are designated as the 'pale' type. To test this hypothesis, rats were subjected to a global cerebral insult by filling the vasculature with a plasma substitute, which was either left stagnant or was flowing, and was either oxygenated (hypoxic flow) or nitrogenated (anoxic flow). Light and electron microscopy of the brain following 10 to 60 min of hypoxic or anoxic ischaemia disclosed that, under all three circumstances, the predominant nerve cell injury was of the pale type. The results indicate that some additional factors present in whole blood (but not in the plasma substitute) are needed during or after the insult to induce in quantity the dark type of ischaemic nerve cell injury.
D000208:Acute Disease; D000818:Animals; D001921:Brain / Q000473:pathology*; D002545:Brain Ischemia / Q000473:pathology*; D002560:Cerebrovascular Circulation; D004569:Electroencephalography; D000860:Hypoxia / Q000473:pathology* / Q000503:physiopathology; D008297:Male; D009474:Neurons / Q000648:ultrastructure; D051381:Rats; D011919:Rats, Inbred Strains