Popis: |
In vivo experimental investigations in the cortex of cat brains with the new, ultramicro oxygen electrode (2), (3) have produced surprising results that need to be correlated with adequate convectiondiffusion theory for proper analysis and future predictions. Transient changes (Figure 1) forced on arterial oxygen partial pressure (oxygen tension) of healthy cats produced tissue responses similar to that shown in Figures 2 and 3. On returning to normal conditions, oxygen tension was observed to “overshoot” normal values before leveling out at the previously recorded normal level. Identical experiments performed on the same animals when under conditions of intravascular red cell aggregation (sludge), hemorrhage, or hemorrhage combined with aggregation produced tissue responses similar to that shown in Figure 4. In these latter cases of pathologic physiology the “reoxygenation time” was greatly extended, and no overshoot was recorded. |