Heterogeneity of oxygen delivery in normoxic and hypoxic states: a fluorometer study

Abstract

An on-line, real-time histogram display of heterogeneity of O2 delivery to perfused and in situ organs is afforded by a flying-spot fluorometer that provides excitation for either oxidized flavoprotein of the mitochondrial space or reduced pyridine nucleotide of mitochondrial and cytosolic spaces. Emission from the 2 fluorochromes is acquired at 104-105 data points/s and histograms of the fluorescence intensity versus the number of occurrences of that intensity are displayed at 1-10 .times./s. The histograms show alterations of the intensity and of the degree of heterogeneity of the redox states of perfused heart with model coronary occlusion, of perfused and in situ rat liver, and of rat and gerbil models of stroke. The percentage change of O2 delivery to the intracellular space can be calculated from the areas under the histogram.