Respiratory Control and Swelling in Rat Liver Mitochrondria: Effect of 60Co Gamma Radiation and Injected Nutrient.
ARMED FORCES RADIOBIOLOGY RESEARCH INST BETHESDA MD
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The objective of the study was to compare the relative effects of three treatments with that of radiation on the lag time for mitochrondrial swelling and the respiratory control during oxidation of succinate. The three treatments were dietary supplementation with ethyl linoleate, time of feeding, and an intraperitoneal injection of a soluble diet. Control and experimental rats from each of the eight different treatment groups were bilaterally exposed to 1000 rads of 60Co gamma rays. Liver mitochondria were collected from the 16 different groups 24 hours later for assay. Iron-induced mitochondrial swelling was used as an index of structural integrity. Respiratory control of adenosine diphosphate stimulated oxidation of succinate was selected as an index of functional integrity. Results indicate that the intraperitoneal injection of a soluble diet significantly increased the lag time for swelling in every group given the injection in comparison with uninjected controls. The effect of radiation that tends to decrease the lag time is reversed by the dominant effect of the injection. In the assay for respiratory control, either whole-body irradiation or injection of a soluble diet significantly increased the respiratory control values above those for untreated controls. The significant effects were consistently observed in all treated groups. A direct and injurious effect of irradiation was not found in rat liver mitochondria. Author