Effect of 1–2–4 Dinitrophenol on Oxygen Uptake of Rat Tissue

Abstract

Since Cutting and Tainter 1 and Magne, Mayer and Plantefol 2 have observed that small quantities of dinitrophenol cause a marked acceleration of the metabolism of animals, it seemed desirable to determine whether this drug accelerates the oxygen uptake of excised tissue.

The experiments here reported are a continuation of those given in a previous preliminary report. 3 The preparation of the rat tissue slices and the measurement of the oxygen uptake was done as previously described, 4 the tissue being suspended in glucose phosphate (pH 7.4) Ringer's solution. Four Warburg vessels were employed in each instance, 2 serving for the control observations. The following experiments were performed. The oxygen uptake of rat liver, kidney and muscle tissue obtained from rats previously injected with dinitrophenol was determined when the tissue was suspended in normal Ringer's solution. Three or more animals were employed in each case. The oxygen uptake of rat liver and kidney tissue obtained from normal animals was also determined when suspended in Ringer's solution containing the drug. In these experiments 2 or more animals were employed for each concentration of the drug. The oxygen uptake of normal rat liver was determined in 5 separate experiments when suspended in normal dog serum and serum from dogs previously injected with dinitrophenol. The response of the rat liver and kidney tissue in the presence of the drug was likewise compared with that obtained employing frog liver and kidney tissue.

The oxygen uptake of rat liver, kidney and muscle obtained from rats previously injected with dinitrophenol did not show an increased oxygen uptake when compared with tissue obtained from control uninjected rats. As a matter of fact, if anything, a slightly decreased rate of oxygen uptake was noted when the tissue from the treated animals was employed. Normal rat liver when suspended in Ringer's solution containing dinitrophenol (dinitrophenol, sodium salt was employed in the following concentrations: 0.005, 0.01, 0.05, 0.1, 0.5 and 1.0 mg. per 100 cc.) showed a questionable increase in the rate of the oxygen uptake in concentrations of the drug of 0.01, 0.05 and 0.1 mg. per 100 cc. (average maximum of 15% obtained with 0.01 mg. per 100 cc.).