INFLUENCE OF TEMPERATURE ON THE STIMULATION OF OXYGEN CONSUMPTION OF ISOLATED BRAIN AND KIDNEY BY 2-4 DINITROPHENOL

¹ From the Department of Physiology, Stanford University, California

The intensity of the acceleration of oxygen consumption of excised rat cerebral cortex and kidney cortex by a given concentration of DNP (3.35 x 10^–5 M) varies with temperature. The maximum percentage increase in respiration occurred at 32°C. in cerebral cortex and at 22°C. in kidney cortex. These observations support the hypothesis of Hall (4) that abolition of the cold defense reactions in hypothermic cats by DNP is consequent upon a relative increase in the metabolism of the temperature regulating centers with accompanying decrease in the sensitivity of these centers to the effects of cold stimuli.

Values of the temperature coefficient, Q₁₀, for the respiration of excised cerebral and kidney cortex were calculated for small intervals over the range 10° to 42°C. For both tissues there was a progressive decrease in Q₁₀ from 10° to 30°C., followed by a definite rise in the range 30° to 35°C., with diminution on further rise in temperature.