EFFECT OF TEMPERATURE ON ELECTROLYTE METABOLISM OF ISOLATED FROG SKIN

Abstract

A study is presented on the effect of temperature on unidirectional active ion transport, resting electrolyte equilibrium (electrolyte composition), and oxygen consumption in isolated frog skin. The aims were twofold: first, to find out whether the rate of active transport can be changed without affecting the Na+ and K+ balance of skin itself; second, to arrive at minimal ΔNa/ΔO2 values by correlating quantitatively inhibition of active ion transport with inhibition of O2 consumption. NaCl transport was maximal at 20°C. At 28° and at temperatures below 20°, rate of NaCl transport was diminished. In many instances NaCl transport was diminished in skins which maintained their normal Na+ and K+ content. In several cases, however, neither rate of transport nor resting electrolyte equilibrium was affected; in other cases, both were. O2 consumption decreased when lowering the temperature over the range from 28 to 10°C. From a plot of log QOO2 against 1/T an activation energy of µ 13,700 cal. was calculated, valid for the range from 10 to 20°C. It appeared that µ was smaller for temperatures above 20°C. Working between 10 and 20°, it was found that, on the average, 4 to 5 equivalents of Na+ were transported for one mole of O2 consumed in skins with undisturbed resting electrolyte equilibrium.