Electrolyte Metabolism of Isolated Frog Skin

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 minlmal ANa/AO2 values by correlating quantitatively inhibition of active ion transport with inhibition of O2 consumption. NaC1 transport was maximal at 20°C. At 28 ° and at temperatures below 20 °, rate of NaCI transport was diminished. In many instances NaCI transport was diminished in skinq 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 Qo2 against 1/T an activation energy of # = 13,700 cal. was calculated, valid for the range from 10 to 20°C. I t appeared that # was smaller for temperatures above 20°C. Working between l0 and 20 °, it was found that, on the average, 4 to 5 equivalents of Na + were transported for one m01e of O2 consumed in skins with undisturbed resting electrolyte equilibrium.