Seasonal differences in drug- and temperature-dependent changes of the sodium transport across the isolated frog skin.
In two series of experiments, one conducted in the spring (May-June) and the other in the fall (September-November), the influence of raising temperature of the medium and of vasopressin, insulin and ethacrynic acid on polarized sodium transport in the epithelium of frog skin in vitro was studied. Net sodium transport was determined electrometrically, and active and passive components of transport by the isotope method. Raising temperature markedly increased both components, as well as net flux and electric potential of the membrane in the spring months, but not in the fall. Regardless of the character and extent of the effect on transport, raising temperature of the medium had no qualitative or quantitative influence on the action of vasopressin, insulin or ethacrynic acid.
D000818:Animals; D001692:Biological Transport / Q000187:drug effects; D004848:Epithelium / Q000378:metabolism; D004976:Ethacrynic Acid / Q000494:pharmacology*; D007328:Insulin / Q000494:pharmacology*; D008564:Membrane Potentials / Q000187:drug effects; D011896:Rana temporaria; D012621:Seasons; D012867:Skin / Q000378:metabolism*; D012964:Sodium / Q000378:metabolism*; D013696:Temperature; D014667:Vasopressins / Q000494:pharmacology*
D007328:Insulin; D014667:Vasopressins; D012964:Sodium; D004976:Ethacrynic Acid