[Participation of Na, K-ATPase in the mechanism of isotonic fluid absorption by the epithelium of the frog gallbladder].

In experiments on the isolated frog gallbladders it was shown that addition of ouabain (1.10(-4) M) or noradrenaline 3.10(-6) M) into the incubation Ringer solution from the serous surface of the gallbladder and also replacement of K+ in the solution for the equivalent quantity of Na+ ions caused a reduction of the absorption of isotonic fluid by the epithelium and a fall of the Na,K-ATPase activity in its cells. Noradrenaline also cased a reduction of Mg-ATPase activity. A significant positive correlation was found between the transport rate of the isotonic fluid by the epithelium and the Na,K-ATPase activity in its cells.