Sodium, potassium, chloride, and water in frog gastric mucosa
Davenport, H.W.; Alzamora, F.
American Journal of Physiology 202: 711-715
In fresh mucosas Na is 45-52, K 52-60, and Cl 39-41 mEq/kg. In mucosas incubated 4 hr at 25 C in salt solution, equilibrium volume of radioiodinated serum albumin (RISA) is 231 [plus or minus] 7 ml/kg. Other volumes are inulin 383 [plus or minus] 14, mannitol 515 [plus or minus] 22, arabinose 550 [plus or minus] 22. During incubation with or without 0.1 mM histamine, mucosal Na remains constant at 72 [plus or minus] 2, K rises from 51 [plus or minus] 1 to 63 [plus or minus] 1, and Cl falls from 50 [plus or minus] 3 to 32 [plus or minus] 4 mEq/kg. With 0.1 mM 2,4-dinitrophenol, Na and Cl rise while K falls. When [Na]o is constant, mucosal Na remains constant, but K and Cl are direct linear functions of [K]o and [Cl]o. When [K]o replaces [Na]0 mole for mole, mucosal Na falls and K rises. Mucosas stripped of surface epithelial cells have the following volumes: RISA 336 [plus or minus] 13, inulin 500 [plus or minus] 23, arabinose 629 [plus or minus] 38 ml/kg. On incubation Na and K are approximately constant but Cl falls.