Datensatz

Zusammenfassung

1. The isolated perfused rat liver was poisoned with phalloidin at different pH values. The pH of the perfusion medium was shifted from 7.5 to 7.1 by change of [HCO3−] from 50 mM to 10 mM and from 7.5 to 6.6 by change of the pCO2 from about 40 mm Hg to about 500 mm Hg. Transmembrane water shifts were monitored as changes in the dextran concentration of the perfusion medium measured polarimetrically. Potassium shifts were calculated from the changes of the potassium concentration of the perfusion medium. 2. The potassium loss of the liver 240 min after poisoning was reduced to about 75% at pH 7.1 and to about 50% at pH 6.6 compared with experiments at pH 7.5. 3. A change in pH of the perfusion medium from 7.5 to 6.6 120 min after poisoning led to an uptake of 38±10% of the potassium previously released, and to water uptake. 4. At low pH phalloidin induced a strong transmembrane water uptake in the isolated perfused rat liver, which was higher at high perfusion pressure. A change in pH from 6.6 to 7.5 150 min after poisoning led to a complete release of the water previously taken up, and to potassium release.