The effect of metal ions and antidiuretic hormone on oxygen consumption in toad bladder.
1. The sodium-dependent oxygen consumption of pieces of toad bladder (Bufo marinus) has been investigated using an oxygen electrode.2. The effect of polyvalent cations (Ca(2+), Sr(2+), Mg(2+), Eu(3+), La(3+) and Mn(2+)) on sodium-dependent oxygen consumption has been measured. All cations inhibited oxygen consumption, the order of effectiveness being Ca(2+) > Sr(2+) > Mg(2+) > Mn(2+) > Eu(3+) > La(3+).3. Treatment of bladder pieces with antidiuretic hormone (50 m-u./ml.) decreased the effectiveness of Ca(2+) and Sr(2+) as inhibitors of sodium-dependent oxygen consumption. Mn(2+), Eu(2+) and La(2+) were more effective after hormonal treatment, while the effectiveness of Mg(2+) was unaltered.4. The results have been interpreted in terms of a model in which sodium entry to the transporting mechanisms of the epithelium is controlled by Ca(2+), and in which antidiuretic hormone alters Ca(2+) binding and so affects sodium transport.
D000818:Animals; D001665:Binding Sites; D001692:Biological Transport; D002024:Bufo marinus; D002118:Calcium / Q000378:metabolism / Q000494:pharmacology; D003864:Depression, Chemical; D004848:Epithelium / Q000378:metabolism; D005063:Europium / Q000494:pharmacology; D006863:Hydrogen-Ion Concentration; D066298:In Vitro Techniques; D007811:Lanthanum / Q000494:pharmacology; D008274:Magnesium / Q000494:pharmacology; D008345:Manganese / Q000494:pharmacology; D008670:Metals / Q000494:pharmacology*; D008954:Models, Biological; D010101:Oxygen Consumption / Q000187:drug effects*; D012964:Sodium / Q000378:metabolism; D013324:Strontium / Q000494:pharmacology; D001743:Urinary Bladder / Q000187:drug effects / Q000378:metabolism*; D014667:Vasopressins / Q000494:pharmacology*
D008670:Metals; D014667:Vasopressins; D008345:Manganese; D005063:Europium; D007811:Lanthanum; D012964:Sodium; D008274:Magnesium; D002118:Calcium; D013324:Strontium