Rabinowitz L, Denham S C, Gunther R A
Am J Physiol. 1977 Sep;233(3):F213-6. doi: 10.1152/ajprenal.1977.233.3.F213.
When sheep rapidly eat a meal of dry feed a period of antinatriuresis and antidiuresis is rapidly initiated and lasts for 2-3 hrs. This is followed by a postprandial period of natriuresis and diuresis. This study tested the hypothesis that the postprandial natriuresis was due to a reduction in the secretion of aldosterone. In unanesthetized ewes of about 50 kg body wt, measurements were made of sodium and potassium excretion beginning in the terminal phase of the feed-induced antinatriuresis and continuing through the period of postprandial natriuresis. Aldosterone, given by constant infusion at a physiological dose (10 microgram/h), inhibited the natriuresis. Spironolactone, a competitive inhibitor of aldosterone given as a single intravenous injection of 5 mg/kg body wt, did not significantly increase the natriuresis. These results support the stated hypothesis. Neither aldosterone nor spironolactone had a significant effect on potassium excretion. This finding supports earlier view that aldosterone has only a small role in the homeostatic control of potassium excretion in sheep.
当绵羊快速进食一顿干饲料后，会迅速开始一段抗利尿钠排泄和抗利尿期，持续2至3小时。随后是餐后利尿钠排泄和利尿期。本研究检验了餐后利尿钠排泄是由于醛固酮分泌减少这一假设。在体重约50千克的未麻醉母羊中，从饲料诱导的抗利尿钠排泄末期开始，持续至餐后利尿钠排泄期，测量钠和钾的排泄量。以生理剂量（10微克/小时）持续输注醛固酮可抑制利尿钠排泄。螺内酯，一种醛固酮竞争性抑制剂，以5毫克/千克体重单次静脉注射，并未显著增加利尿钠排泄。这些结果支持了上述假设。醛固酮和螺内酯对钾排泄均无显著影响。这一发现支持了早期观点，即醛固酮在绵羊钾排泄的稳态控制中仅起很小的作用。
