Frommer J P, Ayus J C
Miner Electrolyte Metab. 1985;11(2):91-6.
Spontaneous variations in urinary flow and electrolyte excretion are well known to occur both in man and in the non-human primate. Data on these spontaneous variations is scarce in the dog, an animal which is widely used in physiological investigations. Our study was designed to characterize the spontaneous pattern of renal hemodynamics, urine flow and electrolyte excretion in the awake dog both under conditions of minimal surgical stress (group I), and after routine preparatory surgery (group II). Our results show significant spontaneous variation for urine flow and urinary excretion of Na, K, Cl, HCO3, Ca, PO4 and Mg for both groups of dogs. Urinary excretion of Na, K, PO4 and Mg was significantly higher for group II than for group I (p less than 0.05). Glomerular filtration rate and effective renal plasma flow (estimated from the clearance of p-aminohippurate) were measured in group II and showed no spontaneous variation. Our study shows that there is diurnal urinary electrolyte excretion variation in the dog which is exaggerated by small changes in the experimental protocol. These variations need to be considered when evaluating experimental maneuvers that induce changes in the renal handling of electrolytes in the dog.
众所周知，人类和非人类灵长类动物的尿流和电解质排泄都会出现自发变化。在生理研究中广泛使用的犬类动物，关于这些自发变化的数据却很稀少。我们的研究旨在描述清醒犬在最小手术应激条件下（第一组）和常规预备手术后（第二组）的肾脏血流动力学、尿流和电解质排泄的自发模式。我们的结果显示，两组犬的尿流以及钠、钾、氯、碳酸氢根、钙、磷酸根和镁的尿排泄均存在显著的自发变化。第二组犬的钠、钾、磷酸根和镁的尿排泄显著高于第一组（p小于0.05）。在第二组中测量了肾小球滤过率和有效肾血浆流量（根据对氨基马尿酸清除率估算），未显示出自发变化。我们的研究表明，犬存在昼夜尿电解质排泄变化，实验方案的微小变化会使其加剧。在评估诱导犬电解质肾脏处理变化的实验操作时，需要考虑这些变化。
