Valtonen M, Eriksson L
Acta Physiol Scand. 1977 Jul;100(3):340-6. doi: 10.1111/j.1748-1716.1977.tb05959.x.
Two female reindeer were hydrated by administration of (10% of b.wt.) water into the rumen. The diuretic response was very fast and strong but the urea and electrolyte excretion were little affected. Dehydration was carried out by not giving the reindeer water for 48 h. This water deprivation caused a loss of up to 20% of their body weight. The urine osmolality did not exceed 840 mosm/kg H2O, although the plasma osmolality rose from 300 to 346 and 368 mosm/kg H2O respectively. The plasma and urine urea concentrations were elevated during dehydration, while the urine urea excretion did not increase. Urine sodium concentration did not increase. When the urine flow rate, after two days of water deprivation, decreased to half of the original, the urine Na+ concentrations, instead of increasing, went down to half of the original. So did the potassium excretion. When ADH was injected intravenously into hydrated animals a dose of 30 mU of ADH was needed to induce antidiuresis or increased excretion of potassium. The resistance to ADH and the low relative thickness of the medulla confirm the limited capacity of reindeer kidney to concentrate urine or to excrete a solute load. On the other hand, reindeer is able rapidly to excrete surplus water without affecting the electrolyte or nitrogen balance.
给两只雌性驯鹿通过瘤胃注入（体重的10%）水进行补液。利尿反应非常迅速且强烈，但尿素和电解质排泄受影响较小。通过48小时不给驯鹿供水来造成脱水。这种缺水导致它们体重减轻高达20%。尽管血浆渗透压分别从300升高到346和368 mosm/kg H₂O，但尿渗透压未超过840 mosm/kg H₂O。脱水期间血浆和尿尿素浓度升高，而尿尿素排泄并未增加。尿钠浓度也未增加。缺水两天后，当尿流率降至原来的一半时，尿Na⁺浓度非但没有增加，反而降至原来的一半。钾排泄情况也是如此。给补液后的动物静脉注射抗利尿激素（ADH）时，需要30 mU的ADH剂量才能诱导抗利尿或增加钾排泄。对ADH的抵抗以及髓质相对较薄表明驯鹿肾脏浓缩尿液或排泄溶质负荷的能力有限。另一方面，驯鹿能够迅速排出多余水分而不影响电解质或氮平衡。
