Department of Pathology, School of Medicine, University of California San Diego, 9500 Gilman Drive, Mail Code 0679, La Jolla, CA 92093, USA.
J Comp Physiol B. 2010 Apr;180(4):563-76. doi: 10.1007/s00360-009-0439-0. Epub 2010 Jan 1.
Bottlenose dolphins (Tursiops truncatus) are marine mammals with body water needs challenged by little access to fresh water and constant exposure to salt water. Osmoregulation has been studied in marine mammals for a century. Research assessing the effects of ingested fresh water or seawater in dolphins, however, has been limited to few animals and sampling times. Nine 16- to 25-h studies were conducted on eight adult dolphins to assess the hourly impact of fresh water, seawater, and seawater with protein ingestion on plasma and urine osmolality, urine flow rate (ufr), urinary and plasma solute concentrations, and solute clearance rates. Fresh water ingestion increased ufr. Fresh water ingestion also decreased plasma and urine osmolality, sodium and chloride urine concentrations, and solute excretion rates. Seawater ingestion resulted in increased ufr, sodium, chloride, and potassium urine concentrations, sodium excretion rates, and urine osmolality. Seawater with protein ingestion was associated with increased ufr, plasma osmolality, sodium excretion, and sodium, chloride, potassium, and urea urine concentrations. In conclusion, bottlenose dolphins appear to maintain water and plasma solute balance after ingesting fresh water or seawater by altering urine osmolality and solute clearance. Ingestion of protein with seawater appears to further push osmoregulation limits and urine solute concentrations in dolphins.
宽吻海豚（Tursiops truncatus）是一种海洋哺乳动物，由于很少有机会接触淡水，并且经常暴露在海水中，因此其身体对水分的需求受到挑战。海洋哺乳动物的渗透调节作用已经研究了一个世纪。然而，评估海豚摄入淡水或海水的影响的研究仅限于少数动物和采样时间。对 8 只成年海豚进行了 9 项 16-25 小时的研究，以评估淡水、海水和海水加蛋白质摄入对血浆和尿液渗透压、尿流率（ufr）、尿和血浆溶质浓度以及溶质清除率的每小时影响。摄入淡水会增加 ufr。淡水摄入还会降低血浆和尿液渗透压、钠和氯尿浓度以及溶质排泄率。摄入海水会导致 ufr、钠、氯和钾尿浓度、钠排泄率以及尿液渗透压增加。摄入含蛋白质的海水与 ufr、血浆渗透压、钠排泄以及钠、氯、钾和尿素尿浓度增加有关。总之，宽吻海豚在摄入淡水或海水后似乎通过改变尿液渗透压和溶质清除率来维持水和血浆溶质平衡。摄入含蛋白质的海水似乎进一步推动了海豚的渗透调节极限和尿液溶质浓度。
