van Vonderen Ilse K, Kooistra Hans S, Timmermans-Sprang Elpetra P M, Meij Björn P, Rijnberk Ad
Department of Clinical Sciences of Companion Animals, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands.
J Vet Intern Med. 2004 Nov-Dec;18(6):800-6. doi: 10.1892/0891-6640(2004)18<800:vrtosi>2.0.co;2.
Common disorders of water homeostasis leading to polyuria include a variety of endocrine, metabolic, and renal disturbances. After exclusion of most of these conditions, the diagnostic dilemma of differentiating between central diabetes insipidus, primary polydipsia, and nephrogenic diabetes insipidus may remain. Here, we report on 18 young dogs with polyuria that had been present in most cases since the dogs were puppies. The conditions were categorized according to the plasma vasopressin (VP) response to hypertonicity. The VP response to osmotic stimulation was tested by IV infusion of 20% NaCl for 2 hours. The VP response in all dogs was abnormal. Three categories could be distinguished: an exaggerated response (n = 3), a subnormal response (n = 4), and a nonlinear response with high plasma VP concentrations unrelated to increases in plasma osmolality (n = 11). The VP response to hypertonicity did not consistently distinguish among different clinical entities. In the 9 dogs with variations in urine osmolality compatible with primary polydipsia, exaggerated, subnormal, and nonlinear responses were observed. Examination of the present data questions the generally accepted notion that VP measurements during hypertonic saline infusion are the "gold standard" for the diagnostic interpretation of causes of polydipsia and polyuria. Studies of the peripheral reflection in plasma of the pulsatile VP release in healthy and polyuric individuals, with and without osmotic provocation, should be performed.
导致多尿的常见水平衡紊乱包括多种内分泌、代谢和肾脏疾病。在排除大多数这些情况后，区分中枢性尿崩症、原发性烦渴和肾性尿崩症的诊断难题可能仍然存在。在此，我们报告了18只患有多尿的幼犬，大多数情况下这种症状自幼犬时期就已出现。根据血浆血管加压素（VP）对高渗状态的反应对这些情况进行分类。通过静脉输注20%氯化钠2小时来测试VP对渗透刺激的反应。所有犬的VP反应均异常。可区分出三类：反应过度（n = 3）、反应低下（n = 4）以及血浆VP浓度高且与血浆渗透压升高无关的非线性反应（n = 11）。VP对高渗状态的反应并不能始终区分不同的临床实体。在9只尿渗透压变化符合原发性烦渴的犬中，观察到了反应过度、反应低下和非线性反应。对现有数据的研究对普遍接受的观点提出了质疑，即高渗盐水输注期间的VP测量是多饮多尿病因诊断性解释的“金标准”。应该对健康个体和多尿个体在有或无渗透刺激情况下血浆中脉动性VP释放的外周反射进行研究。
