Vasopressin response to osmotic stimulation in 18 young dogs with polyuria and polydipsia.

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 role of vasopressin in dogs with polyuria].

Polyuria and polydipsia (PUPD) occur frequently in dogs and may be caused by a variety of endocrine, metabolic, and renal disturbances. The studies described in this PhD Thesis, which was defended in January 2004 in Utrecht, investigated the role of the antidiuretic hormone vasopressin (VP) in the pathogenesis of different forms of canine polyuria. Experiments in healthy dogs demonstrated that the ranges of urine specific gravity and urine osmolality are much larger than previously thought.

Urinary aquaporin-2 excretion in dogs: a marker for collecting duct responsiveness to vasopressin.

In humans, the urinary aquaporin-2 (U-AQP2) excretion closely parallels changes in vasopressin (VP) action and has been proposed as a marker for collecting duct responsiveness to VP. This report describes the development of a radioimmunoassay for the measurement of U-AQP2 excretion in dogs. In addition, the localization of AQP2 in the canine kidney was investigated by immunohistochemistry.

Pulsatile secretion pattern of vasopressin under basal conditions, after water deprivation, and during osmotic stimulation in dogs.

Measurement of plasma osmolality (Posm) and plasma vasopressin (VP) concentration in response to hypertonicity is regarded as the gold standard for the assessment of VP release in polyuric conditions. Yet the interpretation of the VP curve as a function of Posm may be hampered by the occurrence of VP pulses. To determine whether VP is secreted in a pulsatile fashion in the dog and whether stimulation of VP release changes the secretion pattern of VP, we measured VP at 2-min intervals for 2 h under basal conditions, after 12 h of water deprivation, and during osmotic stimulation with hypertonic saline (20%) in eight healthy dogs.

Vasopressin secretion in response to osmotic stimulation and effects of desmopressin on urinary concentrating capacity in dogs with pyometra.

Objective: To determine vasopressin (VP) secretory capacity during osmotic stimulation and the response to desmopressin treatment in dogs with pyometra and control dogs.

Animals: 6 dogs with pyometra before and after ovariohysterectomy and 6 control dogs.

Procedure: Urine osmolality (Uosm) was measured during 12 hours.