Browse by author
Lookup NU author(s): Dianne Smith, Professor Peter Baylis
Full text for this publication is not currently held within this repository. Alternative links are provided below where available.
The syndrome of inappropriate antidiuretic hormone (SIADH) is characterized by euvolemic hyponatremia. Patients with SIADH continue to drink normal amounts of fluid, despite plasma osmolalities well below the physiological osmotic threshold for onset of thirst. The regulation of thirst has not been previously studied in SIADH. We studied the characteristics of osmotically stimulated thirst and arginine vasopressin (AVP) secretion in eight subjects with SIADH and eight healthy controls and the nonosmotic suppression of thirst and AVP during drinking in the same subjects. Subjects underwent a 2-h infusion of hypertonic ( 855 mmol/l) NaCl solution, followed by 30 min of free access to water. Thirst rose significantly in both SIADH (1.5 +/- 0.6 to 8.0 +/- 1.2 cm, P < 0.0001) and controls (1.8 +/- 0.8 to 8.4 +/- 1.5 cm, P < 0.0001), but the osmotic threshold for thirst was lower in SIADH ( 264 +/- 5.5 vs. 285.9 +/- 2.8 mosmol/ kgH(2)O, P < 0.0001). SIADH subjects drank volumes of water similar to controls after cessation of the infusion (948.8 +/- 207.6 vs. 1,091 +/- 184 ml, P = 0.23). The act of drinking suppressed thirst in both SIADH and controls but did not suppress plasma AVP concentrations in SIADH compared with controls ( P = 0.007). We conclude that there is downward resetting of the osmotic threshold for thirst in SIADH but that thirst responds to osmotic stimulation and is suppressed by drinking around the lowered set point. In addition, we demonstrated that drinking does not completely suppress plasma AVP in SIADH.
Author(s): Smith D, Moore K, Tormey W, Baylis PH, Thompson CJ
Publication type: Article
Publication status: Published
Journal: American Journal of Physiology: Endocrinology and Metabolism
Year: 2004
Volume: 287
Issue: 5
Pages: E1019-E1023
ISSN (print): 0193-1849
ISSN (electronic): 1522-1555
Publisher: American Physiological Society
URL: http://dx.doi.org/10.1152/ajpendo.00033.2004
DOI: 10.1152/ajpendo.00033.2004
Altmetrics provided by Altmetric
