AJP - Regulatory, Integrative and Comparative Physiology, Vol 251, Issue 2 214-R217, Copyright © 1986 by American Physiological Society

ARTICLES

Oral hypertonic saline causes transient fall of vasopressin in humans

J. R. Seckl, T. D. Williams and S. L. Lightman

After dehydration, oral rehydration causes a fall in plasma arginine vasopressin (AVP) that precedes changes in plasma osmolality. To investigate further the stimulus for this effect, its specificity, and association with thirst, six volunteers were deprived of water for 24 h and given a salt load on two separate occasions. On each study day they then drank rapidly 10 ml/kg of either tap water or hypertonic saline (360 mosmol/kg). There was a significant fall in plasma AVP from 2.0 +/- 0.3 to 1.2 +/- 0.4 pmol/l (P less than 0.05) 5 min after drinking water and from 1.8 +/- 0.3 to 0.9 +/- 0.2 pmol/l (P less than 0.05) after hypertonic saline. Plasma osmolality fell 30-60 min after water and was unchanged after saline. Plasma renin activity, oxytocin, and total protein all remained unchanged. All subjects reported diminished thirst after hypertonic saline. Gargling with water reduced thirst but did not affect plasma AVP. There appears to be a drinking-mediated neuroendocrine reflex that decreases plasma AVP irrespective of the osmolality of the liquid consumed. The sensation of thirst did not correlate with plasma osmolality and was not always related to plasma AVP concentration.

This article has been cited by other articles:

				R. W. Kenefick, C. M. Maresh, L. E. Armstrong, D. Riebe, M. E. Echegaray, and J. W. Castellani Rehydration with fluid of varying tonicities: effects on fluid regulatory hormones and exercise performance in the heat J Appl Physiol, May 1, 2007; 102(5): 1899 - 1905. [Abstract] [Full Text] [PDF]

				M. L. Hoffmann, M. DenBleyker, J. C. Smith, and E. M. Stricker Inhibition of thirst when dehydrated rats drink water or saline Am J Physiol Regulatory Integrative Comp Physiol, May 1, 2006; 290(5): R1199 - R1207. [Abstract] [Full Text] [PDF]

				D. Smith, K. Moore, W. Tormey, P. H. Baylis, and C. J. Thompson Downward resetting of the osmotic threshold for thirst in patients with SIADH Am J Physiol Endocrinol Metab, November 1, 2004; 287(5): E1019 - E1023. [Abstract] [Full Text] [PDF]

				H. Nonoguchi, T. Inoue, T. Mori, Y. Nakayama, Y. Kohda, K. Tomita, H. Amlal, S. Sheriff, and M. Soleimani Regulation of aquaporin-2 by metabolic acidosis Am J Physiol Cell Physiol, September 1, 2004; 287(3): C814 - C815. [Full Text] [PDF]

				E. M. Stricker, J. B. Callahan, W. Huang, and A. F. Sved Early osmoregulatory stimulation of neurohypophyseal hormone secretion and thirst after gastric NaCl loads Am J Physiol Regulatory Integrative Comp Physiol, June 1, 2002; 282(6): R1710 - R1717. [Abstract] [Full Text] [PDF]

				R. W. Kenefick, C. M. Maresh, L. E. Armstrong, J. W. Castellani, D. Riebe, M. E. Echegaray, and S. A. Kavorous Plasma vasopressin and aldosterone responses to oral and intravenous saline rehydration J Appl Physiol, December 1, 2000; 89(6): 2117 - 2122. [Abstract] [Full Text] [PDF]