title: Effects of high altitude and water deprivation on arginine vasopressin release in men.
abstract: High-altitude exposure changes the distribution of body water and electrolytes. Arginine vasopressin (AVP) may influence these alterations. The purpose of this study was to examine the effect of a 24-h water deprivation trial (WDT) on AVP release after differing altitude exposures. Seven healthy males (age 22 +/- 1 yr, height 176 +/- 2 cm, mass 75.3 +/- 1.8 kg) completed three WDTs: at sea level (SL), after acute altitude exposure (2 days) to 4,300 m (AA), and after prolonged altitude exposure (20 days) to 4,300 m (PA). Body mass, standing and supine blood pressures, plasma osmolality (Posm), and plasma AVP (PAVP) were measured at 0, 12, 16, and 24 h of each WDT. Urine volume was measured at each void throughout testing. Baseline Posm increased from SL to altitude (SL 291.7 +/- 0.8 mosmol/kgH2O, AA 299.6 +/- 2.2 mosmol/kgH2O, PA 302.3 +/- 1.5 mosmol/kgH2O, P < 0.05); however, baseline PAVP measurements were similar. Despite similar Posm values, the maximal PAVP response during the WDT (at 16 h) was greater at altitude than at SL (SL 1.7 +/- 0.5 pg/ml, AA 6.4 +/- 0.7 pg/ml, PA 8.7 +/- 0.9 pg/ml, P < 0.05). In conclusion, hypoxia appeared to alter AVP regulation by raising the osmotic threshold and increasing AVP responsiveness above that threshold.
authors.affiliation: Department of Kinesiology, Human Performance Laboratory, University of Connecticut, 2095 Hillside Road, U-1110, Storrs, CT 06269-1110, USA. carl.maresh@uconn.edu
authors.forename: C M
authors.initials: CM
authors.lastname: Maresh
authors.forename: W J
authors.initials: WJ
authors.lastname: Kraemer
authors.forename: D A
authors.initials: DA
authors.lastname: Judelson
authors.forename: J L
authors.initials: JL
authors.lastname: VanHeest
authors.forename: L
authors.initials: L
authors.lastname: Trad
authors.forename: J M
authors.initials: JM
authors.lastname: Kulikowich
authors.forename: K L
authors.initials: KL
authors.lastname: Goetz
authors.forename: A
authors.initials: A
authors.lastname: Cymerman
authors.forename: A J
authors.initials: AJ
authors.lastname: Hamilton
mesh_terms: D000328:Adult; D000531:Altitude; D001127:Arginine Vasopressin / Q000097:blood*; D006801:Humans; D008297:Male; D009994:Osmolar Concentration; D014868:Water Deprivation / Q000502:physiology*; D014882:Water-Electrolyte Balance / Q000502:physiology*
chemical_list: D001127:Arginine Vasopressin