This Article Full Text Full Text (PDF) Submit a related Letter to the Editor Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Copyright Permission Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Saito, T. Articles by Saito, T. Search for Related Content PubMed PubMed Citation Articles by Saito, T. Articles by Saito, T.

Urinary Excretion of Aquaporin-2 in the Diagnosis of Central Diabetes Insipidus¹

Division of Endocrinology and Metabolism (Ta.S., S.I., T.N., K.R., A.K. K.H., To.S.), Department of Medicine, Jichi Medical School, Tochigi 329–04; and Second Department of Internal Medicine (S.S., F.M.), Tokyo Medical and Dental University, Tokyo 113, Japan

Address all correspondence and requests for reprints to: San-e Ishikawa, M.D., Division of Endocrinology and Metabolism, Department of Medicine, Jichi Medical School, 3311–1 Yakushiji Minamikawachi-machi, Tochigi, 329–04, Japan. E-mail: saneiskw{at}jichi.ac.jp

We determined whether alteration in urinary excretion of aquaporin-2 (UAQP-2) is of value to diagnose central diabetes insipidus (CDI). First, UAQP-2 was determined in 16 normal subjects under ad libitum water drinking (n = 6) and after an overnight dehydration (n = 10). UAQP-2 has a positive correlation with plasma arginine vasopressin (AVP) levels (r = 0.61, P < 0.05) but not with urinary osmolality (Uosm). Second, a hypertonic saline (5% NaCl)-infusion test was studied in 5 normal subjects (21 to 25 yr old) and 10 patients with CDI (22–68 yr). After drinking water ad libitum, they were given 20 mL/kg water orally and then given 5% NaCl (0.05 mL/kg·min) iv for 120 min. Finally, 0.1 U of AVP was administered iv. During the period, 30-min urine collections were made. In the normal subjects, after the infusion of 5% NaCl, plasma AVP levels and Uosm markedly increased in parallel with an increase in plasma osmolality (Posm, 294–320 mOsm/kg H₂O; Uosm, 102–737 mOsm/kg H₂O; AVP, 0.4–2.6 pg/mL, P < 0.001). In the CDI patients, plasma AVP and Uosm failed to increase, despite an increase in Posm (Posm, 306–332; Uosm, 102–164; AVP, 0.9–1.2). UAQP-2 was markedly greater in the normal subjects than the CDI patients (7.2 vs. 0.9 pmol/L/mg creatinine, P < 0.05) under water intake ad libitum. UAQP-2 was changeable in the wide range in physiological condition. After the 5%-NaCl infusion, UAQP-2 elevated to 12.5 from 0.9 pmol/L·mg creatinine in the normal subjects. In contrast, UAQP-2 remained low during the 5%-NaCl infusion in the CDI patients. Exogenous AVP promptly increased UAQP-2 to a similar extent in two groups of the normal subjects and the CDI patients. These results indicate that measurement of UAQP-2 is of value to diagnose CDI in the 5%-NaCl infusion test.

This article has been cited by other articles:

				L. Murer, F. Addabbo, M. Carmosino, G. Procino, G. Tamma, G. Montini, W. Rigamonti, P. Zucchetta, M. Della Vella, A. Venturini, et al. Selective Decrease in Urinary Aquaporin 2 and Increase in Prostaglandin E2 Excretion Is Associated with Postobstructive Polyuria in Human Congenital Hydronephrosis J. Am. Soc. Nephrol., October 1, 2004; 15(10): 2705 - 2712. [Abstract] [Full Text] [PDF]

				P Ivarsen, J Frokiaer, N K Aagaard, E F Hansen, F Bendtsen, S Nielsen, and H Vilstrup Increased urinary excretion of aquaporin 2 in patients with liver cirrhosis Gut, August 1, 2003; 52(8): 1194 - 1199. [Abstract] [Full Text] [PDF]

				G. Valenti, A. Laera, S. Gouraud, G. Pace, G. Aceto, R. Penza, F. P. Selvaggi, and M. Svelto Low-calcium diet in hypercalciuric enuretic children restores AQP2 excretion and improves clinical symptoms Am J Physiol Renal Physiol, November 1, 2002; 283(5): F895 - F903. [Abstract] [Full Text] [PDF]

				S.-e Ishikawa, T. Saito, A. Fukagawa, M. Higashiyama, T. Nakamura, I. Kusaka, S. Nagasaka, K. Honda, and T. Saito Close Association of Urinary Excretion of Aquaporin-2 with Appropriate and Inappropriate Arginine Vasopressin-Dependent Antidiuresis in Hyponatremia in Elderly Subjects J. Clin. Endocrinol. Metab., April 1, 2001; 86(4): 1665 - 1671. [Abstract] [Full Text]

				J. A. McKEE, S. KUMAR, C. A. ECELBARGER, P. FERNÁNDEZ-LLAMA, J. TERRIS, and M. A. KNEPPER Detection of Na+ Transporter Proteins in Urine J. Am. Soc. Nephrol., November 1, 2000; 11(11): 2128 - 2132. [Abstract] [Full Text]

				T. Saito, S.-E Ishikawa, F. Ando, M. Higashiyama, S. Nagasaka, S. Sasaki, and T. Saito Vasopressin-dependent upregulation of aquaporin-2 gene expression in glucocorticoid-deficient rats Am J Physiol Renal Physiol, September 1, 2000; 279(3): F502 - F508. [Abstract] [Full Text] [PDF]

				R. Baumgarten, M. H. J. van de Pol, P. M. T. Deen, C. H. van Os, and J. F. M. Wetzels Dissociation between urine osmolality and urinary excretion of aquaporin-2 in healthy volunteers Nephrol. Dial. Transplant., August 1, 2000; 15(8): 1155 - 1161. [Abstract] [Full Text] [PDF]

				T. Saito, S.-E Ishikawa, S. Sasaki, M. Higashiyama, S. Nagasaka, N. Fujita, K. Fushimi, F. Marumo, and T. Saito Lack of vasopressin-independent upregulation of AQP-2 gene expression in homozygous Brattleboro rats Am J Physiol Regulatory Integrative Comp Physiol, August 1, 1999; 277(2): R427 - R433. [Abstract] [Full Text] [PDF]

				T. Saito, S.-e Ishikawa, T. Ito, H. Oda, F. Ando, M. Higashiyama, S. Nagasaka, M. Hieda, and T. Saito Urinary Excretion of Aquaporin-2 Water Channel Differentiates Psychogenic Polydipsia from Central Diabetes Insipidus J. Clin. Endocrinol. Metab., June 1, 1999; 84(6): 2235 - 2237. [Abstract] [Full Text]

				D. Marples, J. Frokiaer, and S. Nielsen Long-term regulation of aquaporins in the kidney Am J Physiol Renal Physiol, March 1, 1999; 276(3): F331 - F339. [Abstract] [Full Text] [PDF]

				T. Saito, S.-e Ishikawa, F. Ando, N. Okada, T. Nakamura, I. Kusaka, M. Higashiyama, S. Nagasaka, and T. Saito Exaggerated Urinary Excretion of Aquaporin-2 in the Pathological State of Impaired Water Excretion Dependent upon Arginine Vasopressin J. Clin. Endocrinol. Metab., November 1, 1998; 83(11): 4034 - 4040. [Abstract] [Full Text]