Urinary aquaporin-2 excretion during early human development
2006 (English)In: Pediatric nephrology (Berlin, West), ISSN 0931-041X, E-ISSN 1432-198X, Vol. 21, no 7, 947-952 p.Article in journal (Refereed) Published
This study was undertaken to assess one of the determinants of kidney concentrating capacity, aquaporin-2 (AQP2), in order to understand the physiopathology of water balance in newborn babies. Urinary AQP2 excretion has been shown to be proportional to AQP2 level in the apical plasma membrane of the kidney collecting ducts and has been suggested as a marker of vasopressin (AVP) action. Urinary AQP2 excretion in the early postnatal period and at 3 weeks of age was measured in 123 neonates admitted during a 6-month period to the neonatal intensive care unit of the Children's Hospital of Toulouse, France. Clinical and biochemical data were collected for each child. During the first days after birth, higher urinary AQP2 was observed in boys than in girls (P=0.01) and positively correlated with urinary sodium/potassium (Na/K) ratio (r=0.33, P=0.01). When the babies had reached 3 weeks of age, urinary AQP2 was proportional to the gestational age at birth (r=0.33, P=0.0068) and daily weight gain (r=0.36, P=0.003). It did not correlate with urinary osmolality, which was overall very low in all babies. Urinary AQP2 was decreased in conditions of impaired renal function (r=-0.42, P=0.0005) and acidosis (P=0.03). Prenatal corticosteroid treatment had no significant impact on urinary AQP2 level. Our data show that urinary AQP2 correlates with the overall maturity of tubular function in human neonates. In babies at this early age, urinary AQP2 cannot serve as a direct marker of the renal action of AVP but reflects AQP2 expression level associated with different physiopathological conditions.
Place, publisher, year, edition, pages
2006. Vol. 21, no 7, 947-952 p.
water channel, newborn, renal maturation, water balance, collecting duct
Cell Biology Physiology Pediatrics Urology and Nephrology
IdentifiersURN: urn:nbn:se:kth:diva-80463DOI: 10.1007/s00467-006-0143-1ISI: 000238293200009PubMedID: 16773405OAI: oai:DiVA.org:kth-80463DiVA: diva2:496373
QC 201203022012-02-092012-02-092012-03-02Bibliographically approved