title: Creatinine, urea, uric acid, water and electrolytes renal handling in the healthy oldest old.
abstract: RENAL PHYSIOLOGY IN THE HEALTHY OLDEST OLD HAS THE FOLLOWING CHARACTERISTICS, IN COMPARISON WITH THE RENAL PHYSIOLOGY IN THE YOUNG: a reduced creatinine clearance, tubular pattern of creatinine back-filtration, preserved proximal tubule sodium reabsorption and uric acid secretion, reduced sodium reabsorption in the thick ascending loop of Henle, reduced free water clearance, increased urea excretion, presence of medulla hypotonicity, reduced urinary dilution and concentration capabilities, and finally a reduced collecting tubules response to furosemide which expresses a reduced potassium excretion in this segment due to a sort of aldosterone resistance. All physiological changes of the aged kidney are the same in both genders.
authors.affiliation: Carlos Guido Musso, José Ricardo Jauregui, Ageing Biology Unit, Hospital Italiano of Buenos Aires, Gascón 450, Argentina.
authors.forename: Carlos Guido
authors.initials: CG
authors.lastname: Musso
authors.forename: Joaquín
authors.initials: J
authors.lastname: Alvarez Gregori
authors.forename: José Ricardo
authors.initials: JR
authors.lastname: Jauregui
authors.forename: Juan Florencio
authors.initials: JF
authors.lastname: Macías Núñez
keywords: Ageing; Creatinine; Electrolytes; Oldest old; Renal; Urea; Uric acid; Water