title: Effects of endothelin-3 on water and sodium excretion during extracellular volume expansion.
abstract: The aim of the present study was to elucidate the role of an IV dose of endothelin-3 (ET-3) (5 ng Kg-1 min-1) on mean arterial pressure (MAP), on diuresis and natriuresis in control and in volume expanded anesthetized rats. A systemic infusion of ET-3 in normal rats (Group I) increased MAP and produced a trend of increasing diuresis, without changes in natriuresis. A 10% body weight expansion (Group II) increased diuresis and natriuresis without changes in MAP. The simultaneous infusion of ET-3 and expansion with saline (Group III) resulted in an increase in MAP, an enhanced diuretic response, and a natriuresis of similar magnitude to that observed in Group II. These results suggest that the diuresis produced by a low dose of exogenous ET-3 in control rats, is independent of sodium excretion. Furthermore, the enhanced diuresis caused by ET-3 during expansion is greater than the addition of ET-3 and expansion effects, suggesting that new mechanisms are triggered in order to maintain volume and salt homeostasis in this state.
authors.affiliation: Cátedras de Biología Celular e Histología, Departmento de Ciencias Biologicas, Facultad de Farmacia y Bioquimica, Universidad de Buenos Aires, Argentina. mmajow@huemul.ffyb.uba.ar
authors.forename: M P
authors.initials: MP
authors.lastname: Majowicz
authors.forename: M A
authors.initials: MA
authors.lastname: Costa
authors.forename: A M
authors.initials: AM
authors.lastname: Balaszczuk
authors.forename: N A
authors.initials: NA
authors.lastname: Vidal
authors.forename: K A
authors.initials: KA
authors.lastname: Bombicino
authors.forename: C T
authors.initials: CT
authors.lastname: Arranz
mesh_terms: D000818:Animals; D001794:Blood Pressure / Q000502:physiology; D048429:Cell Size / Q000502:physiology; D004231:Diuresis / Q000502:physiology; D019334:Endothelin-3 / Q000502:physiology*; D005110:Extracellular Space / Q000378:metabolism*; D008297:Male; D009318:Natriuresis / Q000502:physiology; D051381:Rats; D017208:Rats, Wistar; D012964:Sodium / Q000378:metabolism*; D014867:Water / Q000378:metabolism*
chemical_list: D019334:Endothelin-3; D014867:Water; D012964:Sodium