Solute-free water retention in preascitic cirrhotic rats following intravenous water loading

• Autorzy: Sansoe G. , Aragno M. , Smedile A. , Rizzetto M. , Rosina F.
• Języki publikacji: EN

Abstrakty

EN

Increased extracellular fluid volume (ECF) characterizes compensated cirrhosis. To identify the mechanisms of fluid retention in cirrhosis through clearance methods, 10 control and 10 preascitic rats with CCl4-induced cirrhosis were studied following i.v. loading with 1 ml 5% glucose solution. Glomerular filtration rate and renal plasma flow were evaluated through inulin and para-aminohippurate clearances; water and electrolyte handling was assessed measuring urine and plasma osmolarity, electrolyte excretions, and tubular solute-free water reabsorption (TFWR = osmolar clearance minus urinary output); ECF was assessed through hormonal status determination. After water loading, cirrhotic rats had increased ECF (lower plasma renin activity and aldosterone and higher atrial natriuretic peptide levels, all P<0.03), solute-free water retention (increased TFWR and decreased plasma osmolarity, all P<0.05), reduced absolute and fractional sodium excretions (P<0.05). Cirrhotic rats showed sodium retention in the medullary thick ascending limb of Henle’s loop (i.e. increased values of TFWR for any given value of osmolar clearance). Trans-tubular potassium gradient in medullary collecting duct was similar in the two groups (P=0.55), ruling out aldosterone-dependent sodium retention and potassium hyper-secretion. In experimental preascitic cirrhosis NaCl retention in the ascending limb of Henle’s loop increases medullary interstitial tonicity leading to vasopressin-independent water back-diffusion in thin descending limb of Henle’s loop and collecting duct.

Słowa kluczowe

EN

extracellular fluid; cirrhosis; liver cirrhosis; ascites; sodium retention; water metabolism

• Wydawca: -
• Czasopismo: Journal of Physiology and Pharmacology
• Rocznik: 2009
• Tom: 60
• Numer: 4
• Opis fizyczny: p.111-117,fig.,ref.

Twórcy

autor

Sansoe G.

• Divisione di Gastroenterologia, Ospedale Gradenigo, C.so Regina Margherita 10, 10153 Torino, Italy

autor

Aragno M.

autor

Smedile A.

autor

Rizzetto M.

autor

Rosina F.