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Solute-free water retention in preascitic cirrhotic rats following intravenous water loading.
- Source :
-
Journal of physiology and pharmacology : an official journal of the Polish Physiological Society [J Physiol Pharmacol] 2009 Dec; Vol. 60 (4), pp. 111-7. - Publication Year :
- 2009
-
Abstract
- 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 CCl(4)-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.
- Subjects :
- Aldosterone blood
Animals
Atrial Natriuretic Factor blood
Extracellular Fluid physiology
Glomerular Filtration Rate
Kidney blood supply
Kidney Tubules, Distal metabolism
Liver Cirrhosis chemically induced
Male
Osmolar Concentration
Potassium blood
Potassium urine
Rats
Rats, Wistar
Renin blood
Sodium administration & dosage
Sodium blood
Sodium urine
Vasopressins blood
Water administration & dosage
Liver Cirrhosis physiopathology
Loop of Henle physiopathology
Water-Electrolyte Imbalance physiopathology
Subjects
Details
- Language :
- English
- ISSN :
- 1899-1505
- Volume :
- 60
- Issue :
- 4
- Database :
- MEDLINE
- Journal :
- Journal of physiology and pharmacology : an official journal of the Polish Physiological Society
- Publication Type :
- Academic Journal
- Accession number :
- 20065504