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The Role of the Liver in Acid-Base Regulation

  • D. Häussinger
Conference paper

Abstract

Traditionally, lungs and kidneys are viewed as sole and principal organs being involved in systemic acid-base homeostasis in mammals, but this view is not entirely compatible with basic principles of chemistry (for review see [1–6]). Recent conceptual developments point to a role of the liver in pH homeostasis in addition to the well-established role of lungs and kidneys [1–6]. Hepatic and renal nitrogen metabolism are linked by an interorgan glutamine flux, which couples both renal ammoniagenesis and hepatic ureogenesis to systemic acid base regulation. A hepatic role in this interorgan team effort is based upon several features. (i) The presence of a quantitatively important and liver-specific pathway for irreversible removal of metabolically generated bicarbonate, i.e. urea synthesis. (ii) A structural-functional organization, which uncouples urea cycle flux control from the vital need to maintain ammonium homeostasis. (iii) A sensitive and complex control of bicarbonate disposal via hepatic ureogenesis by the extracellular acid-base status, suggestive for a feed-back control loop between the acid-base status and the rate of bicarbonate elimination, i.e. a hepatic bicarbonate-homeostatic response. (iv) Inhibition of amino acid uptake into the liver at the level of plasma membrane transport in acidosis, which may result in a shift of amino acid catabolism to extrahepatic tissues under these conditions. Some pathophysiological implications arising from the acid-base regulation of the liver are discussed.

Keywords

Glutamine Synthetase Urea Cycle Metabolic Alkalosis Amino Acid Uptake Urea Synthesis 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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© Springer-Verlag Italia, Milano 1998

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  • D. Häussinger

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