Liver and systemic pH-regulation.
Traditionally, lungs and kidneys are viewed as principal organs being involved in systemic acid-base homeostasis in mammals, but this view is not entirely compatible with basic principles of chemistry [for reviews see (1-3)]. Accordingly, a new acidbase concept was developed including an important role of the liver. Hepatic urea synthesis is an energy-driven, irreversible neutralization of the strong base HCO3- by the weak acid NH4+ and a potent feed-back regulation circuit adjusts urea cycle flux, i.e. irreversible hepatic HCO3- elimination, to the requirements of the acid base situation. Accordingly, the liver becomes a major organ for maintenance of HCO3- homeostasis and several implications for clinical medicine are derived from this "new" liver function.
Häussinger
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Medizinische Universitätsklinik, University of Freiburg.
D000136:Acid-Base Equilibrium; D001639:Bicarbonates / Q000378:metabolism; D006706:Homeostasis; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008099:Liver / Q000378:metabolism*; D008107:Liver Diseases / Q000378:metabolism; D008930:Mitochondria, Liver / Q000378:metabolism; D014508:Urea / Q000378:metabolism
D001639:Bicarbonates; D014508:Urea