Sub-micromolar concentrations of extramitochondrial Ca2+ stimulate the rate of citrulline synthesis by rat liver mitochondria.
1. In the presence of physiological concentrations of Na+ and Mg2+, the rate of citrulline synthesis by isolated rat liver mitochondria respiring on a range of substrates was stimulated by up to 60% when the extramitochondrial Ca2+ concentration was raised from 130 pM to 770 nM. 2. Our findings suggest that hormonal stimulation of the urea cycle may be mediated by Ca2+.
Johnston
J D
JD
Department of Biochemistry, University of Cambridge, U.K.
Brand
M D
MD
D000818:Animals; D002118:Calcium / Q000502:physiology*; D002956:Citrulline / Q000096:biosynthesis*; D008274:Magnesium / Q000378:metabolism; D008930:Mitochondria, Liver / Q000378:metabolism*; D051381:Rats; D012964:Sodium / Q000378:metabolism
D002956:Citrulline; D012964:Sodium; D008274:Magnesium; D002118:Calcium