A study of stabilization of gluconeogenic activity in rat liver slices by calcium and manganese ions.
1. The effect of some bivalent cations on gluconeogenesis by the rat liver-slice preparation has been investigated. 2. Ca(2+) and Mn(2+) stimulated glucose production from a range of substrates but not from glycerol. Mg(2+) had no effect on the rate of glucose production. 3. Ca(2+) were required to maintain phosphoenolpyruvate carboxylase activity in the slice preparation. 4. Ca(2+) and Mn(2+), but not Mg(2+), retarded the release of lysosomal enzymes from the slice into the incubation medium. 5. It is proposed that Ca(2+) and Mn(2+) stimulate glucose production by stabilizing the lysosome system in the liver-slice preparation. 6. The value of the liver-slice preparation as a means of measuring hepatic gluconeogenesis is discussed.
D000409:Alanine / Q000378:metabolism; D000818:Animals; D002118:Calcium / Q000494:pharmacology*; D002262:Carboxy-Lyases / Q000378:metabolism; D005943:Gluconeogenesis / Q000187:drug effects*; D005947:Glucose / Q000096:biosynthesis; D005973:Glutamine / Q000378:metabolism; D005990:Glycerol / Q000378:metabolism; D066298:In Vitro Techniques; D007773:Lactates / Q000378:metabolism; D008099:Liver / Q000187:drug effects* / Q000201:enzymology / Q000378:metabolism; D008112:Liver Glycogen / Q000378:metabolism; D008247:Lysosomes / Q000201:enzymology; D008274:Magnesium / Q000494:pharmacology; D008345:Manganese / Q000494:pharmacology*; D010728:Phosphoenolpyruvate; D011773:Pyruvates / Q000378:metabolism; D051381:Rats; D012694:Serine / Q000378:metabolism
D007773:Lactates; D008112:Liver Glycogen; D011773:Pyruvates; D005973:Glutamine; D008345:Manganese; D012694:Serine; D010728:Phosphoenolpyruvate; D002262:Carboxy-Lyases; D008274:Magnesium; D005947:Glucose; D000409:Alanine; D005990:Glycerol; D002118:Calcium