A study of stabilization of gluconeogenic activity in rat liver slices by calcium and manganese ions

ABSTRACT

The effect of some bivalent cations on gluconeogenesis by the rat liver-slice preparation has been investigated. Ca2+ and Mn2+ stimulated glucose production from a range of substrates but not from glycerol. Mg2+ had no effect on the rate of glucose production. Ca2+ were required to maintain phosphoenolpyruvate carboxylase activity in the slice preparation. Ca2+ and Mn2+, but not Mg2+, retarded the release of lysosomal enzymes from the slice into the incubation medium. It is proposed that Ca+ and mn2+ stimulate glucose production by stabilizing the lysosome system in the liver-slice preparation. The value of the liver-slice preparation as a means of measuring hepatic gluconeogenesis is discussed (AU)