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. 1991 May 1;275(Pt 3):805–807. doi: 10.1042/bj2750805

Liver glucose-6-phosphatase activity is not modulated by physiological intracellular Ca2+ concentrations.

R Fulceri 1, G Bellomo 1, A Gamberucci 1, A Benedetti 1
PMCID: PMC1150127  PMID: 1645522

Abstract

1. In the presence of MgATP and increasing amounts of added Ca2+, isolated liver microsomal vesicles accumulate approx. 10 nmol of Ca2+/mg of protein and buffer ambient free Ca2+ at increasing concentrations (0.22-10.9 microM). Under these experimental conditions, microsomal glucose-6-phosphatase activity is unaffected by the concentration of extravesicular free Ca2+. 2. Different levels of intravesicular Ca2+ were obtained by treating microsomes with the Ca2+ ionophore A23187 and by stimulating active microsomal Ca2+ accumulation with Pi (3 mM). In both instances, microsomal glucose-6-phosphatase activity is unaffected by the level of intravesicular Ca2+.

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Selected References

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