The influence of Ca2+ on gluconeogenesis stimulation by glucagon in the liver of arthritic rats

ABSTRACT

Ca2+ participates in the stimulation of hepatic gluconeogenesis by glucagon and there is evidence that Ca2+ fluxes are modified in arthritic rats. These findings raise the question whether hepatic gluconeogenesis in arthritic rats responds differently to glucagon and Ca2+. The experimental system was the isolated perfused rat liver. In the presence of Ca2+, stimulation of hepatic gluconeogenesis by glucagon in arthritic rats was equal to that in normal rats in absolute terms, but higher in relative terms (104.5 and 45.2 percent, respectively). In the absence of Ca2+, however, stimulation of hepatic gluconeogenesis by glucagon in arthritic rats was smaller in both absolute and relative terms (18.5 and 41.9 percent, respectively). It can be concluded that the Ca2+-dependent component of gluconeogenesis activation by glucagon is more important in arthritic than in normal rats