Early, reversible plasma membrane injury in galactosamine-induced liver cell death

Administration to rats of D-galactosamine (400 mg/kg) produces liver cell death that develops during the first 24 hours. Plasma membranes isolated within the first few hours from these animals show a 40% reduction in 5'-nucleotidase activity and a two-fold increase in maximum negative ellipticity determined by circular dichroism. Simultaneous administration of uridine prevents liver cell death and these early alterations in the plasma membranes. Uridine also prevents cell death if administered for up to 3 hours after galactosamine. The 5'nucleotidase activity reduced when uridine is administered for up to 2-1/2 hours after galactosamine. Changes in the liver calcium ion concentration accompany these plasma membrane alterations. Uridine will prevent and reverse the changes in calcium content in parallel to its ability to reverse the membrane alterations. The significance of these findings with respect to the mechanism of galactosamine-induced liver cell death is discussed.