Treatment with glucagon in addition to blood transfusion was compared with blood transfusion alone after one hour of hemorrhagic shock in the rat. In liver tissue Na+ increased and K+ decreased during haemorrhagic shock. After treatment the initial values were restored equally in both groups within ten minutes. Incubation of liver slices in cold Krebs' solution resulted in a pronounced increase in Na+ and decrease in K+, the values being partially restored to initial levels after subsequent incubation at 37 degrees. Thirty minutes after treatment the liver slices obtained from rats given glucagon showed a more normal ion composition after leaching and rewarming than slices from rats not given glucagon. ATP decreased and glucose and lactate increased in liver tissue during hemorrhagic shock. These variables were partially restored 30 minutes after treatment. No difference between the treatment groups was noted. Animals trreated with glucagon were, however, more efficient in reducing the elevated blood lactate level. The results suggest that the use of glucagon in the treatment of hemorrhagic shock might be of benefit for cellular function in the liver.