Comparison of the acute toxicity of endothal and cantharidic acid on mouse liver in vivo.

Endothal and cantharidic acid were administered intraperitoneally to mice at 75 and 10 mg/kg, respectively, to compare their acute toxicity on liver tissue in vivo. Within 45 min both treatments caused extreme liver enlargement and congestion. Hepatic glycogenolysis was increased as evidenced by elevations in blood glucose and hepatic glycogen phosphorylase levels and by corresponding reductions in hepatic glycogen content and glycogen synthase activity. Endothal decreased hepatic ATP concentrations, although neither compound altered mitochondrial Mg2+-ATPase activity. Microsomal Mg2+-ATPase levels, however, were reduced by both treatments. There were no indications that reactive intermediates were involved in the toxicity of either compound. The results show that endothal and cantharidic acid act directly and cause similar biochemical changes in mouse liver in vivo.