The information available indicates that following hepatic ischemia and reflow, there is decreased tissue ATP levels, decreased tissue and mitochondrial magnesium levels, and decreased mitochondrial capability. Associated with these changes are altered cellular functions. Administration of ATP-MgCl2 following ischemia significantly improves total and microcirculatory blood flow, tissue and mitochondrial magnesium levels, tissue ATP stores, cellular functions, and the survival of animals. In contrast to ATP-MgCl2, administration of ATP or MgCl2 alone after ischemia was ineffective in improving cellular functions and tissue and mitochondrial magnesium levels. ATP-MgCl2 therefore appears to be a promising adjunct to the treatment of shock and ischemia.