For comparison of the extent of metabolite content alteration caused by etiologically different types of shock, septic peritonitis and hemorrhagic shock (mean arterial blood pressure at 40 mm Hg for 1 h or 2 h) were produced in rats. Contents of metabolites were determined in the liver and the muscle. Characteristic differences were found in the alteration modes of hepatic lactate level, muscle adenine nucleotide concentrations, and muscle protein content between these shock models. Rapid and significant alterations were observed in the levels of adenine nucleotides, glucose-6-phosphate and lactate in the liver in both types of shock. Hepatic energy charge and contents of glycogen and protein also significantly decreased. On the other hand, noticeable changes in the muscles were elevation of lactate level and the decrease of phosphocreatine and protein concentrations. Another distinct change was the decrease of total adenine nucleotide content in the muscle of septic rats, whereas it remained unchanged in the muscle of hemorrhagic shock rats. Thus, the changes of metabolite levels did not occur simultaneously in different tissues, and their rate and magnitude varied between different types of shock. The difference in adaptive response of metabolism may result in pathophysiologic diversity in shock.