Hemorrhagic shock was produced in conscious rats by cannulating the subclavian arteries and bleeding the animals to a mean arterial pressure of 40 mm.Hg, which was maintained for one hour (early shock) or 2 hours (late shock). Analysis of diaphragm (working muscle) showed that there was a significant decrease in adenosine triphosphate (ATP), adenosine diphosphate (ADP), and creatine phosphate levels beginning with early shock, whereas in soleus muscle (resting muscle) these changes were not observed until late shock. Decreases in adenine nucleotides of diaphragm were less than in working organs such as liver and kidney in early shock. This suggests that the extent of decrease in adenine nucleotides during shock may be related to the metabolic activity of the organ. © 1976.