Spinal cord arteries and arterioles of adult female rats were examined histochemically to determine their metabolic profiles. The metabolic pathways evaluated included those related to aerobic (oxidative phosphorylation, Kreb's cycle and respiratory chain) and anaerobic (glycolysis) capacity, hexosemonophosphate-shunt activity, beta-oxidation of fat and adenosine triphosphate utilization. The amounts of deoxyribonucleic and ribonucleic acids were determined as an indication of protein synthesis. The present findings indicate that arteries of the rat spinal cord are metabolically active with high capacities for both aerobic and anaerobic metabolism, and possess a significant potential for nucleic acid and protein synthesis. Lipid catabolism, via beta-oxidation of fat, may serve as one source of energy. The arteries also demonstrate a high capacity for utilization of adenosine triphosphate. In contrast, the spinal cord arterioles show a lower capacity for aerobic metabolism and lipid utilization, while anaerobic glycolysis may be a main source of energy. The arterioles also demonstrate a significant potential for nucleic acid and protein synthesis, in addition to a high capacity for adenosine triphosphate utilization.