RESUMEN
Ganglionic and cortical arteries and arterioles in 15 aging Sprague-Dowley rats were histochemically examined to evaluate their metabolic profiles using bright-field microscopy semiquantitatively. Lactate dehydrogenase showed significant reactivity which increased with vessel diameter in cortical and ganglionic vessels in all groups examined. Suceinate dehydrogenase showed trace to moderate reactivity in both cortical and ganglionic vessels. Glucose-6-phosphate dchydrogenase showed zero to trace reactivity in cortical and ganglionic vessels, suggesting less synthetic capacity of nuclear acids and proteins. Myosin ATPase showed strong to very strong reactivity which decreased slightly with vessel diameter in all groups tested, indicating high rate of utilizing ATP in smooth muscle. Little difference of enzyme reactivity was found among cortical and ganglionic vessels and vessels from different parts of caudatoputamcn. In conclusion, both cortical and ganglionic vessels are metabolically active, with significant anaerobic glycolysis, but with decrease in capacity observable for aerobic metabolism.