ABSTRACT
The distribution of three mitochondrial enzymes: dihydrolipoamide succinyltransferase, dihydrolipoamide acetyltransferase, and beta-subunit of ATP synthase, were examined in the nucleus basalis of Meynert, substantia nigra, locus coeruleus, hippocampus, and cerebral cortex of monkey brain by immunocytochemical staining. Dihydrolipoamide succinyltransferase and dihydrolipoamide acetyltransferase had parallel distribution in the substantia nigra, but dihydrolipoamide acetyltransferase was rich in the locus coeruleus, nucleus basalis of Meynert, and especially in the hippocampus in comparison with dihydrolipoamide succinyltransferase. The ATP synthase beta-subunit was strikingly rich in many neurons of the locus coeruleus and cerebral cortex in comparison with dihydrolipoamide acetyltransferase and dihydrolipoamide succinyltransferase. These results show that these mitochondrial enzymes are not expressed synchronously in the neurons of brain, suggesting the differential regulation of mitochondrial enzymes and the heterogeneity of mitochondria.
