Ontogeny and distribution of cysteine sulfinate transaminase in the rat brain.

Cysteine sulfinate transaminase catalyzes the conversion of cysteine sulfinate and alpha-ketoglutarate to beta-sulfonyl pyruvate and glutamate and is present in high concentration in neuronal tissue. During development, levels of cysteine sulfinate transaminase in whole rat brain homogenate increase twofold between days 10 and 21. At maturity, high levels of the enzyme are present in the synaptosomal fraction. The highest level of enzyme activity was in the hypothalamus, approximately three- to fourfold greater than any other region examined. These data suggest that cysteine sulfinate transaminase may have an important role in the metabolism of neurotransmitters and their precursors.