Activities of Aromatic L-Amino Acid Decarboxylase with L-Dopa as Substrate in Brush-Border- and Basolateral Membranes and Cytoplasm Obtained from Rat Renal Cortex

Abstract

Activities of aromatic L-amino acid decarboxylase (AADC) with L-dopa as its substrate were determined in the plasma membranes and other cellular components isolated from rat renal cortex. The cytoplasm contained a high level of AADC activity, but much lower levels were found in the brush-border- and basolateral membranes. The main site involved in the formation of dopamine from L-dopa was considered to be the cytoplasm, with participation of neither the brush-border- nor the basolateral membranes.