| Abstract: | The metabolism of estradiol 17-sulfate by subcellular localization enzymes of pheochromocytoma tissue obtained from a 41-year old female was investigated. In any incubations under the presence of NADH and NADPH, metabolites hydroxylated at the C-2, C-4, C-6 beta, C-7 alpha and C-7 beta positions were produced. These hydroxylations are considered to occur without cleavage of the sulfate group. The 2-hydroxylation at the substrate concentration of 100 microM by mitochondria, microsomes and cytosol fractions occurred at rates of 141, 222 and 167 pmol/mg protein/30 min, respectively; the corresponding rates for the 4-hydroxylation were 24, 40 and 38 pmol/mg protein/30 min. Mitochondrial 2- and 4-hydroxylations were enhanced by addition of calcium ion (Ca2+) into the incubation medium. |
