Cysteine dioxygenase: regional expression of activity in rat brain

The levels of expression of cysteine dioxygenase (CDO) protein and activity were investigated in nine functionally distinct regions of the rat brain before and after induction with methionine by Western analysis and an activity assay. Activity expression ranged from no activity in the brain-stem to high activity expression in the olfactory bulb and basal ganglia. Upon exposure to 400 mg/l methionine for 5 days, significant induction of expression was observed in the basal ganglia, brain-stem, cerebellum, hippocampus, midbrain and olfactory bulb. Protein expression appeared to correlate with activity expression when levels before and after induction were compared. This non-uniformity of expression may reflect different physiological functions of CDO in these areas.