The effects of carbon disulphide exposure on brain catecholamines in rats

1. Rats exposed to 2.0 mg/1. carbon disulphide (CS(2)) in the inspired air for 2 days, 4 h a day, showed a 13% decrease in their brain noradrenaline concentration and a 16% increase in their brain dopamine concentration.2. After exposure for 5 or 10 days there was a further decrease in the concentration of noradrenaline in the brain, but brain dopamine returned to the control level.3. In animals treated intraperitoneally with 2.0 mg/kg reserpine and exposed 2 and 3 days later to 2.0 mg/1. CS(2) for 4 h per day, the brain dopamine concentration showed a 77% increase compared with the unexposed reserpinized animals, but the noradrenaline concentration remained unchanged.4. The dopamine concentrations in the adrenals after 10 days' exposure to 2.0 mg/1. CS(2) were 67% to 100% higher than in the control animals. In reserpinized rats, 2 days' exposure to CS(2) nearly trebled the dopamine content of adrenals.5. Exposure to CS(2) had no effect on the tyrosine concentration in the brain, and there was no change in the brain monoamine oxidase (MAO) activity. Tyrosine in the brain showed a 30 to 96% increase in concentration and MAO activity, using kynuramine as substrate, showed an approximately 5% increase 0.5 to 2 h after the subcutaneous administration of 500 mg/kg sodium diethyldithiocarbamate.6. CS(2) at 10(-2)M or lower concentrations had no inhibitory effect on the brain MAO activity in vitro. Diethyldithiocarbamate inhibited MAO at 10(-2)M, but not at 10(-3)M or lower concentrations.