Interaction of (+)-amphetamine with cerebral dopaminergic neurones in two strains of mice, that show different temperature responses to this drug.

1. (+)-Amphetamine sulphate elicits a dose-dependent hyperthermia in NMRI mice but it does not significantly increase the body temperature of C(3)H mice.2. When low doses of (+)-amphetamine are given, the body temperature of C(3)H mice decreases.3. (+)-Amphetamine decreases the noradrenaline concentration in the brain-stem and increases the homovanillic acid concentration (HVA) in the striatum of NMRI mice, but only slightly reduces the noradrenaline concentration and does not change the HVA concentration in the brains of C(3)H mice.4. The two strains appear to show a difference in the metabolism of dopamine in the striatum. The rates at which dopamine disappears from the tissue after blocking catecholamine synthesis with alpha-methyltyrosine and the rates at which HVA accumulates after blocking the active transport of this metabolite out of the brain with probenecid suggest that the turnover of dopamine is lower in C(3)H mice than in NMRI mice.