Impaired dopamine function and muscular rigidity induced by 6-aminonicotinamide in rats.

In corpus striatum, 6-aminonicotinamide (6-AN), 10 mg/kg i.p. lowered the concentration of dopamine and markedly reduced the disappearance of dopamine after synthesis inhibition with alpha-methyl-p-tyrosine. In the dopamine-rich part of the limbic system, the formation of DOPA after decarboxylase inhibition with 3-hydroxybenzylhydrazine was decreased. In diencephalon, 6-AN altered neither the steady-state level nor the utilization of noradrenaline. The data suggest that the muscular rigidity induced by 6-AN may be associated with disruption of dopaminergic transmission.