Catalepsy induced by α-methyl-p-tyrosine and d-amphetamine: The rÔle of catecholamine metabolism

1432-2072

Catalepsy ; Catecholamine Metabolism ; Amphetamine ; α-Methyl-p-tyrosine

Springer Online Journal Archives 1860-2000

Medicine

Abstract The effect of inhibition of monoamine oxidase (MAO), catechol-O-methyltransferase (COMT) and Dopa-decarboxylase on the catalepsy induced by d-amphetamine in α-methyl-p-tyrosine (α-MpT) treated rats has been investigated. Administration of an MAO inhibitor concomitant with α-MpT slightly antagonized the cataleptic state, but when given 2 h later was without an appreciable effect. Only when an inhibitor was injected at an extremely high dose level 18 h prior to α-MpT did catalepsy fail to develop. Following COMT inhibition the cataleptic state was enhanced. After Dopa decarboxylase inhibition the catalepsy developed as usual for the first 3 h post-amphetamine, but then declined in intensity. It is concluded that neither deaminated nor O-methylated products are responsible for the development of catalepsy. In fact, the indication is that the catalepsy may be antagonised by an O-methylated derivative. A possible explanation for the action of the Dopa decarboxylase inhibitor is discussed.

Electronic Resource