Pharmacology of Akinesia—Investigations on 3,4-Dimethoxyphenylethylamine

Abstract

AKINESIA in Parkinson's disease is a complex phenomenon which resembles catalepsy and includes a reduction in motor activity as well as a certain degree of catatonia (maintenance of a fixed passively imposed position). Akinesia as a clinical sign may be connected with changes in the metabolism of dopamine (DA), a substance involved in the pathogenesis of Parkinson's disease¹. Experimental investigations in animals strengthen the evidence for a relationship between catecholamines and control of motility. Fisher and Lopez Amalfara² found that epinephrine (E) and norepinephrine (NE) caused a motor depression, while Ernst³ produced a striking akineto-rigid syndrome in cats with injections of two possible dopamine metabolites: 3,4-dimethoxy-phenylethylamine (DIMPEA) and 4-methoxyphenylethylamine (4-MEPEA), both structurally related to mescaline (3,4,5-trimethoxyphenylethylamine). These investigations gained further significance with the identification of DIMPEA in the urine of schizophrenic patients by Friedhoff and Van Winkle⁴ and others since⁵. This same compound was found by Barbeau et al. in high concentration in the urine of clinically akinetic parkinsonian patients⁶.