Biomaterial Database

Elevated dopa decarboxylase activity in living brain of patients with psychosis. 1994

J Reith, and C Benkelfat, and A Sherwin, and Y Yasuhara, and H Kuwabara, and F Andermann, and S Bachneff, and P Cumming, and M Diksic, and S E Dyve, and P Etienne, and A C Evans, and S Lal, and M Shevell, and G Savard, and D F Wong, and G Chouinard, and A Gjedde

McConnell Brain Imaging Center, Montreal Neurological Institute, PQ Canada.

The hypofrontality theory of the pathogenesis of schizophrenia predicts that cortical lesions cause psychosis. During a search for abnormalities of catecholaminergic neurotransmission in patients with complex partial seizures of the mesial temporal lobe, we discovered an increase of the rate of metabolism of an exogenous dopa tracer (6-[18F]fluoro-L-dopa) in the neostriatum of a subgroup of patients with a history of psychosis. When specifically assayed for this abnormality, patients with schizophrenia revealed the same significant increase of the rate of metabolism in the striatum. The finding is consistent with the theory that a state of psychosis arises when episodic dopamine excess is superimposed on a trait of basic dopamine deficiency in the striatum. The finding is explained by the hypothesis that cortical insufficiency, a proposed pathogenetic mechanism of both disorders, causes an up-regulation of the enzymes responsible for dopa turnover in the neostriatum as well as the receptors mediating dopaminergic neurotransmission.

UI	MeSH Term	Description	Entries
D008297	Male		Males
D011618	Psychotic Disorders	Disorders in which there is a loss of ego boundaries or a gross impairment in reality testing with delusions or prominent hallucinations. (From DSM-IV, 1994)	Psychoses,Psychosis, Brief Reactive,Schizoaffective Disorder,Schizophreniform Disorders,Psychosis,Brief Reactive Psychoses,Brief Reactive Psychosis,Disorder, Psychotic,Disorder, Schizoaffective,Disorder, Schizophreniform,Disorders, Psychotic,Disorders, Schizoaffective,Disorders, Schizophreniform,Psychoses, Brief Reactive,Psychotic Disorder,Reactive Psychoses, Brief,Reactive Psychosis, Brief,Schizoaffective Disorders,Schizophreniform Disorder
D001921	Brain	The part of CENTRAL NERVOUS SYSTEM that is contained within the skull (CRANIUM). Arising from the NEURAL TUBE, the embryonic brain is comprised of three major parts including PROSENCEPHALON (the forebrain); MESENCEPHALON (the midbrain); and RHOMBENCEPHALON (the hindbrain). The developed brain consists of CEREBRUM; CEREBELLUM; and other structures in the BRAIN STEM.	Encephalon
D004295	Dihydroxyphenylalanine	A beta-hydroxylated derivative of phenylalanine. The D-form of dihydroxyphenylalanine has less physiologic activity than the L-form and is commonly used experimentally to determine whether the pharmacological effects of LEVODOPA are stereospecific.	Dopa,3,4-Dihydroxyphenylalanine,3-Hydroxy-DL-tyrosine,Dihydroxyphenylalanine Hydrochloride, (2:1),beta-Hydroxytyrosine,3 Hydroxy DL tyrosine,3,4 Dihydroxyphenylalanine,beta Hydroxytyrosine
D004296	Dopa Decarboxylase	One of the AROMATIC-L-AMINO-ACID DECARBOXYLASES, this enzyme is responsible for the conversion of DOPA to DOPAMINE. It is of clinical importance in the treatment of Parkinson's disease.	Decarboxylase, Dopa
D005260	Female		Females
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D000328	Adult	A person having attained full growth or maturity. Adults are of 19 through 44 years of age. For a person between 19 and 24 years of age, YOUNG ADULT is available.	Adults
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D012559	Schizophrenia	A severe emotional disorder of psychotic depth characteristically marked by a retreat from reality with delusion formation, HALLUCINATIONS, emotional disharmony, and regressive behavior.	Dementia Praecox,Schizophrenic Disorders,Disorder, Schizophrenic,Disorders, Schizophrenic,Schizophrenias,Schizophrenic Disorder