Biomaterial Database

Activity of tryptophan hydroxylase in brain of hereditary predisposed to catalepsy rats. 1992

A V Kulikov, and E Y Kozlachkova, and N K Popova

Institute of Cytology and Genetics, Siberian Branch, Academy of Sciences of Russia, Novosibirsk.

The activity of the rate-limiting enzyme of serotonin biosynthesis, tryptophan hydroxylase (TPH), was studied in the brain of rats bred for 20 generations for predisposition to catalepsy (an excessive freezing). Increased TPH activity was found in the striatum but not in the hippocampus and midbrain of cataleptic rats compared with Wistar ones. Km for the enzyme from the striatum of cataleptics was twice as low as that in control rats, although no difference in their Vmax was found. The increase in TPH activity in the striatum of cataleptics was nonadditive with its activation induced by incubation in vitro of the enzyme under phosphorylating conditions and could be completely reversed with alkaline phosphatase. An administration of p-chlorophenylalanine, an irreversible inhibitor of TPH, decreased the duration of freezing in cataleptic rats. These findings indicate that hereditary predisposition to catalepsy is associated with increased TPH activity in the striatum due to local phosphorylation of the enzyme and suggest an essential role of the activation of striatal TPH in genetic predisposition to catalepsy.

UI	MeSH Term	Description	Entries
D007700	Kinetics	The rate dynamics in chemical or physical systems.
D008297	Male		Males
D010134	Fenclonine	A selective and irreversible inhibitor of tryptophan hydroxylase, a rate-limiting enzyme in the biosynthesis of serotonin (5-HYDROXYTRYPTAMINE). Fenclonine acts pharmacologically to deplete endogenous levels of serotonin.	p-Chlorophenylalanine,para-Chlorophenylalanine,CP-10,188,DL-3-(4-Chlorophenyl)alanine,Fenclonin,Fenclonine (L)-Isomer,Fenclonine Hydrobromide,Fenclonine Hydrochloride,Fenclonine, (D)-Isomer,Hydrobromide, Fenclonine,Hydrochloride, Fenclonine,para Chlorophenylalanine
D010766	Phosphorylation	The introduction of a phosphoryl group into a compound through the formation of an ester bond between the compound and a phosphorus moiety.	Phosphorylations
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
D002375	Catalepsy	A condition characterized by inactivity, decreased responsiveness to stimuli, and a tendency to maintain an immobile posture. The limbs tend to remain in whatever position they are placed (waxy flexibility). Catalepsy may be associated with PSYCHOTIC DISORDERS (e.g., SCHIZOPHRENIA, CATATONIC), nervous system drug toxicity, and other conditions.	Cerea Flexibilitas,Flexibility, Waxy,Anochlesia,Anochlesias,Catalepsies,Flexibilitas, Cerea,Flexibilities, Waxy,Waxy Flexibilities,Waxy Flexibility
D000469	Alkaline Phosphatase	An enzyme that catalyzes the conversion of an orthophosphoric monoester and water to an alcohol and orthophosphate. EC 3.1.3.1.
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
D014365	Tryptophan Hydroxylase	An enzyme that catalyzes the hydroxylation of TRYPTOPHAN to 5-HYDROXYTRYPTOPHAN in the presence of NADPH and molecular oxygen. It is important in the biosynthesis of SEROTONIN.	Tryptophan Monooxygenase,Hydroxylase, Tryptophan,Monooxygenase, Tryptophan
D051381	Rats	The common name for the genus Rattus.	Rattus,Rats, Laboratory,Rats, Norway,Rattus norvegicus,Laboratory Rat,Laboratory Rats,Norway Rat,Norway Rats,Rat,Rat, Laboratory,Rat, Norway,norvegicus, Rattus