L-Tyrosine

L-Tyrosine is a non-essential amino acid which can inhibit citrate synthase activity in the posterior cortex.

Research Areas >> Neurological Disease

Natural Products >> Others

Human Endogenous Metabolite

Results show that L-Tyrosine in vitro inhibits citrate synthase activity in the posterior cortex (2.0 and 4.0 mM), malate dehydrogenase is not altered by L-Tyrosine and succinate dehydrogenase is increased in the posterior cortex (0.1, 1.0, 2.0 and 4.0 mM), hippocampus (1.0, 2.0 and 4.0 mM), striatum (4.0 mM) and liver (0.1, 1.0, 2.0 and 4.0 mM). When complex I activity is analyzed, inhibition is observed in hippocampus (4.0 mM). In addition to inhibition in the hippocampus, complex II also is inhibited in the posterior cortex (0.1, 1.0, 2.0 and 4.0 mM) and liver (1.0, 2.0 and 4.0 mM). For complex II–III, activity is not altered by L-Tyrosine, and complex IV activity has decreased in the posterior cortex (1.0, 2.0 and 4.0 mM) following treatment with L-Tyrosine[1].

The acute administration of L-Tyrosine inhibits the activity of citrate synthase in the posterior cortex and liver; however, in the striatum, the activity is increased. The results also demonstrate that acute administration of L-Tyrosine inhibits malate dehydrogenase and complex II, II–III and IV of the mitochondrial respiratory chain activity in the posterior cortex and liver of rats. The succinate dehydrogenase enzyme and complex I activity are inhibited in the posterior cortex and increased in the striatum. Furthermore, energy metabolism in the hippocampus is not amended by an acute administration of L-Tyrosine[1].

Posterior cortex, hippocampus, striatum and liver supernatants of 30-day-old rats are pre-incubated for 30 min at 30°C in the presence of L-Tyrosine (Tyr) at final concentrations ranging from 0.1, 1.0, 2.0 or 4.0 mM, and the activities of citrate synthase, malate dehydrogenase and respiratory chain complexes I, II, II–III and IV are evaluated[1].

The equivalent of 500 mg/kg body weight of free L-Tyrosine is intraperitoneally administered in 30-day-old rats. Controls receive in saline solution. About 1 h after injections, rats are killed by decapitation without anesthesia[1].

[1]. Ferreira GK, et al. Effect of L-tyrosine in vitro and in vivo on energy metabolism parameters in brain and liver of young rats. Neurotox Res. 2013 May;23(4):327-35.

3-Methyladenine | Hydrocortisone | Acetylcysteine(N-acetylcysteine) | Retinoic acid | Melatonine | Dinoprostone | Nicotinamide | Adenosine triphosphate | 4-Acetamidophenol | Prostaglandin E1 | Dehydroepiandrosterone | Corticosterone | Progesterone | Docosahexaenoic Acid | NAD+

MOLECULAR FORMULA :

C9-H11-N-O3

MOLECULAR WEIGHT :

181.21

WISWESSER LINE NOTATION :

QVYZ1R DQ

HEALTH HAZARD DATA

ACUTE TOXICITY DATA

TYPE OF TEST :

LD50 - Lethal dose, 50 percent kill

ROUTE OF EXPOSURE :

Intraperitoneal

SPECIES OBSERVED :

Rodent - mouse

DOSE/DURATION :

>1450 mg/kg

TOXIC EFFECTS :

Details of toxic effects not reported other than lethal dose value

TYPE OF TEST :

TDLo - Lowest published toxic dose

ROUTE OF EXPOSURE :

Oral

SPECIES OBSERVED :

Rodent - rat

DOSE/DURATION :

42 gm/kg/2W-C

TOXIC EFFECTS :

Behavioral - food intake (animal) Biochemical - Metabolism (Intermediary) - amino acids (including renal excretion) Related to Chronic Data - death

TYPE OF TEST :

TDLo - Lowest published toxic dose

ROUTE OF EXPOSURE :

Oral

DOSE :

20750 mg/kg

SEX/DURATION :

female 15-19 day(s) after conception

TOXIC EFFECTS :

Reproductive - Effects on Embryo or Fetus - other effects to embryo

TYPE OF TEST :

TDLo - Lowest published toxic dose

ROUTE OF EXPOSURE :

Oral

DOSE :

5 gm/kg

SEX/DURATION :

female 11-20 day(s) after conception

TOXIC EFFECTS :

Reproductive - Effects on Newborn - behavioral

TYPE OF TEST :

TDLo - Lowest published toxic dose

ROUTE OF EXPOSURE :

Oral

DOSE :

3500 mg/kg

SEX/DURATION :

female 15-21 day(s) after conception

TOXIC EFFECTS :

Reproductive - Specific Developmental Abnormalities - Central Nervous System

TYPE OF TEST :

TDLo - Lowest published toxic dose

ROUTE OF EXPOSURE :

Subcutaneous

DOSE :

150 mg/kg

SEX/DURATION :

female 3 day(s) pre-mating

TOXIC EFFECTS :

Reproductive - Maternal Effects - ovaries, fallopian tubes

TYPE OF TEST :

TDLo - Lowest published toxic dose

ROUTE OF EXPOSURE :

Oral

DOSE :

3 gm/kg

SEX/DURATION :

female 29-31 day(s) after conception

TOXIC EFFECTS :

Reproductive - Effects on Newborn - biochemical and metabolic

MUTATION DATA

TYPE OF TEST :

Sister chromatid exchange

TEST SYSTEM :

Human Lymphocyte

DOSE/DURATION :

10 mg/L

REFERENCE :

MUREAV Mutation Research. (Elsevier Science Pub. B.V., POB 211, 1000 AE Amsterdam, Netherlands) V.1- 1964- Volume(issue)/page/year: 372,75,1996 *** NIOSH STANDARDS DEVELOPMENT AND SURVEILLANCE DATA *** NIOSH OCCUPATIONAL EXPOSURE SURVEY DATA : NOHS - National Occupational Hazard Survey (1974) NOHS Hazard Code - 81869 No. of Facilities: 133 (estimated) No. of Industries: 2 No. of Occupations: 4 No. of Employees: 1421 (estimated) NOES - National Occupational Exposure Survey (1983) NOES Hazard Code - 81869 No. of Facilities: 275 (estimated) No. of Industries: 3 No. of Occupations: 12 No. of Employees: 14731 (estimated) No. of Female Employees: 12371 (estimated)