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Toxicological information

Repeated dose toxicity: other routes

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Administrative data

Endpoint:
short-term repeated dose toxicity: other route
Type of information:
experimental study
Adequacy of study:
other information
Study period:
1980
Reliability:
4 (not assignable)
Rationale for reliability incl. deficiencies:
other: Study in Japanese with brief English summary

Data source

Reference
Reference Type:
publication
Title:
Toxicological studies on N-Acetyl-L-Tryptophan. II. Subacute toxicity in rats
Author:
Kawaguchi Y, Kotera K & Takemoto Y
Year:
1980
Bibliographic source:
Iyakuhin Kenkyu 11, 646-665

Materials and methods

GLP compliance:
no

Test material

Reference
Name:
Unnamed
Type:
Constituent

Test animals

Species:
rat
Strain:
Wistar
Sex:
male/female

Administration / exposure

Route of administration:
intraperitoneal
Vehicle:
not specified
Duration of treatment / exposure:
30 days
Frequency of treatment:
daily
Doses / concentrations
Remarks:
Doses / Concentrations:
500, 1000 or 2000 mg/kg bw/d
No. of animals per sex per dose:
no data

Examinations

Observations and examinations performed and frequency:
Body weight, body weight gain, food and water consumption, haematology, clinical biochemistry, urine analysis
Sacrifice and pathology:
absolute and relative organ weights of relevant organs, histopathological examination

Results and discussion

Effect levels

Dose descriptor:
NOAEL
Effect level:
500 mg/kg bw/day
Sex:
male/female

Target system / organ toxicity

Critical effects observed:
not specified

Applicant's summary and conclusion

Conclusions:
In the L-tryptophan dosed animals, death, depression of motor activity, inhibition of body weight gain, reduction of food consumption, increase of water consumption and urinary volume, and piloerection were observed in the both sexes given >= 1000 mg/kg bw/d. Serum biochemistry showed elevation of GOT activity in both of the males given 2000 mg/kg bw/d and in females given above 1000 mg/kg bw/d. Elevation of ALP activity was noted and liver and kidney weights increased in females at all doses. In the histopathological examination, hepatocyte hypertrophy as well as atrophy of thymus was observed in animals at above 1000 mg/kg bw/d.
Executive summary:

In the L-tryptophan dosed animals, death, depression of motor activity, inhibition of body weight gain, reduction of food consumption, increase of water consumption and urinary volume, and piloerection were observed in the both sexes given >= 1000 mg/kg bw/d. Serum biochemistry showed elevation of GOT activity in both of the males given 2000 mg/kg bw/d and in females given above 1000 mg/kg bw/d. Elevation of ALP activity was noted and liver and kidney weights increased in females at all doses. In the histopathological examination, hepatocyte hypertrophy as well as atrophy of thymus was observed in animals at above 1000 mg/kg bw/d.