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Toxicological information

Direct observations: clinical cases, poisoning incidents and other

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Administrative data

Endpoint:
direct observations: clinical cases, poisoning incidents and other
Type of information:
migrated information: read-across from supporting substance (structural analogue or surrogate)
Adequacy of study:
supporting study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Non-GLP, non-guideline in vitro study, published in peer reviewed literature, minor restrictions in reporting but otherwise adequate for assessment.

Data source

Reference
Reference Type:
publication
Title:
Expression and activities of class IV alcohol dehydrogenase and class III aldehyde dehydrogenase in human mouth
Author:
Dong Y, Peng T, Yin S
Year:
1996
Bibliographic source:
Alcohol, 13, 257-262

Materials and methods

Study type:
other: in vitro
Endpoint addressed:
basic toxicokinetics
Test guideline
Qualifier:
no guideline followed
Principles of method if other than guideline:
The activities of alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH) in human gingiva and lingual tissue were determined in vitro.
GLP compliance:
not specified

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report): acetaldehyde
- Source: E. Merck, Darmstadt, Germany
- Purity: analytical grade and redistilled before use

Method

Type of population:
general
Subjects:
- Subjects exposed: Adult donors
- Number of subjects exposed: 24
- Age: 42 ± 12 years
- Race: Chinese
- Other: with no history of alcoholism. Gingiva and lingual mucosa were used for the in vitro enzyme assay
Ethical approval:
confirmed, but no further information available
Details on exposure:
Tissue samples were homogenised, centrifuged and the supernatants used for enzyme activity measurements. ALDH activity was determined spectrophotometrically using acetaldehyde as substrate. ALDH isozymes were identified using isoelectric focussing. Kinetic data were evaluated using the HYPER statistical program.

Results and discussion

Results of examinations:
Class IIIx-ALDH3 was detected in oral mucosa. Human oral ALDH activities (Vmax at a substrate concentration of 20 mM) were 4.25 ± 0.57 and 1.82 ± 0.10 nmol/min/mg protein in gingiva (n=24) and tongue (n=3) respectively.

Applicant's summary and conclusion

Conclusions:
ALDH activity was detected in gingiva and lingual tissue; this activity was associated with a high Km isozyme (ALDH3).