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Toxicological information

Specific investigations: other studies

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Administrative data

Endpoint:
specific investigations: other studies
Type of information:
experimental study
Adequacy of study:
supporting study
Reliability:
4 (not assignable)
Rationale for reliability incl. deficiencies:
other: No GLP compliance and no data on guidelines requirements.

Data source

Reference
Reference Type:
publication
Title:
Unnamed
Year:
1974
Report Date:
1974

Materials and methods

Principles of method if other than guideline:
Exposure of rats to 44 different odour substances and examination of olfactory bulbs.
GLP compliance:
no
Type of method:
in vivo
Endpoint addressed:
not applicable

Test material

Reference
Name:
Unnamed
Type:
Constituent

Test animals

Species:
rat
Strain:
Wistar
Sex:
not specified
Details on test animals and environmental conditions:
TEST ANIMALS
- Age at study initiation: 2 weeks
- Weight at study initiation: 28-39 g
- Housing: cylindrical cages, with closed tops

ENVIRONMENTAL CONDITIONS
- Air changes: 0,6 litre X sec-1

Administration / exposure

Route of administration:
inhalation
Vehicle:
unchanged (no vehicle)
Analytical verification of doses or concentrations:
yes
Details on analytical verification of doses or concentrations:
Each substance was introduced into the air stream from a glass bottle, the content of which was weighed before and after the experiments to measure the concentration of substance in the stream.
Duration of treatment / exposure:
For IBA: 4 weeks and 8 weeks
Frequency of treatment:
Continous
Doses / concentrations
Remarks:
Doses / Concentrations:
7.9 E(-9) M
Basis:
analytical conc.
No. of animals per sex per dose:
For IBA: 3 animals
Control animals:
yes

Results and discussion

Any other information on results incl. tables

Administration of IBA 7.9 E-9 M (1.551 mg/m3):

after 4 weeks: mean weight of animals at sacrifice: 107 g

after 8 weeks: mean weight of animals at sacrifice: 220 g

Applicant's summary and conclusion

Conclusions:
For IBA was observed a specific pattern of mitral cell degeneration in the olfactory bulb: a heavy 'degeneration' of granule cells in the ventral area of the bulb.
Executive summary:

Rats have been exposed to a variety of constant odorous environments from 2 weeks of age for periods from 1 to 12 weeks. They have been compared with control litter-mates exposed to a non-odorised milieu for the same periods. For each of 44 different odours a specific pattern of mitral cell degeneration was observed in the olfactory bulb; the pattern and extent of this 'selective degeneration' did not appear to be correlated with the concentration of the odorant. The pattern of degeneration in coronal sections was maintained through the antero-posterior extent of the bulb in most cases. These results suggest a topological representation of different odours in the olfactory bulb. The implications of selective degeneration in the study of odour-quality discrimination are discussed.