Registration Dossier

Administrative data

Endpoint:
specific investigations: methaemoglobinaemia
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Acceptable publication which meets basic scientific principles

Data source

Referenceopen allclose all

Reference Type:
publication
Title:
Methemoglobin induced by carcinogenic aminoazo dyes in rats
Author:
Lin JK, Hsu SM, Wu YH
Year:
1972
Bibliographic source:
Biochem Pharmacol 21: pp. 2147-50
Reference Type:
secondary source
Title:
4-Aminoazobenzene. BUA-Stoffbericht 217
Author:
Beratergremium für Altstoffe (BUA)
Year:
1998
Bibliographic source:
BUA der Gesellschaft dt. Chemiker, S. Hirzel Wissenschaftliche Verlagsgesellschaft, Stuttgart

Materials and methods

Test guideline
Qualifier:
no guideline followed
Principles of method if other than guideline:
Application of 4-Aminoazobenzene intraperitoneally. Analysis of hematological changes.
GLP compliance:
no
Type of method:
in vivo

Test material

Reference
Name:
Unnamed
Type:
Constituent

Test animals

Species:
rat
Strain:
Sprague-Dawley
Sex:
male
Details on test animals and environmental conditions:
TEST ANIMALS
- Weight at study initiation: 200-260g or 250-300g, respectively

Administration / exposure

Route of administration:
intraperitoneal
Vehicle:
peanut oil
Analytical verification of doses or concentrations:
not specified
Duration of treatment / exposure:
after i.p. application analysis after 1h, 4h, 7h, and 10h
Frequency of treatment:
single dose
Post exposure period:
not applicable
Doses / concentrations
Remarks:
Doses / Concentrations:
0.323, 0.161, 0.08, 0.04, 0.02 mmol/kg
Basis:
other: nominal dose
No. of animals per sex per dose:
1h: n=10; 4h: n=5; 7h: n=5; 10h: n=5
0.323mmol/kg: n=10 (after 1h), n=5 (after 4h)
0.161mmol/kg: n=4 (after 1h), n=4 (after 4h)
0.080mmol/kg: n=4 (after 1h), n=4 (after 4h)
0.040mmol/kg: n=3 (after 1h), n=3 (after 4h)
0.020mol/kg: n=3 (after 1h), n=3 (after 4h)
Control animals:
not specified
Details on study design:
Formation of methemoglobin. The concentration of methemoglobin (as percentage of total hemoglobin) in the blood of rats injected i.p. with Aminoazobenzene in 0.5ml peanut oil were determined. After the tested compounds were injected, the blood (0.5 - 0.7ml) of rats was collected at a given time interval by heart puncture under ether anesthesia.

Examinations

Examinations:
The blood was transferred to an oxalated tube (potassium oxalate, 1.5mg/ml of blood) and mixed thoroughly by gentle swirling. The concentration of methemoglobin in the collected sample was determined within 20 min, according to a spectrophotometric method, and calculated.
Positive control:
no data

Results and discussion

Any other information on results incl. tables

1 hour after injection 66.6% of total hemoglobin was detected as methemoglobin. Level decreased time-dependent. 10 hours after injection Met-HB level was 7.2%.

Aminoazobenzene Methemoglobin (% of total Hb)
mmol/kg 1hour 4 hours
0.323 66.6 ± 5.2 44.5 ± 6.2
0.161 53.1 ± 3.1 39.6 ± 2.6
0.080 48.9 ± 4.8 31.4 ± 3.7
0.040 24.6 ± 3.0 6.2 ± 0.2
0.020 18.5 ± 1.1 2.2 ± 0.2

Applicant's summary and conclusion