Aziridine

Genetic toxicity: in vivo

Administrative data

Endpoint:

in vivo mammalian somatic cell study: cytogenicity / erythrocyte micronucleus

Remarks:

Type of genotoxicity: chromosome aberration

Type of information:

experimental study

Adequacy of study:

key study

Study period:

January - March 1974

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Meets generally accepted scientific standards, well documented and acceptable for assessment

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1975

Report date:

1975

Materials and methods

Principles of method if other than guideline:

The study was conducted according to the method described by Boller K & Schmid W (1970) for the Chinese hamster.
Boller K & Schmid W (1970). Humangenetik 11: 35 -53.

GLP compliance:

no

Type of assay:

micronucleus assay

Test material

Test material information

Constituent 1

Reference substance name:

Ethylenimine

IUPAC Name:

Ethylenimine

Details on test material:

- Name of test material (as cited in study report): Aethylenimin
- Physical state: liquid
- Analytical purity: 100 % (stabilised by NaOH)

Test animals

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: WIGA, Sulzfeld
- Age at study initiation: no data
- Weight at study initiation: 200 -250 g
- Housing: 3 animals/cage
- Diet (ad libitum): Altromin-R (Altrogge, Lage/Lippe)
- Water: ad libitum



ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22 ± 2
- Humidity (%): 55 ± 5
- Photoperiod (hrs dark / hrs light): 12 h / 12 h

Administration / exposure

Route of administration:

intraperitoneal

Vehicle:

- Vehicle(s)/solvent(s) used: none

Duration of treatment / exposure:

acute exposure (one application) / repeated dose exposure (5 applications)

Frequency of treatment:

1 or 5 applications

Post exposure period:

not applicable

Doses / concentrations

Remarks:

Doses / Concentrations:
1.16 and 2.9 µl/kg bw (corresponding to approx. 0.96 and 2.41 mg/kg bw) (Recalculation based on relative density at 24 °C = 0.83)
Basis:
other: actually applied

No. of animals per sex per dose:

3

Control animals:

yes, concurrent no treatment

other: sodium chloride

Positive control(s):

As positive control mutagenic cytostatic Trenimon (= 2,3,5-tris-ethylenimino-benzochinon-1,4) was applied in the same way.
- Route of administration: intraperitoneal
- Doses / concentrations: 1 X 50 and 1 X 125 µg/kg bw (acute), and 5 X 50 and 5 X 25 µg/kg bw (repeated dose), respectively

Examinations

Tissues and cell types examined:

Femoral bone marrow cells were collected.

Details of tissue and slide preparation:

CRITERIA FOR DOSE SELECTION:
Dose selection was based on acute toxicity study by the intraperitoneal route.


TREATMENT AND SAMPLING TIMES:
After single application of the test substance, the rats were sacrificed 4, 24 or 48h after application. After repeated application (5 times) of the test substance, the rats were sacrificed 4h after the last application.


DETAILS OF SLIDE PREPARATION:
Femoral bone marrow cells were collected. Smears were prepared and stained according to May-Grünwald. 5000 erythrocytes and 500 nucleated cells were counted.

Evaluation criteria:

No data

Statistics:

Statistical evaluation was done using the t-test.
 

Results and discussion

Test results

Sex:

male/female

Genotoxicity:

positive

Toxicity:

no effects

Vehicle controls validity:

not applicable

Negative controls validity:

valid

Positive controls validity:

valid

Any other information on results incl. tables

Animals sacrificed 4h after single injection:

No biological relevant increase in the frequency of micronuclei in erythrocytes was observed after injection of 0.96 or 2.41 mg/kg bw of the test substance. 

 

Injection of 0.05 or 0.125 mg Trenimon/kg bw caused an increase in the number of micronuclei only in females.

 

Animals sacrificed 24h after single injection:

No significant increase in the frequency of micronuclei in erythrocytes was observed after injection of 0.96 or 2.41 mg/ kg bw of the test substance.

 

Injection of 0.05 or 0.125 mg Trenimon/kg bw caused an increase in the number of micronuclei in males, whereas in females only injection of 0.05 mg Trenimon/kg bw had a significant effect.

 

Animals sacrificed 48h after single injection:

After injection of 2.41 mg/kg bw of the test substance an increased number of micronuclei were observed in the erythrocytes of males and females.

No significant increase in the frequency of micronuclei in erythrocytes was observed after injection of 0.96 mg/kg bw of the test substance.

 

Injection of 0.125 mg Trenimon/kg bw caused an increase in the number of micronuclei in males, whereas injection of 0.05 mg Trenimon/kg bw caused an increased number of micronuclei containing erythrocytes both in males and females.

 

Animals sacrificed 4h after repeated application:

After 5 injections of 2.41 mg/kg bw of the test substance no increase in the number of micronuclei was observed. In males 5 injections of 0.96 mg/kg bw caused a significant increase in the number of micronuclei compared to the NaCl-treated control (P<0.005) and the untreated control (P<0.05).

 

Injection of 0.05 or 0.025 mg Trenimon/kg bw caused a significant increase in the number of micronuclei in males and females.

 

In conclusion, the test substance showed a chromosome damaging effect under the experimental conditions used.

Male rats:

 

Test substance	Time of sacrifice [h]	Dose  [mg/kg bw]	Micronuclei in polychrom. eryth. [%]	Micronuclei in normochrom. eryth. [%]	Micronuclei in total eryth. [%]
Ethylenimine	4	1 X 2.41	4.63	1.73	6.37 **
	4	1 X 0.96	3.93	1.23	5.17
	24	1 X 2.41	6.23	2.74	8.70*
	24	1 X 0.96	4.63	0.67	5.30
	48	1 X 2.41	5.83	0.47	6.30***
	48	1 X 0.96	2.40	1.13	3.53*
	4	5 X 2.41	4.80	0.63	5.43
	4	5 X 0.96	7.27	2.00	9.27***
Trenimon	4	1 X 0.125	3.57	3.10	6.67**
	4	1 X 0.05	4.50	1.70	6.20**
	24	1 X 0.125	9.07	2.93	12.0***
	24	1 X 0.05	17.80	4.27	22.67***
	48	1 X 0.125	4.53	4.67	9.20***
	48	1 X 0.05	5.57	1.77	7.33***
	4	5 X 0.05	12.73	7.11	19.84***
	4	5 X 0.025	10.47	4.70	15.17***
Sodium chloride	4	1 X 5.0 mL/kg	4.22	1.77	5.98**
	24	1 X 5.0 mL/kg	3.40	1.50	4.90
	48	1 X 5.0 mL/kg	3.32	1.17	4.48
	4	5 X 5.0 mL/kg	3.48	0.90	4.38
Untreated	4	-	2.84	0.80	3.64
	24	-	4.23	0.89	5.13
	48	-	3.12	0.85	3.97
	4	-	3.93	1.24	5.18

* Statistical significance compared to NaCl control

** Statistical significance compared to untreated control

*** Statistical significance compared to both controls

Female rats:

 

Test substance	Time of sacrifice [h]	Dose  [mg/kg bw]	Micronuclei in polychrom. eryth. [%]	Micronuclei in normochrom. eryth. [%]	Micronuclei in total eryth. [%]
Ethylenimine	4	1 X 2.41	4.07	1.30	5.37
	4	1 X 0.96	3.33	1.30	4.60
	24	1 X 2.41	3.67	0.97	4.63*
	24	1 X 0.96	3.87	0.77	4.63*
	48	1 X 2.41	5.80	1.63	7.43***
	48	1 X 0.96	1.90	2.43	4.33
	4	5 X 2.41	4.63	1.20	5.83**
	4	5 X 0.96	3.50	1.53	5.03
Trenimon	4	1 X 0.125	11.93	5.47	17.40***
	4	1 X 0.05	6.37	2.93	9.30***
	24	1 X 0.125	3.53	1.60	5.13
	24	1 X 0.05	10.53	3.20	13.73***
	48	1 X 0.125	3.03	2.60	5.63
	48	1 X 0.05	7.33	3.00	10.33***
	4	5 X 0.05	7.80	4.45	12.25***
	4	5 X 0.025	8.97	5.27	14.23***
Sodium chloride	4	1 X 5.0 mL/kg	3.70	1.40	5.10
	24	1 X 5.0 mL/kg	3.90	2.02	5.92**
	48	1 X 5.0 mL/kg	3.18	1.68	4.87
	4	5 X 5.0 mL/kg	3.60	1.45	5.05**
Untreated	4	-	2.91	1.33	4.24
	24	-	2.78	0.98	3.76
	48	-	2.82	1.40	4.22
	4	-	2.76	0.84	3.60

* Statistical significance compared to NaCl control

** Statistical significance compared to untreated control

*** Statistical significance compared to both controls

 

 

Applicant's summary and conclusion

Conclusions:

Interpretation of results (migrated information): positive