1,3,5-triazine-2,4,6-triamine phosphate

Genetic toxicity: in vivo

Administrative data

Endpoint:

in vivo mammalian somatic cell study: cytogenicity / erythrocyte micronucleus

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Data source

Reference

Reference 1

Reference Type:

secondary source

Title:

Unnamed

Year:

1993

Reference 2

Reference Type:

publication

Title:

Evaluation of a Three-Exposure Mouse Bone Marrow Micronucleus Protocol: Results With 49 Chemicals

Author:

Shelby M.D. et al.

Year:

1993

Bibliographic source:

Environ. Mol. Mutagen., 21, 160-179

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 474 (Mammalian Erythrocyte Micronucleus Test)

Deviations:

yes

Remarks:

only 5-7 males per dose used, differing staining agent

Principles of method if other than guideline:

Standard protocol of the US National Toxicology Program

GLP compliance:

not specified

Type of assay:

other: micronucleus assay

Test material

Test material information

Constituent 1

Reference substance name:

Melamine

EC Number:

203-615-4

EC Name:

Melamine

Cas Number:

108-78-1

Molecular formula:

C3H6N6

IUPAC Name:

1,3,5-triazine-2,4,6-triamine

Test animals

Species:

mouse

Strain:

B6C3F1

Sex:

male

Administration / exposure

Route of administration:

intraperitoneal

Vehicle:

- Vehicle(s)/solvent(s) used: corn oil

Details on exposure:

Injection volume was 0.4 mL

Duration of treatment / exposure:

3 days

Frequency of treatment:

one injection/day on 3 consecutive days

Post exposure period:

1st study: For evaluation of bone marrow smears animals were sacrificed 24 hours after the 3rd exposure; for evaluation of peripheral blood smears
animals were sacrificed 48 hours after the 3rd exposure
2nd study: animals were sacrificed 24 hours after the 3rd exposure for both evaluation of bone marrow smears and evaluation of peripheral blood smears.

Doses / concentrations

Doses / concentrations 1

Dose / conc.:

0 other: mg/kg bw

Remarks:

1st study

Doses / concentrations 2

Dose / conc.:

500 other: mg/kg bw

Remarks:

1st study

Doses / concentrations 3

Dose / conc.:

1 000 other: mg/kg bw

Remarks:

1st study

Doses / concentrations 4

Dose / conc.:

2 000 other: mg/kg bw

Remarks:

1st study

Doses / concentrations 5

Dose / conc.:

1 000 other: mg/kg bw

Remarks:

2nd study

Doses / concentrations 6

Dose / conc.:

2 000 other: mg/kg bw

Remarks:

2nd study

No. of animals per sex per dose:

5 (exemption: only 3 animals were scored at the concentration of 2000 mg/kg bw in the first study)

Control animals:

yes, concurrent vehicle

Positive control(s):

7,12-dimethylbenzanthracene (12.5 mg/kg)

Examinations

Tissues and cell types examined:

bone marrow and peripheral blood

Details of tissue and slide preparation:

DETAILS OF SLIDE PREPARATION:
Staining with acridine orange

METHOD OF ANALYSIS:
Bone marrow:
Slides were evaluated for the number of MN-PCE among 2000 PCE and for the percentage of PCE among 200 erythrocytes.
Peripheral blood:
According to the NTP-Standard protocol 2000 PCEs are evaluated for the number of MN-PCE and 1000 erythrocytes are evaluated for teh percentage of PCE among erythrocytes.

Evaluation criteria:

A positive response is determined by statistical difference from the control group.

Statistics:

The data were analyzed using the Micronucleus Assay Data Management and Statistical software package (version 1.4 ), which was designed specifically for in vivo micronucleus data. The level of significance was set at an alpha level of 0.05.
To determine whether a specific treatment result ed in a significant increase in MN -PCE, the number of MN-PCE were pooled within each dose group and analyzed by a one- tailed trend test. In the software package used , the trend test incorporates a variance inflation factor to account for excess animal variability. In the event that the increase in the dose response cu rve is nonmonotonic , the software program allows for the data to be analyzed for a significant positive trend after data at the highest dose only has been excluded . However, in this event, the alpha level is adjusted to 0 .01 to protect against false positives.
The %PCE data were analyzed by an analysis of variance (ANOVA) test based on pooled data. Pairwise comparisons between each group and the concurrent solvent control group was by an unadjusted one-tailed Pearson chi -squared test which incorporated the calculated variance inflation factor for the study

Results and discussion

Test results

Key result

Sex:

male

Genotoxicity:

negative

Toxicity:

no effects

Vehicle controls validity:

valid

Negative controls validity:

not applicable

Positive controls validity:

valid

Additional information on results:

No signs of toxicity were observed

Any other information on results incl. tables

Table 1: MN data analysis

	Dose (mg/kg)	MN-PCE/1000 (No. of animals scored)	P value (a)	Survival	%PCEs (b)
1^st study, bone marrow (Sample collection time: 24 hours)			0.003
	0	2.10 +/- 0.62 (5)		5/5	57.3
	500	1.80 +/-0.34 (5)	0.685	5/5	56.6
	1000	2.20 +/- 0.25 (5)	0.439	5/5	57.1
	2000	3.80 +/- 0.70 (5)	0.013	6/6	56.1
	Positive control	6.90 +/- 0.87 (5)	0.0001	-	-
2^nd study, bone marrow (Sample collection time: 24 hours)			0.340
	0	4.60 +/- 0.64 (5)		5/5	60.9
	1000	4.20 +/- 1.21 (5)	0.596	5/5	51.7
	2000	5.30 +/- 1.59 (5)	0.344	5/6	56.3
	Positive control	8.40 +/- 0.56 (5)		-	-
1st study, peripheral blood (c) (Sample collection time: 48 hours)			0.964
	0	2.70 +/- 0.26 (5)		5/5	1.2
	500	3.50 +/- 0.91 (5)	0.154	5/5	1.5
	1000	2.40 +/- 0.56 (5)	0.663	5/5	1.1
	2000	1.50 +/- 0.76 (3)	0.940	3/5	1.2
2nd study, peripheral blood (Sample collection time: 24 hours)			0.411
	0	4.10 +/- 0.73 (5)		no data available	no data available
	1000	3.60 +/- 0.93 (5)	0.716	no data available	no data available
	2000	4.30 +/- 0.56 (5)	0.413	no data available	no data available
	Positive control	8.40 +/- 0.40 (5)	0.0001	no data available	no data available

(a) omitting the high dose value

 (b) ((No. of PCEs)/(No. of PCEs + No. of NCEs)) x 100

(c) no data on positive control available