Lanthanum trinitrate

Genetic toxicity: in vivo

Administrative data

Endpoint:

in vivo mammalian germ cell study: cytogenicity / chromosome aberration

Remarks:

Type of genotoxicity: chromosome aberration

Type of information:

experimental study

Adequacy of study:

disregarded due to major methodological deficiencies

Reliability:

4 (not assignable)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

This publication reports the results of mutagenic and teratogenic tests from rare earth compounds in general. The material and methods section is substantially incomplete, main part of the results are not reported and discussion/conclusion/references parts are inexistant.

Cross-reference

Reason / purpose for cross-reference:

reference to same study

Data source

Reference

Reference Type:

publication

Title:

The investigation of mutagenicity and teratogenicity from rare earth compounds

Author:

Mu C & Shi W

Materials and methods

Test guideline

Qualifier:

no guideline followed

Principles of method if other than guideline:

Wistar rats and Kunming species mice were administrated orally with 1, 10 and 100 mg/kg mixed rare earth nitrate each day during 5 days. Chromosome aberration and micronucleus rates were measured in the rats and mice marrow cells after the period of administration. The filial generation marrow cells were also investigated at the 3rd month after birth.

GLP compliance:

no

Type of assay:

other: in vivo chromosome aberration and micronucleus

Test material

Test material information

Constituent 1

Reference substance name:

mixed rare earth nitrate

IUPAC Name:

mixed rare earth nitrate

Details on test material:

The following paragraph has been directly taken from the publication, and contains uncertainties and inaccurate information:

"The mixed rare earth nitrate is provided by Shangqiu Chemical Smeltery in Henan Province. The RexOy content is 38.71%, specific activities of α and β are 1.43E-08 and 1.67E-09 Ci/kg respectively. The main components are Ce 38.7%, La 39.16%, Nd 15.52%, Pr 5.3% and Sm 1.88%. The sole rare-earth compounds include La2O3, Sm2O3, Eu2O3, YCL3, ScCl3, NdCl3, Cd2O3, Pr6O13 and NiCl2 as positive control substance. Their purity is all over 99.9%".

Test animals

Species:

other: rats and mice

Strain:

other: Wistar rats and Kunming mice

Sex:

not specified

Administration / exposure

Route of administration:

oral: feed

Details on exposure:

Two periods of exposure were investigated:

(1) daily oral administration during 5 days

(2) feeding with the forage containing rare earth nitrate for 3-6 months

Duration of treatment / exposure:

(1) 5 days
(2) 3-6 months

Frequency of treatment:

(1) daily (no data about the frequency per day)
(2) no data, assumed to be daily

Post exposure period:

no data

Doses / concentrations

Doses / concentrations 1

Remarks:

Doses / Concentrations:
1, 10, 100 mg/kg
Basis:
nominal conc.

Doses / concentrations 2

Remarks:

Doses / Concentrations:
100, 1000 and 10000 ppm
Basis:
nominal conc.

No. of animals per sex per dose:

5 animals per dose (no data about species nor sex)
Apparently, the filial generation was also subjected to examination.

Control animals:

yes, concurrent no treatment

Positive control(s):

none

Examinations

Tissues and cell types examined:

marrow cells

Details of tissue and slide preparation:

no data

Evaluation criteria:

none

Statistics:

no data

Results and discussion

Test results

Sex:

not specified

Genotoxicity:

negative

Toxicity:

not examined

Vehicle controls validity:

not specified

Negative controls validity:

other: rates near the results of two other unknown authors

Positive controls validity:

not applicable

Additional information on results:

(1) After a 5-day exposure to mixed rare earth nitrate, no increase of aberration rate of marrow cells was observed. There was no significant difference in comparison with the control group. The micronucleus rate was also within the normal range (Table 1).

(2) During the third month, there was an increasing tendency with dosage in the aberration rate of marrow cells from experimental mice, but there was no significant difference between each group and the control. In the 6th month and 3rd month of the filial generation, the marrow cell-aberration rate had no change (Table 2).

Any other information on results incl. tables

Table 1: Changes of aberration rate and micronucleus rate of marrow cells in rats after administration RE (first exposure)

Group	Number of animals	Aberration rate %	Micronucleus rate %
Control	5	0.33±0.45	0.23±0.06
1 mg/kg	5	0.33±0.28	0.32±0.05
10 mg/kg	5	0.24±0.45	0.27±0.08
100 mg/kg	5	0.33±0.48	0.23±0.06

Table 2: Changes of Aberration rate of marrow cell of mice

Group	Num. Anim.	Parent. 3rd %	Paren. 6th %	Filial 3rd %
Control	6	0.66±0.24	-	0.68 ± 0.31
100 ppm	6	0.79 ±0.51	0.68 ±0.22	0.67±0.51
1000 ppm	6	0.84 ±0.53	0.45 ±0.44	0.70 ±0.25
10000 ppm	6	0.94 ±0.35	-	-

Applicant's summary and conclusion

Conclusions:

Interpretation of results (migrated information): negative
Under the conditions of these tests, mixed rare earth nitrate does not have mutagenic effect on marrow cells.