Lanthanum trinitrate

Developmental toxicity / teratogenicity

Administrative data

Endpoint:

developmental toxicity

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. Therefore this publication is scored 4 for reliability.

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:

A traditional teratogenic test and a feeding taratogenic test was reported to be conducted.
The traditional one consisted of oral administration of mixed rare earth nitrate to rats from 8th to 14th day after pregnancy and observation of fetus.
The feeding one consisted of feeding young rats with the test mix and observing the effects on rate of gestation, growth and development of embryos and skeleton development seven months after administration.

GLP compliance:

no

Limit test:

no

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:

rat

Strain:

Wistar

Details on test animals or test system and environmental conditions:

no data

Administration / exposure

Route of administration:

oral: feed

Details on exposure:

(1) Traditionnal teratogenic test: oral administration of 10 and 100 mg/kg mixed rare earth nitrate
(2) Feeding teratogenic test: yound rats were fed with 100 nad 1000 ppm rare earth forage

Analytical verification of doses or concentrations:

no

Details on mating procedure:

Feeding teratogenic test: seven months after administration, males and females fed with the same dosage were mated in one cage.

Duration of treatment / exposure:

Traditionnal teratogenic test: administration from 8th to the 14th day after pregnancy
Feeding teratogenic test: no data

Frequency of treatment:

no data

Duration of test:

no data

Control animals:

yes, concurrent no treatment

other: positive control: pentachlorolphenol sodium

Examinations

Maternal examinations:

Feeding teratogenic test: Rate of gestation

Fetal examinations:

Traditionnal teratogenic test: Rate of live fetus and average live fetus per litter
Feeding teratogenic test: Growth and development of embryo, skeleton development

Results and discussion

Results: maternal animals

Maternal developmental toxicity

Details on maternal toxic effects:

Maternal toxic effects:no effects

Results (fetuses)

Details on embryotoxic / teratogenic effects:

Embryotoxic / teratogenic effects:no effects

Details on embryotoxic / teratogenic effects:
Traditionnal teratogenic test: The rate of live fetus and the average live fetuses per litter had no distinct difference against the negative control group. It indicated that the embryo toxicity is low. The dead and absorbed fetuses in the positive control group reached 39.3%.
The average weight, length and tail length of embryos rats in three rare earth groups are higher than those of the negative, but the three parameters of animals in the positive group are apparently lower than the negative and rare earth groups.

Feeding teratogenic test: The results showed that there were no effects on the rate of gestation growth and development of embryo and the skeleton development. Among 133 embryos rats in the 100 ppm group, there was one malformation. There was not any deformity of internal organs in each group.

Fetal abnormalities

Abnormalities:

not specified

Overall developmental toxicity

Developmental effects observed:

not specified

Applicant's summary and conclusion

Conclusions:

Under the conditions of these tests, no teratogenic effect was described after oral administration of mixed rare earth nitrate to rats.