Test No. 241: The Larval Amphibian Growth and Development Assay (LAGDA)
The test guideline of the Larval Amphibian Growth and Development Assay (LAGDA) describes
a toxicity test with an amphibian species (African clawed frog (Xenopus laevis)) that
considers growth and development from fertilization through the early juvenile period.
It is an assay (typically 16 weeks) that assesses early development, metamorphosis,
survival, growth, and partial reproductive maturation. It also enables measurement
of a suite of other endpoints that allows for diagnostic evaluation of suspected endocrine
disrupting chemicals (EDCs) or other types of developmental and reproductive toxicants.
The LAGDA serves as a higher tier test with an amphibian for collecting more comprehensive
concentration-response information on adverse effects suitable for use in hazard identification
and characterization, and in ecological risk assessment. The general experimental
design entails exposing X. laevis embryos at Nieuwkoop and Faber (NF) stage 8-10 (3)
to a minimum of four different concentrations of test chemical and control(s) until
10 weeks after the median time to NF stage 62. There are four replicates in each
test concentration with eight replicates for the control. Endpoints evaluated during
the course of the exposure (at the interim sub-sample and final sample at completion
of the test) include those indicative of generalized toxicity: mortality, abnormal
behaviour, and growth determinations (length and weight), as well as endpoints designed
to characterize specific endocrine toxicity modes of action targeting oestrogen, androgen
or thyroid-mediated physiological processes.
Published on July 28, 2015Also available in: French
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