Dm. Sailstad et al., EVALUATION OF SEVERAL VARIATIONS OF THE MOUSE EAR SWELLING TEST (MEST) FOR DETECTION OF WEAK AND MODERATE CONTACT SENSITIZERS, Toxicology methods, 3(3), 1993, pp. 169-182
The ability of a chemical to cause contact sensitization has tradition
ally been evaluated in animal models typically using the guinea pig. H
owever, these methods are expensive and require subjective analysis of
erythema, which makes evaluation of dyes difficult. The mouse ear swe
lling test (MEST) is a more quantitative and less costly method, but i
t has not always been reliable for the detection of moderate and weak
sensitizers. To identify a MEST that can reliably detect weak sensitiz
ers, several published MEST procedures were examined using the strong
sensitizer 2,4-dinitrofluorobenzene (DNFB) and three weaker sensitizer
s, glutaraldehyde, formalin, and an azo dye (Solvent Red 1 [SR 1 ]). A
lmost all variations of the MEST procedures detected the strong sensit
izer (DNFB) after optimizing the chemical concentration and sensitizin
g procedure; however, only one protocol detected the weaker sensitizer
s, glutaraldehyde, formalin, and SR1. This sensitive MEST protocol req
uired test animals to be fed a vitamin A-supplemented diet for 4 weeks
prior to sensitization. We concluded that the use of a vitamin A diet
with the MEST proved to be the best procedure to enhance the sensitiv
ity and detection of weak sensitizers.