A method for accurate measurement of cutaneous irritancy of trichothecenes

Conventional skin irritation bioassays for trichothecenes are semiquantitative because test animals vary in sensitivity, and the intensity of cutaneous inflammation is poorly correlated with dose. A quantitative bioassay was therefore devised for toxicological studies on the irritancy of trichothecenes. A graded series of six standard solutions of T-2 toxin (10-60 micrograms/mL) in 2 microL volumes was applied to the shaved skin of young female Wistar rats. Each test sample was applied at least twice to each of five rats. After 48 hours, reactions were rated in units of equivalent concentrations of T-2 toxin, so that measurements were independent of the intensity of inflammatory reaction. Mean concentrations of replicate measurements of test solutions of T-2 toxin between 10 and 60 micrograms/mL were precise (SEM less than 1.6 micrograms/mL) and accurate (within 13% of actual concentrations).