Abstract
Utility of Japanese White rabbit mutants with hypotrichosis (htr strain) was investigated in dermal toxicity studies. In the primary irritation study, the primary irritation indices (P.I.I.) by application of hexachlorophene and 3, 3’, 4’, 5-tetrachlorosalicylanilide (TCSA) were higher in the htr rabbits than in the control, haired rabbits. The P.I.I. by application of Tween 80 and sodium lauryl sulfate (SLS) were similar between the htr rabbits and the control rabbits. In the 16-day cumulative irritation study, irritation scores induced by SLS and sodium hydroxide were lower in the htr rabbits than in the control rabbits throughout the observation periods. However, approximately 30% of the dorsal skin of the control rabbits underwent the anagen phase of the hair cycle during the cumulative periods, resulting in difficulty to apply the chemicals and to estimate the skin reactions. In the phototoxicity study, irritation scores of the htr rabbits treated with 8-methoxypsoralen and TCSA were similar to those of the control rabbits. These results revealed advantages of the htr rabbits in the administration of test chemicals and the evaluation of skin reactions, suggesting the usefulness of htr rabbits for dermal toxicity studies.
