Production of Ultraviolet-Light-Induced Skin Erythema in the Hairless Rat: A Comparison with the Haired Rat in Screening for Anti-Inflammatory Drugs

In a study from 1979, hairless rats were compared to haired rats to assess the onset of ultraviolet-light-induced skin erythema and the efficacy of anti-inflammatory drugs in preventing it. The study found that the onset of erythema in hairless rats closely matched that in haired rats, and both phenylbutazone (30 mg/kg orally) and fluocinolone acetonide (10 mg/kg subcutaneously) had equivalent anti-erythemic effects on both types of rats. Groups of 5 male hairless rats were used in the experiments. The hairless rat, which does not require depilation before irradiation, was suggested as a useful alternative model for such studies. The study concluded that the hairless rat could be an attractive alternative for screening anti-inflammatory drugs, as it avoids the potentially damaging step of depilation required for haired rats.