Induction of Ornithine Decarboxylase Activity in Hairless Rat Epidermis as a Pharmacological Model: Validation of the Animal Model

The study used hairless Sprague Dawley rats to evaluate the effect of retinoids on inhibiting epidermal ornithine decarboxylase activity induced by sellotape stripping. The research involved 100 rats (50 males and 50 females) aged 4 to 11 weeks. It was found that hair growth occurred at 6-7 weeks and 10-11 weeks, with more pronounced development in males. Sellotape stripping was more effective in females, and the induction of ornithine decarboxylase was highest in rats aged 5-6 weeks, stabilizing between 6-12 weeks. The study concluded that female rats aged about 8 weeks provided the most reproducible response and ease of use for this model.