A Murine Model for Inducing and Manipulating Hair Follicle Regression: Effects of Dexamethasone and Cyclosporin A

In 1994, researchers developed a mouse model to study hair follicle regression using dexamethasone (DEX) and cyclosporin A (CsA). They found that applying DEX topically significantly accelerated the onset of the catagen phase in the hair growth cycle, which was confirmed through morphometric histology. Conversely, high doses of CsA inhibited this process. The study involved 23 test mice and 14 control mice. The findings suggest that this model could be useful for screening drugs that block catagen and for studying the biology of hair follicle regression. The study also implies that DEX and CsA may affect similar signal transduction pathways that are important for the transition from the anagen (growth) phase to the catagen (regression) phase, which could be potential targets for hair growth-modulatory drugs.