Influence of ciclosporin on epidermal proliferation after mechanical skin irritation.

In mice (NMRI and hr/hr), ciclosporin, subcutaneously administered once daily over 7-10 days, influenced epidermal hyperproliferation induced by abrasion of superficial epidermal layers. While in vehicle-treated control animals the mechanical irritation of skin caused an increase in 3H-thymidine triphosphate incorporation rate into DNA and also in epidermal thickness of tail and flank skin, the hyperproliferative response was diminished in ciclosporin-treated animals. Thus, only a slight increase of the 3H-thymidine triphosphate incorporation rate and of epidermal thickness was measured after pretreatment with ciclosporin, the effect being dose-dependent. The strongest inhibitory activity was found after application of 30 mg/kg BW. These findings indicate that the immunosuppressive peptide ciclosporin inhibits the epidermal proliferation in vivo.