Differences in Activity of Minoxidil and Cyclosporin A on Hair Growth in Nude and Normal Mice: Comparisons of In Vivo and In Vitro Studies

The study assessed the effects of minoxidil and cyclosporin A on hair growth in nude mice, revealing that minoxidil did not influence hair growth in these mice, while cyclosporin A increased peak hair growth when administered orally. In vitro tests showed minoxidil stimulated hair growth in normal mice follicles but not in nude mice, whereas cyclosporin A stimulated growth in nude mice follicles only. The findings suggested that cyclosporin A could compensate for a genetic defect in nude mice follicles, unlike minoxidil, indicating that nude mice are not suitable for studying minoxidil effects but may be useful for exploring the genetic influences on hair growth.