Uptake Kinetics and the Effect of Minoxidil on Human Keratinocyte Cultures

The study investigated the uptake kinetics of minoxidil in human keratinocyte cultures and its effects on cell proliferation. Minoxidil was rapidly absorbed by keratinocytes, reaching half of its maximum uptake in 3 hours, although specific receptors were not identified. At concentrations above 100 micrograms/ml, minoxidil inhibited DNA and protein synthesis, but this effect was reversible up to 400 micrograms/ml. Notably, at 100 micrograms/ml, minoxidil extended the duration of cell division and increased cell density compared to controls. This prolongation of keratinocyte proliferation might have contributed to minoxidil's positive impact on hair growth.