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 for minoxidil were not identified, high concentrations (over 100 micrograms/ml) inhibited DNA and protein synthesis, with inhibition being reversible up to 400 micrograms/ml. At 100 micrograms/ml, minoxidil prolonged cell division and increased cell density compared to controls. This suggested that minoxidil's ability to extend the proliferative capacity of keratinocytes might contribute to its positive effects on hair growth.