Effects of Hypertrichotic Agents on Follicular and Nonfollicular Cells In Vitro

The study investigated the effects of hypertrichotic agents, minoxidil and cyclosporin, on DNA synthesis in cultured follicular and nonfollicular cells from human and macaque scalps. Minoxidil significantly increased DNA synthesis in all follicular cells, indicating a specific affinity and proliferative effect on hair follicular cells, with the maximum effect observed at specific concentrations for different cell types. In contrast, nonfollicular cells showed no response to minoxidil, and 3T3 cells were suppressed. Cyclosporin, despite being a known hypertrichotic agent, did not show a direct proliferative effect on cultured follicular cells and appeared to suppress both follicular and nonfollicular cells, suggesting a different mechanism of action from minoxidil.