Modulation of Dermal Cell Activity During Hair Growth in the Rat

The study investigated the interaction between connective tissue cells and hair growth in rats using radioautography with various labeling compounds. It was found that the connective tissue surrounding hair bulbs contains cells with cyclic metabolic activity that aligns with the hair growth cycle. During the anagen 4 substage, there was a significant increase in DNA synthesis in dermal cells, particularly endothelial and migratory cells. RNA and protein synthesis activities were also observed across all cell types, though they were less influenced by the hair cycle. These findings provided a foundation for understanding similar processes in conditions like alopecia areata.