Membrane-limited granules in sinus hair gelatinous membrane in mice

Electron dense membrane limited granules were observed in basal cells of the outer root sheath and in connective tissue sheath of the anagen sinus hair of mice. These granules were oval or round in configuration, and were 150--180 nm in size. They were considered to represent structures related to collagenolytic activity to accelerate elongation of anagen hair.