Expression of transglutaminase I in human anagen hair follicles.

The expression of the transglutaminase I in human anagen hair follicles was studied by an immunohistochemical staining. In the bulbar and suprabulbar portions of anagen hair follicles, transglutaminase I was detected on the hair cuticle and the three layers of the inner root sheath. Subsequently, the positive staining became translocated to the inner site of the outer root sheath in the middle part of the hair follicle. In the upper portion of the hair follicle transglutaminase I was detected in the internal part of the outer root sheath and the surface epidermis. Therefore, it was suggested that the expression of transglutaminase I might be closely associated with the terminal keratinization in the anagen hair follicles.