Immunohistochemical study of angiotensin receptors in human anagen hair follicles and basal cell carcinoma.

BACKGROUND: Angiotensin receptors are the specific receptors of angiotensin II of the renin-angiotensin system. However, expression of the receptors in hair follicles has not been determined.

OBJECTS: To clarify the expression and localization of angiotensin receptors in human anagen hair follicles and basal cell carcinomas.

METHODS: We studied immunohistochemically the expression of angiotensin type 1(AT1) and type 2 (AT2) receptors in human anagen hair follicles and in 16 cases of basal cell carcinoma (BCC) (nine of solid BCC of the circumscribed type, two of adenoid BCC, five of BCC with follicular differentiation).

RESULTS: Our experiments demonstrated the localization of AT1 in the inner root sheath and the inner layers of the outer root sheath. In BCC, positive staining with AT1 was revealed in the tumour cells of basal cell carcinoma with follicular differentiation.

CONCLUSIONS: AT1 may have a role in association with follicular keratinization. Studying AT1 distribution may be useful in understanding the pathophysiology of human hair follicles and the hair follicle-associated tumours.