The Effects of Testosterone on Skin Barrier / 대한피부과학회지

BACKGROUND: Although there are no known gender-related differences in permeability barrier function in adults, estrogen accelerates whereas testosterone retards barrier development in fetal skin. However, there have been few studies concerning the effects of testosterone on the skin barrier. OBJECT: We evaluated the effects and mechanisms of testosterone on the skin barrier. METHODS: In this experiment, hairless mice were divided into three groups; sham-operated, castrated and testosterone-replacement castrated group. Testosterone was administered subcutaneously once a day for 7 days. We performed a skin biopsy at 7 days and performed hematoxyline-eosin staining, calcium-ion capture cytometry and the immunohistochemical examination of involucrin, loricrin, filaggrin and proliferating cell nuclear antigen (PCNA). The specimens were prepared for electron microscopy using RuO4 and OsO4 postfixation. RESULTS: The results were summarized as follows 1. Light microscopic findings of the testosterone-replacement castrated group showed apparent hyperkeratosis and acanthosis, not present in the sham-operated and castrated group. 2. Whereas the expression of involucrin, loricrin and filaggrin of immunohistochemical staining and in situ hybridization of the sham-operated and castrated group were normal, it was abnormal in the testosterone-replacement castrated group. 3. Labelling indices for PCNA in the sham-operated and castrated group were not statistically different, but the testosterone-replacement castrated group showed a marked increase of PCNA labeling index. 4. Wherease the calcium gradient was normal in the sham-operated and castrated group, it was distorted in the testosterone-replacement castrated group. Calcium deposition was increased through all layers of the epidermis and the calcium gradient disappeared in the testosterone-replacement castrated group. 5. Normal looking membrane structure was observed in the sham-operated and castrated group, but a membrane structure which appeared fragmented, incomplete lipid bilayer structures and prominent dilatation of lacunar domains were observed only in the testosterone-replacement castrated group. CONCLUSION: From the above results, it is concluded that there is a functional alteration of the epidermal barrier induced by testosterone, including the formation of an abnormal cornified envelope and also incomplete lipid synthesis.

The Changes of Epidermal Lipid and Calcium in the Lesion of Skin Tumor and Non-tumor of Hairless Mice Induced by Vinyl Carbamate Epoxide and TPA / 대한피부과학회지

BACKGROUND: Chemically induced epidermal carcinogenesis is usually divided into two stages, the initiation and promotion. The initiation involves conversion of some epidermal cells into latent neoplastic cells and the promotion is proliferation of the transformed cells. Ethyl carbamate (EC) has been identified at low microgram quantities in various fermented beverages, distilled products and tobacco smoke. It has been known as a initiator of tumor. Oxidation of the ethyl group of EC is followed by dehydration to yield the carcinogen vinyl carbamate (VC). This is further oxidized to vinyl carbamate epoxide (VCO). VC and VCO proved to be much more carcinogenic than EC. OBJECT: This study is attemped to investigate the skin tumor and non-skin tumor in hairless mice induced by application of 12-0-tetradecanoyl-phorbol-13-acetate (TPA) on the skin initiated with VCO and its relationship with calcium gradient and epidermal lipid. METHODS: In this experiment, the tumor induction was performed by painting the mouse skin once a week for five weeks with VCO solution, and then 12-0-tetradecanoyl-phobol-13-acetate (TPA) was treated in the same manner twice a week for 40 weeks. We biopsied the skin at 5, 10, 25, 30, 35 and 40 weeks and stained the specimens with hematoxylin-eosin, Ru04 postfixation and ion capture cytochemistry for calcium staining. RESULTS: The results are summerized as follows 1. Cellular proliferation, hyperkeratosis and dysplasia of the epidermis were more prominent in skin tumors than non-skin tumors. Papillomas were developed at 8 weeks after application of VCO- TPA but not TPA alone. The occurrence of keratoacanthoma and squamous cell carcinoma was 33 and 39 weeks, respectively. 2. Calcium gradient was distorted in the only TPA treatment group but normal in the control group. Calcium deposition was increased through all layers of epidermis and the calcium gradient was disappeared in the epidermis of tumors in the VCO-TPA treatment group. These findings were similar to papilloma, keratoacanthoma and squamous cell carcinoma. 3. Fragmented, incomplete lipid bilayer formation, dilated intercellular spaces and multiple lacunar domains were prominent in the VCO-TPA and TPA treatment groups but not in the control group. The VCO-TPA treatment group has shown more epidermal lipid damage than that of the only TPA treatment group. 4. Diploid DNA histogram patterns were observed in all the control and TPA treatment groups. But aneuploidy was observed in 1 of 3 keratoacanthomas and 3 of 3 squamous cell carcinomas. CONCLUSION: From the above results, it is concluded that various skin tumors, such as papilloma, keratoacanthoma and squamous cell carcinoma or non-skin tumor were produced by VCO. Skin tumors showed various, distinctive light microscopic or electron microscopic changes compared to the non-skin tumor. It is thought that intercellular lipid change and calcium gradient disappearance in the epidermis have an important role in the carcinogenesis.

Dry Skin

Though there is ambiguity in its medical definition, dry skin is a frequent skin problem of increasing importance these days. Generally "dry skin" denotes the status of skin showing erythema, roughness, scales, and itching resulted from low water content in the skin. Abnormalities in epidermal lipids, natural moisturizing factors, or corneocyte desquamation are regarded as important factors in its pathophysiology. It is not only accompanied with skin aging, but with various kinds of skin and systemic diseases(such as atopic dermatitis, ichthyosis, chronic renal failure, and diabetes mellitus). Important principles in the management or treatment of dry skin are preventing excessive washing and keeping moisture in the epidermis. For gentle cleansing, mild surfactants are better than the soap. Moisturizers are applied to the surface of skin to increase epidermal water content. Two different kinds of moisturizers are used as a mixture for the best result. Humectants are the material that draw water from the air or dermis. And emollients are the material that protects membrane by preventing water from evaporating from the epidermis. Though moisturizers are very helpful in management of dry skin, harmful result may happen by inadequate selection and wrong use.