Expression of Mu-Opiate Receptor in Human Epidermis and Keratinocytes

The study demonstrated that human epidermal keratinocytes expressed μ-opiate receptors at both mRNA and protein levels, with higher protein levels in the basal layer. Functional assays showed that incubation with Naloxone or β-endorphin significantly downregulated μ-opiate receptor expression, indicating a functional role in the epidermis. Immunohistochemistry revealed specific staining in the basal and suprabasal layers, sweat gland ducts, and hair follicles. These findings suggested that μ-opiate receptors played a role in skin physiology, potentially influencing skin diseases, wound healing, and itch perception, highlighting the interaction between the neural system and skin.