Innervation and receptor profiles of the human apocrine (epitrichial) sweat gland: routes for intervention in bromhidrosis

Summary Background Human apocrine (epitrichial) sweat glands secrete in response to local or systemic administration of catecholamines and cholinergic agonists. As the process of secretion in human apocrine glands is not fully understood and no literature detailing the expression of adrenergic, cholinergic and purinergic receptors is available, there is a need to know the receptor types. Such data could provide new approaches for the treatment of axillary bromhidrosis. Objectives To investigate the localization of nerve fibres, adrenergic, cholinergic and purinergic receptors in human axillary apocrine sweat glands by immunohistochemistry. Methods Human axillary apocrine sweat glands were investigated by serial sectioning of paraffin wax‐embedded skin samples from volunteers. Sections were examined by light microscopy and immunohistochemistry, using antibodies against neurofilament, α‐ and β‐adrenoceptors, P2Y1, P2Y2 and P2Y4 purinoceptors, and M3 cholinoceptors. Results Neurofilaments were found near the eccrine but not the apocrine gland. Apocrine glands demonstrated the presence of β‐2 and β‐3 adrenoceptors in the secretory coil of the gland, but not α‐1, β‐1 or M3 receptors. Glandular purinergic staining (P2Y1, P2Y2 and P2Y4) was found in what looked like myoepithelial cells, while P2Y1 and P2Y2 staining was found on apical membranes and diffusely throughout secretory cells. Eccrine gland staining acted as internal positive controls. Conclusions No nerve fibres were found near the apocrine gland, suggesting that any catecholamine influence is through humoral effects and that glands could be influenced by β‐adrenoceptor subtypes and purinoceptors. Blockage of both these types of receptors offers a route to controlling apocrine secretion from axillary glands and reducing the opportunity for the development of bromhidrosis.