Self-regulated endocrine systems in the skin

Abstract

The skin is the main physical barrier between the environment and internal homeostasis; functionally it is highly complex and expresses endocrine activities with self-regulatory properties. This skin neuroendocrine system comprises locally produced neuro-endocrine mediators that interact with corresponding specific receptors through para or autocrine mechanisms. While there are also systemic effects of cutaneously produced hormones exemplified by vitamin D3 and PTHrP, the most important function of this system would be the modulation of responses to noxious agents. Solar radiation, the most significant environmental stressor is already known to significantly affect cutaneous endocrine activities. Ultimately, the skin neuroendocrine system would act to preserve cutaneous structural and functional integrity to maintain systemic homeostasis.