Melatonin Induces a Stimulatory Action on the Scrotal Skin Components of Soay Ram in the Non-Breeding Season

In a study involving 15 adult Soay rams, melatonin was found to have a stimulatory effect on various components of the scrotal skin during the non-breeding season. The melatonin-treated group exhibited a significant increase in the thickness of the epidermis, the cross-sectional area of blood capillaries, and nerve fibers compared to the control group. There was also hypertrophy and hyperplasia in the sebaceous glands, an increase in the number and diameter of apocrine sweat glands, and enhanced secretory activity. The study observed a higher number of telocytes around nerve fibers and blood vessels, an increase in Langerhans cells within the epidermal layer, and a rise in the number of dendritic cells in the dermis, all showing strong immunoreactivity to various proteins. Additionally, there was a significant increase in Merkel cells, and the secretory granules in sweat glands showed strong reactivity for synaptophysin. Overall, melatonin administration induced a stimulatory effect on keratinocytes, non-keratinocytes, sebaceous and sweat glands, hair follicles, and the vascular, neuronal, and cellular constituents of the dermis.