Melatonin induces a stimulatory action on the scrotal skin components of Soay ram in the non-breeding season

Abstract

Fifteen adult Soay rams were employed in this study to investigate the effect of melatonin on the scrotal skin using histological, histochemical, and morphometrical analysis. the results revealed that the melatonin treated group showed a significant increase in the thickness of the epidermis, the cross-sectional area of blood capillaries and nerve fibers compared with the control one. In addition, obvious hypertrophy and hyperplasia were detected in the sebaceous glands in association with a significant increase in the number and diameter of apocrine sweat glands with well-developed secretory activity. S100 protein and cytokeratin-19 strongly stained the basal cells of sebaceous glands in the melatonin treated group incomparable to the control group. Moreover, the nerve fibers were intensively immunoreacted for S100 and cytokeratin proteins in the melatonin treated group in contrast to the control one. A high number of telocytes (TCs) could be identified in the treated group around the nerve fibers and blood vessels in the dermis. The number of Langerhans cells showed a significant increase in the melatonin groups that were identified by MHC II and PGP 9.5 within the epidermal layer. Furthermore, a significant increase in the number of dendritic cells was identified in the melatonin group, which were distributed within the dermis, around hair follicles, sebaceous glands, and sweat glands and were strongly expressed PGP-9.5, MHC-II, VAMP, SNAP, keratin-5, and cytokeratin-19 immunoreactivity. Notably, Merkel cells showed a significant increase in the number in the melatonin group that could be stained against nestin, SNAP, and VAMP. On the other hand, the secretory granules in sweat glands were exhibited a strong positive reactivity for synaptophysin in melatonin group. The current study showed that the administration of melatonin induced a stimulatory effect on keratinocytes, non-keratinocytes, sebaceous and sweat glands, hair follicles, as well as the vascular, neuronal, and cellular constituents of the dermis. Melatonin is a Multitasking hormone that performs several functions to protect the body from different environmental conditions 1. Melatonin is not only produced by the Pineal gland but also synthesized by the ovary, testes, retina, Harderian gland and skin 2-4. Melatonin acts as an anti-inflammatory, antioxidant, anti-cancer agent, and exhibited strong anti-aging characters 5,6. The skin is considered the largest organ and covered 7-12% of the body and performs several vital functions 7. The skin is made of two distinguished parts, epidermis and dermis. The superficial one was the epidermis and formed mainly of keratinocytes and non-keratinocytes. Keratinocytes proliferation is regulated by melatonin 8. On the other hand, the non-keratinocytes including Langerhans cells that act as immune cells (dendritic cells of the epidermis), Merkel cells represent neuroendocrine cells of the epidermis and melanocytes, which are the main source of melanin that responsible for skin pigmentation and protection from ultr...

Genetic Signatures of Selection for Cashmere Traits in Chinese Goats

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Melatonin administration provokes the activity of dendritic reticular cells in the seminal vesicle of Soay ram during the non-breeding season

“…To demonstrate the dendritic cells in the seminal glands of Soay rams, six different antibodies were used including, anti-estrogen receptor alpha (ER-α), anti-progesterone, CD3, CD117, CD34, MHCII, CD56 and S-100 protein (Table 1 ). These antibodies have been validated in various studies in sheep 33 , 40 , 56 . In addition, most of used antibodies in the current study their cross reactivity was proved in bovine and goat (ruminants) according to manufacturer data sheet or not tested yet.…”

S100 Proteins as Novel Therapeutic Targets in Psoriasis and Other Autoimmune Diseases

“…In some cases, also other metal ions, including zinc or copper, can be banded by S100 proteins and contribute to their activation. Mustafa et al [ 189 ] demonstrated that melatonin also can increase the expression of S100 proteins in scrotal skin. Moreover, Hussein et al [ 190 ] showed that melatonin increases the S100 proteins’ expression in the connective tissue capsule and the adrenal cortex of Soay rams.…”