Reparative regeneration of rat skin under influence of hollow cathode lamp (HCL) with manganese and copper line spectrum emission

The influence of local light exposure by a hollow cathode lamp with a typical manganese and copper (HCL-Mn, Cu) line emission spectrum on the posttraumatic regeneration of rat skin has been investigated. We performed a comparative analysis of the morphology and differentiation potential of rat skin on the 15th and 24th days after a full-thickness skin wound was made to the dorsum. The injured area was irradiated for 30 s every day for 2 weeks. Fifteen days after the loss of the scab, reepithelialization and the recovery of hair growth were monitored (visual observations), unlike in the control rats, which still had their scabs at 24 days. Histological analysis revealed that, as differs from the nonirradiated control group, upon exposure to HCL-Mn, Cu resulted in an increased number of hair follicles and sebaceous glands, as well as a decreased number of blood vessels and a horizontal orientation of collagen fibers. Immunohistochemical assay with antibodies to dendritic cell marker OX-62 revealed the highest cell number of dermal dendritic cells 15 days after exposure; at 24 days, their number was decreased. In the control group, the number of dermal dendritic cells was significantly lower. Immunohistochemical assay with pan-keratin antibodies 15 days after the surgery revealed a high number of cells that express different types of keratins distributed in most parts of the epidermis in control animals, whereas, in the experimental group, this number was significantly lower and concentrated closer to the external part of the epidermis. The number of keratin 19-positive cells in experimental animals was higher 15, rather than 24, days after the surgery as compared to control rats. Thus, manganese and copper spectrum emissions stimulate innate immunity; accelerate the recovery of the derma, skin epithelium, and other skin derivates; and facilitates wound healing.