engleski

The impact of Alpha-melanocyte-stimulating Hormone on the Corneal Re-epithelialization in Rats

Alpha– melanocyte– stimulating hormone (α – MSH) is one of the initial fragments of the molecule ACTH. Additional to its role in skin– darkening, α – MSH also possesses a strong immuno– modulating, anti– inflammatory, antipyretic and antimicrobial properties. Its cytoprotective properties are also known, realised through inhibition of pro– inflammatory cytokines and the impact, inhibition of NO and neopterin synthesis by monocytes, inhibition of neutrophil migration and synthesis of prostaglandin as well as the increased production of IL– 10. Alpha– MSH has also been found in some eye structures including the cornea. However, its role in corneal re– epithelialization has not been sufficiently examined. In this study we intended to analyse the impact of α – MSH on the corneal re– epithelialization, reduction of eye irritation caused by epithelium erosion and the possibility of blocking its impact with the complementary peptides. Test animals were assigned into nine (9) groups which were treated as follows: the control group was treated by physiological solution, 5 groups by α – MSH drops in concentration ranging from saturation to inefficiency, 2 groups were treated by α – MSH drops in ED50 and ED50/10 doses together with the equimolar dose of complementary peptide, and one group of healthy animals to which the most effective α – MSH dose was applied. Drops were applied immediately after eroding, after 2, 8 and 16 hours. The photographs were taken every 0, 2, 8 16 and 24 hours. After test completion the histological analysis of cornea was made, the photographs digitally evaluated, and the erosion extent defined. Alpha– MSH has caused a faster rate of epithelialization in concentrations of 1 mg/100 ml, 1 mg/1000 ml and 1 mg/10000 ml 16 hours after debridement and the latter two concentrations 24 hours after debridement, respectively. By antisense peptides the possibility of impact blocking has been established. In several concentrations a significant decrease of eye stimulus was established. Histological slices have shown a decreased number of neutrophils in corneas treated by α – MSH in contrast to the control group. In view of the mentioned results it would be beneficiary to undertake further study of the α – MSH role in the re– epithelialization as a potentially useful peptide to be used in the human medicine.

alpha-MSH; cornea; re-epithelization; impact; rat; eye; drops

nije evidentirano