THE ROLE OF NITRIC OXIDE AND PEROXYNITRITE IN THE ERYTHEMAL PERIOD OF ULTRAVIOLET-INDUCED SKIN DAMAGE.

Abstract

The aim: To study the activity of inducible NO synthase in the blood, the content of NO metabolites and peroxynitrite in the skin and blood of guinea pigs during erythema periods after local ultraviolet skin irradiation. Materials and methods: The studies were carried out on 24 guinea pigs, subjected to local ultraviolet irradiation. The control group consisted of intact guinea pigs (n=6). After 2, 4 hours, on the 3rd, 8th day, the activity of inducible NO synthase (in blood), the content of total NO metabolites, nitrite anion, nitrates, peroxynitrite (in blood and skin) were determined. Results: An increase in the level of peroxynitrite in the blood and of all NO metabolites in the skin was noted 2 hours after irradiation. After 4 hours activation of inducible NO synthase in the blood was observed, accompanied by an increase in the content of all NO metabolites and peroxynitrite both in the blood and in the skin. On the 3rd day high levels of excessive synthesis of NO and peroxynitrite in the blood and skin were also revealed due to the induced expression of this enzyme in the blood. On the 8th day the activity of inducible NO synthase remained high in the blood, which led to the accumulation of all NO metabolites and peroxynitrite in the blood and skin. Conclusions: Thus, local ultraviolet irradiation of the skin of guinea pigs leads to the activation of inducible NO synthase in the blood and an increase in NO synthesis and peroxynitrite in the blood and skin.