Oksidativni stres i antioksidativna odbrana u koži pacova sa termalnom povredom

Abstract

Changes in the activity and level of some antioxidative defense system components were determined in the rat skin during hypo- (ebb) and hypermetabolic (flow) phase of thermal trauma. At the same time, the effects of enzymatic (superoxide dismutase) and non-enzymatic (vitamin E and glutathione) antioxidants, as well as of L-arginine applied on the scalded skin area in different combinations in the form of a lyposomal ointment on endogenous antioxidative defense components were studied both in the injured and uninjured skin. In scalded skin during hypometabolic phase, a decrease in activity of superoxide dismutase, catalase, glutathione peroxidase glutathione reductase, as well as in the level of vitamin E was observed in comparison with the control. This decrease was accompanied by a complete loss of glutathione and the activity of glutathione-S-transferase and thioredoxin reductase. The same trend of changes was recorded in hypermetabolic phase. In the uninjured skin of scalded animals, the activities of superoxide dismutase, catalase, glutathione peroxidase and glutathione reductase were at the control level both in hypo- and hypermetabolic phase. Also, no changes in vitamin E content were found while the activities of thioredoxin reductase and glutathione-S-transferase were increased. Glutathione level in this group of animals was decreased the decrease being more prominent in hyper- then in hypometabolic phase. The ointments applied to the injured parts of the skin expressed protective effects observed as an increase in vitamin E level and an attenuation of glutathione reductase activity inhibition.

Promene u aktivnosti i količini komponenti antioksidativne odbrane u koži pacova praćene su u hipometaboličkoj (ebb) i hipermetaboličkoj (flow) fazi termalne traume. Efekti primene egzogenih enzimskih (superoksid dismutaza) i neenzimskih (vitamin E i glutation) antioksidanata i L-arginina, nanesenih na oštećenu kožu u obliku lipozomalne kreme, na endogene komponente antioksidativne odbrane ispitivani su i u oštećenoj i u neoštećenoj koži. U oštećenoj koži u hipometaboličkoj fazi dolazi do smanjenja aktivnosti superoksid dismutaze, katalaze, glutation peroksidaze, glutation reduktaze i količine vitamina E, i potpunog gubitka glutationa i aktivnosti glutation-S-transferaze i tioredoksin reduktaze. Promene su iste i u hipermetaboličkoj fazi u poređenju sa kontrolama. U koži, koja nije direktno oštećena, aktivnost superoksid dismutaze, katalaze, glutation peroksidaze i glutation reduktaze i količina vitamina E se ne menja u odnosu na kontrolu ni u hipo ni u hipermetaboličkoj fazi. Aktivnost tioredoksin reduktaze i glutation-S-transferaze povećava se u obe faze. Količina glutationa smanjuje se više u hipermetaboličkoj nego u hipometaboličkoj fazi. Efekti supstanci nanesenih na oštećenu kožu, izraziti su u smislu povećanja količine vitamina E. Takođe njihov protektivni efekat prisutan je i kada je u pitanju nivo GR aktivnosti u oštećenoj koži.