PE10. Efectul protector al vitaminei A in stresul oxidativ indus de radiatiile ultraviolete
Vitamina A este un important antioxidant care interfereaza cu productia de radicali liberi ai oxigenului si blocheaza peroxidarea lipidelor. Radiatiile ultraviolete reprezinta una dintre principalele surse de poducere a radicalilor liberi.
Autorii au studiat experimental efectul radiatiilor ultraviolete si implicarea acestora in producerea radicalilor liberi. In aceasta lucrare s-a determinat nivelul seric de radicali liberi ai oxigenului la sobolani rasa Wistar, indirect prin determinarea peroxizilor lipidici (metoda colorimetrica cu acid tiobarbituric) si prin nivelul seric al ceruloplasminei (tehnica Ravin). Aceste valori au fost determinate la un lot de animale expuse la radiatii ultraviolete (l =320-400nm) timp de 30 de minute, in doua zile consecutive, animalele fiind „protejate" prin administrare de vitamina A. Rezltatele au fost comparate cu un lot de control de animale care nu au fost expuse la radiatii ultraviolete, precum si cu un lot de animale expuse la radiatii dar neprotejate.
Rezultatele au aratat o descrestere semnificativa a peroxizilor lipidici (1,92 mmoli/ml) si o crestere a ceruloplasminei, ca antioxidant seric, (34,72 mg%) la animalele protejate cu vitamina A fata de cele neprotejate cu antioxidanti.
PE10. The Protective Effect of Vitamin A in the Oxidative Stress Induced by Ultraviolet Radiations
The vitamin A is an important antioxidant which interfers with peroxide radicals and blocks the lipid peroxidation. The ultravilet radiations are one of the main sources of oxygen.
The authors have studied the effect of ultraviolet radiations on the mechanisms of the free radicals production. The present study determined teh seric level of oxygen free radicals in Wistar rats, indirectly by the values of lipid peroxides (colorimetric method with thibarbituric acid) and the seric ceruloplasmine (Ravin technique). These values were measured in a group of animals exposed to ultraviolet radiation (l=320-400nm) for 30 minutes, in 2 consecutive days, the animals being compared to those of a group of animals not exposed to radiations, and also with another group exposed to ultraviolet radiations, but having no antioxidant protection.
The analyze of the results pointed out a significant decrease of lipid peroxides (1,92 mmoli/ml) and an increase of seric antioxidant ceruloplasmine (37,72 mg%) in animals protected with vitamin A as compared to the animals with no protection by antioxidants.