Loss of adaptation to oxidative stress asa mechanism for aortic damage in aging rats

ABSTRACT

Cells are armed with a vast repertoire of antioxidant defence mechanisms to preventthe accumulation of oxidative damage. The cellular adaptive response is animportant antioxidant mechanism against physiological and pathophysiologicaloxidative alterations in a cell’s microenvironment. The aim of this paper was to study,in the rat aorta, whether this adaptive response and the inflammation associated withoxidative stress were expressed throughout the aging process. We examined the rataorta, as it is a very sensitive tissue to oxidative stress. Male Wistar rats of 1.5, 3, 12,18 and 24 months of age were used. Superoxide anion (O2-) generation; levels of twoantioxidant enzymes, superoxide dismutase (SOD) and catalase; and the levels ofprostaglandin E2 (PGE2), an inflammatory marker, were measured. The results forrats at different ages were compared with those for 3 months of age. A balancebetween production of O2- and SOD activity was found in the aorta of rats from 1.5to 12 months old. Oxidative stress was present in the aorta of old animals (18-24months), due to a failure in the mechanisms of adaptation to oxidative stress. Theobserved increase in PGE2 levels in these rats reflected an inflammatory response. Alltogether suggest that vascular oxidative stress and the inflammatory process observedin the old groups of rats could be closely related to vascular aging. Our results alsoremark the importance of the adaptative response to oxidative stress (AU)

RESUMEN

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