Abstract

Oxidative stress causes hypertrophy and apoptosis, which are both implicated in various pathogenesis, particularly in cardiovascular diseases. Within this framework, we chose toanalyze certain physiopathological aspects (lipid peroxidation, proliferation, extracellular matrix remodeling, hypertrophy and oncosis conducting the cell to apoptosis) induced byhydrogen peroxide on adventitial fibroblasts in culture of Psammomys obesus. In secondary culture, the fibroblasts were exposed to 1.2 mM of H₂O₂ during 24 h. Thecellular proliferation was evaluated by counting. A morphological and morphometric study was carried out after a coloring of the cells with orange acridine and May Grunwald Giemsa. The quantification of total malonaldehyde, total proteins and total collagens was carried out in the extra and intracellular compartments. The proportioning of NO wascarried out by the determination of the concentration of total nitrites. The main results obtained indicated a reduction in cellular proliferation, an oncosis, a compensatoryhypertrophy of the fibroblasts, a hypercondensation of chromatin, which is typical ofapoptotic cells, an increase in malonaldehyde and nitrite production. Alterations such as a decrease in the production of proteins and total collagens were observed in the extracellular compartment of the cultured fibroblasts. Oxidative stress caused by high amounts of H₂O₂ induces biochemical deteriorations marked by an overproduction ofNO, of malondialdéhyde as well as a reduction in proteins and total collagens. These biochemical disturbances are at the origin of the morphological deteriorations which are responsible for the loss of cellular viability leading to apoptosis.

Key words: Adventitial fibroblasts, oxidative stress, cellular culture, H₂O₂, apoptosis.