Abstract: There is growing interest in the activity of sulfur-containing compounds on redox balance in physiological and pathological conditions, considering that some of these compounds have not only antioxidative but
also pro-oxidative activities. The aim of this study was to assess possible differences in the effects of various
sulfur-containing compounds on redox balance of cardiovascular system in its physiological state and in the
early onset of hyperhomocysteinemia. This experimental study divided Wistar albino rats into two groups:
saline-treated (control) and DL-homocysteine-treated (experimental group). Rats from experimental group were
subjected to subchronic subcutaneous administration of DL-homocysteine at dose of 0.45 Ïmol/g body weight
twice a day for 2 weeks. At the end of this period, rats were sacrificed, and blood samples were collected to be
analyzed for homocysteine concentration and systemic oxidative stress. Isolated rat hearts were excised and
attached to the Langendorff apparatus. To assess the effects of acute administration of L-methionine, L-cysteine, N-acetylcysteine, and sodium hydrogen sulfide, the hearts were perfused individually with each of the
mentioned substances at the same single dose of 0.5 mmol/L for 5 min. In collected samples of coronary venous
effluent oxidative stress biomarkers were determined using spectrophotometry. Total homocysteine level was
significantly higher in the experimental group than in the control group, and the effects of applied sulfur-containing compounds were significantly different in experimental and control groups. DL-homocysteine induced
considerable changes in the functioning of a cardiovascular system even before an increase in plasma homocysteine values, and action of sulfur-containing compounds varied depending on the presence of homocysteine.
