Investigating the sulfhydryl redox status in the hypotensive acute effects of peroxyl radicals

Post-prandial hypotension is a well-known phenomenon. We aimed to investigate, in the absence of immune and metabolic interfering factors, the correlation of the plasma antioxidant capacity with the early alterations of blood pressure induced by peroxyl radicals. We previously suggested that the hypotensive effect of acute infusion of peroxyl radical generators in rats could be mediated by sulfhydryl (SH) redox status. Therefore, in this study we evaluated the plasma SH, peroxides (ROOH) and both lipophilic (LAC) and hydrophilic (HAC) antioxidant capacity, before, during and after the hypotension induced by 2,2’-azobis- (2-amidinopropane) dihydrochloride (AAPH) and 2,2’-Azobis 2,4-di-methylvaleronitrile (AMVN). As a result AAPH infusion induced a rapid decrease of HAC and SH, these effects were followed by a strong increase of both markers, whereas AMVN treatment was unable to change the HAC and SH values. On the other hand AMVN reduced plasma LAC and increased ROOH, while, in the animals treated with AAPH, ROOH and LAC were decreased and unchanged, respectively. Therefore, SH redox status seems to be not involved in the hypotensive acute effects of peroxyl radicals. Further studies are needed to better understand the mechanisms responsible for paradoxical effects of acute oxidative stress