Molecular mechanisms underlying disease programming during postnatal development in a model induced by the inhibition of endothelin system: oxidative stress.

ORONEL, L.H.; CZERNICZYNIEC, A.; ORTIZ, M.C.; LORES ARNAIZ, S.; MAGNANELLI, M.A.; ALBERTONI BORGHESE, F.; MAJOWICZ, M.

Mar del Plata

Congreso; LXVII Reunión Anual de la Sociedad Argentina de Investigación Clínica (SAIC); 2022

Sociedad Argentina de Investigación Clínica

We showed that Endothelin (ET) inhibition during the early postnatal period (PNP) with Bosentan (20 mg/kg/day), a dual ET receptor antagonist (ERA), increases TBARS levels in kidney homogenates of male rats, indicating an increase in lipid peroxidation. Given the importance of oxidative stress as one of the mechanisms underlying disease programming during development, in the present work we evaluated O2•- (superoxide anion) production and some pro- and anti-oxidant enzymes in crude mitochondrial fractions in 7 day old Sprague-Dawley rats. To this end, four experimental groups were studied: control males (CM), ERA-treated males (ERA-M), control females (CF) and ERA-treated females (ERA-F). We determined: O2•- production, Catalase (Cat) and Glutathione Peroxidase (GPx) activities by spectrophotometric methods, NADPH-Oxidase (NOX) activity by a fluorometric method and NOX-4 expression by Western Blot. Statistics: two-way ANOVA followed by Bonferroni post-test.We found a tendency to increase in O2•- production in ERA-M vs CM (13.27 ± 3.35 vs 8.68 ± 2.66 nmol/min.mg). We found a decrease in Cat activity in ERA-M vs CM (p＜0.01) and an increase in ERA-F vs CF (p＜0.05), while no significant changes in GPx activity were observed among experimental groups. Contrary to what we expected, there was a tendency to decrease in NOX activity (232,294 ± 85,163 vs 359,738 ± 50,543 AU mg protein-1) and NOX-4 expression (1.0 ± 0.4 vs 1.3 ± 0.5 AU, change from control) in ERA-M vs CM. The last result suggests that the tendency to increase in O2•- is not due to an increased NOX-4 expression/activity. However, it could be due to the contribution of mitochondrial Complex I and III, to a decreased SOD activity and/or to peroxisomal reactive oxygen species production (also present in the mitochondrial fraction). The decrease in Cat activity in ERA-M and the increase in ERA-F indicates a sex difference, being females more protected than males against ERA inhibition in PNP.