Effects of heme oxygenase induction in adrenocortical functiion in a rat model of insulin resistance

VECINO, CV; WISZNIEWSKI, M; SANCHEZ PUCH, S; CYMERYNG, CB; REPETTO, EM; CALANNI JS

Mar del Plata

Congreso; LXI REUNIÓN ANUAL DE LA SOCIEDAD ARGENTINA DE INVESTIGACIÓN CLÍNICA; 2016

Sociedad Argentina de Investigación Clínica

Previousstudies from our laboratory have shown morphological and functional changes in theadrenal gland upon the establishment of insulin resistance (IR) in rats by theadministration of a sucrose rich diet (SRD). Our results indicated that inthese animals, oxidative stress is generated within the adrenal cortex. Giventhe cytoprotective function associated with the activity of heme oxygenase 1 (HO-1)we hypothesize that HO-1 induction by hemin may mitigate these effects.Wistaradult male rats were randomly distributed into four groups (n=4): Control (C),Hemin (H), SRD and SRD + Hemin (DRS + H). Both SRD groups received 30% sucrosein the drinking water for 12 weeks. H and SRD + H rats were treated with hemin(15 mg/ kg ip/48 h) during the last two weeks of treatment and all animals weresacrificed 48 h after the last dose of hemin was administered. The insulintolerance test (ITT) and the ACTH stimulation test were used to evaluateperipheral insulin sensitivity (0.75 IU insulin/ kg ip) and the adrenalresponse capacity, respectively. Plasma corticosterone levels were determinedby RIA, and both HO-1 and catalase expression levels were assessed by westernblotting.Ourresults showed that, compared to controls, rats from DRS and DRS + H groups exhibiteda significant decrease in insulin sensitivity (p