Effects of prenatal stress on oxidatie status of brain and liver in young mice. Role of melatonin.

PALLARÉS M; CHAUFAN G; CUTRERA R; RÍOS DE MOLINA M

Montevideo, Uruguay

Simposio; VIII Simposio SETAC Latinoamericana; 2007

Objectives. To evaluate prenatal stress and melatonin effects on the oxidative status of brain and liver in young adult mice. Methods. Pregnant Swiss mice were divided on: Control (C), Stress (S), Melatonin (MT) and S+MT. Stress consisted on a 3 daily- 45? session of restraint between 15th and 20th day of gestation; MT was provided with the drinking water (25 mg/l) from 7th day till delivery. At the age of 45 days, offspring were decapitated. Organs were dissected, homogenized and centrifuged (11.000xg). Supernatants were used for analysis. Lipid peroxidation: Malondialdheyde (MDA) levels were measured using the thiobarbituric acid fluorometric assay. Superoxide dismutase Activity (SOD): was assayed spectrophotometrically by following the velocity of reduction of the nitro-blue-tetrozodium. Reduced glutathione levels (GSH): were estimated by analysing the absorbance of reduced 5,5?-Dithiobis-(2-nitrobenzoic acid). Data were analyzed by two-way ANOVA. Results. Female?s brains: S treatment increased SOD activity (p=0,04) and diminished MDA levels, regarding C (p=0,012). Moreover GSH levels were augmented in S+MT group (p=0,001). Male?s brains: GSH levels were high in both prenatally stressed groups (p=0.008) but MDA levels were only reduced in S+MT (p=0,02). Livers data: differential antioxidant status were found on S+MT groups; while in females, SOD activity was diminished (p=0,047), GSH levels were significantly high in this group (p=0,023). In males, only SOD was increased (p=0,048) Conclusions. Surprisingly, enhanced antioxidants levels were found on prenatally stressed brain?s mice. Indeed MT seems to improve these effects and also increase protective effects on liver.