Circadian Study of Antioxidant Defense System in the Hippocampus of Aged Rats Subjected to Caloric Restriction

ALTAMIRANO, FERNANDO GABRIEL; CASTRO PASCUAL, IVANNA CARLA; FERRAMOLA, MARIANA LUCILA; DELGADO, SILVIA MARCELA; ANZULOVICH, ANA CECILIA; LACOSTE, MARÍA GABRIELA

Córdoba

Congreso; XXXIII Congreso Anual de la Sociedad Argentina de Investigación en Neurociencias; 2018

Sociedad Argentina de Investigación en Neurociencias

Oxidative stress plays a critical role in brain aging. Caloric restriction (CR) is the most accepted approach to slow the aging process and delay many age-related diseases. Previously, we showed circadian rhythms in the expresión and activity of antioxidant enzymes in the hippocampus of young rats that were abolished in the old animals. In the present work, we investigated temporal patterns of catalase (CAT) and glutathione peroxidase (GPx) expression and activity, as well as Nrf2 mRNA levels, in the hippocampus of aged rats under CR. Holtzman male rats were fed with a diet reduced by 40% in calories during the last 3 months prior to the 22 months of age. The mRNA levels were determined by RT-PCR and the enzymatic activity were evaluated by kinetics assays in hippocampi isolated every 4 hr during a 24-hr period. Interestingly, we observed CR restored the circadian rhythmicity of all the studied parameters (Chronosfit: p < .05). In addition, CR accentuated the rhythms of the amplitudes and the mesor of both CAT and GPx (t test: p < .05 and p < .05, respectively), and the Nrf2 mesor (t test: p < .05). CR restores the 24-hr patterns of antioxidant defenses in aged animals. Restoration of temporal coordination could be one of the basis of CR efficiency and provide promising prospects against neurodegenerative diseases and cognitive decline.This study was supported by PICT 2010-1139-ANPCyT and PROICO 2-0314-UNSL, Argentina.