Abstract

Introduction

Materials & Methods

Results

Discussion & Conclusion

References

Discussion
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We studied the diurnal and age-dependent changes in serum total antioxidant activity (STAA) in male Wistar rats, as well as the role of the pineal gland in these possible variations. The assays were carried out by exposing aliquots of brain phospholipid liposome suspension to peroxidation induced by ferric (150 uM) and ferrous (50 uM) chloride, 1h at 37C, in presence or not of the serum studied (20ul). Reactions were stopped by cooling tubes and adding butylated-hydroytoluene (0.5%). The extend of the lipid peroxidation was measured by the formation of thiobarbituric acid-reactive products. We studied the STAA in 4 or 24-month-old rats, in blood samples obtained either at middle of light period or 4h after the onset of darkness. Furthermore, 4-month-old animals were pinealectomized and STAA studied in diurnal and nocturnal samples obtained before and 10 days after surgery. The STAA in 4-month-old animals was significantly lower in nocturnal than in diurnal samples. This diurnal rhythm in STAA disappeared in the aged rats, which also showed a STAA lower than younger animals. Pinealectomy abolishes the STAA daily rhythm in young rats. These results supports a role of the pineal gland in the control of the serum antioxidative status.

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Poster Number PAmediavilla0423
Keywords: Pineal, Antioxidant, Daily rhythm, Aging, Peroxidation