title: Effects of fasting and refeeding on the antioxidant system in cockerels and pullets.
abstract: The effect of fasting and refeeding on total antioxidant status (TAS), glutathione peroxidase (GSH-Px) activity and concentration of some non-enzymatic antioxidant compounds was studied in cockerels and pullets. Blood was collected before and after 48-h fasting and 24 h after refeeding. In cockerels, fasting resulted in a significant decrease of TAS and uric acid concentration. After refeeding, the concentration of TAS remained significantly lower as compared to the control level. At the same time, blood plasma level of total lipids increased in comparison to the control and post-fasting values. In pullets, fasting resulted in a significant decrease of whole blood haemolysate GSH-Px activity and blood plasma concentrations of albumin and uric acid. Simultaneously, a significant increase in total lipids and cholesterol was obtained. In pullets, refeeding resulted in a further decrease of TAS to undetectable values, a significant decrease of blood plasma cholesterol, and a significant increase of GSH-Px in the whole blood haemolysate and in blood plasma uric acid content. The results indicate that fasting has a negative impact on the antioxidant defence system of the blood, which leads to a reduced resistance to oxidative stress in both cockerels and pullets. However, pullets seem to be more susceptible to fasting-provoked oxidative stress than cockerels.
authors.affiliation: Department of Physiology and Radiobiology, Faculty of Veterinary Medicine, University of Zagreb, Heinzelova 55, 10000 Zagreb, Croatia. tur@vef.hr
authors.forename: Suzana
authors.initials: S
authors.lastname: Milinković-Tur
authors.forename: Z
authors.initials: Z
authors.lastname: Stojević
authors.forename: Jasna
authors.initials: J
authors.lastname: Pirsljin
authors.forename: Maja
authors.initials: M
authors.lastname: Zdelar-Tuk
authors.forename: Nina
authors.initials: N
authors.lastname: Poljicak-Milas
authors.forename: Blanka Beer
authors.initials: BB
authors.lastname: Ljubić
authors.forename: Bojana
authors.initials: B
authors.lastname: Gradinski-Vrbanac
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000378:metabolism*; D002645:Chickens / Q000097:blood / Q000378:metabolism; D002784:Cholesterol / Q000097:blood; D005215:Fasting / Q000097:blood*; D005979:Glutathione Peroxidase / Q000378:metabolism*; D050356:Lipid Metabolism; D008055:Lipids / Q000097:blood; D010084:Oxidation-Reduction; D018384:Oxidative Stress; D019518:Postprandial Period; D011897:Random Allocation; D013997:Time Factors
chemical_list: D000975:Antioxidants; D008055:Lipids; D002784:Cholesterol; D005979:Glutathione Peroxidase