title: Lipid status, paraoxonase-1 activity and metabolic parameters in serum of heifers and lactating cows related to oxidative stress.
abstract: The objective of this study was to investigate serum lipids, metabolic parameters and activity of the anti-oxidative enzyme paraoxonase-1 (PON1). The study was conducted on non-pregnant heifers with optimal health status and on healthy dairy cows in the period of intensive lactation, assuming that the energy and metabolic demands during lactation reduce anti-oxidative protection. Total cholesterol and HDL-cholesterol concentrations were significantly higher (P<0.05) in lactating cows than in heifers. Bilirubin concentration and γ-glutamyltransferase (GGT) activity were also significantly higher in lactating cows (P<0.05), indicating increased hepatic efforts of cows to meet energy requirements for lactation. Significantly lower PON1 activity and PON1/HDL ratio in lactating cows compared to heifers (P<0.05) showed that metabolic efforts during pregnancy, parturition and lactation influence PON1 activity due to oxidative stress. Concurrent increase in total and HDL-cholesterol during lactation indicated that the HDL particle is a major carrier of cholesterol in cows.
authors.affiliation: Institute of Cardiovascular Prevention and Rehabilitation Zagreb, Draškovićeva 13, Zagreb, Croatia.
authors.forename: M
authors.initials: M
authors.lastname: Antončić-Svetina
authors.forename: R
authors.initials: R
authors.lastname: Turk
authors.forename: A
authors.initials: A
authors.lastname: Svetina
authors.forename: D
authors.initials: D
authors.lastname: Gereš
authors.forename: B
authors.initials: B
authors.lastname: Rekić
authors.forename: D
authors.initials: D
authors.lastname: Juretić
mesh_terms: D000818:Animals; D043303:Aryldialkylphosphatase / Q000235:genetics / Q000378:metabolism*; D002417:Cattle / Q000097:blood* / Q000378:metabolism*; D004734:Energy Metabolism / Q000502:physiology; D005260:Female; D007774:Lactation / Q000502:physiology*; D008055:Lipids / Q000097:blood*; D018384:Oxidative Stress / Q000502:physiology*
chemical_list: D008055:Lipids; D043303:Aryldialkylphosphatase