Postpartum levels of 8-iso-prostaglandin F2α in plasma and milk phospholipid fractions as biomarker of oxidative stress in first-lactating dairy cows

• Published in: Prostaglandins & other lipid mediators Vol. 112; pp. 34 - 38
• Main Authors: Vernunft, A., Viergutz, T., Plinski, C., Weitzel, J.M.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01-08-2014
• Subjects: 8-Isoprostane; Animals; Biomarker; Biomarkers - analysis; Biomarkers - blood; Cattle - physiology; Dinoprost - analogs & derivatives; Dinoprost - analysis; Dinoprost - blood; F2-isoprostane; Female; Fertility; Lactation - physiology; Milk - chemistry; Oxidative stress; Oxidative Stress - physiology; Phospholipids - analysis; Phospholipids - blood; Phospholipids - chemistry; Postpartum Period - blood; Postpartum Period - metabolism; Oxidative stress; 8-Isoprostane; F2-isoprostane; Biomarker; Fertility; F-isoprostane
• ISSN: 1098-8823
• DOI: 10.1016/j.prostaglandins.2014.07.004

•8-iso-PGF2α as biomarker of oxidative stress in dairy cows.•Higher 8-iso-PGF2α concentrations in heifers compared to cows.•8-iso-PGF2α is detectable from milk phospholipids.•Milk 8-iso-PGF2α levels correlates with plasma concentrations.•8-iso-PGF2α concentrations did not correlate with milk yield.
F2-isoprostanes such as 8-iso-prostaglandin F2 (8-iso-PGF2α) are formed by free radical-catalyzed mechanisms from membrane phospholipids and from low density lipoproteins through peroxidation of arachidonic acid. Esterified 8-iso-PGF2α is cleaved by phospholipases, circulates in blood and is excreted as putatively harmful oxidatively modified lipid via the kidney into urine. In this study we demonstrate that 8-iso-PGF2α concentrations in plasma samples from heifers are higher (p<0.005) compared to those from first-lactating dairy cows at 71 days postpartum. Furthermore, plasma 8-iso-PGF2α concentrations vary with ovarian activity and differ in response to luteolytic initiation as well as activation of the hypothalamic–pituitary–gonadal axis between heifers and first-lactating cows. Sustainable concentrations of 8-iso-PGF2α (50–150pg/ml) are detectable in the phospholipid fraction of milk, suggesting milk as an additional excretion route for 8-isoprostanes. Plasma levels largely paralleled levels in milk (p<0.001). Plasma phospholipid 8-iso-PGF2α concentrations in cyclic cows decreased (p<0.05) from day 38 to day 71 postpartum, whereas milk phospholipid 8-iso-PGF2α rather increased (p<0.05). Cyclic cows tend to have higher 8-isoprostane levels compared to acyclic animals. In contrast to lipohydroperoxides, concentration of 8-iso-PGF2α were not correlated with milk yield (p>0.05). Our data indicate 8-iso-PGF2α may be a novel biomarker of oxidative stress in dairy cow, which is detectable in blood as well as in milk.