title: Dietary zinc deficiency affects blood linoleic acid: dihomo-γ-linolenic acid (LA:DGLA) ratio; a sensitive physiological marker of zinc status in vivo (Gallus gallus).
abstract: Zinc is a vital micronutrient used for over 300 enzymatic reactions and multiple biochemical and structural processes in the body. To date, sensitive and specific biological markers of zinc status are still needed. The aim of this study was to evaluate Gallus gallus as an in vivo model in the context of assessing the sensitivity of a previously unexplored potential zinc biomarker, the erythrocyte linoleic acid: dihomo-γ-linolenic acid (LA:DGLA) ratio. Diets identical in composition were formulated and two groups of birds (n = 12) were randomly separated upon hatching into two diets, Zn⁺ (zinc adequate control, 42.3 μg/g zinc), and Zn⁻ (zinc deficient, 2.5 μg/g zinc). Dietary zinc intake, body weight, serum zinc, and the erythrocyte fatty acid profile were measured weekly. At the conclusion of the study, tissues were collected for gene expression analysis. Body weight, feed consumption, zinc intake, and serum zinc were higher in the Zn⁺ control versus Zn⁻ group (p < 0.05). Hepatic TNF-α, IL-1β, and IL-6 gene expression were higher in the Zn⁺ control group (p < 0.05), and hepatic Δ⁶ desaturase was significantly higher in the Zn⁺ group (p < 0.001). The LA:DGLA ratio was significantly elevated in the Zn⁻ group compared to the Zn⁺ group (22.6 ± 0.5 and 18.5 ± 0.5, % w/w, respectively, p < 0.001). This study suggests erythrocyte LA:DGLA is able to differentiate zinc status between zinc adequate and zinc deficient birds, and may be a sensitive biomarker to assess dietary zinc manipulation.
authors.affiliation: USDA-ARS, Robert Holley Center for Agriculture & Health, Ithaca, NY 14853, USA. smr292@cornell.edu.
authors.forename: Spenser
authors.initials: S
authors.lastname: Reed
authors.affiliation: Department of Food Science, Cornell University, Ithaca, NY 14853, USA. xq37@cornell.edu.
authors.forename: Xia
authors.initials: X
authors.lastname: Qin
authors.affiliation: Division of Nutritional Sciences, Cornell University, Ithaca, NY 14853, USA. Rinat.Ran-Ressler@rd.nestle.com.
authors.forename: Rinat
authors.initials: R
authors.lastname: Ran-Ressler
authors.affiliation: Division of Nutritional Sciences, Cornell University, Ithaca, NY 14853, USA. jtb4@cornell.edu.
authors.forename: James Thomas
authors.initials: JT
authors.lastname: Brenna
authors.affiliation: USDA-ARS, Robert Holley Center for Agriculture & Health, Ithaca, NY 14853, USA. raymond.glahn@ars.usda.gov.
authors.forename: Raymond P
authors.initials: RP
authors.lastname: Glahn
authors.affiliation: USDA-ARS, Robert Holley Center for Agriculture & Health, Ithaca, NY 14853, USA. et79@cornell.edu.
authors.forename: Elad
authors.initials: E
authors.lastname: Tako
mesh_terms: D015126:8,11,14-Eicosatrienoic Acid / Q000097:blood*; D000818:Animals; D015415:Biomarkers / Q000097:blood; D001835:Body Weight; D002645:Chickens; D004032:Diet / Q000662:veterinary; D004912:Erythrocytes / Q000378:metabolism; D005227:Fatty Acids / Q000032:analysis; D015870:Gene Expression; D053583:Interleukin-1beta / Q000378:metabolism; D015850:Interleukin-6 / Q000378:metabolism; D019787:Linoleic Acid / Q000097:blood*; D008099:Liver / Q000187:drug effects / Q000201:enzymology; D009752:Nutritional Status; D010833:Phytic Acid / Q000032:analysis; D012337:RNA, Ribosomal, 18S / Q000235:genetics; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism; D015032:Zinc / Q000008:administration & dosage* / Q000172:deficiency*
chemical_list: D015415:Biomarkers; D005227:Fatty Acids; D053583:Interleukin-1beta; D015850:Interleukin-6; D012337:RNA, Ribosomal, 18S; D014409:Tumor Necrosis Factor-alpha; D010833:Phytic Acid; D019787:Linoleic Acid; D015126:8,11,14-Eicosatrienoic Acid; D015032:Zinc