|YANG, QU - University Of Maryland|
|GARCIA, MIRIAM - University Of Maryland|
|SHOLTE, CYNTHIA - University Of Maryland|
|SCHROEDER, GUILLERMO - Cargill Nutraceuticals|
|MOYES, KASEY - University Of Maryland|
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 3/14/2017
Publication Date: 6/24/2017
Citation: Yang, Q., Elsasser, T.H., Kahl, S., Garcia, M., Sholte, C., Connor, E.E., Schroeder, G., Moyes, K. 2017. The determination of concentrations of tocopherol isoforms in whole tissues and mitochondria via high-performance liquid chromatography after short-term supplementation in dairy cows. Meeting Abstract. 100(Suppl. 2):32 (abstr. M71).
Interpretive Summary: N/A
Technical Abstract: Mitochondria are cell organelles vulnerable to stress and may be damaged either by reactive oxygen or nitrogen species during the stress response. The antioxidant tocopherol may be useful in protecting mitochondrial health. The objective of our study was to determine the pattern of change in the concentrations of 4 isoforms of tocopherol (alpha-, beta-, gamma-, and delta-tocopherol) in whole tissue and mitochondrial fraction from bovine liver and mammary gland after short-term feeding of a vegetable-derived oil (Tmix) particularly enriched with gamma- and delta-tocopherol (9% alpha-, 1% beta-, 24% delta-, and 62% gamma-tocopherol). Nine healthy, multiparous Holstein cows (> 90 days in milk) were assigned to dietary control (Notoc; n = 4) or tocopherol-fed treatment groups (n = 5; TOC; ~260 g Tmix/cow×d-1, top-dressed) and fed for 9 consecutive days. On d 10 of feeding, tissues were harvested at slaughter and mitochondria were isolated. Tocopherol isoform concentrations were determined by HPLC and data were analyzed as a complete randomized design. Significance was declared at P = 0.05. Concentrations of gamma-tocopherol increased (0.01 vs. 0.07 µg/mg) in liver mitochondria from TOC cows compared to Notoc cows. In whole tissues and mitochondria, the alpha-isoform concentrations were higher than the gamma-isoform. The accumulated portions of the alpha-isoform to the gamma-isoform were similar for mitochondria and whole tissues regardless of tissue source differences. Regardless of tocopherol isoform or sample source (i.e., whole tissue vs. mitochondria), the liver accumulated higher total tocopherol concentration when compared with the mammary gland (8.2 vs.2.7 µg/g, respectively). Limited concentrations of beta- and delta-isoform were detected in whole tissues and mitochondria. In conclusion, the liver had higher tocopherol (alpha- and gamma-isoforms) concentrations than the mammary gland suggesting that the liver may be preferred over the mammary gland for tocopherol accumulation. The alpha-isoform accumulated at higher concentrations than the gamma-isoform in liver perhaps due to a higher affinity of tocopherol transport and binding proteins for alpha-tocopherol when compared with the gamma-isoform.