Anti-peroxidation effects of vitamin E on low density lipoprotein and milk fat globule membrane of lactating goats: in vivo versus metal ion challenge in vitro.
Ruminants are animals with mild oxidation risk considering characteristics of their plasma. The purpose of the present study was to determine if surplus vitamin E supplementation further improved their peroxidation status. Four lactating goats (Capra ibex ibex) receiving a single intramuscular injection of 3000 IU d-alpha-tocopheryl acetate were monitored daily for a week. Plasma and milk levels of thiobarbituric acid reactive substances (TBARS) were measured to estimate the peroxidation status of overall body and mammary gland, respectively. Lipid hydroperoxide content of low density lipoprotein (LDL) and milk fat globule membrane (MFGM) were determined both immediately after isolation and after metal ion challenge to evaluate their spontaneous peroxidation in vivo and peroxidation susceptibility in vitro, respectively. The results showed that while plasma and milk levels of alpha-tocopherol peaked at day 2, the corresponding TBARS dropped to their lowest weekly levels. Content of preformed lipid hydroperoxides in LDL and MFGM remained unchanged (P>0.05) during the study period, while peroxidation in LDL and MFGM on extended exposure to Cu(2+) was prevented by vitamin E enrichment. Therefore, surplus vitamin E was beneficial to the peroxidation-resistant mechanisms of the overall body and those specifically within mammary gland of lactating goats. Furthermore, peroxidation resistance of LDL and MFGM to copper challenge in vitro also benefited from vitamin E enrichment despite the fact their endogenous peroxidation seemed unresponsive. The hypothesis that peroxidation of LDL and MFGM of lactating goats in situ, which proceeds with metal ion-independent mechanisms, is minor was discussed.
Yang
Duo-Yih
DY
Department of Animal Science, National Chung Hsing University, 250 Kuo Kuang Road, Taichung 402, Taiwan.
Chang
Chai-Ju
CJ
Peh
Huo-Cheng
HC
Chen
Ming-Tsao
MT
D000818:Animals; D002138:Calibration; D002784:Cholesterol / Q000378:metabolism; D003300:Copper / Q000737:chemistry; D004591:Electrophoresis, Polyacrylamide Gel; D006017:Glycolipids / Q000737:chemistry*; D006023:Glycoproteins / Q000737:chemistry*; D006041:Goats; D007477:Ions; D007501:Iron / Q000378:metabolism; D007774:Lactation; D066292:Lipid Droplets; D015227:Lipid Peroxidation; D008074:Lipoproteins / Q000097:blood; D008077:Lipoproteins, LDL / Q000737:chemistry / Q000378:metabolism*; D010636:Phenols; D013454:Sulfoxides; D017392:Thiobarbituric Acid Reactive Substances; D014280:Triglycerides / Q000097:blood; D014810:Vitamin E / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology*; D014992:Xylenes / Q000737:chemistry; D024502:alpha-Tocopherol / Q000378:metabolism
D006017:Glycolipids; D006023:Glycoproteins; D007477:Ions; D008074:Lipoproteins; D008077:Lipoproteins, LDL; D010636:Phenols; D013454:Sulfoxides; D017392:Thiobarbituric Acid Reactive Substances; D014280:Triglycerides; D014992:Xylenes; C110367:milk fat globule; D014810:Vitamin E; D003300:Copper; D002784:Cholesterol; D007501:Iron; D024502:alpha-Tocopherol; C016833:xylenol orange