The role of Δ9-desaturase in the production of cis-9, trans-11 CLA
| Autor: | Benjamin A. Corl, Bliss S. Phillips, Lance H. Baumgard, D.A. Dwyer, Dale E. Bauman, J. Mikko Griinari |
|---|---|
| Rok vydání: | 2001 |
| Předmět: |
Endocrinology
Diabetes and Metabolism Linoleic acid Conjugated linoleic acid Clinical Biochemistry Endogeny Biology Biochemistry 03 medical and health sciences chemistry.chemical_compound Latin square Lactation medicine Food science Molecular Biology 030304 developmental biology chemistry.chemical_classification 0303 health sciences Nutrition and Dietetics 0402 animal and dairy science food and beverages Fatty acid 04 agricultural and veterinary sciences 040201 dairy & animal science Cis trans isomerization Stearoyl-CoA Desaturase medicine.anatomical_structure chemistry lipids (amino acids peptides and proteins) |
| Zdroj: | The Journal of Nutritional Biochemistry. 12:622-630 |
| ISSN: | 0955-2863 |
| DOI: | 10.1016/s0955-2863(01)00180-2 |
| Popis: | Biomedical studies with animal models have demonstrated that cis-9, trans-11 conjugated linoleic acid (CLA), the predominant isomer found in milk fat from dairy cows, has anticarcinogenic effects. We recently demonstrated endogenous synthesis of cis-9, trans-11 CLA from ruminally derived trans-11 C18:1 by Delta(9)-desaturase in lactating dairy cows. The present study further examined endogenous synthesis of cis-9, trans-11 CLA and quantified its importance by increasing substrate supply using partially hydrogenated vegetable oil (PHVO) as a source of trans-11 C18:1 and blocking endogenous synthesis using sterculic oil (SO) as a source of cyclopropene fatty acids which specifically inhibit Delta(9)-desaturase. Four cows were abomasally infused with 1) control, 2) PHVO, 3) SO, and 4) PHVO+SO in a 4 x 4 Latin square design. With infusion of PHVO, cis-9, trans-11 CLA was increased by 17% in milk fat. Consistent with inhibition of desaturase, SO treatments increased milk fat ratios for the fatty acid pairs effected by Delta(9)-desaturase, C14:0/cis-9 C14:1, C16:0/cis-9 C16:1, and C18:0/cis-9 C18:1. The role of endogenous synthesis of CLA was evident from the 60-65% reduction in cis-9, trans-11 CLA which occurred in milk fat with SO treatments. cis-9 C14:1 originates from desaturation of C14:0 by Delta(9)-desaturase and can be used to estimate the extent of SO inhibition of Delta(9)-desaturase. When this correction factor was applied, endogenous synthesis was estimated to account for 78% of the total cis-9, trans-11 CLA in milk fat. Thus, endogenous synthesis was the major source of cis-9, trans-11 CLA in milk fat of lactating cows. |
| Databáze: | OpenAIRE |
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