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Ontogeny of the desaturase‐elongase pathway in neonatal pigs fed arachidonic acid
Author(s) -
Jacobi Sheila K.,
Lin Xi,
Corl Benjamin,
Odle Jack
Publication year - 2009
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.23.1_supplement.lb430
Subject(s) - arachidonic acid , polyunsaturated fatty acid , eicosapentaenoic acid , medicine , biology , fatty acid , metabolism , endocrinology , small intestine , biochemistry , chemistry , enzyme
This study evaluated the effects of supplementation of ARA on delta‐6‐desaturase (D6D) and delta‐5‐desaturase (D5D) mRNA abundance and synthesis of ARA in the intestine and liver. Day old pigs (n=96) were fed a milk based formula for 4, 8, and 16 d. Diets contained either no polyunsaturated fatty acids (0% ARA, negative control), 0.5% ARA, 2.5% ARA, 5% ARA or 5% eicosapentaenoic acid (EPA) of total fatty acids. A sow fed reference group (SRC n=18) also was included. The mRNA relative abundance increased differentially (diet x age interaction, P < 0.05) from d4 to d16 in pigs fed 0.5% (D6D‐55%, D5D‐66%) versus 5% (D6D‐60%, D5D‐64%) ARA diets in the intestine. Transcript abundance of D6D and D5D were not affected by diet in the liver (P>0.05), however, there was a precipitous decrease between birth and d4 (~5‐fold, P<0.05). To measure flux through the desaturase‐elongase pathway we incubated liver and intestinal mucosa with 13 C‐linoleate(C18:2, n‐6) and traced its metabolism to ARA via GC/MS. In the intestine accumulation rate (nmol/g tissue/h) of 13 C‐ARA was not affected by piglet age, but doubled in pigs fed 5%ARA compared with pigs fed 0.5% ARA. Furthermore, accumulation of 13 C18:3, n‐6 indicated that, among ARA fed pigs, D6D activity was highest in those fed 5% ARA, and this activity was equal to that measured in SRC pigs (P<0.05). Supported by CSREES, USDA NRI 2005‐35200‐16174.