Abstract
Essential fatty acids are interconverted by desaturases and elongases to eicosanoid precursors. In essential fatty acid deficiency (EFAD) an increased hepatic interconversion of linoleic acid (18:2) to arachidonic acid (20:4n-6) has been demonstrated in vivo. We now cultured Hep G2 cells under EFAD conditions. 20:3n-6 appeared in EFAD cells, but also in controls. After adding 14C-18:2 to the medium, interconversion products and their distribution in different lipids were studied by HPLC. When trace amounts 18:2 were incubated, 38% were converted by the EFAD cells after 21 h, vs 6% by controls. 20% was converted to 20:4 by EFAD cells vs 14% by controls. EFAD cells preferentially distributed more 18:2 and conversion products to neutral fats and to phosphatidyl ethanolamine, but less to cardiolipin than controls did, when incubated with trace amount 18:2, but not with 1 mM 18:2. A relative accumulation of radioactivity in 20:3 was observed. In conclusion; in EFAD Hep G2 cells delta-6- and delta-5-desaturase both were found to be upregulated and eicosanoid precursors were distributed more into phosphatidyl ethanolamine. Delta-5-desaturase had a rate limiting property as well as delta-6-desaturase.
Original language | English |
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Pages (from-to) | 437-42 |
Number of pages | 6 |
Journal | Prostaglandins, Leukotrienes and Essential Fatty Acids |
Volume | 56 |
Issue number | 6 |
DOIs | |
Publication status | Published - 1997 Jun |
Externally published | Yes |
Subject classification (UKÄ)
- Cell and Molecular Biology
Free keywords
- Arachidonic Acid/metabolism
- Cell Line
- Fatty Acid Desaturases/metabolism
- Fatty Acids/metabolism
- Fatty Acids, Essential/deficiency
- Humans
- Kinetics
- Linoleic Acid
- Linoleic Acids/metabolism
- Linoleoyl-CoA Desaturase
- Phospholipids/metabolism
- Up-Regulation