Skip to Main Content
Melissa Hoernis

Dietary γ-Linolenic Acid Supports Arachidonic Acid Enrichment in Feline Red Cell Membranes

Hoernis, Melissa1; Trevizan, Luciano1; Bauer, John1,2

1Companion Animal Nutrition Lab, Texas A&M University, College Station, TX, USA; 2Faculty of Nutrition, Texas A&M University, College Station, TX, USA

Melissa Hoernis

Objective – The objective of the study was to evaluate the in vivo synthesis of arachidonic acid from various metabolic precursors by measuring arachidonic acid incorporation into feline red blood cell membranes.  The aims of this study were two-fold.  The first aim was to show whether the ∆-6 desaturase enzyme could be induced by feeding high amounts of its substrate (linoleic acid) and the second aim was to determine whether bypassing the ∆-6 enzymatic step could produce adequate amounts of arachidonic acid.

Animals or Sample Population – Twenty-nine female intact cats, 2 years of age, were divided into three feeding groups.

Procedure – The first group, the control group, was fed a diet low, but adequate, in linoleic acid; the second group was fed a diet high in linoleic acid and the third group was fed a diet containing adequate amounts of linoleic acid and high amounts of γ-linolenic acid (the product of ∆-6 desaturase).  After 56 days of feeding, blood samples were collected by the saphenous vein into tubes containing EDTA.  Red blood cell membranes were isolated from the samples and lipid extraction was performed.  Thin layer chromatography was used to fractionate the membrane phospholipids.  The fatty acids were then trans-methylated for analysis by gas chromatography.

Results – High dietary γ-linolenic acid produced statistically higher amounts of arachidonic acid in feline red cell membrane.  High dietary linoleic acid did not produce statistically higher amounts of arachidonic acid in red cell membranes.

Conclusions and Clinical Relevance – ∆-6 desaturase activities were not induced with high dietary linoleate.  Feeding high dietary γ-lionolineic acid was successful at bypassing the ∆-6 enzymatic step and produced increased amounts of arachidonic acid. These findings establish that cats may have an active ∆-5 desaturase enzyme.  It is concluded that diets containing high amounts of γ-linolenic acid (GLA) are suitable for supporting fatty acid nutritional needs of feline species.