Mouse Strain Impacts Fatty Acid Uptake and Trafficking in Liver, Heart, and Brain: A Comparison of C57BL/6 and Swiss Webster Mice

Abstract C57BL/6 and Swiss Webster mice are used to study lipid metabolism, although differences in fatty acid uptake between these strains have not been reported. Using a steady state kinetic model, [1-14C]16:0, [1-14C]20:4n-6, or [1-14C]22:6n-3 was infused into awake, adult male mice and uptake into liver, heart, and brain determined. The integrated area of [1-14C]20:4n-6 in plasma was significantly increased in C57BL/6 mice, but [1-14C]16:0 and [1-14C]22:6n-3 were not different between groups. In heart, uptake of [1-14C]20:4n-6 was increased 1.7-fold in C57BL/6 mice. However, trafficking of [1-14C]22:6n-3 into the organic fraction of heart was significantly decreased 33 % in C57BL/6 mice. Although there were limited differences in fatty acid tracer trafficking in liver or brain, [1-14C]16:0 incorporation into liver neutral lipids was decreased 18 % in C57BL/6 mice. In heart, the amount of [1-14C]16:0 and [1-14C]22:6n-3 incorporated into total phospholipids were decreased 45 and 49 %, respectively, in C57BL/6 mice. This was accounted for by a 53 and 37 % decrease in [1-14C]16:0 and 44 and 52 % decrease in [1-14C]22:6n-3 entering ethanolamine glycerophospholipids and choline glycerophospholipids, respectively. In contrast, there was a significant increase in [1-14C]20:4n-6 esterification into all heart phospholipids of C57BL/6 mice. Although changes in uptake were limited to heart, several significant differences were found in fatty acid trafficking in...
Source: Lipids - Category: Lipidology Source Type: research