Incorporation of essential and non‐essential fatty acids into distinct lipid classes in cultured bovine and porcine liver and small intestine explants

Abstract

This study investigated fatty acid (FA) esterification patterns in ruminant and non-ruminant liver and small intestine (SI) explants. Explants were incubated in media containing 14C-labeled essential FA (EFA; C18:2 or C18:3) or non-EFA (C16:0 or C18:1), to track esterification of FA into lipid classes. Mean FA uptake was greater for porcine than bovine liver explants (23.9 vs 15.9±1.8 nmol/2 h/150 mg tissue, P=0.03). Liver cultures of both species incorporated more non-EFA than EFA (22.9 vs 16.9±1.6 nmol/2 h/150 mg tissue, P<0.001). Porcine SI cultures esterified more non-EFA than EFA (17.9 vs 12.4±2.0 nmol/2 h/150 mg tissue, P<0.001). Bovine liver and SI explants esterified more FA into triglyceride (TG) than phospholipid (PL) (Liver: 2.4 vs 1.4±0.4 nmol/2 h/150 mg tissue, P=0.04, SI: 3.5 vs 2.4±0.3 nmol/2 h/150 mg tissue, P=0.01). Porcine liver and SI explants did not exhibit preferential esterification of FA into either lipid class. Culture with EFA increased PL:TG in bovine liver explants, compared to non-EFA culture (0.68 vs 0.49±0.1 nmol/2 h/150 mg tissue, P=0.01). There was no difference in PL:TG in bovine SI explants, or porcine liver and SI explants cultured with EFA or non-EFA. Results suggest differing liver esterification patterns in bovids and porcids, with esterification patterns of ruminants possibly facilitating greater EFA esterification into PL. Support provided by NSF grant IOS-0920491.