Study objectives: To investigate whether a
diet enriched with fish and borage oils, with their high
polyunsaturated fatty acid (PUFA) content, alters surfactant
composition and function during endotoxemia.
Prospective, randomized, blinded, controlled animal study.
Setting: Research laboratory at a medical center.
Participants: Thirty-six 15- to 25-kg, disease-free,
castrated male pigs.
Diets and measurements: Three
groups of pigs (n = 12 per group) were fed for 8 days diets
containing either ω-6 fatty acids (FAs) (corn oil; diet A), orω
-3 FAs (fish oil; diet B), or a combination of ω-6 and ω-3 FAs
(borage and fish oils; diet C). Eight of 12 pigs in each group received
a 0.1-mg/kg bolus of Escherichia coli endotoxin followed
by a continuous infusion (0.075 mg/kg/h). One lung was subsequently
isolated ex vivo, and pressure-volume curves were
measured. The contralateral lung was lavaged, and surfactant was
analyzed for total and individual phospholipids and FA composition.
Minimum and maximum surface tension was measured by bubble
Results: Pigs fed either diet B or C
had increased oleic acid (C18:1 ω-9), eicosapentaenoic
acid (EPA; C20:5 ω-3), docosahexaenoic acid
(C22:6 ω-3), and total ω-3 and monounsaturated FAs in
their surfactant PUFA pools. The relative percentage of linoleic acid
(C18:2 ω-6) and total ω-6 FAs were significantly lower
from pigs fed diets B and C compared with diet A. Palmitic acid
(C16:0) concentrations, the primary FA in surfactant, had a
tendency to be lower in pigs fed diets B and C. There were no
demonstrable effects on surfactant function or pulmonary
Conclusions: Diets containing EPA or EPA
and γ-linolenic acid altered the PUFA composition of pulmonary
surfactant, but without demonstrable effects on surfactant function
during porcine endotoxemia.