Effects of eicosapentaenoic and gamma-linolenic acids (dietary lipids) on pulmonary surfactant composition and function during porcine endotoxemia.
OBJECTIVE
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.


METHODS
Prospective, randomized, blinded, controlled animal study.


METHODS
Research laboratory at a medical center.


METHODS
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 omega-6 fatty acids (FAs) (corn oil; diet A), or omega-3 FAs (fish oil; diet B), or a combination of omega-6 and omega-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 surfactometry.


RESULTS
Pigs fed either diet B or C had increased oleic acid (C(18:1) omega-9), eicosapentaenoic acid (EPA; C(20:5) omega-3), docosahexaenoic acid (C(22:6) omega-3), and total omega-3 and monounsaturated FAs in their surfactant PUFA pools. The relative percentage of linoleic acid (C(18:2) omega-6) and total omega-6 FAs were significantly lower from pigs fed diets B and C compared with diet A. Palmitic acid (C(16:0)) 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 compliance.


CONCLUSIONS
Diets containing EPA or EPA and gamma-linolenic acid altered the PUFA composition of pulmonary surfactant, but without demonstrable effects on surfactant function during porcine endotoxemia.
Murray
M J
MJ
Departments of Anesthesiology, Mayo Clinic, Rochester, MN 55905, USA. murray.michael@mayo.edu
Kanazi
G
G
Moukabary
K
K
Tazelaar
H D
HD
DeMichele
S J
SJ
D000818:Animals; D004041:Dietary Fats; D015118:Eicosapentaenoic Acid / Q000494:pharmacology*; D019446:Endotoxemia / Q000503:physiopathology*; D004750:Enteral Nutrition; D005231:Fatty Acids, Unsaturated / Q000378:metabolism; D008168:Lung / Q000187:drug effects / Q000503:physiopathology; D008170:Lung Compliance / Q000187:drug effects / Q000502:physiology; D008297:Male; D011663:Pulmonary Surfactants / Q000187:drug effects* / Q000502:physiology; D013552:Swine; D017965:gamma-Linolenic Acid / Q000494:pharmacology*
D004041:Dietary Fats; D005231:Fatty Acids, Unsaturated; D011663:Pulmonary Surfactants; D017965:gamma-Linolenic Acid; D015118:Eicosapentaenoic Acid