Dietary enrichment with omega-3 fatty acids partially protects against lipopolysaccharide-induced atrial depression in rats.
We tested the hypothesis that pretreatment with a diet enriched with omega-3 fatty acids can prevent lipopolysaccharide (LPS)-induced atrial dysfunction. Sprague-Dawley rats were fed a diet containing 20% safflower oil (control diet; CD) or 19.5% menhaden/0.5% safflower oil (experimental diet; ED). After 28 days, the animals were injected I.V. with LPS (20 mg/kg) or normal saline (S). Two hours later, the atria were harvested, connected to a force displacement transducer-amplifier-recorder system and maintained in vitro in oxygenated 37.5 degrees C Krebs-Henseleit buffer. Force of contraction indexed to body weight (FOCI; g/kg) and maximal rate of rise of contraction (dF/dt, g/sec) and relaxation (-dF/dt, g/sec) were similar in the CD-S (n = 6) and ED-S (n = 6) groups. FOCI, dF/dt, and -dF/dt were lower (P less than 0.05) in rats injected with LPS compared with rats injected with S irrespective of diet, but were significantly higher (P less than 0.05) in LPS-ED rats (n = 11) compared with LPS-CD rats (n = 11). Chronotropic and inotropic responses to graded doses (0.1, 0.5, 1.0, and 5.0 microM) of isoproterenol were not significantly different among groups. LPS-induced production of thromboxane B2 but not 6-keto-prostaglandin F1 alpha, was inhibited in ED fed rats. The ED did not enhance survival when rats were challenged with a 20 mg/kg I.V. dose of LPS. These results indicate that dietary enrichment with omega-3 fatty acids in rats partially protects against LPS-induced alterations in atrial function but does not change mortality after an LD100 dose of LPS.
Heard
S O
SO
Department of Anesthesiology, University of Massachusetts Medical Center, Worcester 01655.
McGuire
K
K
Haw
M P
MP
Forse
R A
RA
Blackburn
G L
GL
Fink
M P
MP
D015121:6-Ketoprostaglandin F1 alpha / Q000032:analysis; D000818:Animals; D016275:Atrial Function / Q000187:drug effects*; D004041:Dietary Fats / Q000494:pharmacology*; D015525:Fatty Acids, Omega-3 / Q000494:pharmacology*; D008070:Lipopolysaccharides / Q000633:toxicity*; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D013929:Thromboxane B2 / Q000032:analysis
D004041:Dietary Fats; D015525:Fatty Acids, Omega-3; D008070:Lipopolysaccharides; D013929:Thromboxane B2; D015121:6-Ketoprostaglandin F1 alpha