Is the reduction of myocardial infarct size by dietary fish oil the result of altered platelet function?

• Published in: The American heart journal Vol. 127; no. 4; pp. 744 - 755
• Main Authors: Zhu, Bo-qing, Sievers, Richard E., Sun, Yi-ping, Morse-Fisher, Nancy, Parmley, William W., Wolfe, Christopher L.
• Format: Journal Article
• Language: English
• Published: New York, NY Mosby, Inc 01.04.1994; Elsevier
• Subjects: Animals; Biological and medical sciences; Bleeding Time; Blood Platelets - chemistry; Blood Platelets - drug effects; Cardiology. Vascular system; Coronary heart disease; Docosahexaenoic Acids - analysis; Docosahexaenoic Acids - blood; Eicosapentaenoic Acid - analysis; Eicosapentaenoic Acid - blood; Fish Oils - administration & dosage; Fish Oils - pharmacology; Heart; Hemodynamics - drug effects; Medical sciences; Myocardial Infarction - diet therapy; Myocardial Infarction - pathology; Myocardial Ischemia; Myocardium - chemistry; Rats; Rats, Sprague-Dawley; Infarct; Rat; Size; Rodentia; Cardiovascular disease; Coronary heart disease; Myocardial disease; Fish oil; Mechanism; Vertebrata; Experimental disease; Reduction; Mammalia; Diet therapy; Diet; Animal; Platelet function; Myocardium
• ISSN: 0002-8703; 1097-6744
• DOI: 10.1016/0002-8703(94)90540-1

Sprague-Dawley rats fed a diet containing 12% fish oil (18% eicosapentaenoic acid [EPA] and 12% docosahexaenoic acid [DHA]), for 1 week (group I, n = 9) or 8 weeks (group III, n = 42) and controls (group II, n = 8; group IV, n = 36, respectively) were subjected to 35 minutes of left coronary artery occlusion followed by 120 minutes of reperfusion. Compared to the controls, infarct size was significantly reduced in group III (15% ± 2%, n = 42 vs 34% ± 4%, n = 36; p < 0.001; infarct mass/risk area ×100%), but no change in group I (39% ± 5%, n = 9 vs 35% ± 5%, n = 8; p = not significant). Bleeding time was prolonged in group III (290 ± 73 sec) compared to group IV (99 ± 10 sec, p = 0.015). ω-3 fatty acid (EPA and DHA) levels in platelets were significantly higher in the rats fed 8 weeks of fish oil (group III) compared to the controls (group IV) and the rats fed 8 weeks of fish oil and then a regular diet until bleeding time normalized (group V) (7.2% ± 0.6% vs 1.2% ± 0.2% and 4.9% ± 0.5%; 3.8% ± 0.7% vs 1.8% ± 0.3% and 2.8% ± 0.6%, p < 0.001 and 0.05, respectively). These data indicate that long-term (8 weeks) dietary fish oil supplementation significantly reduces infarct size; short-term (1 week) does not. This reduction of infarct size appears to correlate with altered platelet function and EPA and DHA levels in platelets.