Effects of a 4-week freshwater fish (trout) diet on platelet aggregation, platelet fatty acids, serum lipids, and coagulation factors

Eight healthy subjects consumed a diet in which all animal products were replaced by 750 g/day of freshwater trout. Platelet eicosapentaenoic acid (EPA) as a percentage of total platelet fatty acids rose from a prediet level of 0.2 +/- 0.4% to 3.4 +/- 1.6% after 4 weeks on the diet. Platelet arachidonic acid remained unchanged. Platelets became more hyperaggregable to collagen (p less than .025) but became hypoaggregable to arachidonic acid (p less than .05). The Ivy bleeding time became prolonged rising from a mean of 148 seconds before the diet to 168 seconds at 2 weeks and 202 seconds at 4 weeks. Serum lipids, coagulation profiles, and blood pressure remained unchanged. The changes induced by this diet were much less marked than changes induced by marine fish diets and diets supplemented by marine fish oil extracts, despite the fact that an equivalent amount of EPA was consumed and incorporated into platelets. These findings suggest that other substances, in addition to n-3 unsaturated fatty acids, may be responsible for the antithrombotic properties of marine fish.     

Diets rich in saturated n-9 and n-3 fatty acids differentially affect the fatty acid composition of phospholipids and function of rat platelets

The aim of the present study was to determine whether dietary intake of monounsaturated or long chain n-3 fatty acids could be effective in lowering platelet responsiveness through modulation of platelet phospholipid composition. Rats were fed diets containing 20% fat with equal cholesterol and 13a-tocopherol contents. These diets were supplemented with saturated, oleic or n-3 fatty acids, n-3 polyunsaturated fatty acids being added either pure, as eicosapentaenoic and docosahexaenoic ethyl esters, or as MaxEPA oil. Dietary n-3 fatty acids did not affect the oxidation status of plasma lipids. Oleic acid- and saturated fatty acid-rich diets led to similar enrichment of platelet phospholipids in arachidonic acid and to comparable thromboxane A(2) generation on stimulation with collagen or thrombin. Platelets of n-3-fed groups were differently enriched in eicosapentaenoic and docosahexaenoic acids at the expense of arachidonic acid. These groups displayed similar thromboxane A(2) production, although levels were lower than those for groups fed with oleic- or saturated fatty acid-rich diets. Only the MaxEPA diet led to a reduction in platelet reactivity, measurable as a small decrease in the aggregation induced by collagen. This diet was also responsible for a high cholesteroUphospholipid ratio and low a-tocopherol content in platelets. Overall results indicated that (i) only MaxEPA reduced platelet reactivity and (ii) this effect was moderate and apparently unrelated to platelet arachidonic acid content, membrane cholesterol to phospholipid ratio or thromboxane A(2) production.     

Fatty acids in human platelets and plasma. Dietary seal oil decreases sensitivity toward microbubbles

Platelet aggregation induced by microbubbles (simulating microbubbles developing during deep sea diving or clinical situations such as extracorporeal circulation) in platelet rich plasma was measured in 11 male volunteers before and after intake of 15 ml seal oil (Pagophilus groenlandica) per day for 2 weeks. The relative content of arachidonic acid (AA) decreased in platelets from all individuals, whereas the content of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) increased. Also in plasma, the relative content of EPA and DHA increased, while the change in AA content was small but variable. Generally, the platelet content of oleic acid increased while the linoleic acid decreased. Intake of seal oil decreased platelet aggregation induced by microbubbles. A significant correlation between aggregation in platelet-rich plasma (PRP) and the AA content in platelets was shown, while there was a significant negative correlation between oleic acid content and platelet aggregation. In whole blood, however, seal oil intake did not result in less platelet aggregation using ADP and U-46619 as agonists.     

Plasma lipid levels and platelet and neutrophil function in patients with vascular disease following fish oil and olive oil supplementation.

This double-blind study was designed to examine and compare the effects of supplementing the existing diet with fish oil or olive oil on lipids and cell function in patients with peripheral vascular disease. Thirty-two patients with symptomatic and angiographically demonstrated peripheral vascular disease were screened, matched, and randomly allocated to take either 15 g/d fish oil or olive oil for 4 weeks. Fish oil reduced serum triglyceride levels by 26%, but increased total cholesterol levels due to a significant increase in both low-density lipoprotein cholesterol (LDL-C) and high-density lipoprotein-2 cholesterol (HDL2-C). There was a nonsignificant decrease in HDL3-C levels. Olive oil reduced total cholesterol levels, accountable to a significantly decrease in LDL-C levels. Serum thromboxane B2 (TXB2) levels remained unchanged following fish oil, but were significantly increased by olive oil. Urinary excretion of TXB2 and 6-keto-PGF1 alpha was unaffected by either oil supplement. Platelet aggregation, which was measured in platelet-rich plasma in response to two doses of collagen or platelet-activating factor (PAF), was significantly reduced after fish oil, but was increased by olive oil. Following fish oil, there was a significant increase in eicosapentaenoic acid (EPA, 20:5) and docosahexaenoic acid (DHA, 22:6) levels and a decrease in arachidonic acid content of platelet phospholipids. The platelet fatty acid composition after olive oil was unchanged. Fish oil decreased neutrophil leukotriene B4 (LTB4) generation following calcium ionophore stimulation by 33%, while leukotriene B5 levels increased significantly. Neutrophil PAF production and plasma lyso-PAF were unaffected by either oil.(ABSTRACT TRUNCATED AT 250 WORDS)     

Diets rich in saturated n-9 and n-3 fatty acids differentially affect the fatty acid composition of phospholipids and function of rat platelets

The aim of the present study was to determine whether dietary intake of monounsaturated or long chain n-3 fatty acids could be effective in lowering platelet responsiveness through modulation of platelet phospholipid composition. Rats were fed diets containing 20% fat with equal cholesterol and 13a-tocopherol contents. These diets were supplemented with saturated, oleic or n-3 fatty acids, n-3 polyunsaturated fatty acids being added either pure, as eicosapentaenoic and docosahexaenoic ethyl esters, or as MaxEPA oil. Dietary n-3 fatty acids did not affect the oxidation status of plasma lipids. Oleic acid- and saturated fatty acid-rich diets led to similar enrichment of platelet phospholipids in arachidonic acid and to comparable thromboxane A₂ generation on stimulation with collagen or thrombin. Platelets of n-3-fed groups were differently enriched in eicosapentaenoic and docosahexaenoic acids at the expense of arachidonic acid. These groups displayed similar thromboxane A₂ production, although levels were lower than those for groups fed with oleic- or saturated fatty acid-rich diets. Only the MaxEPA diet led to a reduction in platelet reactivity, measurable as a small decrease in the aggregation induced by collagen. This diet was also responsible for a high cholesteroUphospholipid ratio and low a-tocopherol content in platelets. Overall results indicated that (i) only MaxEPA reduced platelet reactivity and (ii) this effect was moderate and apparently unrelated to platelet arachidonic acid content, membrane cholesterol to phospholipid ratio or thromboxane A₂ production.     

Monoclonal Antibody to Human Platelet Glycoprotein I II. EFFECTS ON HUMAN PLATELET FUNCTION

S ummary . The effect on platelet function of a monoclonal platelet antibody to platelet membrane glycoprotein I was tested. This antibody, AN51, inhibited ristocetin or bovine factor VIII-induced aggregation but did not modify ADP, collagen type I or type III, thrombin or arachidonic acid induced aggregations. Furthermore, the adhesion-aggregation of platelets induced by microfibrils was also inhibited by the antibody. Platelet adhesion to rabbit aorta subendothelium was impaired by the antibody. The persistent adhesion of platelets to collagenase-treated subendothelium was also inhibited. These findings strongly suggested that platelet membrane glycoprotein I could interact with a non-collagenic microfibrillar component of subendothelium. The binding of factor VIII/von Willebrand factor to platelet membrane in the presence of ristocetin was decreased in the presence of the antibody. Platelet membrane glycoprotein I could, thus, be a binding site for factor VIII/von Willebrand factor to allow platelet adhesion to subendothelium.     

The Effect of Cod Liver Oil in Two Populations with Low and High Intake of Dietary Fish

ABSTRACT Two subgroups of healthy males from an inland and a coastal community in Norway with a traditionally low and high consumption of dietary fish were given a dietary supplement of 20 ml cod liver oil rich in n-3 polyunsaturated fatty acids for 3 weeks. Cod liver oil induced an increase in serum high density lipoprotein (HDL) cholesterol in men from the inland. Both groups showed a prolonged primary bleeding time, whereas platelet aggregation and thromboxane A₂ production induced by collagen were mainly unaffected. Platelet phospholipid fatty acids showed similar changes in both groups with a decrease in n-6 and an increase in n-3 polyunsaturated fatty acids. No changes were observed in total cholesterol or platelet phospholipid content. This study shows that dietary supplement with cod liver oil induces changes in serum lipids and platelets that may reduce the tendency to thrombosis both in subjects with a low and in those with a high intake of dietary fish. The effects were more pronounced in the subjects with a traditionally low fish consumption.     

Effect of polyunsaturated fatty acids of the n-3 and n-6 series on lipid composition and eicosanoid synthesis of platelets and aorta and on immunological induction of atherosclerosis in rabbits

The effect of dietary fish oil (rich in n-3 polyunsaturated fatty acids (PUFA], corn oil (rich in n-6 PUFA) and coconut oil (low in n-3 and n-6 PUFA) on the induction of atherosclerosis by serum sickness in rabbits was investigated over a 12-month period. Dietary fish oil led to a significant increase in the level of eicosapentaenoic acid (EPA) in all platelet phospholipid fractions and to a significant reduction in the level of platelet phosphatidylethanolamine arachidonic acid (AA). In aortic total phospholipids, rabbits given fish oil showed a significant reduction in AA and a significant increase in EPA. Rabbits given fish oil showed significantly lower collagen-induced platelet thromboxane A2 release and aortic production of 6-keto-PGF1 alpha. Serum total immune complex levels and anti-horse serum IgG levels were not influenced by diet. There was a significant reduction in total aortic atherosclerosis in fish oil-fed animals compared with coconut oil fed animals.     

Platelet function during ticlopidine and eicosapentaenoic Acid administration in patients with coronary heart disease

Antiplatelet drugs have been reported to be useful in unstable angina. This study was designed to investigate the effects of simultaneous administration of ticlopidine and eicosapentaenoic acid (EPA) on platelet function in coronary heart disease (CHD) patients. Ticlopidine significantly reduced platelet aggregation induced by ADP and collagen with no effect on arachidonate metabolism. The aggregation responses to collagen, ADP and arachidonate were not altered significantly by EPA (as fish oil) intake whereas thromboxane A(2) formation was reduced, but not completely inhibited. Combined therapy seems to achieve a more marked degree of inhibition of aggregation together with a fall in the urinary excretion of 11-dehydrothromboxane B(2) metabolite. Therefore, in CHD patients ticlopidine therapy plus fish oil administration could be useful to inhibit two different mechanisms (TxA(2)- and ADP-dependent) of platelet activation.     

Platelet function, thromboxane formation and blood pressure control during supplementation of the Western diet with cod liver oil

Epidemiologic and experimental data suggest an antiatherothrombotic potential of omega-3 polyunsaturated fatty acids. Therefore, the Western diet, which supplies predominantly omega-6 polyunsaturated fatty acids, was supplemented with 40 ml/day of cod liver oil, which provides about 10 g of omega-3 polyunsaturated fatty acids daily, for 25 days in eight volunteers. The omega-3 polyunsaturated fatty acids were incorporated in platelet and erythrocyte membrane phospholipids at the expense of omega-6 polyunsaturated fatty acids. Bleeding time increased (p less than 0.01) and platelet count (p less than 0.05), platelet aggregation upon ADP and collagen (p less than 0.01-0.05), and associated thromboxane B2 formation (p less than 0.01) decreased. Blood pressure (p less than 0.05) and blood pressure response to norepinephrine (p less than 0.01) and angiotensin II (NS) fell, without major changes in plasma catecholamines, renin, urinary aldosterone, kallikrein, prostaglandins E2 and F2 alpha and red cell cation fluxes. Biochemical and functional changes were reversed 4 weeks after cod liver oil was discontinued. Formation of prostaglandins derived from eicosapentaenoic acid and interference of eicosapentaenoic acid with formation and action of prostaglandins derived from arachidonic acid were evident in vitro. Whatever the mechanism, this moderate supplement of omega-3 polyunsaturated fatty acids markedly changed membrane phospholipids, which was associated with a shift toward less reactive platelets and a blunted circulatory response to pressure hormones.     

Release of arachidonic acid from human platelets. A key role for the potentiation of platelet aggregability in normal subjects as well as in those with nephrotic syndrome

Low (nonaggregating) concentrations of collagen that potentiate platelet aggregation did not induce the formation of measurable amount of malondialdehyde (MDA) but released small but significant amounts of radioactivity from 14C-arachidonic acid-labeled platelets. A major portion of the radioactive compounds released by nonaggregating concentrations of collagen existed as arachidonic acid and a minor part as thromboxane B2. The nephrotic syndrome enhances platelet aggregability, and this effect is abolished by correcting hypoalbuminemia in vitro and in vivo by the addition of albumin, which is the main carrier for free fatty acids, including arachidonic acid. Human albumin (fatty acid free) inhibited collagen-induced aggregation, MDA formation, and release of the radioactivity from 14C-arachidonic acid-labeled platelets in normals as well as in those with nephrotic syndrome. These data support our hypothesis that the main mechanism responsible for the potentiation of platelet aggregation is the release of arachidonic acid from platelet membrane phospholipids via the activation of phospholipase A2. Furthermore, enhanced platelet aggregation in the nephrotic syndrome was at least partly attributable to an increased availability of arachidonic acid released secondary to hypoalbuminemia. Albumin inhibits aggregation probably by binding to released arachidonic acid preventing arachidonic acid from being metabolized to potent aggregating substances, endoperoxides and thromboxane A2. The mechanism of release of arachidonic acid may play a key role in the potentiation of platelet aggregability in normals as well as in pathologic conditions such as the nephrotic syndrome.     

Tumor necrosis factor-alpha as trigger of platelet activation in patients with heart failure

The clinical history of patients with heart failure (HF) is complicated by arterial thromboembolism. Platelet activation is reported in this population, but the underlying mechanism has not been clarified. Forty-two patients with HF scored according to New York Heart Association (NYHA) classification had higher levels of collagen-induced platelet aggregation, platelet tumor necrosis factor-alpha (TNF-alpha) receptor expression, and serum thromboxane B2 and higher circulating levels of TNF-alpha than 20 healthy subjects. Coincubation of platelets from HF patients with an inhibitor of TNF-alpha receptors significantly reduced collagen-induced platelet aggregation. In vitro study demonstrated that TNF-alpha amplified the platelet response to collagen; this effect was inhibited by TNF-alpha receptor antagonist and inhibitors of arachidonic acid metabolism. This study showed that TNF-alpha behaves as a trigger of platelet activation through stimulation of the arachidonic acid pathway.     

A Study of Platelet Retention by Glass Bead Columns (''Platelet Adhesiveness'' in Normal Subjects)

S ummary . Platelet adhesiveness tests using glass bead columns were performed in 54 normal subjects. Native blood was forced through the columns by a syringe pump at a flow rate of 6 ml/min, and effluent blood was collected in four aliquots of 2 ml each. The first two aliquots demonstrated a progressive increase in per cent platelet adhesiveness with maximum adhesiveness achieved in the second aliquot. The third and fourth aliquots showed decreased adhesiveness with a progressive broadening of the range of normal. In 11 of the 54 normal subjects the fourth aliquot of effluent blood contained more platelets than the original whole blood and indicated that platelets previously retained by the column were being returned to the effluent. The per cent platelet adhesiveness in the first aliquot did not vary with the platelet count. However, the absolute number of platelets retained by the column increased as the platelet count increased. Moreover, the number of platelets retained from a given aliquot was directly proportional to the number of platelets retained from previous aliquots. The return of platelets to the effluent in the fourth aliquot was associated with the smallest number of platelets retained from the first three aliquots. Adenosine inhibited the retention of platelets by glass bead columns. Retention of platelets by glass bead columns appears to be determined by platelet adhesion to glass surfaces, platelet to platelet aggregation due to released ADP, and spontaneous platelet disaggregation which becomes evident when the initial number of retained platelets provides an insufficient amount of ADP to sustain aggregation.     

Platelet aggregations, fatty acids, clotting factors and serum lipids in rural and urban blacks, and urban whites in South Africa

Platelet fatty acids, platelet aggregations, and coagulation factors were measured in 27 rural blacks, 27 urban blacks and 39 urban whites. Platelets were significantly less aggregable to collagen and arachidonic acid in in both black groups as compared to whites (p less than 0.01), but there were no significant differences in ADP or epinephrine aggregation between these groups. Factor VIII coagulant activity was much higher in rural and urban blacks than whites (p less than 0.001), and the partial thromboplastin times were shorter (p less than 0.005). Platelet arachidonic acid showed a marked difference between the groups, being 16.4 +/- 5.4% of total platelet fatty acids in the rural blacks, 19.9 +/- 4.2% in the urban blacks and 22.6 +/- 3.3% in the whites (p less than 0.001). Whites had higher LDL and lower HDL cholesterol than blacks (p less than 0.005). These findings suggest that in addition to the well known association of raised LDL cholesterol and acute myocardial infarction, platelet aggregation patterns and platelet arachidonic acid levels may be associated risk factors in coronary thrombosis.     

Characterization of platelet function in cyclic hematopoietic dogs

Platelet aggregation to incremental doses of eight different platelet agonists (collagen, thrombin, platelet-activating factor [PAF], arachidonic acid [AA] plus epinephrine, the calcium ionophore A23187, ADP, phospholipase C [PLC], and 12-O-tetradecanoyl phorbol-13-acetate [TPA]) was compared in normal (N) and cyclic hematopoietic (CH) dogs. Platelet aggregation was defective with collagen, PAF, TPA, and possibly thrombin as agonists but normal when ADP, PLC, arachidonic acid plus epinephrine, and A23187 were used as agonists with CH platelets. In heterozygous CH dogs, platelet aggregation was intermediately defective when tested with collagen and PAF as agonists. Thromboxane B2 (TXB2) concentrations (mean +/- SD; pg/10(6) platelets), as measured by RIA, were similar in CH and normal dogs both prior to (CH: 7.6 +/- 7.0; N: 5.5 +/- 3.9) and after collagen stimulation (collagen: 141.3 +/- 42.5; 123.1 +/- 38.4). Granule storage pools of serotonin and platelet adenine nucleotides were markedly decreased in homozygous CH but not heterozygous CH dogs. Thrombin stimulated phosphorylation of 40- and 20-kd proteins in platelets from CH and normal dogs to an equal extent. However, collagen-stimulated phosphorylation of the 40- but not the 20-kd protein was significantly decreased in platelets from CH dogs. These data suggest that there is a biochemical defect in platelets from CH dogs that results in storage pool disease and decreased phosphorylation of a 40-kd protein.     

Altered platelet function in cirrhosis of the liver: impairment of inositol lipid and arachidonic acid metabolism in response to agonists

Hemorrhagic disorders are common in patients with liver cirrhosis and result from several factors including impaired platelet function. We evaluated platelet aggregation and arachidonic acid metabolism in response to standard agonists in platelet-rich plasma from 12 cirrhotic patients with mild impairment of liver function (Child A), 12 patients with severe liver dysfunction (Child B and C) and 12 healthy subjects. Platelet aggregation and thromboxane A2 production were consistently reduced in patients with severe liver impairment. To determine whether the platelet dysfunction is due to an intrinsic platelet defect or a circulating inhibitor, we measured platelet aggregation and thromboxane A2 synthesis on washed platelets in healthy subjects and in Child B and C patients. The aggregating response of washed platelets in response to thrombin, collagen and arachidonic acid was markedly reduced, suggesting an intrinsic platelet defect. The biochemical events underlying platelet aggregation were investigated by prelabeling platelets with [1-14C]arachidonic acid. Thrombin-induced activation of phospholipase C (measured as the release of [1-14C]phosphatidic acid) and phospholipase A2 (measured as the release of [1-14C]arachidonic acid and its metabolites) was greatly impaired in platelets from patients with severe liver impairment. We conclude that in advanced cirrhosis there is a severe reduction in platelet aggregatory response to physiologic agonists due to an intrinsic platelet defect which is related to an impairment of the platelet transmembrane signaling mechanism induced by receptor stimulation.     

Docosahexaenoic acid and docosapentanoic acid incorporation into human platelets after 24 and 72 hours: inhibitory effects on platelet reactivity

Short-term in vitro platelet membrane lipid enrichment studies and feeding trials of human subjects with eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) have shown a decreased reactivity in the platelet response to collagen. In this study, exogenous albumin-bound n-3 polyunsaturated fatty acids (PUFAs), namely EPA, DHA and docosapentanoic acid (DPA) were added to platelet suspensions and maintained at 22 degrees C for 24 and 72 hours. Subsequently, the aggregation response to agonist stimulation and the morphological appearance of the platelets were evaluated. A significant enrichment of platelet phospholipids (PL) in n-3 fatty acids occurred upon incubation with n-3 PUFAs in vitro, which was accompanied by a decrease in the aggregation response to collagen and preservation of platelet morphology compared with non-supplemented control platelet preparations. The inhibitory effect of the n-3 PUFAs appeared to be surface mediated in the case of DHA and DPA because the platelet response to agonist returned when the fatty acids were removed by washing. The platelet aggregation response after storage at 22 degrees C was also evaluated in platelet suspensions collected from healthy individuals before and after 42 days of dietary supplementation with seal oil, rich in DPA and DHA. Unlike the in vitro supplementation, in vivo modification and enrichment of platelet PLs by ingestion of seal oil did not appear to improve platelet function during storage relative to the placebo group.     

Platelet adhesion to collagen in individuals lacking glycoprotein IV

The Naka isoantigen is expressed on glycoprotein (GP) IV (CD36), a platelet membrane GP that has been identified as having a role in platelet interactions with collagen and thrombospondin and in binding Plasmodium falciparum-infected erythrocytes to endothelial cells and melanoma cells. We have studied normal platelets and Naka- platelets from two Japanese donors that have 1% of GPIV by concentration- dependent antibody binding and flow cytometry. We studied the adherence of normal and Naka- platelets to types I, III, and IV collagen in static and to type I collagen in flowing systems at high shear force. We have also studied aggregation of normal and Naka- platelets to type I collagen. Naka- platelets showed normal or increased aggregation to type I collagen and normal adhesion to types I, III, and IV collagen in the presence of Mg++ or EDTA. Platelet aggregation and adhesion were inhibited by the anti-alpha 2 beta 1 antibody 176D7 to the same extent in Naka- as in normal platelets. We also studied endogenous thrombospondin surface expression and found that thrombin-stimulated Naka- platelets expressed the same amount of thrombospondin as did normal platelets. From our studies with Naka- platelets, we cannot identify a definitive role for GPIV in platelet aggregation, in adhesion to types I, III, and IV collagen, or in endogenous thrombospondin binding to platelets.     

Effect of latex-stimulated granulocytes on platelet aggregation in man

The effect of granulocytes on human platelet aggregation was investigated in vitro. Platelet function was assayed by photometric technique. Incubation of platelets with latex-stimulated granulocytes for 1 h at room temperature resulted in total inhibition of arachidonic acid-induced platelet aggregation. ADP-induced platelet aggregation was suppressed, lacked secondary wave and was pursued by swift disaggregation. Platelet aggregates induced by collagen dispersed faster under the influence of stimulated granulocytes. The present results indicate that granulocytes may play a role in the hemostatic mechanism in man.     

The effects of dietary omega 3 fatty acids on platelet composition and function in man: a prospective, controlled study

The rarity of atherosclerotic vascular disease and a mild bruising tendency in Greenland Eskimos has been linked to their ingestion of omega 3 fatty acids contained in foods obtained from the sea. Previous studies have shown that feeding salmon oil to normal volunteers resulted in reductions of plasma cholesterol and triglycerides. We wished to learn whether salmon oil feeding would result in the incorporation of omega 3 fatty acids into platelets and whether platelet function or platelet-vessel interaction would be altered. Diets containing salmon oils led to the incorporation of eicosapentaenoic acid (C20:5 omega 3) into platelets (6.1%) with a reduction in arachidonic acid (C20:4 omega 6). The ratio of C20:5/C20:4 increased from 0.0045 on the control diet to 0.3 on the salmon diet. Bleeding times were prolonged (from 6.75 to 10 min, p less than 0.005), platelet retention on glass beads was mildly reduced (from 89% to 78%, p less than 0.0005), and platelet aggregation in response to dilute concentrations of ADP was inhibited in the subjects ingesting the salmon oil. We conclude that in normal subjects dietary omega 2 fatty acids derived from salmon oil are incorporated into platelet phospholipids and that these changes are accompanied by alterations in bleeding time and platelet function.