Effects of dietary supplementation with fish oil on atherosclerosis and myocardial injury during acute coronary occlusion-reperfusion in diet-induced hypercholesterolemic rabbits

Higher glutathione peroxidase expression in thoracic aorta as a protective factor against oxidative stress and atherosclerosis in rabbits

BACKGROUND AND AIMS

Atherosclerosis develops in different locations of the vasculature with different degree, which may result from different antioxidant/prooxidant status. This study investigated the effect of high-fat, high-cholesterol chows, with or without vitamin E supplement (450 mg/kg diet), on lipid peroxide levels, glutathione peroxidase expression, and atheroma formation in ascending aorta, pulmonary arteries and thoracic aorta.

METHODS

Sixty-four rabbits were divided to be fed with 4 different chows for 6 weeks. The percentage of atherosclerosis was measured. Plasma and vascular glutathione peroxidase activity and mRNA expression, and lipid peroxide levels were also assayed.

RESULTS

Rabbits on high-fat, high-cholesterol chows had higher lipid peroxide levels and more atherosclerosis in ascending aorta and pulmonary arteries. Tissues in thoracic aorta had higher glutathione peroxidase activity and mRNA expression without any significant increase in lipid peroxide levels and atherosclerosis. Vitamin E supplement decreased plasma lipid peroxide levels, but not in tissues, and thus could not prevent atherosclerosis.

CONCLUSION

Higher glutathione peroxidase expression in the thoracic aorta inhibits oxidative stress enhancement and atheroma progression induced by high-fat, high-cholesterol chows. Vitamin E supplement at the current dosage and duration could not prevent atheroma formation.

The effects of recurrent Pseudomonas aeruginosa infection on pulmonary parenchyma and vasculature in rats fed on a cholesterol-rich diet

It has been demonstrated that both hypercholesterolemia and infectious agents are contributing factors in atherosclerosis but their combined effect on the pulmonary vascular bed is not known. To answer this question, the authors tried to demonstrate the effects of recurrent infection on pulmonary parenchyma and vascular system in cholesterol-fed rats. Sixty-six rats were randomly divided into 4 groups: Groups I (control), II (cholesterol-rich diet), III (recurrent pulmonary Pseudomonas aeruginosa infection), IV (cholesterol-rich diet + recurrent infection). After 6 months serum cholesterol levels didn't increase in any of the groups. Central pulmonary artery wall thickness was increased in group IV (P < .0001). Although not significant, peripheral pulmonary artery wall thickness was increased in group IV. In rats fed on a cholesterol-rich diet, recurrent infection caused a significant increase in atherosclerosis, although serum cholesterol levels didn't increase. Infection and cholesterol-rich diet have a synergistic effect on atherosclerosis in the pulmonary vascular system in rats even in the absence of hypercholesterolemia.

Effects of fish oil and vitamin E on the antioxidant defense system in diet-induced hypercholesterolemic rabbits

This study was designed to investigate the effects of fish oil and vitamin E on the antioxidant defense system in hypercholesterolemic rabbits. A high fat and cholesterol diet, with or without supplement by fish oil and/or a vitamin E supplement, was fed to rabbits for 6 weeks. Compared to the reference diet of regular laboratory rabbit chow, a high fat and cholesterol-enriched diet increased atheroma formation, plasma lipid and peroxide levels, decreased blood glutathione levels, and reduced plasma glutathione reductase, glutathione peroxidase, and catalase activities. Fish oil supplementation significantly reduced atheroma and increased glutathione reductase and glutathione peroxidase activities and blood glutathione levels, but increased plasma lipid peroxide levels. Vitamin E supplementation of the fish oil diet enhanced the beneficial effects by increasing glutathione reductase activity and decreasing peroxide levels. These results indicate that a high fat and cholesterol diet attenuates blood glutathione levels and plasma antioxidant enzyme activities, which may account for some of its atherogenic properties. Consumption of fish oil enhances antioxidative defenses against the oxidative stress imposed by hypercholesterolemia, and vitamin E further enhances these beneficial effects.

The role of vitamin E on the anti-atherosclerotic effect of fish oil in diet-induced hypercholesterolemic rabbits

The role of vitamin E on the anti-atherosclerotic effect of fish oil in diet-induced hypercholesterolemic rabbits was studied in male New Zealand white rabbits. The animals were randomly divided into six groups of 14 each according to the chow given them. Group I, control, rabbits were fed regular laboratory rabbit chow. In addition to the regular chow, Group II rabbits were fed a high (1%) cholesterol-enriched diet. Group III had the same diet as Group II plus 450 mg vitamin E/1000 g chow. Group IV also had the same diet as Group II plus 10% fish oil, but without vitamin E. Group V's diet contained 1% cholesterol, 10% fish oil, and 450 mg vitamin E/1000 g chow. Group VI had the same diet as Group V, but with 150 mg vitamin E/1000 g chow. At the end of a 6-week feeding, the ascending aorta from seven rabbits from each group was harvested for the analysis of prostanoid production, thiobarbituric acid reactive substances (TBARS), superoxide dismutase activity, and cholesterol and vitamin E levels; the same tissue from the other seven rabbits from each group was obtained for the delineation of atherosclerotic lesions by planimetry after the Sudan IV stain. The high cholesterol diet-treated rabbits had worse prostanoid synthesis and higher TBARS levels, which paralleled the severity of the atherosclerosis. Vitamin E or fish oil supplementation in a high cholesterol diet had beneficial prostanoid production, reduced aortic TBARS levels, and attenuated atherosclerotic lesions; these effects were potentiated when vitamin E and fish oil were combined together. The atherosclerotic lesion reduction in rabbits treated with high cholesterol plus fish oil and 450 mg vitamin E/1000 g chow reached statistical significance (P < 0.05) compared to high cholesterol and the same dose of vitamin E-treated rabbits. The rabbits treated with high cholesterol plus fish oil, but without vitamin E or with 150 mg vitamin E/1000 g chow showed an increased plasma creatine kinase activity at 4 (P < 0.01 and 0.05, respectively) and 6 (P < 0.001 and 0.01, respectively) week of feeding. These results suggest that vitamin E and/or fish oil attenuate atherosclerosis in high cholesterol-fed rabbits; vitamin E and fish oil potentiated the effect of each other. Furthermore, without sufficient vitamin E supplementation, rabbits treated with high cholesterol plus fish oil will show an elevation of plasma creatine kinase activity.

Vitamin E supplementation attenuates myointimal proliferation of the abdominal aorta after balloon injury in diet-induced hypercholesterolemic rabbits

The effects of vitamin E supplementation in a dose of 450 mg/1000 g chow on the myointimal proliferation of the abdominal aorta after balloon injury were studied in 4 groups of rabbits (24 each). The animals were fed regular diet, regular diet plus vitamin E, 1% cholesterol-enriched diet, and 1% cholesterol-enriched diet plus vitamin E. Each animal underwent a balloon injury of the abdominal aorta and left common iliac artery after 2 weeks of feeding. The animals remained on their respective diets thereafter. In 8 balloon-injured and 8 sham-operated animals of each group, the abdominal aortas were harvested 3 days after the procedure for the analysis of prostacyclin and thromboxane A2 synthesis, thiobarbituric acid reactive substances (TBARS) levels, enzyme activities of glutathione reductase (GR) and glutathione peroxidase (GP) as well as reduced (GSH) and oxidized (GSSG) glutathione levels, 3H-thymidine uptake, cholesterol as well as vitamin E contents. In the other 8 balloon-injured rabbits of each group, the tissue was harvested 3 weeks later for the morphometric study. In dependent of high cholesterol feeding, the vitamin E-treated rabbits had lower aortic production of thromboxane B2, higher 6-keto-PGF1 alpha and higher 6-keto-PGF1 alpha/thromboxane B2 ratios in both procedures. The aortic TBARS levels of the rabbits treated high cholesterol alone were significantly higher than the other three groups in both procedures. Balloon injury had a trend to increase TBARS levels and had significantly higher 3H-thymidine uptake (each p < 0.001) than sham operation in each group. Vitamin E supplement to high cholesterol diet or regular chow reduced aortic TBARS levels (p < 0.005 and 0.01, respectively) and 3H-thymidine uptake (p < 0.05 and 0.01, respectively), as well as attenuated myointimal proliferation of the abdominal aorta and left common iliac artery after balloon injury; but only supplement to high cholesterol diet reached statistical significances (both p < 0.05 compared to rabbits fed high cholesterol alone). These results suggest that vitamin E supplement changes prostanoid metabolism to a favorable pattern and reduces lipid peroxidation of the abdominal aortic wall, thus attenuates myointimal proliferation after balloon injury; these presentations are particularly obvious in diet-induced hypercholesterolemic rabbits.

Dyslipidemias have a detrimental effect on left ventricular systolic function in patients with a first acute myocardial infarction

Several large-scale clinical trials have shown that lipid-lowering interventions are associated with reduced coronary events and mortality. However, whether dyslipidemias have a detrimental effect on the evolution of myocardial infarction (MI) is still unknown. To examine whether dyslipidemias can aggravate myocardial vulnerability following MI, 165 patients with a first MI were studied. All patients underwent measurements of serum lipid profiles 1 week and 3 months after MI, a radionuclide ventriculographic study, and a coronary angiographic study. The patients were divided into 3 groups according to their 3-month serum cholesterol levels (group 1, <200 mg/dl; group 2, 200 to 240 mg/dl; group 3, >240 mg/dl). Groups 1, 2, and 3 consisted of 66, 59, and 40 patients, respectively. Group 3 had a higher Gensini score than groups 1 and 2, although this was not statistically significant (p = 0.13). The postinfarct left ventricular ejection fraction (LVEF) was highest in group 1 (53 +/- 13%), at mid level in group 2 (43 +/- 14%), and lowest in group 3 (35 +/- 11%) (p < 0.0001). A significant negative correlation between 3-month low-density lipoprotein (LDL) cholesterol (r = -0.55, p < 0.0001) and the postinfarct LVEF was found. The product of peak creatine kinase (CK(MAX)) and time to CK(MAX) (p = 0.001), and patency of the infarct-related artery (p = 0.009), rather than variables of coronary atherosclerosis, were also independent predictors of the postinfarct LVEF. Increases in 1-week LDL cholesterol and decreases in 1-week high-density lipoprotein cholesterol were associated with a higher CK(MAX) and a lower patency rate of the infarct-related artery, respectively. This study revealed that dyslipidemias per se, especially LDL cholesterol, had a detrimental effect on the postinfarct LVEF; this effect might be independent of the atherogenic properties of dyslipidemias.

Comparison of aorta and pulmonary artery: I. Early cholesterol accumulation and relative susceptibility to atheromatous lesions

In rabbits, the pulmonary artery and the aorta are susceptible to atherosclerosis. However, susceptibility of the pulmonary artery, compared with the aortic arch, to atherosclerosis and the relationship between the accumulation of cholesterol during the early stages of atherogenesis and the development of atheromatous lesions for these arterial regions remain to be clarified. Cholesterol concentrations for the pulmonary artery and aorta were measured in normal rabbits and in rabbits fed a 0.5% cholesterol diet for 8, 12, and 16 days and 17 weeks. In normal rabbits, the rank order of arterial cholesterol concentrations was pulmonary artery>aortic arch>descending thoracic aorta, with concentrations of total and nonesterified cholesterol 17% and 25% (both P<.05) greater, respectively, for the pulmonary artery than for the descending thoracic aorta. Rank order remained the same during 16 days of cholesterol feeding, but differences between arterial regions were exaggerated. After rabbits were fed cholesterol for 16 days, total and esterified cholesterol concentrations were 57% and 920% (both P<.01) greater, respectively, for the pulmonary artery than for the descending thoracic aorta, with much smaller differences between the aortic regions. In contrast, after rabbits were fed cholesterol for 17 weeks, concentrations of total, esterified, and nonesterified cholesterol were similar for the pulmonary artery and aortic arch, but these forms of cholesterol were increased 100%, 130%, and 53% (all P<.03), respectively, for the aortic arch compared with the descending thoracic aorta. Cholesterol concentrations for the pulmonary artery were positively associated with those for the aortic regions during the first 16 days of cholesterol feeding, but for rabbits fed cholesterol for 17 weeks the associations were either negative or absent. These results indicate that relative rates of cholesterol accumulation in the pulmonary artery and aorta differ at different stages of atherogenesis and suggest that the balance between processes that deliver cholesterol to, and remove cholesterol from, the artery may change in different ways in these arterial regions during atherogenesis.

Comparison of aorta and pulmonary artery: II. LDL transport and metabolism correlate with susceptibility to atherosclerosis

The pulmonary artery and the aorta are similarly susceptible to atherosclerosis in rabbits. However, the mechanism(s) that accounts for this is not yet known. This study investigated the hypothesis that one or more aspects of arterial low-density lipoprotein (LDL) transport and metabolism might explain the similar susceptibility of the aortic arch and pulmonary artery to atherosclerosis and the increased susceptibility of these arterial regions compared with the descending thoracic aorta. We determined permeability to LDL, rates of LDL degradation, and concentrations of undegraded LDL for the intima-media of normal rabbits and those fed cholesterol for approximately 8 days. Intima-media permeability did not differ between corresponding arterial regions of normal rabbits and rabbits fed cholesterol for 8 days and was similar for the aortic arch and pulmonary artery. Rates of LDL degradation and concentrations of undegraded LDL for the intima-media were influenced by cholesterol feeding. These measures were reduced in fractional terms but increased in absolute terms as a result of hypercholesterolemia, without differences between corresponding parameters for the pulmonary artery and aortic arch. However, permeability to LDL, rates of LDL degradation, and concentrations of undegraded LDL were increased for the intima-media of the aortic arch compared with the descending thoracic aorta. Similar, although not always significant, trends were evident for the comparison of the pulmonary artery and descending thoracic aorta. Differences in LDL transport and metabolism and changes after feeding cholesterol for 8 days parallel the relative susceptibility to atherosclerosis for the three arterial regions studied. These results support the role of arterial LDL transport and metabolism in atherogenesis and potentially provide a mechanistic explanation for the differences in susceptibility to atherosclerosis for these three arterial regions.

n-3 fatty acids and lipoproteins: comparison of results from human and animal studies

The impact of n-3 fatty acids (FA) on blood lipoprotein levels has been examined in many studies over the last 15 yr in both animals and humans. Studies in humans first demonstrated the potent triglyceride-lowering effect of n-3 FA, and these were followed up with animal studies to unravel the mechanism of action. This paper reviews the reported effects of n-3 FA on blood lipoproteins in 72 placebo-controlled human trials, at least 2 wk in length and providing 7 or less g of n-3 FA/day. Trials in normolipidemic subjects (triglycerides < 2.0 mM; 177 mg/dL) were compared to those in hypertriglyceridemic patients (triglycerides > or = 2.0 mM). In the healthy subjects, mean triglyceride levels decreased by 25% (P < 0.0001), and total cholesterol (C) levels increased by 2% (P < 0.009) due to the combined increases in low density lipoprotein (LDL)-C (4%, P < 0.02) and high density lipoprotein (HDL)-C (3%, P < 0.008). In the patients, triglyceride levels decreased by 28% (P < 0.0001), LDL-C rose by 7% (P < 0.0001), but neither total C nor HDL-C changed significantly. Although the effect on triglyceride levels is also observed in rats and swine, it is rarely seen in mice, rabbits, monkeys, dogs, and hamsters. Whereas n-3 FA have only a minor impact on lipoprotein C levels in humans, they often markedly lower both total C and HDL-C levels in animals, especially monkeys. These differences are not widely appreciated and must be taken into account when studying the effects of n-3 FA on lipoprotein metabolism.

Fish oil supplementation attenuates myointimal proliferation of the abdominal aorta after balloon injury in diet-induced hypercholesterolemic rabbits

The effects of supplementing with fish oil on the myointimal proliferation of the abdominal aorta after balloon injury were studied in control and in rabbits fed a 1% cholesterol-enriched diet, with and without 10% fish oil supplementation. Twenty-one animals in each group underwent a balloon injury of the abdominal aorta and left common iliac artery after 2 weeks of feeding. The animals remained on their respective diets thereafter. In 7 balloon-injured and 7 sham-operated animals of each group, the abdominal aorta was harvested 3 days later for the analysis of prostanoids, malondialdehyde, superoxide dismutase activity, [3H]thymidine uptake, and cholesterol levels. In the other 7 balloon-injured rabbits of each group, the tissue was harvested 3 weeks later for morphometric study. The fish oil-treated rabbits had the lowest aortic production of thromboxane B2 levels and the highest 6-keto-PGF1 alpha/thromboxane B2 ratios among the three groups after balloon injury. The aortic malondialdehyde levels of the cholesterol-fed rabbits were significantly higher than the other two groups (each P < 0.001) independent of balloon injury. The myointimal proliferation of the abdominal aorta and left common iliac artery in the fish oil-treated rabbits was less severe than in the cholesterol-fed animals (both P < 0.001) and was comparable with the controls. These results suggest that a fish oil supplement changes prostanoid metabolism to a favorable pattern and reduces lipid peroxidation on the abdominal aortic wall, thus attenuating myointimal proliferation after balloon injury in diet-induced hypercholesterolemic rabbits.

Ischemia-Induced Transplant Arteriosclerosis in the Rat

The effect of cold graft ischemia time on the development of transplant arteriosclerosis was investigated. Aorta grafts from DA or PVG rats were stored in a cold perfusion solution for 1, 4, or 24 hours before being orthotopically transplanted to PVG recipients. After observation times ranging from 2 to 8 weeks, the grafts were examined for various cell populations. Regional changes in the intima and media layers were measured by using an image analysis system. The arteriosclerosis-like changes seen in syngeneic grafts with the longest ischemia time could be almost as prominent as those seen in the al-logeneic transplants. The magnitude of the regional intima changes in the syngeneic group correlated well with the ischemia time and in the allogeneic group with the observation time. The cell composition found in the intima and media of the allogeneic vessels consisted of macrophages, T-lymphocytes, MHC class II-expressing cells, and smooth muscle cells, whereas the syngeneic grafts contained almost exclusively smooth muscle cells and macro-phages. We therefore conclude that the damage due to prolonged cold ischemia time is sufficient to cause pronounced graft arteriosclerosis. The patho-physiological mechanism leading to ischemia-induced arteriosclerosis is different from the one seen in the allogeneic situation. (Arterio-scler Throtnb Vase Biol . 1995;15:145-155.)

Effects of fish oil supplementation on the changes in myocardial cyclic adenosine monophosphate, inositol 1,4,5-triphosphate and mitochondrial calcium levels during acute coronary occlusion-reperfusion in cholesterol-fed rabbits

We studied the changes in myocardial second messengers and mitochondrial calcium levels during acute coronary occlusion-reperfusion in New Zealand white male rabbits fed a high cholesterol diet with or without fish oil supplementation. Group I, control rabbits, were fed a standard laboratory rabbit chow. In addition to the standard chow, Group II rabbits received a 1% cholesterol-enriched diet for 2 weeks, while Group III rabbits were fed a 1% cholesterol and 10% fish oil supplemented diet for 2 weeks. Acute coronary occlusion for 10 min or 1 h was induced by ligating the marginal branch of the left circumflex coronary artery. The vessel was then reperfused for 1 or 4 h in short- and long-term ischemia studies respectively. In the short-term ischemia study, myocardial samples taken from the cholesterol-fed rabbits had the highest cyclic adenosine monophosphate, inositol 1,4,5-triphosphate and mitochondrial calcium levels among the normal (nonischemic) and the ischemic areas of the three groups. The cholesterol and fish oil treated rabbits significantly suppressed the elevation of cyclic adenosine monophosphate (P < 0.05 compared with the cholesterol-fed rabbits in normal and ischemic areas respectively), but did not significantly attenuate the elevation of inositol 1,4,5-triphosphate and calcium levels. In the long-term ischemia study, the cholesterol-fed rabbits had the highest levels of these three messengers among the normal areas. However, only inositol 1,4,5-triphosphate level reached statistical significance (P < 0.05 compared with control). This group of rabbits had the lowest level of cyclic adenosine monophosphate, but the highest inositol 1,4,5-triphosphate and calcium levels among the ischemic areas.(ABSTRACT TRUNCATED AT 250 WORDS)

Fish oil and the prevention and regression of atherosclerosis

Epidemiological studies in the seventies have put forward that dietary rather than genetic factors are responsible for the lower incidence of ischemic heart disease in Greenland Inuit and have generated a large body of both in vitro and in vivo experimental studies, exploring the putative favorable effects of fish (oil) on atherogenesis and its risk factors. The first part of this report reviews the in vivo animal studies, concentrating on the hypercholesterolemic models and the arterialized vein graft model. In the hypercholesterolemic animal studies, the results are inconclusive as the studies reporting a protective effect are matched by the number of studies showing no effect or an adverse effect. The diversity in species, dose of fish oil, duration of study, type of vessel studied and type of fish oil preparation (content of n-3 fatty acids, unesterified n-3 fatty acids, ethylesters or triglycerides) could all contribute. Furthermore, the definitions and criteria used in the literature to evaluate atherogenesis are diverse and it appears that while one parameter is affected, another is not necessarily modified in the same direction, stressing the importance of extending the analysis of the effects on atherogenesis to more than one parameter. We also believe that it is time to reach a consensus as to which animal model mimics most closely a particular human situation. Only in appropriate models, investigating more than one atherosclerosis variable, can the effects of a putative anti-atherogenic drug or diet be verified. In the veno-arterial autograft model, mimicking the patient after coronary bypass grafting, dietary fish oil has been consistently effective in preventing accelerated graft intima proliferation. It could therefore be of interest to evaluate the effects of fish oil on graft patency in patients after coronary bypass surgery after a period of years. The results from studies on restenosis after percutaneous transluminal angioplasty are also reviewed and it is concluded that the two large scale trials, that are currently underway, might reliably answer the question whether fish oil is effective as a non-pharmacological adjuvants in the prevention of restenosis. Lastly, the studies on the effects of fish oil on the regression of experimental atherosclerosis are reviewed. In view of the small number of studies (i.e., four) investigating the effects of fish oil on the regression of atherosclerosis, it is premature to draw any conclusion, and therefore further experimental work is required.

Fish oil supplementation attenuates free radical generation in short-term coronary occlusion-reperfusion in cholesterol-fed rabbits

We studied the changes in lipid peroxidation and prostanoid metabolism in short-term coronary occlusion-reperfusion in controls and those rabbits (11 in each group) fed a 1% high cholesterol diet with or without 10% fish oil supplementation for one week. Acute coronary occlusion for 10 minutes was induced by ligating the marginal branch of the left circumflex coronary artery. The vessels were then reperfused for 1 hour. The cholesterol and fish oil treated rabbits had the lowest malondialdehyde levels both in the ischemic and non-ischemic (normal) areas, the least increase of malondialdehyde level in the ischemic area, and the highest 6-keto-PGF1 alpha/thromboxane B2 ratio in the non-ischemic area after reperfusion among the 3 groups. These rabbits had the highest myocardial superoxide dismutase levels both in the ischemic and normal areas, and the least decrease of superoxide dismutase level in the ischemic area. These data suggest that rabbits fed a high cholesterol diet with fish oil supplementation had an attenuated lipid peroxidation, which reflected a reduced free radical generation during a short-term coronary occlusion followed by reperfusion.

Effects of dietary supplementation with fish oil on prostanoid metabolism during acute coronary occlusion with or without reperfusion in diet-induced hypercholesterolemic rabbits

We studied the changes in myocardial and aortic concentrations of prostacyclin and thromboxane A2 during acute coronary occlusion with or without reperfusion in rabbits fed with a cholesterol-enriched diet with or without fish oil supplementation for a short (5 days) or long period (6 weeks). New Zealand white male rabbits were divided into 5 groups: Group I, 15 control rabbits fed with a laboratory standard rabbit chow. In addition to the standard chow, the 4 study groups were treated with cholesterol or fish oil. Group II, 17 rabbits fed with a 1% high cholesterol diet for 5 days. Group III, 16 rabbits fed with a diet containing 1% cholesterol and 10% fish oil for 5 days. Group IV, 17 rabbits fed with the same diet as group II for 6 weeks. Group V, 18 rabbits fed with the same diet as group III for 6 weeks. Each group of rabbits was randomly divided into the coronary occlusion or occlusion-reperfusion mode of experiment. Acute coronary occlusion was induced by ligating the marginal branch of the left circumflex coronary artery for 1 h. Subsequent reperfusion for 4 h was performed in the occlusion-reperfusion rabbits. The aortic tissue above the aortic valve and the ischemic and normal (nonischemic) areas of the left ventricle were excised for the measurement of 6-keto-PGF1 alpha and thromboxane B2 levels by radioimmunoassay. Both during coronary occlusion and occlusion-reperfusion, rabbits showed higher myocardial concentrations of 6-keto-PGF1 alpha and thromboxane B2 in the ischemic area than in the normal myocardium.(ABSTRACT TRUNCATED AT 250 WORDS)