Fatty Acid Composition Of Heart Research Articles

Effect of Selection for High Activity-Related Metabolism on Membrane Phospholipid Fatty Acid Composition in Bank Voles.

Endothermy, high basal metabolic rates (BMRs), and high locomotor-related metabolism were important steps in the evolution of mammals. It has been proposed that the composition of membrane phospholipid fatty acids plays an important role in energy metabolism and exercise muscle physiology. In particular, the membrane pacemaker theory of metabolism suggests that an increase in cell membrane fatty acid unsaturation would result in an increase in BMR. We aimed to determine whether membrane phospholipid fatty acid composition of heart, liver, and gastrocnemius muscles differed between lines of bank voles selected for high swim-induced aerobic metabolism-which also evolved an increased BMR-and unselected control lines. Proportions of fatty acids significantly differed among the organs: liver was the least unsaturated, whereas the gastrocnemius muscles were most unsaturated. However, fatty acid proportions of the heart and liver did not differ significantly between selected and control lines. In gastrocnemius muscles, significant differences between selection directions were found: compared to control lines, membranes of selected voles were richer in saturated C18:0 and unsaturated C18:2n-6 and C18:3n-3, whereas the pattern was reversed for saturated C16:0 and unsaturated C20:4n-6. Neither unsaturation index nor other combined indexes of fatty acid proportions differed between lines. Thus, our results do not support the membrane pacemaker hypothesis. However, the differences between selected and control lines in gastrocnemius muscles reflect chain lengths rather than number of double bonds and are probably related to differences in locomotor activity per se rather than to differences in the basal or routine metabolic rate.

P 22: Omega-3 polyunsaturated fatty acids alleviates heart pump function in Type I diabetic cardiomyopathy

The term ““diabetic cardiomyopathy””, which was first proposed by Rubler in 1972 describes myocardial dysfunction in the absence of coronary heart disease, hypertension or heart valve defects. However, from 70s of previous century is known about the omega-3 polyunsaturated fatty acids (PUFAs), which are potent cardioprotectors. Despite the success of diabetology, the mechanisms of omega-3 PUFAs influence on the heart function in diabetes mellitus remains unresolved. In this study we aimed to evaluate the effects of omega-3 PUFAs on cardiac performance in rats with experimental diabetes. Experiments were fulfilled on male Wistar rats, weighing 140–270 g, who were divided into 3 groups: 1 - control, 2 - rats with streptozotocin-induced diabetes (50 mg/kg), 3 - rats with streptozotocin-induced diabetes, which received 45% of omega-3 PUFAscontaining drug Epadol during 4 weeks. Rats were anesthetized with Urethane, fixed and right carotid artery was preparated. Ultraminiature catheter 2F («Millar Instruments», USA) was injected through the right carotid artery retrograde into the left ventricle. The fatty acids composition in heart homogenates was determined by gas chromatography. We demonstrate that omega-3 fatty acid treatment of diabetic rats modifies fatty acid composition of heart by increasing omega-3 PUFAs content. Additionally, supplemented omega-3 fatty acids significantly prevent body and heart weight loss and reduce blood glucose level, induced by streptozotocin. Our data indicates the impairment of the heart pump function in animals with diabetes. We established that cardiac output declined to 36,78% (P<0,05), ejection fraction to 29,12% (P<0,05), stroke volume to 35,65% (P<0,05), stroke work to 70,13% (P<0,05). Omega-3 PUFAs under similar conditions restores pump function - increases ejection fraction at 35,37% (P<0.05), stroke volume at 40,76% (P<0,05), stroke work at 68,02% (P<0,05) and cardiac output at 15,32%. In 2 group of rats diastolic dysfunction was found - the time constants of active relaxation Tau (Weiss) reduced to 50,63% (P<0,05) and Tau (Glantz) to 59,77%, the minimum rate of myocardial relaxation dP/dtmin slightly increased. Effect omega-3 PUFAs on diastolic function is characterized by the increase of Tau (Weiss) to 64,39% (P<0,05) and Tau (Glantz) to 11,32% (P<0,05) and a slight decrease value of dP/dtmin. Omega-3 PUFAs had almost no impact on the maximum rate of pressure increase in dP/dt max under diabetes. These novel data indicate that modification of fatty acid composition of cardiac membranes by omega-3 fatty acids prevents the pump, diastolic function alterations induced by streptozotocin. It is assumed that omega-3 PUFAs treatment will lead to a decreased risk of cardiovascular complications in diabetes. These results indicate the prospects of further studies to use omega-3 PUFAs in the treatment of diabetes.

Dietary long-chain polyunsaturated fatty acids modify heart, kidney, and lung fatty acid composition in weanling rats.

The fatty acid composition of heart, kidney, and lung was studied in weanling rats fed three diets differing in their polyunsaturated fatty acid content for 0, 2, and 4 wk. The first group had a 10% w/w fat semipurified diet which consisted of a mixture of olive oil (62.5%), soybean oil (11.1%), and refined coconut oil (26.4%) and provided 18:1n-9, 18:2n-6, and 18:3n-3 in similar amounts to a maternal human milk (diet HO). The second group received 7% of HO fat and 3% fish oil (0.4% 20:4n-6 and 5% 22:6n-3 of total fatty acids) (diet FO), and the third group was fed 7% HO fat, 1.5% of the same fish oil, and 1.5% of a purified pig brain phospholipid concentrate (0.6% 20:4n-6 and 3.5% 22:6n-3 of total fatty acids) (diet FO + BPL). The experimental diets increased tissue monounsaturated fatty acids in comparison with rats at weaning. Tissue lipid content of 20:4n-6 was increased and 22:6n-3 decreased in Group HO compared with weanling rats, whereas opposite changes were observed in Group FO. Feeding diet FO + BPL increased 22:6n:3 in tissue lipids compared with diet HO, and increased 20:4n-6 content in relation to diet FO. Our results indicate that rat heart, kidney, and lung are highly responsive to dietary n-3 and n-6 long-chain polyunsaturated fatty acids during postnatal life.

A High Omega 3 Fatty Acid Diet Alters Fatty Acid Composition of Heart, Liver, Kidney, Adipose Tissue and Skeletal Muscle in Swine

The fatty acid profiles and total lipid contents of two skeletal muscles, adipose tissue, heart, liver and kidney of swine fed a diet rich in omega 3 (n-3) fatty acids (i.e., 5% fish oil) was investigated. These values were compared to those determined for animals which were fed an equal caloric diet low in n-3 fatty acids (i.e., 5% coconut oil). All supplementations were given over a 13-week period. The lipids were extracted with chloroform-methanol, trans-esterified and the relative fatty acid methyl-esters concentrations were determined using capillary gas chromatography. The fish oil diet significantly enhanced the relative amounts of n-3 fatty acids (i.e., eicosapentaenoic acid and docosahexaenoic acid) in all tissues examined. In the heart, liver and kidney, the increases in n-3 fatty acids were compensated by decreases primarily in arachidonic acid, but in the other tissues the contents of lauric and myristic acids were also reduced. In general, the n-3 fatty acid contents were 40-165% higher in the animals fed the fish oil. Supplementation of n-3 fatty acids in swine induced a significant incorporation of these fatty acids throughout the body, however the extent of this incorporation differed between tissues perhaps due to tissue-specific metabolic pathways.

Essential Fatty Acid Nutrition of the American Alligator (Alligator mississippiensis)

The essential fatty acid (EFA) nutrition of young American alligators (Alligator mississippiensis) was examined by feeding a variety of fats/oils with potential EFA activity. Over a 12-wk period, alligators fed diets containing 2.5 or 5.0% chicken liver oil grew longer and heavier and converted feed to body mass more efficiently than alligators fed other fat/oil combinations that lacked or contained only trace amounts of arachidonic acid [20:4(n-6)]. Alligators fed an EFA-deficient diet (containing only coconut fat as the dietary fat) were the slowest-growing animals and converted feed to body mass least efficiently. However, over a 41-wk feeding period, alligators fed this diet showed no obvious external signs of deficiency other than being reduced in size and unthrifty. Fatty acid composition of heart, liver, muscle, skin and adipose tissue lipids was influenced markedly by dietary fat composition. Tissues varied significantly in response to dietary fat composition. Heart lipids contained the lowest levels of short- and medium-chain fatty acids and the highest levels of arachidonic acid. Arachidonic acid levels were less influenced by diet than were levels of other 20- and 22-carbon polyunsaturated fatty acids. Radiotracer studies indicated that linoleic acid was converted to arachidonic acid in the liver. Nevertheless, tissue arachidonic acid levels also appeared to be maintained by concentration from dietary sources and selective conservation. It appears that a dietary source of arachidonic acid may be required for a maximum rate of growth.

Dietary carbohydrate influences tissue fatty acid and lipid composition in the copper-deficient rat

Fructose and copper have been shown independently to influence long chain fatty acid metabolism. Since fructose feeding exacerbates copper deficiency, their possible interaction with respect to tissue long chain fatty acid and lipid composition was studied. Weanling male Sprague-Dawley rats were given diets containing 0.6 or 6 mg/kg copper. The carbohydrate source (627 g/kg) was either fructose or corn starch. After 3 wk, fatty acid profiles and total lipids in heart and liver were analyzed. Copper-deficient rats fed fructose had more severe signs of copper deficiency than those fed starch, according to heart/body wt ratio, hematocrit, and liver copper content. The fatty acid composition of heart and liver triacylglycerol was significantly different between groups, but the changes did not correlate with the severity of copper deficiency. In heart, phosphatidylinositol and phosphatidylserine, arachidonic acid and docosapentaenoic acid (n-6) were increased 193 and 217%, respectively, p less than 0.05) in rats given the copper-deficient diet containing fructose. Changes in the long chain fatty acids in heart phospholipids may be related to the higher mortality commonly observed in rats fed a copper-deficient diet containing fructose.

Effects of ethanol ingestion on the unsaturated fatty acids from various tissues

Chronic ethanol ingestion markedly altered the fatty acid composition of heart, liver and brain. The most consistent observation was a decrease in the arachidonate/linoleate ratio (20:4/18:2). In general, there was a decrease in 20:4 and an increase in 18:2. Further, there were decreases in the other polyenes presnt in these tissues. The time course development of effects on 20:4/18:2 ratio showed a 15% decrease after one day of ethanol feeding, a 21% decrease after 2 days and a 21% decrease after 7 days. The decrease seemed to level off at about a 40% decrease after 76 days. Because there was a decrease in 20:4 and an increase in 18:2, the microsomal desaturase activity was measured. A 70% decrease in the Δ 9 desaturase activity was observed after chronic ethanol feeding. Even after 1 day of ethanol feeding, the Δ 9 desaturase was inhibited 66–72%. The Δ 5 or Δ 6 desaturase have not been measured at this time; however, the data from the Δ 9 desaturase measurements strongly suggest that the desaturases are involved with the ethanol-induced changes in the 20:4/18:2 ratios and in other unsaturated fatty acids.

Lipid content and fatty acid composition of heart and muscle of the BIO 82.62 cardiomyopathic hamster

Microscopic and analytical studies of the lipids in the heart and muscle of the BIO 82.62 myopathic hamsters and age-matched normal animals at the average ages of 33, 67, and 108 days were performed. Microscopic examinations did not show increased lipid depositions in the hearts of the diseased animals as was found in the BIO 14.6 strain. No consistent differences in the lipid content of the cardiomyopathic hamsters (BIO 82.62) and age-matched controls were observed in the three age groups except in the cholesterol content of muscle. Cholesterol increased significantly (P less than 0.01) in the 67 and 108 day old animals. This increase elevated the cholesterol/phospholipid ratio. Analysis of the fatty acid composition of triglycerides showed that the cardiomyopathic hamsters store more saturated fatty acids in both heart and muscle than do their normal counterparts. The abundance of more saturated fatty acids may imply that either the desaturation mechanism is altered in the diseased animals or that unsaturated fatty acids are preferentially utilized in other processes.

VITAMIN E AND HIGH OR LOW ERUCIC ACID RAPESEED OILS IN BROILER DIETS

Regular rapeseed oil (RSO) from rapeseed containing approximately 25% erucic acid (C22:1) and low erucic acid rapeseed oils (LEAR) containing approximately 2.5% C22:1 prepared from the Oro (ORO and hydrogenated Oro oil, HORO) and Span (SPO) varieties of rapeseed were compared against soybean oil (SBO) or lard (LA) in diets for broilers. Two diets were formulated from each oil or fat, one containing no supplementary vitamin E, the other containing 30 mg/kg of supplementary vitamin E. Each ration was fed to two groups of 10 broiler-type chicks from day-old to 8 wk of age. Growth, lipid content and fatty acid composition of heart, liver and spleen tissues and plasma cholesterol levels were studied. Average body weight was highest in the chickens fed the SBO-, LA-, ORO- or HORO-containing diets, intermediate for SPO and lowest for the RSO-containing diet. Inclusion of supplementary vitamin E in the oil or fat-containing diets improved the growth rate in all cases. However, vitamin E status did not appear to be related to the deleterious effects reported with feeding high levels of rapeseed oil. No treatment effects were noted on the total lipid concentrations in heart and liver tissue. The total lipid concentration in the spleen was somewhat higher in chickens fed RSO than in those fed the other oils. RSO led to a relatively high, while LEAR oils led to minimal, tissue incorporation of C22: 1. Erucic acid concentration was highest in adipose tissue (9.2%), followed by breast muscle (6.8%), spleen (5.9%), cardiac tissue (4.8%) and liver (2.6%). Plasma cholesterol concentrations (PC) were highest in the chickens fed the RSO- and SPO-containing diets (122 mg % and 134 mg %, respectively); the other oils led to lower PC levels (approximately 100 mg %). It appears that the liver tissue can metabolize C22: 1 better than the other body tissues studied, perhaps by increased oxidation or by increased transport as cholesterol esters.

Low Erucic Acid Rapeseed Oils in Rations for Broiler Chickens: Oro and Hydrogenated Oro Oil

The effects of feeding broiler-type chickens rations containing 5% or 15% of a low erucic acid rapeseed oil prepared commercially from the Oro variety of rapeseed (ORO), a commercially hydrogenated Oro oil (HORO) and soybean oil (SBO) on body weight, apparent digestibility of total fatty acids, weights of heart, liver and spleen, total lipid and total fatty acid content of heart and liver and fatty acid composition of heart and liver lipids were studied. The experimental diets were fed ad libitum to the chickens from day old to four weeks of age.Body weight and weights of heart and liver were not influenced significantly by the dietary treatments. Spleen weight was smallest in the group fed the 15% ORO—containing diets.The apparent digestibilities of total fatty acids were similar for ORO and SBO (89.4% and 94.2% for 5% and 15% ORO; 90.9% and 94.7% for 5% and 15% SBO), however they were lower for HORO (85.7% and 90.2% for 5% and 15% HORO).Total lipid and total fatty acid contents of liver were not influenced significantly by the different dietary treatments. Feeding 5% ORO in the diet decreased the content of total fatty acids in heart as compared to feeding 5% HORO or 5% SBO in the diet. The fatty acid composition of heart and liver lipids was influenced by the fatty acid content of the diets. Only small amounts of erucic acid were found in the tissues of the birds fed diets containing ORO or HORO.The inclusion of 5% or 15% of low erucic acid rapeseed oils (ORO and HORO) in diets for broiler chickens proved nutritionally as satisfactory as the inclusion of SBO.