Tissue Lipid Profiles Research Articles

Effects of sodium-orthovanadate and Trigonella foenum-graecum seeds on hepatic and renal lipogenic enzymes and lipid profile during alloxan diabetes.

Sodium-orthovanadate (SOV) and seed powder of Trigonella foenum graecum Linn. (common name: fenugreek, family: Fabaceae) (TSP) besides being potential hypoglycemic agents have also been shown to ameliorate altered lipid metabolism during diabetes. This study evaluates the short-term effect of oral administration of SOV and TSP separately and in concert (for 21 days) on total lipid profile and lipogenic enzymes in tissues of alloxan diabetic rats. Diabetic rats showed 4-fold increase in blood glucose. The level of total lipids, triglycerides and total cholesterol in blood serum increased significantly during diabetes. During diabetes the level of total lipids increased significantly (P < 0.001) in liver and in kidney by 48% and 55%, respectively, compared to control. Triglycerides level increased by 32% (P < 0.01) in liver and by 51% (P < 0.005) in kidney, respectively, compared to control. Total cholesterol level also increased significantly in both liver and kidney (P < 0.01 and P < 0.001, respectively). The activities of NADP-linked enzymes; namely glucose-6-phosphate dehydrogenase (G6PDH), malic enzyme (ME), isocitrate dehydrogenase (ICDH), and the activities of lipogenic enzymes namely ATP-citrate lyase (ATP-CL) and fatty acid synthase (FAS) were decreased significantly in liver and increased in kidney during diabetes as compared to control. SOV and TSP administration to diabetic animals prevented the development of hyperglycemia and alteration in lipid profile in plasma and tissues and maintained it near normal. Maximum prevention was observed in the combined treatment with lower dose of SOV (0.2%) after 21 days. We are presenting for the first time effectiveness of combined treatment of SOV and TSP in amelioration of altered lipid metabolism during experimental type-I diabetes.

Dietary Effects of Natural Conjugated Triene Fatty Acid in Comparison with Trans Fatty Acids of Hydrogenated Fat on Plasma and Tissue Lipid Profile

An attempt has been made to compare the nutritional quality between naturally occurring conjugated octadecatrienoic fatty acid with trans configuration and the trans fatty acids being produced in hydrogenated fats. The karela seed oil (Momordica charantia) (29.2% trans isomer) was used as the source of conjugated trienoic trans fatty acid and hydrogenated fat for trans fatty acid (39.5%). The two fats were fed to male albino rats (Charles Foster strain) for four weeks. Feeding experiment showed comparable results in terms of growth rate, food efficiency ratio (FER) and serum lipid profile. In the third week the growth rate of rats fed hydrogenated fat with trans showed a significant increase than the karela seed oil with trans conjugated trienoic fatty acid fed group. Total cholesterol level of liver was significantly higher in rats fed karela seed oil containing conjugated trienoic fatty acid with trans configuration. The phospholipid content of heart and brain of rats fed karela seed oil was significantly higher than the hydrogenated fat with trans fed group.

Decreased Hepatic Triglyceride Accumulation and Altered Fatty Acid Uptake in Mice with Deletion of the Liver Fatty Acid-binding Protein Gene

Liver fatty acid-binding protein (L-Fabp) is an abundant cytosolic lipid-binding protein with broad substrate specificity, expressed in mammalian enterocytes and hepatocytes. We have generated mice with a targeted deletion of the endogenous L-Fabp gene and have characterized their response to alterations in hepatic fatty acid flux following prolonged fasting. Chow-fed L-Fabp-/- mice were indistinguishable from wild-type littermates with regard to growth, serum and tissue lipid profiles, and fatty acid distribution within hepatic complex lipid species. In response to 48-h fasting, however, wild-type mice demonstrated a approximately 10-fold increase in hepatic triglyceride content while L-Fabp-/- mice demonstrated only a 2-fold increase. Hepatic VLDL secretion was decreased in L-Fabp-/- mice suggesting that the decreased accumulation of hepatic triglyceride was not the result of increased secretion. Fatty acid oxidation, as inferred from serum beta-hydroxybutyrate levels, was increased in response to fasting, although the increase in L-Fabp-/- mice was significantly reduced in comparison to wild-type controls, despite comparable induction of PPAR alpha target genes. Studies in primary hepatocytes revealed indistinguishable initial rates of oleate uptake, but longer intervals revealed reduced rates of uptake in fasted L-Fabp-/- mice. Oleate incorporation into cellular triglyceride and diacylglycerol was reduced in L-Fabp-/- mice although incorporation into phospholipid and cholesterol ester was no different than wild-type controls. These data point to an inducible defect in fatty acid utilization in fasted L-Fabp-/- mice that involves targeting of substrate for use in triglyceride metabolism.

Synergistic effect of Nicorandil and Amlodipine on tissue defense system during experimental myocardial infarction in rats.

The synergistic protective effect of Nicorandil (K(ATP) channel opener) and Amlodipine (calcium channel blocker) on heart tissue antioxidant defense system and lipid profile were examined on isoproterenol induced myocardial infarction in rats. The rats given isoproterenol (150 mg kg(-1) daily, i.p.) for 2 days showed significant changes in antioxidant defense system and lipid profile levels. Pretreatment with Nicorandil (2.5 mg kg(-1) daily, p.o.) and Amlodipine (5.0 mg kg(-1) daily, p.o.) for 3 days significantly prevented these alterations and restored the enzyme activities to near normal. These findings indicate the synergistic protective effect of Nicorandil and Amlodipine on tissue defense system and lipid metabolism during isoproterenol induced cardiac damage.

The Effects of Copper Source and Concentration on Lipid Metabolism in Growing and Finishing Angus Steers

Forty-eight individually fed Angus steers (body weight 220 kg′9.1) were utilized to investigate the effects of copper (Cu) source and concentration on lipid metabolism and carcass quality. Steers were stratified by body weight and initial liver Cu concentration and randomly assigned to one of five groups. Groups were then randomly assigned to treatments. Treatments consisted of: 1) control (no supplemental Cu); 2) 10 mg Cu/kg DM from CuSO 4 ; 3) 10 mg Cu/kg DM from a Cu amino acid complex (Availa Cu) 4) 20 mg Cu/kg DM from CuSO 4 ; and 5) 20 mg Cu/kg DM from Availa Cu. Steers were fed a corn-alfalfa-based growing diet for 56 d. Steers were then switched to a high concentrate finishing diet for 145 d. On day 74 of the finishing phase subcutaneous adipose tissue biopsies were obtained from three steers/treatment to determine basal and stimulated lipolytic rates in vitro. Steers were then slaughtered after receiving the finishing diet for 145 d. Control steers tended (p<0.12) to have lower ceruloplasmin (Cp) activity than Cu supplemented steers. Steers receiving 20 mg Cu/kg DM from Availa Cu had higher (p<0.03) Cp activity than steers receiving 20 mg Cu/kg DM from CuSO 4 . Plasma non-esterified fatty acids were similar across treatments. Steers receiving 10 mg Cu/kg DM from Availa Cu had higher (p<0.02) total plasma cholesterol concentrations relative to steers receiving 10 mg Cu/kg DM from CuSO 4 . Steers receiving 20 mg Cu/kg DM from Availa Cu had lower (p<0.03) plasma triglyceride concentrations than steers supplemented with 20 mg Cu/kg DM from CuSO 4 . Fatty acid profile of longissimus muscle was similar across treatments. Backfat depth tended (p<0.18) to be lower in Cu supplemented steers relative to controls. Steers supplemented with 20 mg Cu/kg DM from Availa Cu had heavier (p<0.03) hot carcass weights and a greater (p<0.02) dressing percentage than steers supplemented with 20 mg Cu/kg DM from CuSO 4 . Furthermore, in vitro basal (p<0.06) and epinephrine stimulated (p<0.04) lipolytic rates of subcutaneous adipose tissue were higher in Cu supplemented steers relative to controls. The results of this study suggest that Cu supplementation has minimal effects on blood and lean tissue lipid profile. However, it appears that Cu may play a role in lipid metabolism in subcutaneous adipose tissue.

Hypolipidemic Effect of Black Pepper (Piper nigrum Linn.) in Rats Fed High Fat Diet

Effect of administering black pepper (Piper nigrum Linn.), one of the commonly consumed spices and its active principle piperine, to high fat fed rats was studied for a period of 10 weeks. Black pepper at two different doses of 250mg/kg body weight and 500mg/kg body weight and piperine at 20mg/kg body weight were made into a coarse solution with distilled water and administered orally by intragastric intubation daily. The plasma and tissue lipid profile showed a remarkable reduction in the levels of total cholesterol (both the free and ester cholesterol fractions), free fatty acids, phospholipids and triglycerides in black pepper as well as in the piperine treated groups. Moreover, supplementation of the high fat fed rats with black pepper or piperine elevated the concentration of high density lipoprotein-cholesterol and reduced the concentrations of low density lipoprotein-cholesterol and very low density lipoprotein-cholesterol in the plasma as compared with the levels in unsupplemented high fat fed rats. Thus dietary intake of black pepper or piperine was found to reduce the risk of atherosclerosis markedly by virtue of its hypolipidemic and antiatherogenic effects.

Nutritional quality of sesame seed protein fraction extracted with isopropanol.

The nutritional effect of diet containing decorticated sesame seed extracted with isopropanol (DSS-Iso) was evaluated on growth performance, food efficiency ratio, plasma and tissue lipid profile, plasma protein content, and erythrocyte membrane lipid profile of rats on a comparative basis with diets containing casein (control), soybean meal, and decorticated sesame seed extracted with hexane (DSS-Hex). Rats fed a DSS-Iso-based diet showed body weight gain and food efficiency ratio similar to those of the control groups fed diets prepared with casein, soybean meal, and DSS-Hex. However, dietary proteins exerted a separate effect on plasma lipid concentrations of the rats. Rats fed a DSS-Iso-based diet showed significant decreases in plasma total cholesterol (p < 0.01), triglyceride (p < 0.01), and VLDL+LDL cholesterol (p < 0.01) concentrations in comparison to the rats fed diet containing casein. No significant differences in plasma lipid concentrations were observed for the rats fed diets prepared with soybean meal, DSS-Hex, and DSS-Iso. Rats fed the different dietary proteins did not show much variation in plasma proteins, liver lipids, and erythrocyte membrane lipid concentrations, which suggests that DSS-Iso could be a suitable edible protein like casein or soybean meal.

Lipid and fatty acid profiles in rats consuming different high-fat ketogenic diets.

High-fat ketogenic diets are used to treat intractable seizures in children, but little is known of the mechanism by which these diets work or whether fats rich in n-3 polyunsaturates might be beneficial. Tissue lipid and fatty acid profiles were determined in rats consuming very high fat (80 weight%), low-carbohydrate ketogenic diets containing either medium-chain triglyceride, flaxseed oil, butter, or an equal combination of these three fat sources. Ketogenic diets containing butter markedly raised liver triglyceride but had no effect on plasma cholesterol. Unlike the other fats, flaxseed oil in the ketogenic diet did not raise brain cholesterol. Brain total and free fatty acid profiles remained similar in all groups, but there was an increase in the proportion of arachidonate in brain total lipids in the medium-chain triglyceride group, while the two groups consuming flaxseed oil had significantly lower arachidonate in brain, liver, and plasma. The very high dietary intake of alpha-linolenate in the flaxseed group did not change docosahexaenoate levels in the brain. Our previous report based on these diets showed that although ketosis is higher in rats consuming a ketogenic diet based on medium-chain triglyceride oil, seizure resistance in the pentylenetetrazol model is not clearly related to the degree of ketosis achieved. In combination with our present data from the same seizure study, it appears that ketogenic diets with widely differing effects on tissue lipids and fatty acid profiles can confer a similar amount of seizure protection.

Hypotriglyceridemic and hypocholesterolemic effects of anti-diabetic Momordica charantia (karela) fruit extract in streptozotocin-induced diabetic rats

Momordica charantia (karela) is commonly used as an antidiabetic and antihyperglycemic agent in Asian, Oriental and Latin American countries. This study was undertaken to investigate the effects of long term feeding (10 weeks) of M. charantia fruit extract on blood plasma and tissue lipid profiles in normal and streptozotocin (STZ) -induced Type 1 diabetic rats. The results show that there was a significant ( P<0.05) increase in plasma non-esterified cholesterol, triglycerides and phospholipids in STZ-induced diabetic rats, accompanied by a decrease in high density lipoprotein (HDL) -cholesterol. A moderate increase in plasma (LPO) product, malonedialdehyde (MDA), and about two-fold increase in kidney LPO was also observed in STZ-induced diabetic rats. The treatment of diabetic rats with M. charantia fruit extract over a 10-week period returned these levels close to normal. In addition, karela juice also exhibited an inhibitory effect on membrane LPO under in vitro conditions. These results suggest that M. charantia fruit extract exhibits hypolipidemic as well as hypoglycemic effects in the STZ-induced diabetic rat.

Endocrine, metabolic and nutritional factors in obesity and their relative significance as studied by factor analysis.

To evaluate different aspects of obesity, such as body fat distribution, plasma hormone and lipid profiles, adipose tissue composition and dietary intake in an obese population in order to identify the most important factors that contribute to obesity. Eighty-five obese subjects, 30 men and 55 women (age, 30-70 y; body mass index (BMI), 27-35 kg/m2), were studied using anthropometric measurements, computed tomography, adipose tissue composition, serum hormone and lipid profiles and nutritional evaluations. To determine to what extent individual factors contributed to the general process of obesity, the data were subjected to a factor analysis. Three patterns of anthropometric and computed tomography data emerged that accounted for 69% of the variance. Factor 1 defined abdominal obesity and explained 30% of the total variance, factor 2 (gynoid obesity) accounted for 26%; and factor 3 (subcutaneous fat) explained 13% of the total variance. When other factors associated with obesity, such as lipid profile, hormonal profile and fat composition, were introduced, obesity itself, especially abdominal obesity, remained the principal factor, accounting for 23% of total variability. All factors were of secondary importance when dietary characteristics were introduced. In the overall factor analysis, more than 40% of the variability in obesity was related to dietary habits, particularly fat intake, followed by energy and saturated fatty acids intake. Even though obesity is a multifactorial phenomenon, the results suggest that dietary intake, especially fat intake, is the most important factor contributing to obesity. Secondary factors include endocrine and metabolic factors.

Hypolipidemic effect of enzymatically extracted sunflower seed protein fraction

An attempt was made to enzymatically extract the protein fraction (PF) from sunflower seeds and investigate its dietary effect on the growth, plasma and tissue lipid profiles, plasma protein content, erythrocyte membrane lipid profile and organ weights of rats. Extraction of dehulled sunflower seeds in an aqueous medium in the presence of the enzyme pectinase at 50 ± 1 °C and pH 4.5 yielded a protein fraction with low residual chlorogenic acid and fibre contents. Rats fed the sunflower seed protein fraction showed a similar body weight gain and food efficiency ratio as rats fed casein. However, the different dietary proteins had different effects on plasma total cholesterol and triglyceride contents. The rats fed the sunflower seed protein fraction showed a significant decrease in plasma cholesterol (p < 0.02) and triglyceride (p < 0.02) concentrations compared to the casein-fed rats. The PF-fed rats also exhibited a significant difference in erythrocyte membrane phospholipids and phosphatidylcholine/phosphatidylethanolamine ratio. Rats fed the different dietary proteins did not show much variation in plasma protein content, liver and brain lipids and organ weights. These results demonstrate the hypolipidemic action of the sunflower seed protein fraction and that it can be considered a suitable edible protein like casein. © 2000 Society of Chemical Industry

Electrospray ionization mass spectrometric analyses of changes in tissue phospholipid molecular species during the evolution of hyperlipidemia and hyperglycemia in Zucker diabetic fatty rats.

The Zucker diabetic fatty (ZDF) rat is a genetic model of type II diabetes mellitus in which males homozygous for nonfunctional leptin receptors (fa/fa) develop obesity, hyperlipidemia, and hyperglycemia, but rats homozygous for normal receptors (+/+) remain lean and normoglycemic. Insulin resistance develops in young fa/fa rats and is followed by evolution of an insulin secretory defect that triggers hyperglycemia. Because insulin secretion and insulin sensitivity are affected by membrane phospholipid fatty acid composition, we have determined whether metabolic abnormalities in fa/fa rats are associated with changes in tissue phospholipids. Electrospray ionization mass spectrometric analyses of glycerophosphocholine (GPC) and glycerophosphoethanolamine (GPE) molecular species from tissues of prediabetic (6 wk of age) and overtly diabetic (12 wk) fa/fa rats and from +/+ rats of the same ages indicate that arachidonate-containing species from heart, aorta, and liver of prediabetic fa/fa rats made a smaller contribution to GPC total ion current than was the case for +/+ rats. There was a correspondingly larger contribution from species with sn-2 oleate or linoleate substituents in fa/fa heart and aorta. The relative contributions of arachidonate-containing GPC species increased in these tissues as fa/fa rats aged and were equal to or greater than those for +/+ rats by 12 wk. For heart and aorta, relative contributions from GPE species with sn-2 arachidonate or docosahexaenoate substituents to the total ion current increased and those from species with sn-2 oleate or linoleate substituents fell as fa/fa rats aged, but these tissue lipid profiles changed little with age in +/+ rats. GPC and GPE profiles for brain, kidney, sciatic nerve, and red blood cells were similar among fa/fa and +/+ rats at 6 and 12 wk of age, and pancreatic islets from fa/fa and +/+ rats exhibited similar GPC and GPE profiles at 12 wk of age. Under-representation of arachidonate-containing GPC and GPE species in some fa/fa rat tissues at 6 wk could contribute to insulin resistance, but depletion of islet arachidonate-containing GPC and GPE species is unlikely to explain the evolution of the insulin secretory defect that is well-developed by 12 wk of age.

Nutritional quality of sunflower seed protein fraction extracted with isopropanol.

This study investigated the nutritional effect of sunflower seed protein fraction (SSPF) extracted with isopropanol on growth, plasma and tissue lipid profile, protein content and erythrocyte membrane lipid profile of rats. Dehulled sunflower seeds were extracted with isopropanol at 50 +/- 1 degree C resulting in a protein fraction (71.5%) with low residual chlorogenic acid (0.07%) and fiber (3.3%) contents. Rats fed the sunflower seed protein fraction had a similar body weight gain and food efficiency ratios in comparison to those fed casein. Rats fed SSPF in contrast had a significantly higher growth and food efficiency ratio than the rats fed sunflower meal (SM), extracted with hexane. However, dietary proteins exerted a separate effect on plasma total cholesterol, low density lipoprotein (LDL)-cholesterol, low density lipoprotein to high density lipoprotein cholesterol (LDL-C/HDL-C) ratio and triglyceride content. Sunflower seed protein fraction resulted in a significant decrease in plasma cholesterol (p < 0.05) and LDL-cholesterol (p < 0.02) levels compared to the casein fed rats. Membrane phospholipid profile also showed a marked variation with the type of dietary protein. Rats fed SSPF and SM did not show much variation in plasma lipids, plasma proteins, liver and brain lipids and membrane phospholipid concentrations. Protein content, liver and brain lipid profile of the groups fed SSPF and casein were comparable, suggesting that the nutritional value of SSPF is better than SM and equivalent to that of casein.

Long term feeding effects of heated and fried oils on lipids and lipoproteins in rats.

Long term feeding effects (20 weeks) of heated and fried oils at 5 and 20% level in the diet on growth, plasma and tissue lipids were studied in rats. Three vegetable oils of widespread usage viz., peanut oil, sesame oil and coconut oil with varying saturation and unsaturation were chosen for the study. No significant difference in growth rate, feed efficiency ratio, and liver weights were observed. Higher plasma cholesterol levels were observed in heated oil fed group of rats compared to corresponding fried oil groups. Low levels of HDL-c and increased LDL-c and VLDL-c were noted in heated/fried oil groups. Significantly low levels (p < 0.001) of triglyceride were observed in heated/fried sesame oil group of rats. No significant change in phospholipid was observed in any of the groups. Significantly low levels of liver cholesterol and high triglyceride levels (at 20%) were observed in coconut oil group. The fatty acid composition of plasma and liver reflected the type of diet consumed. Although linoleic acid levels were quite low in some of the heated/fried oil groups the arachidonic acid levels were quite high indicating repair mechanism. The results of the study however do not present any deleterious effect on growth, plasma and tissue lipid profile of rats as the conditions employed for heating/frying were not too drastic and the oils were not heat abused.

Postnatal metabolic changes in the pups of rats exposed to toddy (palm wine) during pregnancy and lactation

Female rats were exposed to toddy (palm wine) (24.5 ml kg −1 body weight day −1) and ethanol (0.52 ml kg −1 body weight day −1) before conception and throughout gestation and lactation. For 21 days pups were nursed by their own mothers, afterwards they were fed normal laboratory feed. Examination of the lipid profile of various tissues of 21 day-old pups revealed marked hyperlipidemia. The tissues of 45 day-old pups showed that even though there was some regression in the lipid accumulation, the status of hyperlipidemia prevailed. The lipogenesis was enhanced on both the days studied as evidenced by the increased activity of the lipogenic enzymes, HMG Co A reductase and incorporation of 14C acetate to lipids. Catabolism of cholesterol to bile acids was decreased. The biochemical alterations produced in the pups by toddy and its equivalent in alcohol were different, showing that the non-alcoholic portion of the toddy interfered with the lipid metabolism.

Hypolipidaemic and Antiatherosclerotic Effects ofZingiber officinale in Cholesterol Fed Rabbits

Hyperlipidaemic rabbits when challenged with a 50% EtOH extract of Zingiber officinale showed a reduction in total cholesterol and serum LDL-cholesterol. A reduction in HDL ratio was seen in atherofed rabbits compared with controls which were restored when challenged with the Zingiber extract. An atherogenic index of 4.7 was brought down to 1.2 using plant products. The tissue lipid profiles of liver, heart and aorta showed similar changes to those noticed in serum lipids. Zingiber extract feeding increased the faecal excretion of cholesterol thus suggesting a modulation of absorption.

NMR lipid profiles of cells, tissues, and body fluids: proton NMR analysis of human erythrocyte lipids.

One- and two-dimensional high resolution NMR spectroscopy was applied to determine quantitatively and qualitatively the lipids extracted from human erythrocyte membranes. The relative amounts of the major lipids were determined from the spectra of unfractionated lipid extracts. After HPLC fractionation of the lipid extracts and NMR analysis of the fractions, it was possible to determine the features of the component lipids of each lipid class and to compare, especially, the fatty acid types and composition of the individual major glycerophospholipids. The results of this proton NMR analysis were compared to those obtained elsewhere using classical lipid analytical techniques and found to be in substantial agreement.

Alterations in the tissue lipid profiles of Lamellidens marginalis under ambient ammonia stress.

Alterations in the tissue lipid profiles of Lamellidens marginalis under ambient ammonia stress.

Plasma and tissue fatty acid profiles of growing pigs fed structured or non-structured triacylglycerides containing medium-chain and marine oil fatty acids

Twenty-four growing pigs (18.3 kg body weight) were used in 19-day metabolism trial to determine the effect of n-3/medium-chain triacylglyceride (MCT)-structured triacylglyceride on plasma and tissue lipid profiles. Pigs were allotted to four liquid diets, each providing 19.5% protein (dry matter basis) as Na- and Ca-caseinate + soybean protein isolate. Lipid composition (percentage by weight of total lipid) by treatment was as follows: (I) corn oil:soybean oil:MCT oil (40:10:50), (II) MCT oil:menhaden oil (60:40 as structured triacylglyceride), (III) MCT oil:menhaden oil (60:40 non-structured, physical mixture), and (IV) structured triacylglyceride (as in II):safflower oil:canola oil (80:10:10). Blood samples were obtained on days 0, 12, and 19 with liver and muscle samples obtained on day 19. With the exception of arachidonic acid, plasma fatty acid profiles reflected dietary fatty acid profiles. Plasma arachidonic acid percentage was higher (P < 0.05) in pigs consuming diet 1 despite a lower dietary content of this fatty acid relative to diets II, III, and IV. Platelets from pigs consuming diets II or III had lower percentage linoleic and arachidonic acid percentages on day 19 compared with diet 1, which appeared to be compensated for by elevated eicosapentaenoic and docosahexaenoic acids. Diets II, III, and IV resulted in higher (P < 0.05) percentages of myristic, pentadecenoic, palmitic, palmitoleic, heptadecanoic, heptadecenoic, stearic, linoleic, eicosapentaenoic, docosahexaenoic, and nervonic acids in the liver and elevated (P < 0.05) myristic, palmitic, palmitoleic, stearic, linoleic, and eicosapentaenoic acids in the muscle. Physical form (structured versus non-structured triacylglyceride) did not affect fatty acid profiles.

N.m.r. lipid profiles of cells, tissues and body fluids. Neutral, non-acidic and acidic phospholipid analysis of Bond Elut chromatographic fractions.

Although the advantages of in vitro n.m.r. analysis of cellular lipids have been documented, this purely n.m.r. approach also has drawbacks. Rapid and quantitative separation of total lipids into neutral lipids, non-esterified fatty acids, non-acidic phospholipids and acidic phospholipids using Bond Elut ion-exchange columns as demonstrated here permitted a more quantitative and complete n.m.r. analysis of glycerides, cholesterol, saturated and unsaturated sphingolipids and ether lipids, as well as of diacylcholine and ethanolamine lipids. Acidic lipids were also analysed. The fatty acid compositions of the intact lipids in each of the four Bond Elut fractions were determined from the n.m.r. spectrum of each fraction.