Die Hautoberflächenlipide bei der Psoriasis vulgaris (Ps) -Cholesterin- und Wachsester,Triglyceride und Fettalkohole

The Skin-Surface Lipids in Psoriasis vulgaris (Ps) - Cholesterol Esters, Wax Esters, Triglycerides and Fatty Alcohols The composition of waxes and cholesterol esters, triglycerides and alcohols of hair lipids from subjects with psoriasis vulgaris and control group was determined by gas liquid chromatography. The amount of palmitoleic acid was lower in the lipid group of the waxes and cholesterol esters in psoriasis vulgaris. Triglycerides show two different changes in the fatty acid pattern by psoriasis: 1) the composition of shorter chain fatty acids was distinct lower but 2) patients with a heavy psoriasis show an increase of the shorter chain fatty acids especially lauric acid and a decrease of the longer chain fatty acids. The analysis of the alcohols indicates that psoriatic patients possess a higher content of alcohols with 12,13 and 14 carbonatoms than normal subjects.     

Lipids of cultured hepatoma cells: IV. Effect of serum and lipid upon cellular and media neutral lipids

Minimal deviation hepatoma 7288C cells were cultured in a modified Swim's medium supplemented with decreasing levels of serum, lipid-free serum, lipid-free serum plus fatty acids, and other additives. Cellular and media neutral lipid classes were quantitated, the fatty acids of triglycerides and sterol esters analyzed, and the carbon number distribution of triglycerides determined. Cellular triglyceride biosynthesis virtually was inhibited when the medium was supplemented with bovine serum alone. This inhibition was not observed when the medium was supplemented with fetal calf serum alone or mixtures of fetal calf serum and bovine serum. Cells cultivated on medium supplemented with lipid-free serum plus palmitic or linoleic acids had much lower levels of free and esterified cholesterol. The fatty acid composition of cellular triglycerides and cholesterol esters differed dramatically from the corresponding media lipid classes. Except when linoleic acid was added to the medium, changes in the media serum and lipid levels had only marginal effects upon the fatty acid composition of cellular triglycerides and cholesterol esters. These data, in conjunction with earlier data that showed the media neutral lipid levels did not decrease during cell growth, indicate that these hepatoma cells utilize little or no serum triglycerides and cholesterol esters. Linoleic acid added to the medium dramatically reduced the level of 18∶1 acids in cellular triglycerides and cholesterol esters. Palmitic acid added to the medium did not change the fatty acid compositions significantly. Comparison of experimentally determined and calculated triglyceride carbon number percentages indicated a random distribution of fatty acids in this glyceride. The fatty acid composition of cellular triglycerides was similar to the composition of the cholesterol esters. The lack of characteristic and distinguishable compositions of these two classes that occur in most normal tissues suggests a loss of specificity in the lipid metabolism of this neoplasm at the class level.     

Serum fatty acid profiles after intravenous medium chain triglyceride administration

The serum fatty acid profiles of patients receiving either intravenous medium or long chain triglycerides were studied. Seventeen hospitalized patients, dependent on total parenteral nutrition, were randomly enrolled into a prospective study. The total parenteral nutrition (TPN) delivered amino acids and glucose and either a 75% medium chain triglyceride and 25% long chain triglyceride (MCT group) physical mixture or all long chain triglyceride (LCT group), as the respective fat sources. The amino acids and glucose were given continously, and the lipid was given for 10 hours each day over five days. Fatty acid profiles on serum triglycerides and free fatty acids were done in the morning before any lipid was given and also later in the afternoon, near the end of the lipid administration, on days 1, 3 and 5. Medium chain fatty acids rose quickly in the triglyceride fraction in patients given MCT. Rapid MCT hydrolysis occurred as evidenced by the appearance of medium chain fatty acids in the free fatty acid fraction in the afternoon sampling. Clearance of the hydrolyzed medium chain free fatty acids (MCFFA) occurred so that little, if any, were present in the morning sampling one day later. Long chain fatty acids, as either triglycerides or free fatty acids, showed expected increases during the daily infusion, but not of such relative magnitude as the medium chain fatty acids. Medium chain fatty acid incorporation into the phospholipid or cholesterol ester fractions by the end of the five-day feeding period was present but minimal. As opposed to conventional long chain triglycerides, intravenously administered medium chain triglycerides are hydrolyzed and cleared rapidly and do not accumulate in other lipid fractions, and are therefore a more readily available lipid fuel.     

Plasma and lipoprotein fatty acid composition in glycogen storage disease type I

Nocturnal intragastric feeding has been shown to be an effective means to improve clinical and biochemical features in glycogen storage disease type I (GSD-I). In this study, we investigated the fatty acid patterns in a whole plasma and in circulating lipoproteins in patients on this therapy. The results demonstrated massive concentration of total fatty acids coupled with higher levels of triglycerides, free cholesterol, cholesterol ester and phospholipids. This hyperlipidemia involved all fatty acids without distinction of carbon or bond numbers. However, the increase was more pronounced for saturated than polyunsaturated fatty acids, as was demonstrated by the ratios of both oleic acid to linoleic acid (1.91±0.40 vs 0.80±0.09 in controls) and of ω3+ω6 to ω9 fatty acid families (0.92±0.11 vs 1.66±0.08 in controls). The fatty acid patterns in very low (VLDL), low (LDL) and high (HDL) density lipoprotein showed substantial differences in composition, reflecting an association between an abnormal lipoprotein pattern and essential fatty acid deficiency. Furthermore, GSD-I patients exhibited a significant increase in VLDL (17±2 vs 47±7 mg/dl) and LDL cholesterol (124±7 vs 206±24 mg/dl), coupled with a decrease in HDL cholesterol (49±4 vs 28±3 mg/dl). These data documenting high LDL cholesterol and low HDL cholesterol associated with an increased concentration and proportion of saturated fatty acids suggest that GSD-I patients on nocturnal intragastric feeding are at high risk for atherosclerosis and its complications.     

The Obscure Effect of Tribulus terrestris Saponins Plus Inulin on Liver Morphology,Liver Fatty Acids,Plasma Glucose,and Lipid Profile in SD Rats with and without Induced Type 2 Diabetes Mellitus

Diabetes is a predictor of nonalcoholic fatty liver disease (NAFLD). There are data suggesting that Tribulus terrestris (TT) saponins act as antidiabetic agents and protect against NAFLD. The effect of saponins may be increased by fermentable fibers such as inulin. The aim of the present study was to investigate the influence of TT saponins and TT saponins plus inulin on the plasma lipid profile and liver fatty acids of rats with induced diabetes mellitus type 2 (T2DM). The study was performed on 36 male Sprague–Dawley rats divided into two main groups: control and diabetic. Animals of the diabetic (DM) group were fed a high-fat diet and injected with streptozotocin (low doses). Animals of the control group (nDM) were on a regular diet and were injected with buffer. After the injections, the animals were split into subgroups: three non-diabetic (nDM): (i) control (c-C); (ii) saponin-treated rats (C-Sap); (iii) rats treated with saponins + inulin (C-Sap + IN), and three diabetic subgroups (DM): (iv) control (c-DM); (v) saponin-treated rats (DM-Sap); (vi) rats treated with saponins + inulin (DM-Sap + IN). Liver fatty acids were extracted and analyzed by gas chromatography, and plasma glucose and lipids were measured. The study showed significant changes in liver morphology, liver fatty acids, plasma lipid profile, and plasma glucose. In summary, supplementation with TT saponins or saponins with inulin for one month decreased the level of steatosis in rats with induced type 2 diabetes. Moreover, there were favorable effects on the plasma lipid profile in the rats. However, additional supplementation with inulin had a negative effect on liver morphology (with a microvesicular type of steatosis) in the non-diabetes group. Moreover, supplementation with inulin had a negative effect on plasma glucose in both diabetic and non-diabetic rats. These data show that a diet enriched with fermentable fibers reveals different effects in different organisms, and not all sources and forms of fiber are beneficial to health.     

Stereospecific analysis of maize triglycerides

This is the first report of stereospecific analyses of plant triglycerides isolated from seeds of distinct genotypes rather than from commerically refined oils. Triglycerides from six maize inbreds were analyzed. The strains exhibited a wide range of fatty acid compositions (palmitic acid 7.8–19.1%, oleic acid 17.0–43.0%, linoleic acid 41.6–68.3%). The distribution of the fatty acids among the 1, 2 and 3 positions of the triglycerides was clearly nonrandom for all six strains. At the 2 position of the triglycerides over 98% of the fatty acids were unsaturated. More plamitic and stearic acids were found in position 1 than in 3. The general fatty acid pattern of maize triglycerides was similar to that found in most animal triglycerides.     

The lipid composition of microsomal preparations from lactating bovine mammary tissue

The microsomes isolated from lactating bovine mammary tissue contained 4.3 mg lipid per milligram nitrogen. Phospholipids comprised 83% of the lipids. The neutral lipids were composed of triglycerides (20–30%), diglycerides (5–10%), free fatty acids (15–30%, cholesterol (35–40% and cholesterol esters (10–12%, respectively. Phosphatidylcholine was the predominant phospholipid component (>50%), and the remainder consisted of phosphatidylethanolamine (21–13%), phosphatidylserine (4–6%), phosphatidylinositol (8%), sphingomyelin (9%) and lysophosphatidylcholine (2%) respectively. The composition of the microsomal phospholipids was similar to that of isolated mammary cells and tissue homogenates but quite different from milk and fat globule membrane phospholipids. The triglycerides contained short chain fatty acids but their relative concentrations were lower than in milk triglycerides. The various lipid fractions had a variable proportion of saturated fatty acids, i.e., triglycerides (47.7%), diglycerides (86.7%), free fatty acids (70.6%), phosphatidylcholine (50.6%), phosphatidylethanolamine (50.8%), phosphatidylserine (35.3%), phosphatidylinositol (40.5%) and sphingomyelin (82.3%), respectively. The molecular distribution of fatty acids in the microsomal triglycerides and phosphatidylcholine was similar to that occurring in milk, i.e., the short chain and unsaturated fatty acids were concentrated in the primary positions (sn1 andsn3) of the triglycerides, and the unsaturated acids were preferentially located in positionsn2 of the phosphatidylcholine. The compositional data indicate that mammary microsomes are not the direct source of the phospholipids of the milk fat globule.     

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 agematched 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<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.     

n-3 fatty acids: Antiatherosclerotic effects

The low incidence of cardiovascular disease associated epidemiologically with high consumption of food rich in n-3 fatty acids suggests the possibility that part of the beneficial cardiovascular effects of these natural substances may be due to a reduction of atherosclerosis. This has been recently confirmed in autoptic data and in at least one prospective trial evaluating the progression of coronary atherosclerosis in humans. This paper reviews published literature on n-3 fatty acids and atherosclerosis in animal models and in humans and in vitro experimental data yielding suport to the hypothesis of antiatherosclerotic effects of these substances.     

Modification of goat milk fat triglycerides by immobilized lipase

The lipid fraction of goat milk was subjected to transesterification using a commercially available immobilized lipase to decrease the amount of short- and medium-chain fatty acids (C₄–C₁₄) by enrichment of the reaction mixture with long-chain (C_18:1 and C_18:2) fatty acids. Aliquots were taken during, transesterification at different reaction times and analyzed for triglycerides and their fatty acid components. The gas chromatographic analyses of triglycerides (previously isolated by thinlayer chromatography) showed that at 6 h reaction under the experimental conditions led to the greatest reduction of the low molecular weight triglycerides (C₂₂–C₃₈) and concomitantly to the greatest increase in the higher molecular weight triglycerides (C₄₈–C₅₄). These changes correlated with the variations observed in the fatty acids of the triglyceride fraction.     

Homocysteine and reactive oxygen species in metabolic syndrome,type 2 diabetes mellitus,and atheroscleropathy: The pleiotropic effects of folate supplementation

Homocysteine has emerged as a novel independent marker of risk for the development of cardiovascular disease over the past three decades. Additionally, there is a graded mortality risk associated with an elevated fasting plasma total homocysteine (tHcy). Metabolic syndrome (MS) and type 2 diabetes mellitus (T2DM) are now considered to be a strong coronary heart disease (CHD) risk enhancer and a CHD risk equivalent respectively. Hyperhomocysteinemia (HHcy) in patients with MS and T2DM would be expected to share a similar prevalence to the general population of five to seven percent and of even greater importance is: Declining glomerular filtration and overt diabetic nephropathy is a major determinant of tHcy elevation in MS and T2DM.There are multiple metabolic toxicities resulting in an excess of reactive oxygen species associated with MS, T2DM, and the accelerated atherosclerosis (atheroscleropathy). HHcy is associated with an increased risk of cardiovascular disease, and its individual role and how it interacts with the other multiple toxicities are presented.The water-soluble B vitamins (especially folate and cobalamin-vitamin B₁₂) have been shown to lower HHcy. The absence of the cystathionine beta synthase enzyme in human vascular cells contributes to the importance of a dual role of folic acid in lowering tHcy through remethylation, as well as, its action of being an electron and hydrogen donor to the essential cofactor tetrahydrobiopterin. This folate shuttle facilitates the important recoupling of the uncoupled endothelial nitric oxide synthase enzyme reaction and may restore the synthesis of the omnipotent endothelial nitric oxide to the vasculature.     

Effect of dietary cyclopropene fatty acids on the octadecenoates of individual lipid classes of rat liver and hepatoma

The effect of dietary cyclopropene fatty acids on the concentration of octadecenoate chain positional isomers in individual lipid classes of normal liver, host liver, and hepatoma 7288CTC has been determined. The data revealed the following: (a) Saturated and monoene fatty acid percentages of liver phosphatidylcholines and phosphatidylethanolamines werenot affected, but the percentage of saturated fatty acids of the triglycerides and cholesteryl esters was increased while the monoene percentages decreased. (b) Oleate to vaccenate percentage ratios, previously shown to be characteristic of individual lipid classes, were completely disrupted. (c) Oleate concentrations of the two major liver phospholipids were elevated, and vaccenate levels were dramatically reduced. (d) Cyclopropene fatty acids appear to inhibit monoene elongation. (e) The elevated concentrations of oleate indicate that an alternate route of oleate biosynthesis must exist if the Δ9 desaturation is inhibited by cyclopropene fatty acids as reported previously. (f) In contrast to liver, oleate and vaccenate concentrations in hepatoma were not affected by the dietary cyclopropene fatty acids.     

Total,polar and neutral lipids ofRhizopus arrhizus fischer

The changes in total lipid content, neutral and polar lipids, total fatty acids, and free fatty acids were investigated over a 4 day period in the zygomycete,Rhizopus arrhizus Fischer. The highest concentration of lipids occurred at the 72 hr period. The degree of unsaturation in the total fatty acid fraction increased during the growth period, whereas the degree of unsaturation decreased in the free fatty acid fraction during the same time period. The ratios of neutral to polar lipids over the 4 day period were: 0.75, 0.22, 1.94 and 0.94. The major components of polar lipids were phosphatidyl ethanolamine, lecithin, lysolecithin, and fatty acids. The fatty acids in the mono- and diglycerides were predominately saturated (67–96%). The fatty acids in the triglycerides shifted from a predominately unaturated (69%, 24 hr) to a more saturated pattern (62%, 96 hr).     

Marine n-3 fatty acids: Basic features and background

There is some evidence from epidemiology that intake of n-3 polyunsaturated fatty acids (PUFA) from seafood may protect against coronary artery disease (CAD). This hypothesis is further supported from animal data showing a beneficial effect of n-3 PUFA on thrombosis and atherosclerosis in animals fed fish oils in most, but not all, studies. There are several mechanisms by which an increased intake of marine n-3 PUFA may protect against CAD; the most universal finding is a reduction of plasma triglycerides. It is puzzling, however, that a very low amount of n-3 PUFA, with no known beneficial biochemical effects, seems to be cardioprotective. It has therefore been of paramount interest to perform clinical trials. Such evidence and trials are discussed in later chapters, and the results have been very encouraging.     

The structural analysis of wheat flour glycerolipids

The compositions of the fatty acids in the 1, 2 and 3 positions of the principal glycerolipids and their various stereoisomers were determined. Fatty acids in the 1 and 3 positions of triglycerides were similar in composition and less unsaturated than those in the 2 position. Fatty acids in the 1,2-, 1,3- and 2,3-diglycerides were distributed in a pattern which indicated isomerization ofsn-1,2-diacylglycerol. Lysophosphatidyl choline (the principal monoacyl lipid) consisted of about 80% 1-acyl and 20% 2-acyl isomers. The fatty acid compositions indicated that most of the 2-lysophosphatidyl choline was formed by isomerization of 1-lysophosphatidyl choline. Most of the digly cerides and lysophosphatidyl choline were synthesized in the ripening wheat grain. However a small proportion of these partial glycerides and all of the other minor partial glycerides (monoglycerides, digalactosyl monoglycerides) appeared to be the result of limited lipolysis of the corresponding diacyl lipids in the wheat or in the freshly-milled flour. Fatty acids in the 2 position of all the fully acylated glycerides were very similar in composition, but there were considerable differences in the 1 position fatty acids.     

Lipid metabolism of brain tissue in culture

Tissue explants from frontal lobes of rat brain were used for the study of cerebral fatty acid metabolism. After tissues had been maintained in serum-supplemented medium, a lipid free medium was substituted and metabolic studies were carried out. Under these conditions explants continued to take up lipid precursors for at least 48 hr. Stearic acid 1-C¹⁴, palmitic acid 1-C¹⁴ and lignoceric acid 1-C¹⁴ were bound to cells as the free fatty acids or incorporafed into neutral lipids (particularly triglycerides), glycolipids and phospholipids. In the galactolipid fraction, cerebrosides were the principal radioactive lipids. Choline phosphoglycerides, ethanolamine phosphoglycerides, inositol phosphoglycerides and serine phosphoglycerides were the principal radioactive phospholipids. Fatty acids were incorporated into cellular lipids either unchanged or after desaturation, chain elongation, or both. In a patient with a demyelinating disease, precursor uptake was reduced and chain elongation and desaturation of the fatty acid was diminished. In a patient with generalized G_M2 gangliosidosis, glycolipids other than cerebrosides were labeled to a greater extent than normal. These studies exemplify the usefulness of tissue explants for prolonged metabolic studies in normal and pathological specimens of brain. One of 13 papers presented at the symposium “Lipid Metabolism in Cells in Culture,” AOCS Meeting, Houston, May, 1971.     

The Component Triglycerides and Fatty Acid Distribution of Human Adipose Tissue

The component triglycerides from human adipose tissue of healthy persons have been determined qualitatively and quantitatively by combination of thin-layer-(silver ion impregnated and reversed phase) and gas-chromatography. The intramolecular pattern of fatty acids in primary and secondary OH-groups were measured by GLC after pancreatic lipase hydrolysis. The ratio of unsaturated: saturated acids in the triglyceride is 70 : 30, it changes in sn-2-OH-position to 90 : 10. The preference order of “unsaturated” acids toward the sn-2-position is of the order 14 : 0 > 18 : 2 > 16 : 1 > 18 : 1. From the data the probability coefficients of each acid were estimated. Relationships between the fatty acid composition of triglycerides and 2-monoglycerides were established by four equations. By means of these formulas it is possible to calculate the composition of 2-monoglyceride knowing only the fatty acid composition of the triglyceride. The results of the quantity of component triglycerides have been compared to various theories of acyl group distribution; calculations were made from the fatty acid composition. The distribution pattern of human fat shows a partial molecular percentage character and resembles to 2,1-3-distribution type.     

Lipid composition of morris hepatoma 5123c,and of livers and blood plasma from host and normal rats

The lipid composition of Morris hepatoma 5123c was analyzed together with that of liver and blood plasma from both normal and tumor-bearing rats. The results showed that the liver of tumor-bearing rats contained higher amounts of glycerides, cholesteryl esters, free fatty acids and phospholipids than the liver of normal rats. In the blood plasma of tumor-bearing rats, there was an increase of free cholesterol and triglycerides; this latter difference, however, was not statistically significant. Acyl chain changes in the liver of tumor-bearing rats consisted of an increase of palmitic and oleic acids and a decrease of stearic and arachidonic acids in phosphatidylinositol. Morris hepatoma 5123c contained a lower amount of triglycerides than the livers (both host and normal) and showed a significant decrease of total phospholipids when compared to the host liver. The major acyl chain changes found in Morris hepatoma 5123c compared with both normal and host rat livers were: a) a higher percentage of arachidonic acid together with a lower proportion of palmitic acid in cholesteryl esters; b) an increase of stearic and arachidonic acids and a decrease of palmitic acid in triglycerides; and c) a higher level of palmitic and oleic acids associated with a lower percentage of stearic and C₂₂ polyunsaturated acids in phosphatidylcholine.     

Effect of dietary fat supplementation on the composition and positional distribution of fatty acids in ruminant and porcine glycerides

Dietary fats which were protected from ruminal metabolism were fed to ruminants, and the constituent fatty acids subsequently appeared in the glycerides of tissues and secretory products. These dietary fat induced alterations in tissue lipid composition were particularly apparent when the fat source was enriched with linoleic acid. Similarly, when pigs were fed linoleic-enriched fats, the linoleic acid was incorporated into the adipose tissue triglycerides. Stereospecific analyses were carried out on triglycerides from various tissues and secretory products obtained from animals fed control or linoleate-enriched diets. The analysis of adipose tissue triglycerides showed that linoleate and oleate were preferentially esterified to positions 2 and 3 (cattle and sheep), and positions 1 and 3 (pigs). Of the other major adipose tissue fatty acids, palmitate was preferentially esterified at position 1 (ruminants) and position 2 (pigs), and stearate was preferentially esterified at positions 1 and 3 (ruminants), and position 1 (pigs). Stereospecific analysis of high mol wt milk triglycerides showed that linoleate was either evenly distributed on all three positions (goats), or predominantly on position 3 (cows). Furthermore, the incorporation of this linoleate did not markedly alter the positional specificity of the other major milk triglyceride fatty acids. Of these fatty acids, the short and medium chain length acids (butyratelaurate) were mainly on position 3, myristate and palmitate on positions 1 and 2, and stearate and oleate evenly distributed. Thoracic duct lymph triglycerides from sheep tended to show preferential incorporation of linoleate at position 3, palmitate at position 2, and stearate at position 1 and 3; oleate, on the other hand, tended to be evenly distributed on all three positions of the lymph triglyceride. The stereospecific arrangement of fatty acids in sheep liver triglycerides was similar to that of lymph triglycerides, and this may reflect the uptake of intact or partially hydrolysed chylomicron and/or very low density lipoprotein triglycerides by the liver. There were also some analogies in the stereospecific arrangement of fatty acids on ruminant lymph and milk triglycerides and this may reflect an incomplete hydrolysis of chylomicron and/or very low density lipoprotein triglycerides prior to uptake by the mammary gland. An unusual feature of lymph from sheep fed linoleate was the presence of phospholipids which contained large amounts of linoleate in ca. equal proportion at both positions 1 and 2 of the phospholipid molecule.     

Hepatoma,host liver,and normal rat liver neutral lipids as affected by diet

Groups of normal and hepatoma (7288CTC) bearing rats were maintained on normal chow and fat-free diets for 4 weeks. Normal liver, host liver, and hepatoma neutral lipids were examined in detail and compared. Water content, unaffected by diet was: hepatoma, 82 percent; host liver, 71 percent; and normal liver, 67 percent. The fat-free diet had no effect upon the hepatoma neutral lipids but elevated the triglyceride level in normal and host liver, shifted the triglyceride carbon number distribution to lower mol wt, and elevated the percentage of monoenoic acids in triglycerides and cholesteryl esters. Host triglyceride concentrations were ca. half, and cholesterol levels were reduced moderately relative to normal liver values. Hepatoma cholesterol levels were higher and triglyceride concentrations lower than normal and host liver values. Hepatoma triglycerides differed dramatically from liver and were characterized by increased concentrations of high mol wt species and a fivefold increase in the percentage of C-20 and C-22 fatty acids. The percentage of C-20 and C-22 fatty acids in hepatoma cholesteryl esters also increased ca. fivefold relative to liver. The data indicate that the systems that regulate triglyceride and cholesteryl ester fatty acid composition in liver do not control the compositions of these lipid classes in this hepatoma. The unchanged high level of essential fatty acids in the hepatoma lipids from the fat-free fed animals demonstrates the hepatoma's ability to absorb and conserve specific fatty acids.