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Although linoleic and linolenic acids have been known to be necessary for normal growth and dermal function since 1930, the omega 3 essential fatty acids (EFA) have not received much attention until recently. The two families of acids are metabolized by the same enzymes, making them competitive. Gross deficiencies of omega 6 plus omega 3 EFA have been observed in humans, induced by attempts at total parenteral nutrition (TPN) with preparations devoid of lipids. Deficiency of omega 3 acids has been induced by TPN containing high omega 6 and low omega 3 fatty acids. In natural human populations, a wide range of omega 3 and omega 6 proportions have been found, ranging from high omega 3 and low omega 6 content to low omega 3 and high omega 6 content, showing inverse correlation between sigma omega 6 and sigma omega 3. In humans with neuropathy or impairment of the immune system, significant deficits of omega 3 EFA have been measured.

Adipose tissue was obtained from six women undergoing liposuction twice at 6-mo intervals. Samples obtained bilaterally from abdomen, inner thigh, and outer thigh had fatty acids quantified by gas chromatography. There were no important differences between sides or over time. The saturates 14:0, 16:0, 18:0, and 20:0 were higher in abdominal adipose than in outer thigh (P < 0.002 for all); 16:1 and 18:1 omega 9 were lower in abdomen vs outer thigh (P < 0.01), whereas 18:1 omega 7 and 20:1 omega 9 were unchanged. Polyunsaturates 18:2 omega 6, 20:3 omega 6, and 20:4 omega 6 were higher in outer thigh than in abdomen (P < 0.06), and inner thigh values were intermediate. These changes in fatty acid composition resulted in lower mean triglyceride melting points from abdomen to inner thigh to outer thigh, and suggest that temperature may influence the selection process determining the variation in adipose fatty acid composition with anatomical location. Because the site-specific differences included essential fatty acids, selective uptake as well as potential differences in in situ fatty acid modification are indicated.

Diets rich in meat are claimed to contribute to the high tissue arachidonic acid (20:4 omega 6) content in people in Westernized societies, but there are very few direct data to substantiate this assertion. Because meat contains a variety of long-chain polyunsaturated fatty acids (PUFA) that are susceptible to oxidation, we initially examined the effect of cooking on the long-chain PUFA content of beef, and then determined the effect of ingestion of lean beef on the concentration of long-chain PUFA in plasma phospholipids (PL). First, we examined the effect of grilling (5-15 min) and frying (10 min) different cuts of fat-trimmed lean beef on the long-chain PUFA content. Second, we investigated the effect of including 500 g lean beef daily (raw weight) for 4 wk on the fatty acid content and composition of plasma PL in 33 healthy volunteers. This study was part of a larger trial investigating the effect of lean beef on plasma cholesterol levels. In the first two weeks, the subjects ate a very low-fat diet (10% energy) followed by an increase in the dietary fat by 10% each week for the next 2 wk. The added fat consisted of beef fat, or olive oil (as the oil or a margarine) or safflower oil (as the oil or a margarine). This quantity of beef provided 60, 230, 125, 140 and 20 mg/d, respectively, of eicosatrienoic acid (20:3 omega 6), 20:4 omega 6, eicosapentaenoic acid (20:5 omega 3), docosapentaenoic acid (22:5 omega 3) and docosahexaenoic acid (22:6 omega 3).(ABSTRACT TRUNCATED AT 250 WORDS)

Background: Although Wilson's disease is characterized by an accumulation of copper within hepatocyte lysosomes, the effects of excess copper on hepatic lysosomes are unknown. We studied the effects of excess copper on the structure, physicochemical properties, and pH of hepatocyte lysosomes using a rodent model. Methods: Rats were copper loaded with 0.125% copper acetate in water for 6 weeks. Copper was measured by atomic absorption spectrophotometry. Morphology was studied by electron microscopy. Lysosomal membrane fluidity was studied by fluorescence polarization, and lipid composition was determined by gas chromatography. Hepatocyte lysosomal pH was determined by flow cytometry. Results: Copper overload resulted in a 10-fold increase in hepatic copper. Hepatocyte lysosomes were enlarged and abnormally shaped with a 27-fold increase in copper, increased in vitro fragility, and decreased lysosomal membrane fluidity. Thiobarbituric acid reactive substances, a measure of lipid peroxidation, doubled in isolated lysosomal membranes. Polyunsaturated fatty acids increased, saturated fatty acids decreased, and membrane content of selected fatty acids was modified after copper overload. Lysosomal pH increased from 4.67 ± 0.02 to 4.87 ± 0.02. Conclusions: Copper overload causes alterations in lysosomal morphology, increases lysosomal fragility, decreases membrane fluidity, alters membrane fatty acid composition, and increases lysosomal pH. Copper catalyzed lipid peroxidation represents the likely mechanism for these alterations.

Serum NEFA profiles in Reye's syndrome are reportedly unique with a disproportionate percent made up of polyunsaturated fatty acids some of which are not ordinarily found in the serum. This pattern is also reflected in the serum triglyceride composition as well. As the liver is probably the sole source of the serum triglyceride in Rye's syndrome because patients are vomiting or in coma, the fatty acid acid composition of the liver triglyceride was examined for insight regarding the lipid abnormalities in this disease. Palmitic acid (16:0) and the sum of all the saturated fatty acids in the liver triglycerides were significantly decreased whereas the sum of the monoenoic fatty acids and the products of delta 9 desaturase activity were increased in Reye's samples. When these data were compared to the fatty acid composition of the serum triglyceride from a separate cohort of Reye's and control subjects, certain inferences regarding hepatic delta 9, delta 6, delta 5, and delta 4 desaturase activities and the elongases can be drawn from the liver and serum triglyceride fatty acid profiles which are unique. Collectively, these data reflect considerable intrahepatic fatty acid desaturation and elongation activity and/or acyl transfer from lipid to lipid of various polyunsaturated fatty acids in Reye's syndrome.

Linoleic acid (18:2 omega 6) and linolenic acid (18:3 omega 3) are precursors of two series of essential fatty acids (EFA) formed by alternate desaturations and elongations. In EFA deficiency (EFAD), oleic acid (18:1 omega 9) and palmitoleic acid (16:1 omega 7) undergo the same reactions to form polyunsaturated fatty acids (PUFA) of other structures. Partially hydrogenated soybean oil (PHSO) contains isomeric 18:1 acids that can be converted to unusual isomers of 18:2 by liver microsomes. To test whether 18:2, 20:3, and 20:4 of unusual structure occur in phospholipids as a consequence of EFAD or ingestion of PHSO, rats were fed corn oil, an EFA-deficient diet, or PHSO to provide isomeric 18:1 acids. At 2.5 months the phospholipids were isolated from livers and converted to methyl esters, and the 18:2, 20:2, 20:3, and 20:4 fractions were isolated. The 18:2 and 20:2 fractions were ozonized, and, by using a computer solution of simultaneous equations, the structures and proportions of each isomer were calculated. The 20:3 and 20:4 fractions were analyzed by ozonolysis and capillary gas chromatography. When corn oil was fed, the major isomer in each group was 9,12-18:2, 11,14-20:2, 8,11,14-20:3, and 5,8,11,14-20:4. Patterns in EFAD- and PHSO-fed groups were more diverse, with large proportions of unusual isomers. Feeding EFA-deficient diet and PHSO induced measurable amounts of unusual PUFA at each step of the cascade, and these PUFA may compete in metabolism of normal PUFA and are substrates for oxidative formation of autacoids of unknown structures and function.

We administered borage seed oil (9 capsules/day) for 12 weeks to 7 normal controls and to 7 patients with active rheumatoid arthritis. The therapy provided 1.1 gm/day of gamma-linolenic acid (GLA). GLA administration resulted in increased proportions of its first metabolite, dihomo-gamma-linolenic acid (DGLA), in circulating mononuclear cells. The ratios of DGLA to arachidonic acid and DGLA to stearic acid increased significantly in these cells. Significant reductions in prostaglandin E2, leukotriene B4, and leukotriene C4 produced by stimulated monocytes were seen after 12 weeks of GLA supplementation. The antiinflammatory effects of GLA administration observed in animal models, and the apparent clinical improvement experienced by 6 or 7 rheumatoid arthritis patients given borage seed oil in this open, uncontrolled study may be due in part to reduced generation of arachidonic acid oxygenation products.

Epidemiological and animal-based investigations have indicated that the development of skin cancer is in part associated with poor dietary practices. Lipid content and subsequently the derived fatty acid composition of the diet are believed to play a major role in the development of tumorigenesis. Omega 3 (omega3) fatty acids, including docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), can effectively reduce the risk of skin cancer whereas omega 6 (omega6) fatty acids such as arachidonic acid (AA) reportedly promote risk. To investigate the effects of fatty acids on tumorigenesis, we performed experiments to examine the effects of the omega3 fatty acids EPA and DHA and of the omega6 fatty acid AA on phorbol 12-tetradecanoate 13-acetate (TPA)-induced or epidermal growth factor (EGF)-induced transcription activator protein 1 (AP-1) transactivation and on the subsequent cellular transformation in a mouse epidermal JB6 cell model. DHA treatment resulted in marked inhibition of TPA- and EGF-induced cell transformation by inhibiting AP-1 transactivation. EPA treatment also inhibited TPA-induced AP-1 transactivation and cell transformation but had no effect on EGF-induced transformation. AA treatment had no effect on either TPA- or EGF-induced AP-1 transactivation or transformation, but did abrogate the inhibitory effects of DHA on TPA- or EGF-induced AP-1 transactivation and cell transformation in a dose-dependent manner. The results of this study demonstrate that the inhibitory effects of omega3 fatty acids on tumorigenesis are more significant for DHA than for EPA and are related to an inhibition of AP-1. Similarly, because AA abrogates the beneficial effects of DHA, the dietary ratio of omega6 to omega3 fatty acids may be a significant factor in mediating tumor development.

In 1943 when I began research with Professor George O. Burr on the chemistry of essential fatty acids (EFA), there were no methods to measure individual fatty acids (FA) in tissue lipids. Using the new Beckman (Fullerton, CA) DU spectrophotometer, instrument #6, we explored the use of ultraviolet spectra in the study of auto-oxidation of individual FA, and found that the auto-oxidation of the polyunsaturated fatty acids (PUFA) induced drastic elevations of absorption in the ultraviolet range (Holman et al., 1945). Holman and Burr (1948) then exploited the alkaline conjugation reaction, at high temperature, to induce conjugation of the double bonds of the common essential FA. The fully conjugated polyenoic acids had distinctive absorption bands, which made it possible to distinguish and measure the content of the originally nonconjugated, methylene interrupted diene-, triene-, tetraene-, pentaene-, and hexaene-acids present in biological lipids. Using this new analytical method, we learned next that the lack of PUFA in the diet lowered the amount of arachidonic acid in liver lipids, and that a triene acid, not present in animals fed EFA, appeared in those lipids. Supplementation with corn oil elevated the arachidonic acid, but supplementation with cod liver oil elevated the pentaenoic and hexaenoic acids in all tissues analyzed by Rieckehoff et al. (1949). The dietary fat influenced the lipid composition of the animal!

UNLABELLED Essential fatty acid (EFA) deficiency is a predisposing factor for pulmonary infection with Staphylococcus aureus and Pseudomonas aeruginosa, the two major pathogenic microorganisms in cystic fibrosis (CF). OBJECTIVE The goal of this study was to investigate the essential fatty acid status of CF patients from infancy to 20 years old. MATERIALS AND METHODS Plasma fatty acid profiles for phospholipid (PL) were determined for cord (n = 6), 4 months (n = 40), 16 months (n = 25), 3 y (n = 8), 5-10 y (n = 10), and 10-20 y (n = 10) aged CF patients and compared to their respective control; cord (n = 22), 1-36 months (n = 38) and adult (n = 100). Significance was established by Student's t-test (p < 0.05). RESULTS The plasma PL fatty acid profile for all CF patients, except cord, revealed consistent deficiency in omega 3 and omega 6 EFAs. These deficiencies were most marked at infancy and more pronounced for patients with meconium ileus. CONCLUSIONS AND RELEVANCE EFA deficiency may contribute to the predisposition of CF infants to develop respiratory disease and to the excess cytotoxic activity found in bronchoalveolar lavage fluid at 2 months of age in the majority of screened infants.

The profiles of fatty acids (FAs) of plasma phospholipids (the compartment reflecting the essential FA status of tissue lipids), nonesterified FAs (the precursor pool for autacoid synthesis), urine protein excretion, and glomerular filtration rate were measured before and after supplementation with fish oil in 15 patients with immunoglobulin A nephropathy. In the FA profiles, there was deficient 18:3 omega 3 (alpha-linolenic acid), the parent compound of omega 3 polyunsaturated FA, and deficient chain elongation products of both omega 3 and omega 6 polyunsaturated FAs with replacement by saturated and monounsaturated short-chain, odd-chain, and branched-chain FAs, producing significant loss of omega 3 FA. These alterations indicate nutritional or functional (omega 3) and metabolic (omega 6) deficiencies. Additionally, the mean melting point of the FAs was significantly increased, implying an inherent decrease in cell membrane fluidity. Enhancement of 20: 5 omega 3 (eicosapentaenoic acid) and 22:6 omega 3 (docosahexaenoic acid) and suppression of 20:4 omega 6 (arachidonate) after supplementation with fish oil were accompanied by important decreases in proteinuria and improved glomerular filtration rate. Omega-3 polyunsaturated FAs may favorably influence immunoglobulin A nephropathy through a modulation of the pathologic actions of the omega 6 eicosanoids and other diverse actions on various mediators produced by an initial immune injury.

Objective: The aim was to determine if reduced heart lipid peroxidation in turkeys with two forms of dilated cardiomyopathy, previously reported, was related to an alteration in the lipid composition of the ventricle. Methods: Myocardial lipid composition was measured in turkeys with two types of dilated cardiomyopathy. Twenty six turkeys with naturally occurring dilated cardiomyopathy, six with furazolidone induced dilated cardiomyopathy, and 18 age matched control birds were used at 1 day, 9-10 days, and 38-78 days of age. Left ventricular fatty acid composition of the phospholipid, triglyceride, free fatty acid, and cholesterol ester fractions was analysed using gas chromatography. Results: Significant age related changes were identified in the fatty acid composition of the heart. In the phospholipid fraction, linoleic acid (18:2ω6) values increased with age, while arachidonic acid values decreased. The saturated to unsaturated fatty acid ratio in control hearts was unchanged as a function of age in the phospholipid fraction. In the triglyceride fraction, however, this ratio decreased substantially between newly hatched and nine day old birds and then markedly increased in two month old controls. There was a striking alteration in the saturated to unsaturated fatty acid ratio in the triglyceride fraction of 2 month old cardiomyopathic birds; this ratio was markedly increased in the furazolidone induced cardiomyopathic turkey hearts (5.14 v 2.79 in controls) and markedly diminished (ie, 0.97 to 1.21) in the spontaneously cardiomyopathic turkeys. A significant increase in myristic (14:0) and decrease in linoleic (18:2ω6) acid concentration in the furazolidone group v control and a marked decrease in myristic and increase in linoleic acid concentrations in the spontaneously cardiomyopathic group v controls was present. Conclusions: (1) There is an age related alteration in the fatty acid composition of control turkey hearts. (2) Previously identified reduced lipid peroxidation in furazolidone induced and spontaneous cardiomyopathy in turkeys does not appear to be related to reduced concentration of polyunsaturated fatty acids. (3) The two forms of dilated cardiomyopathy are associated with markedly disparate alterations in the concentration of polyunsaturated fatty acids in the triglyceride fraction of 1-2 month old turkey hearts. The changes may be related, in part, to the pathogenesis in these two different forms of dilated cardiomyopathy. Cardiovascular Research 1994; 28 :407-413

Retinitis pigmentosa (RP) is a hereditary retinal degeneration of unknown etiology, resulting in progressive night blindness, loss of peripheral vision, abnormal retinal pigmentation and reduced electroretinographic response. Docosahexaenoic acid (22:6 omega 3) is found in high concentration in the rod outer segment membranes of the retina. Previous reports of low 22:6 omega 3 in blood lipids or phospholipids in RP patients prompted us to evaluate the complete fatty acid (FA) profiles of plasma phospholipids (PL), cholesteryl esters, triglycerides (TG) and nonesterified fatty acids (NEFA) in ten patients with RP. In the PL fraction, we found significantly depressed levels of 22:6 omega 3, 22:5 omega 3, total omega 3, 22:5 omega 6, 22:4 omega 6 and total omega 6 polyunsaturated FA (PUFA), and elevated total saturated acids. Plasma TG showed normal levels of PUFA, normal total saturated FA and total monounsaturated FA. The NEFA fraction showed significant elevation in total saturated FA with depressed total omega 6 PUFA. Evidence is accumulating mulating that RP is associated with abnormal PUFA and lipid metabolism.

In a group of 19 normal pregnant women, plasma lipids were extracted, phospholipids were isolated, and the fatty acid (FA) compositions were measured by capillary gas chromatography. Blood samples were taken at 36 wk, at labor, and at 6 wk postpartum. The FA profiles showed deficiencies of omega 6 and omega 3 FA (omega indicating the length of the terminal saturated chain), the latter more severe, at all three times. Mean melting point (MMP) was calculated for each sample as an index of "fluidity" based upon all FA present. MMP varied linearly with total polyunsaturated FA and with double bond index, current measures of "fluidity" and essential FA status. MMP was elevated 9-11 degrees C in plasma phospholipids of women during pregnancy and labor and postpartum. Lactating mothers showed less recovery from the deficiencies than did the nonlactating mothers, but neither approached normal at 6 wk. The changes seen in phospholipid profiles suggest a significant transfer of omega 3 and omega 6 polyunsaturated FA from the mother to the fetus. These FA are essential for normal fetal growth and development; their relative deficiency in maternal circulation suggests that dietary supplementation may be indicated.

The accumulation and depletion of trans 18:1 acids in the sciatic nerve phospholipids was studied in rats fed a diet containing 18% partially hydrogenated soybean oil of which 45% was trans 18:1. The nerve phospholipid of rats fed partially hydrogenated soybean oil beginning at weaning age reached a maximum incorporation of trans 18:1 of 0.8% in 4 weeks; whereas the nerve phospholipid of 18-day-old pre-weanling pups of mothers fed the partially hydrogenated soybean oil diet since their weaning contained 3.3% trans 18: l. The trans content decreased rapidly after the weaning of these second-generation rats to a steady-state level 50% higher than the maximum level reached in the first generation. Upon removal of partially hydrogenated soybean oil from the diet, the trans 18:1 of nerve phospholipid decreased much more slowly than from liver or heart phospholipid. Essential fatty acid deficiency had no influence on incorporation or removal of trans 18:1 in nerve phospholipid. The accumulation and depletion of frans 18:1 in nerve phospholipid of second-generation partially hydrogenated soybean oil-fed rats parallelled the changes of polyunsaturated fatty acids and was quite different from the changes observed in 18:0 and cis 18:1. Polyunsaturated fatty acids increased in nerve phospholipid from second but not first-generation rats fed partially hydrogenated soybean oil and declined rapidly when partially hydrogenated soybean oil was removed from the diet.

A cell-free particulate preparation from Butyrivibrio fibrisolvens was used to study the relative rates of isomerization of all cis, cis-methylene-interrupted isomers of octadecadienoic acid. Only two isomers were found to be substrates, the 9,12-isomer was isomerized at 41 ± 4 μmol/min per mg protein, and the 2,5-isomer at 11 ± 1 μmol/min per mg. The product of the isomerization of the 2,5-isomer had an ultraviolet absorption maximum at 233 nm indicating that it was the 3,5-isomer. The isomerization of the 2,5-isomer was studied in detail. Its rate of isomerization was linear with protein concentration up to 0.047 mg/ml, and was linear with substrate concentration up to 48 μM. The pH optimum was 6.8. Below pH 6, the substrate was also subject to spontaneous isomerization. The inhibition of isomerization of the 9,12-isomer by the other isomers was studied. Those isomers in which the double bonds are close to the carboxyl group were the most effective inhibitors. The preparation was also found capable of hydrogenating the conjugated diene product from the 2,5-isomer to a monoene after prolonged incubation.

The influences of zinc-deficiency and reduced food intake on levels of polyunsaturated fatty acids (PUFA) of phospholipids (PL) of lymphoid and nonlymphoid tissues were studied. Weanling male Long-Evans rats were fed ad libitum either a zinc-deficient (ZD) or a zinc-adequate (ZA) diet for 21 days. A pair-fed (PF) group was given the ZA diet in an amount equal to that consumed on the previous day by the ZD group. Linoleic acid (18:2ω6), 18:3ω6 and 20:3ω6 were either equivalent or significantly higher, but arachidonic acid (20:4ω6) and 22:5ω6 were either equivalent or significantly lower in tissues of ZD and PF rats compared to ZA rats. Total ω6 acids and metabolites were either equivalent or significantly lower in tissues of ZD and PF rats compared to ZA rats. In contrast, total ω3 acids and metabolites, and total ω9 acids and emtabolites were either equivalent or significantly higher in ZD and PF rats compared to ZA rats. Changes in PUFA patterns of lymphoid and nonlymphoid tissues of ZD rats were influenced by reduced food intake.

Fatty acid patterns of the serum lipids were measured in 17 children with Reye's syndrome (RS). Serial measurements of total serum free fatty acids (FFA) showed that levels were increased during RS and, after recovery, were significantly lower in the patients who survived. Fatty acid patterns of serum FFA, triglycerides, and phospholipids in patients with RS were significantly different from those in controls. In RS the polyunsaturated fatty acid content of phospholipids was less than control values; in the FFA, it was higher. This was consistent with the possible involvement of increased phospholipase activity. The increase in polyunsaturated fatty acids in FFA, the precursors of prostaglandins, suggests that a grossly disturbed prostaglandin pattern may occur in RS. These changes in lipid metabolism may be related to the abnormal hepatic and neurological functions observed in RS.

The inhibitory effects of the positional isomers of trans-18:1 acids on the desaturation of palmitic acid to palmitoleic (delta 9-desaturase), linoleic to gamma-linolenic (delta 6-desaturase) and eicosa-8,11,14-trienoic to arachidonic acid (delta 5-desaturase) were investigated. These trans-18:1 acids were found to be inhibitory for the microsomal delta 6-, delta 9- and delta 5-desaturases of rat liver. The position of the double bond in the trans-18:1 acids seems to be important in determining the degree of inhibition. At inhibitor/substrate ratio of 3:1, the delta 6-desaturase was most strongly inhibited by trans-delta 3, -delta 4, -delta 7 and -delta 15-18:1 isomers, whereas the delta 9-desaturase was most strongly inhibited by trans-delta3, -delta 5, -delta 7, -delta 10, -delta 12, -delta 13 and -delta 16 isomers. At inhibitor/substrate ratio of 6:1, the delta 5-desaturase was most strongly inhibited by delta 3-, delta 9-, delta 13- and delta 15-isomers. When 18:0 was added to the incubations of 16:0, 18:2 and 20:3 at the same I/S ratios used for the trans-18:1 acids, weak inhibition for delta 9- desaturase and no inhibition for delta 5- and delta 6-desaturases was observed.

The effects of dietary polyunsaturated and saturated fats upon several metabolic phenomena were studied in rats. These included phospholipid (PL) levels in unstimulated spleen lymphoid cells (SLC) and serum; in vitro proliferation of unstimulated SLC from the two groups of rats; the influence of mitogenic concanavalin-A (Con-A) on in vitro proliferation of SLC from the two groups of rats; and the influence of serum from the two groups of rats on SLC proliferation. Weanling male Long-Evans rats were fed ad libitum either a polyunsaturated fatty acid (PUFA)-adequate (safflower oil, SO) or PUFA-deficient (coconut oil, CNO) diet for 21 days. Growth was significantly less in the CNO group than in the SO group. Food intake was not different for the dietary groups. Unstimulated SLC and serum of CNO rats showed changes in fatty acid composition of PL typical of tissue PL in essential fatty acid-deficient (EFA-D) rats. Unstimulated SLC from the two groups cultured in medium containing serum from the same groups showed equivalent rates of in vitro proliferation. In vitro proliferations of SLC were influenced: by the dietary source of SLC but not by the dietary source of serum, used in the culture medium, when the cells were stimulated by suboptimal doses of Con-A; by the dietary source of serum but not by the dietary source of SLC when the cells were stimulated by the optimal dose of Con-A; and by an interaction between source of SLC and serum, when the cells were stimulated by a supra-optimal dose of Con-A. The present study indicates that in vitro proliferation of SLC from PUFA-adequate and PUFA-deficient rats is influenced by both the dietary source of serum used in the culture medium and the concentration of Con-A used for stimulation of the SLC.

Biotin deficiency associated with total parenteral nutrition is an emerging clinical problem; criteria for diagnosis and dosage for treatment are unclear. We have diagnosed and successfully treated biotin deficiency in three patients. Each patient had alopecia totalis, hypotonia, and developmental delay. Two developed the characteristic scaly periorificial dermatitis; one had only an intermittent scaly rash on the cheeks and occipital scalp. Zinc and essential fatty acid supplements were adequate; serum zinc levels and triene/tetraene ratios confirmed sufficiency of these nutrients. None of the patients received biotin prior to diagnosis, and each had decreased excretion of urinary biotin and increased urinary excretion of organic acids diagnostic of deficiency of two biotin-dependent enzymes (methylcrotonyl-coenzyme A carboxylase and priopionyl-coenzyme A carboxylase). Only one patient had a plasma biotin concentration below the normal range (Ochromonicas danica assay). The rash, alopecia, and neurologic findings responded dramatically to biotin therapy (100 micrograms/day in all patients; an initial larger dose of 1 mg/day for 1 week plus 10 mg/day for 7 weeks in one patient), and did not recur. However, abnormal organic acid excretion persisted in one patient who did not receive the larger dose. We conclude that plasma biotin concentration does not reflect biotin status in all cases and speculate that the biotin supplement currently recommended for pediatric patients (20 micrograms/day) may not be adequate therapy for biotin deficiency and might not even be adequate to maintain normal biotin status during TPN.

Low resolution mass spectra of pyrrolidides of isomeric octadecadienoic acids and other polyunsaturated straight chain fatty acids are presented and discussed. The spectra of the pyrrolidides contain mainly ions from the polar part of the molecule and give spectra that are specific for each isomer. The interpretation follows, in most cases, the rule developed for monounsaturated fatty acid pyrrolidides.

Serum was obtained from approximately 10 individuals of each sex from each decade of life from 0 to 90 years of age. Most of the serum samples were obtained from the excess remaining after diagnostic procedures performed for hospitalized patients. The individuals were screened according to tentative diagnosis, and overt cases of diseases known to have effects upon essential fatty acid (EFA) metabolism were eliminated. Serum lipids were separated into phospho- lipids, cholesteryl esters, triglycerides, and free fatty acids. These lipid classes and a sample of the total lipids were subjected to fatty acid analysis by gas chromatography. The data produced were arranged by computer to compare the effects of age upon each fatty acid present and upon each parameter calculated from fatty acid composition for each lipid group and each sex. No significant difference between sexes was found for any individual fatty acid in any lipid, but the average total unsaturation of all lipid classes was significantly higher for males than for females at both 0 and 90 years of age. In cholesteryl esters, and to a lesser extent in phospholipids, the total polyunsaturated fatty acids, the total co6 acids and the sum 18:2e�6 + 20:4w6 - 20:3w9 declined more rapidly with age in females than in males, suggesting a trend toward EFA deficiency, although the ratio 20:3w9/ 20:4�6 did not change significantly. The age and sex differences observed and the SD encountered were much smaller than the changes observed in EFA deficiency, indicating that this population has utility in comparisons with suggested cases of EFA deficiency. The triene/tetraene ratio, 20: 3w9/20:4w6, was found to be 0.1 ± 0.08 for male and female populations, indicating that a ratio above 0.2 should be considered the upper limit of normalcy. Between 0 and 4 months of age, a profound change took place in the patterns of fatty acids in serum lipids. At birth, phosphohipids were low in l8:2c,6 but 20:&,6 and 20:3co9 were elevated. The ratio of 20:3�,9/20:4w6 was 0.16 at birth and decreased progressively during infancy. Some of these observations suggest that at birth the infant has marginal reserves of EFA. The drastic change in composition of serum lipid shortly after birth probably reflects a change in supply of EFA from one rich in 20:4w6 and poor in 18:2�,6 to one high in 18:2�6 and low in 20:4�6. This may have significance in the nutrition of premature or very young infants. Am. J. Clin. Nuir. 32: 2390-2399, 1979.

Geometric and positional isomers of [1-14C] octadecenoic acids have been synthesized by modifications of published procedures. Positional isomers of octadecynoic acids also have been synthesized to obtain the geometric and positional isomers of the unlabeled octadecenoic acid analogs. The syntheses were accomplished by coupling a haloalkyl compound with a substituted acetylene using n-butyl lithium in hexamethylphosphoramide. The coupled product, either a 17- or 18-carbon acetylenic alcohol, could be semihydrogenated and chain extended to afford a carboxy labeled derivative, could be partially hydrogenated and chain extended to afford a carboxyl labeled cis- or trans-octadecenoic acid in the former case. In the latter case, octadecynoic, cis-octadecenoic or trans-octadecenoic acids could be obtained by the appropriate reactions. The methods used in this study enabled the synthesis of 14C-labeled fatty acids in generally higher yields and by simpler reactions than were previously possible.

The intravenous administration of parenteral fat emulsions is widely used in total parenteral nutrition (TPN) to supply essential fatty acids and concentrated energy in a relatively small volume of isotonic solution. They contain very high amounts of linoleic acid and usually about 8% of alpha-linolenic acid calculated in the fat phase (10 or 20% of the total emulsion). Most of the time one emulsion is given as the sole source of fat, giving direct venous entry to a fatty acid composition substantially different from that encountered in a normal diet. Since the latter greatly influences the fatty acid composition of phospholipids which are critical determinants of membrane structural properties influencing a variety of membrane functions (Fig. 1) (enzyme activity, membrane transport, receptor function) and functional precursors of intracellular and intercellular mediators (diacylglycerols, prostaglandins, leukotrienes, hydroxy fatty acids), do we provide the right fatty acid at the right place and the right time for efficient cell cell interaction? In other words, given the three roles of fatty acids--energetic, structural, functional--are we using the best strategy to avoid imbalances between the three roles?

Amides of unsaturated fatty acids give mass spectra which indicate the locations of the double bonds. A survey of several amides of oleic acid was made to evaluate which amide might be most suitable for routine use in elucidation of structure. Methods of preparation of several amides of oleic acid are presented with mass spectral and gas chromatographic data. Tertiary amides have most easily interpretable mass psectra which indicate the position of the double bond in the fatty acid chain. The pyrrolidide is advantageous for fatty acid gas liquid chromatography and mass spectrometry analyses because it can be prepared easily in high yield on a microscale, it is volatile enough for gas liquid chromatographic separations, and it has a simple and easily interpretable mass spectrum which indicates the structure.

The oxidation of alcohols by the dipyridine chromic anhydride complex is judged to be most suitable for the preparation of long-chain aliphatic aldehydes. Thus, cis -9-octadecenol is oxidized in 93% yield within 30 min at room temperature with no detectable alteration of the double bond.

The influence of reduced food intake on metabolism of liver phospholipids (PL) in zinc-deficient (ZD) rats was measured. Wealing male Long-Evans rats were fed ad libitum zinc-deficient (2 micrograms Zn/g diet) and zinc-adequate (20 micrograms Zn/g diet) diets for 21 days. A pair-fed (PF) group was included. ZD and PF rats displayed significantly increased levels of linoleic (18:2 omega 6) and dihomo-gamma-linolenic acid (20:3 omega 6). Both ZD and PF rats displayed increased levels of gamma-linolenic acid (18:3 omega 6), but the increase was significant only in PF rats. ZD and PF rats displayed decreased levels of arachidonic acid (20:4 omega 6), but the decrease was significant only in PF rats. Both ZD and PF rats displayed significantly reduced levels of 22:5 omega 6. Both ZD and PF rats displayed increased products of delta 6 desaturation and decreased products of delta 5 and delta 4 desaturation. Significantly increased products of delta 9 desaturation were noted in both ZD and PF rats. ZD and PF rats displayed significant increases in C20 elongation products. ZD and PF rats displayed significantly decreased levels of omega 6 metabolites but not total omega 6 acids. ZD rats showed significantly increased levels of total omega 3 acids and omega 3 metabolites. ZD and PF rats showed significant increases in omega 9 acids but not significant changes in omega 9 metabolites. This study does not indicate that zinc affects the delta 6 desaturase in the metabolism of essential fatty acids. The aberrations previously attributed to zinc deficiency are probably due to the accompanying decreased food intake.

The effects of the mixed cis- 18:1 isomers and mixed trans- 18:1 isomers present in partially hydrogenated soybean oil (PHSO) upon the patterns of polyunsaturated fatty acids (PUFA) in liver phosphatidylcholine (PC) and phosphatidylethanolamine (PE) were studied in rats fed concentrates of cis- 18:1 or trans- 18:1 isomers isolated as triacylglycerides from PHSO. The cis- 18:1 and trans- 18:1 concentrates were fed at levels equal to those present in PHSO fed at 17.9% of the diet. All diets contained the required amounts of both linoleic and linolenic acids. The trans- 18:1 concentrate was found to suppress the levels of 20:4 omega 6 and 20:3 omega 9, and to increase the levels of 18:2 omega 6 and 20:5 omega 3 in PC and PE. The cis- 18:1 concentrate suppressed 20:4 omega 6 in PC, 20:5 omega 3 in PC and PE, and 18:2 omega 6 in PC, but increased the levels of 20:4 omega 6 in PE, and 20:3 omega 9 in PC and PE. The cis- 18:1 concentrate was more effective than the trans concentrate in suppressing 22:6 omega 3. The trans- 18:1 concentrate was more effective in suppressing 20:4 omega 6. The trans- 18:1 isomers appear to modify PUFA metabolism by inhibition of PUFA synthesis, whereas the cis- 18:1 isomers appear to complete with 2-position fatty acyl transfer and to inhibit omega 3 PUFA acylation.

Severe essential fatty acid deficiency (EFAD) was induced by feeding weanling rats a diet free of essential fatty acids 8 months after weaning. The fatty acid compositions of phospholipids and glycosphingolipids in peripheral nerve myelin were compared in rats with and without EFAD. With the deficient diet, 20:3ω9 was found in the major myelin phospholipids. The level of 18:1 was increased and the levels of 18:2ω6, 20:4ω6, and 22:4ω6 were decreased. Both sphingomyelin and cerebroside showed higher proportion of 24:1 and lower proportions of 24:0 in EFA-deficient rats than in control rats. The fatty acid chain elongating system in myelin cerebroside was also depressed by EFAD. A two- to sevenfold increase of the ratio 20:4ω6 to 20:3ω6 was found in myelin phospholipids of regenerated nerve from rats fed control diet. However, this ratio was suppressed by EFAD diet. The biochemical index (20:3ω9/20:4ω6) for EFAD was not affected by crush injury. These results suggest that dietary EFAD in postweaning rats can induce fatty acid alterations in peripheral nerve myelin without resulting in detectable changes in function or structure and that myelin lipids may be sequestered and reused during nerve degeneration and regeneration.

The potential of the rectal route for administration of essential fatty acids (EFA) as monoglyceride (MG) was investigated. EFA-deficient rats were supplemented with 14 mg linoleic acid/day for 3 days. Supplementation was either by oral administration as corn oil, orally as corn oil-derived MG or rectally as MG. The patterns of polyunsaturated fatty acids (PUFA) in liver and serum lipids, characteristic of EFA deficiency, were altered in the direction of normalcy in similar magnitude by all modes of supplementation, indicating that the rectal route may be useful for administration of EFA. The amounts of phospholipids (PL) and free fatty acids (FFA) in liver changed by all modes of administration. The magnitude of change of total PL and of FFA in liver depended upon the chemical form in which linoleic acid was administered and the route of administration, indicating that these factors affect lipid metabolism.

Rats were fed purified diets containing (i) partially hydrogenated soybean oil as source of isomeric octadecenoic acids, (ii) hydrogenated coconut oil as source of saturated fatty acids, and (iii) a low level of corn oil as low-fat control. All diets contained 18% of the linoleate requirement. Rat liver and heart phospholipids were analyzed by gas/liquid chromatography for fatty acids, and liver, microsomes were assayed for desaturase (acyl-CoA, hydrogen-donor: oxidoreductase, EC 1.14.99.5) activities. Products of desaturation reactions measured analytically provided more information with greater statistical significance than did the enzymatic assays. Rats fed isomeric octadecenoic acids showed more severe essential fatty acid deficiency than did saturated-fat and control groups. The suppression of linoleate metabolites was largely due to decreased delta 5 and delta 6 desaturase activities. At several levels of linoleate, the deficiency was more severe at the higher level of isomeric octadecenoic acids. Increasing the intake of linoleate to 7.5% of calories did not suppress deposition of isomeric unsaturated acids in tissue lipids.

The pyrrolidide and picolinyl ester derivatives of the fatty acids in two natural lipid samples rich in unsaturated fatty acids, pig testis lipids and cod liver oil were satisfactorily resolved on capillary columns of fused silica coated with stationary phases of varying polarity. The picolinyl esters, in particular, when subjected to gas chromatography-mass spectrometry on a column containing a cross-linked methyl silicone, gave distinctive mass spectra, which could be interpreted in terms of both the numbers and positions of the double bonds.

The fatty acid components of the lipids of the seed elaiosomes of a group of pedicillate Trillium species differed only slightly from those of the seeds proper. The fatty acids seem to offer no clue to the range of ant activities associated with myrmecochory in this genus.

The picolinyl ester derivatives of the complete series of isomeric octadecenoates, methylene-interrupted octadecadienoates, and of octadec-9-ynoate have been subjected to gas chromatography-mass spectrometry. A fused-silica capillary column, coated with a cross-linked methyl silicone, was used for the separation. Electron impact spectra were determined at 70 eV. Earlier observations with a limited series of model compounds were confirmed, and it was shown that the picolinyl ester derivatives were of almost universal value in the location of double bonds in such isomers. Difficulties of interpretation arose mainly when the double bonds were close to the carboxyl group.

The fatty acid compositions of serum phospholipids, cholesteryl esters, triglycerides, and free fatty acids were determined on a group of cystic fibrosis patients. These were compared with similar data from random hospitalized patients of the same age groups of both sexes. Fatty acid patterns in all lipid classes were skewed in the direction of essential fatty acid deficiency, but the differences were most dramatic in phospholipids. Many calculated parameters useful as indices of essential fatty acid status indicated that essential fatty acid deficiency exists in cystic fibrosis. Treatment of 11 cystic fibrosis patients with safflower oil (1 g/kg/day) failed to correct the aberrations in fatty acid pattern. The biochemical data suggest that there may be an impairment in conversion of linoleate to arachidonate as well as an impairment of absorption.

1. 1. The influence of sex on the chain elongation, dehydrogenation and incorporation of fatty acids has been studied using a microsomal system. 2. 2. A significant sex difference was found in the elongation of palmitic acid to stearic acid. Female rats performed the elongation with a capacity about twice as high as that of male rats. 3. 3. No sex differences were detected in the ability to perform the dehydrogenation and chain-elongation steps leading from linoleic acid to arachidonic acid. The incorporation of arachidonic acid into complex lipids was not influenced by the sex.

1. 1. Weanling female rats were fed for 100 days, either a fat-free diet or a fat-free diet supplemented with increasing levels of either linoleate or linolenate, and the fatty acid distribution on liver lecithins was then determined. The pattern of distribution was governed by fatty acid composition of the diet and by the level of fatty acids fed. 2. 2. As the level of dietary linoleate increased, changes in fatty acid composition of lecithin occurred in the greatest magnitude in the β-position. Most of the response to changes in dietary linoleate occurring in the fatty acid components esterified at both positions of liver lecithin took place at levels of dietary linoleate 1.2% of calories and less. 3. 3. When linoleate was fed in increasing doses responses of the three principal fatty acids in the α-position of liver lecithin (18 : 0, 16 : 0, and 18 : 1 ω 9) were opposite to those when linolenate was fed. 4. 4. Both linoleate and linolenate exerted strong effects on fatty acid components esterified in the β-position and lesser effects on those in the α-position of liver lecithin.

[9,10-3H]Palmityl-coenzyme A, [9,10-3H]stearyl-coenzyme A and [9,10-3H]-oleoyl-coenzyme A were tested as substrates for shortening the chain by two carbon atoms using liver microsomes from essential fatty acid-deficient rats. The rates of the reaction were 0.87, 0.68 and 0.34 nmole/min per mg microsomal protein, respectively. The coenzyme A thioester of the fatty acid is the active form of the substrate. Under the same conditions, the rate of chain shortening of palmitic acid is only 1/5 that of palmityl-coenzyme A. Both NADP+ and NAD+ are required for maximum enzyme activity. The divalent cations, Mg2+ and Ca2+ tend to inhibit the reaction.

cis- and trans-octadecenoic acid isomers and octadecynoic acid isomers were used to test the bond specificity of unsaturated inhibitors upon desaturation of 18:0 by rat liver microsomes. Among the cis-octadecenoic acids, the 10- and 11-isomers were the strongest inhibitors. Comparison of isomeric cis-octadecenoic acids with isomeric octadecynoic acids revealed that an additional π-bond did not cause significantly stronger depressive effects. trans-Octadecenoic acids were equally or less inhibitory than corresponding cis-isomers.

Supplements of purified fatty acid methyl or ethyl esters were fed at levels of 0.8% of dietary calories to each of seven groups of weanling rats for a period of 60 days. The esters were 9,12-octadecadienoate (18:2) ; 9,12,15-octadecatrienoate (18:3); 10,13-nonadecadienoate (19:2); 5,8,11,14-eicosatetraenoate (20:4); 5,8,11,14,17 - eicosapentaenoate (20:5); 4,7,10,13,16,19-docosahexaenoate (22:6); and 12:13-epoxyoctadeca-9-enoate (epoxyoleate). Rats fed a fat-free diet served as control animals. The effects of these dietary supplements on the fatty acid compositions of the nonphospholipids and phospholipids from liver microsomal and mitochondrial particles, and of unfractionated lipids from liver, testes, epididymal, and heart tissues were determined by gas–liquid chromatography. Epoxyoleate and 19:2, which are structurally related to linoleic acid, did not function as essential fatty acids as judged by the chemical and biological symptoms of fat deficiency. Dietary 20:5 and 22:6, both related to linolenate, were less active than linoleate in preventing the biological symptoms of fat deficiency, but more active in depressing the content of eicosatrienoate. Docosapentaenoic acid of the linoleate family was identified by reductive ozonolysis and shown to increase with an increase in dietary 18:2 or 20:4.

Male rats which had been kept on fat-free diet and which were deficient in essential fatty acids were divided into ten groups. All ten groups received 0.8% of calories of linolenate, and nine received one of three levels of either linoleate, γ-linolenate or arachidonate for a period of six days. The rats were sacrificed, the livers, kidneys and testes were extracted, and the phospholipids, triglycerides and cholesteryl esters were separated by thin-layer chromatography. The fatty acid composition of each was determined by gas-liquid chromatography. The inhibition of the metabolism of linolenic acid by linoleate, γ-linolenate and arachidonate was evidenced in all three lipid classes and in all tissues. The activities in suppressing linolenate metabolism were in the order 20:4 >18:3 >18:2.

Beef and pork testes, graafian follicles and the residual ovaries were extracted and the lipids from each were separated into lipid classes by thin-layer chromatography. The fatty acids from each class were analyzed as their methyl esters by gas-liquid chromatography. The lipids from the reproductive tissues were found to be relatively rich in polyunsaturated acids, many of which did not correspond to the more commonly encountered unsaturated acids. These less familiar acids were identified by comparing their chromatographic characteristics with standards of established composition.