Showing papers in "Lipids in 1975"
TL;DR: Turbot and rainbow trout, which had previously received diets free of fat, were fed fatty acids and the major product of the limited modification found in turbot was the dietary acid elongated by 2 carbon atoms.
Abstract: Turbot and rainbow trout, which had previously received diets free of fat, were fed [1-14C] fatty acids. The distribution of radioactivity in the tissue fatty acids was examined 6 days later. In rainbow trout fed [1-14C] 18∶3ω3, 70% of the radioactivity was present in 22∶6ω3 fatty acid. In contrast, turbot fed [1-14C] 18∶1ω9, 18∶2ω6, or 18∶3ω3 converted only small amounts of labeled fatty acids (3–15%) into fatty acids of longer chain length. The major product of the limited modification found in turbot was the dietary acid elongated by 2 carbon atoms.
262 citations
TL;DR: The results of the present experiments suggested that dietary 20∶4 and 22∶6 were important sources of brain 20∷4 and 21∷6 in the developing rat and possible reasons for these differences are discussed.
Abstract: The incorporation of radioactivity from orally administered linoleic acid-1-14C, linolenic acid-1-14C, arachidonic acid-3Hg, and docosahexaenoic acid-14C into the liver and brain lipids of suckling rats was studied. In both tissues, 22 hr after dosing, 2 distinct levels of incorporation were observed: a low uptake (from 18∶2-1-14C and 18∶3-1-14C) and a high uptake (from 20∶4-3H8 and 22∶6-14C). In adult rats, the incorporation of radioactivity into brain lipids from 18∶2-1-14C and 20∶4-3H was considerably lower than the incorporation into the brains of the young rats. In the livers of the suckling rats, the activity from the 18 carbon acids was associated mostly with the triglyceride fraction, whereas the activity from the 20∶4-3H8 and 22∶6-14C was concentrated in the phospholipid fraction. In the brain lipids, the activity from the different fatty acids was associated predominantly with the phospholipids. In the liver and brain phospholipid fatty acids, some of the activity in the 18∶2-1-14C and 18∶3-1-14C experiments was associated with 20 and 22 carbon polyunsaturated fatty acids; however, radioactivity from orally administered 20∶4-3H8 and 22∶6-14C was incorporated intact into the tissue phospholipid to a much greater extent compared with the incorporation of radioactivity into 20∶4 and 22∶6 in the experiments where 18∶2-1-14C and 18∶3-1-14C, respectively, were administered. Possible reasons for these differences are discussed. Rat milk contains a wide spectrum of polyunsaturated fatty acids, including linoleate, linolenate, arachidonate, and docosahexaenoate. During the suckling period in the rat, there is a rapid deposition of 20∶4 and 22∶6 in the brain. The results of the present experiments suggested that dietary 20∶4 and 22∶6 were important sources of brain 20∶4 and 22∶6 in the developing rat.
200 citations
TL;DR: 13L-Hydroperoxy-9,11-octadecadienoic acid was decomposed rapidly in the presence of hemoglobin.
Abstract: 13L-Hydroperoxy-9,11-octadecadienoic acid was decomposed rapidly in the presence of hemoglobin. The product consisted of five major compounds, i.e. 13-keto-9,11-octadecadienoic acid, 13L-hydroxy-9,11-octadecadienoic acid,erythro-11-hydroxy-12,13-epoxy-9-octadecenoic acid,threo-11-hydroxy-12,13-epoxy-9-octadecenoic acid, and 9DL-hydroxy-12,13-epoxy-10-octadecenoic acid.
145 citations
TL;DR: The structures of furan fatty acids were concluded from oxidative degradations, from mass spectrometry of methyl esters of the novel acids and fatty acids derived from them by opening the ring, and from nuclear magnetic resonance, infrared, and Raman spectra.
Abstract: Fatty acids, recently reported as constitutents of certain fish lipids, were identified to be derivatives of furan (furanoid fish fatty acids). 12,15-Epoxy-13,14-dimethyleicosa-12,14-dienoic acid is predominant among the furan acids and is associated withbis-homologs in regard to chain length. Monomethyl acids, such as 12,15-epoxy-13-methyleicosa-12,14-dienoic, are present in appreciable amounts. The structures were concluded from oxidative degradations, from mass spectrometry of methyl esters of the novel acids and fatty acids derived from them by opening the ring, and from nuclear magnetic resonance, infrared, and Raman spectra. The results from chemical procedures and from spectrometric methods were in aggreement with those obtained with authentic methyl 9,12-epoxyoctadeca-9,11-dienoate. The number of substituents at the furan ring greatly influences hydrogenation, hydrogenolysis, and hydrolysis reactions of the ring.
142 citations
TL;DR: The desaturation of stearic, linoleic, and α-linolenic acids by human liver microsomes were studied, but the desaturation activity obtained was low compared to other mammals and was attributed to fasting, premedication, or the anaesthesia.
Abstract: The desaturation of stearic, linoleic, and α-linolenic acids by human liver microsomes were studied. The microsomes were isolated from liver biopsies obtained during operations. It was shown that human liver microsomes are able to desaturate 1-14C-α-linolenic acid to octadeca-6,9,12,15-tetraenoic acid; 1-14C-linoleic acid to γ-linolenic acid; and 1-14C-stearic acid to oleic acid in the same system described in the rat. However, the desaturation activity obtained was low compared to other mammals. This effect was attributed to fasting, premedication, or the anaesthesia.
126 citations
TL;DR: The increase in free fatty acid levels following decapitation was completely absent in rats sacrificed by the microwave irradiation, and this microwave technique could be a valuable tool in determining free fatty acids and other heat stable compounds in brain tissue.
Abstract: Values are presented for whole brain free fatty acid levels of rats sacrificed by decapitation vs focused microwave irradiation. Free fatty acids were quantitated by specific colorimetric analysis. Within ca. 1 min of sacrifice by either decapitation or microwave, rat whole brain free fatty acid concentrations ranged from ca. 80–100 μg/g fresh tissue. If the brain remained in the head for a total of 5 min after decapitation, free fatty acid levels increased by over 100%. The free fatty acids at this time were enriched with arachidonic acid. The increase in free fatty acid levels following decapitation was completely absent in rats sacrificed by the microwave irradiation. This microwave technique could be a valuable tool in determining free fatty acid and other heat stable compounds in brain tissue.
120 citations
TL;DR: A single step chromatographic procedure which separates a methyl ester mixture containing 0–6 double bonds is described, and purity of each ester recovered from the silver nitrate plate was 98–99%.
Abstract: A single step, silver nitrate thin layer chromatographic procedure which separates a methyl ester mixture containing 0–6 double bonds is described. Purity of each ester recovered from the silver nitrate plate was 98–99%. Recovery of the esters ranged from 100% for saturates to 77% for pentaenes.
118 citations
TL;DR: The physiological specificity of fat digestion in several species of marine fish was studied by incubating a variety of synthetic and natural lipid substrates in fish intestinal fluid with wide variation in the ratio occurred among different batches of intestinal juice.
Abstract: The physiological specificity of fat digestion in several species of marine fish was studied by incubating a variety of synthetic and natural lipid substrates in fish intestinal fluid. Wax ester and triglyceride hydrolyses were studied in vivo and in vitro. In vivo feeding studies showed triglyceride hydrolyses and reesterification in the gut occurred 4 times faster than wax ester metabolism. In vitro comparisons of wax and triglyceride lipolysis always showed triglycerides to be hydrolyzed faster than wax esters; however, wide variation in the ratio occurred among different batches of intestinal juice. Ca. 50% of the 2-monoglycerides formed in the lipolytic sequence were hydrolyzed. Esters of lipase resistant fatty acids (20∶4 and 20∶5) were cleaved faster than normal fatty acid esters (18∶2 and 18∶3). Two of the species studied, the northern anchovy,Engraulis mordax and the jack mackerel,Trachurus symmetricus, empty lipase(s) into their gall bladders and produce phospholipid-free bile.
111 citations
TL;DR: Data obtained by quantitation of the algal methyl esters suggest the possibility that these dinoflagellates synthesize 18∶5ω3 (shorthand) notation for chain length: number of double bonds and position of final double bond counted from the terminal methyl group by a 2 carbon chain shortening of 20∶ 5ω3, rather than by the insertion of a †3 bond into 18∵4ω3.
Abstract: Polar and nonpolar chromatograms of fatty acid methyl esters derived from 11 species of photosynthetic, marine dinoflagellates cultured in modified Erd-Schrieber medium contained a component (4–23%) not identifiable by conventional graphic or arithmetic methods. Hydrogenation followed by gas liquid chromatography of the product showed the unknown component to be a straight chained 18 carbon fatty acid methyl ester. Chemical (CH4) ionization mass spectrometry of the isolated ester gave a spectrum characteristic of methyl esters and a mol wt of 288, indicating an 18 carbon molecule with 5 double bonds, or equivalent unsaturation. The IR spectrum showed that the double bonds are nonconjugated, and all arecis in geometry. Electron impact mass spectrometry of the pyrrolidide derivative provided evidence that double bonds are located in the 3, 9, 15 positions and probably also in the 6 and 12 positions of the molecule. These double bond positions were confirmed by NMR spectrometry. Data obtained by quantitation of the algal methyl esters suggest the possibility that these dinoflagellates synthesize 18∶5ω3 (shorthand) notation for chain length: number of double bonds and position of final double bond counted from the terminal methyl group) by a 2 carbon chain shortening of 20∶5ω3, rather than by the insertion of a †3 bond into 18∶4ω3.
110 citations
TL;DR: Low resolution mass spectra of pyrrolidides of isomeric octadecadienoic acids and other polyunsaturated straight chain fatty acids are presented and discussed and the interpretation follows the rule developed for monounsaturated fatty acid pyrolidides.
Abstract: 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.
103 citations
TL;DR: Attempts at isolation of pure 9-hydroperoxy-10,12-octadecadienoic acid from hydroperoxides obtained by corn lipoxygenase oxygenation of linoleic acid were partially successful with isolation of the 9-Hydroperoxide in 97% purity.
Abstract: A mixture of positional isomers of linoleic acid hydroperoxide was produced from the oxidation of linoleic acid by lipoxygenase from corn or soybean. Chromatography on a column of silicic acid separated 13-hydroperoxy-11,9-octadecadienoic acid in 99+% purity from the mixture obtained by soybean lipoxygenase oxidation of linoleic acid. Attempts at isolation of pure 9-hydroperoxy-10,12-octadecadienoic acid from hydroperoxides obtained by corn lipoxygenase oxygenation of linoleic acid were partially successful with isolation of the 9-hydroperoxide in 97% purity.
TL;DR: The results suggest that the desaturation of linoleic to γ-linolenic acid in vivo is a rate-limiting step in the conversion of linolesic to arachidonic acid.
Abstract: The incorporation of radioactivity from orally administered γ-linolenic acid-1-(14)C and linoleic acid-(3)H into the liver, plasma, and brain lipids of suckling rats was studied. Significantly more radioactivity from the former compound was incorporated into the liver and brain lipids 22 hr after dosing. The distribution of the radioactivity in the fatty acids of the liver and brain lipids was different for each isotope. Most of the(3)H was still associated with linoleic acid, whereas most of the(14)C was in the 20∶3 and 20∶4ω6 fractions. These results suggest that the desaturation of linoleic to γ-linolenic acid in vivo is a rate-limiting step in the conversion of linoleic to arachidonic acid.
TL;DR: The results obtained suggested that the brain lipofuscin employed in the present study consisted mainly of polymeric lipid and phospholipid structures along with amino acids either bound to the lipids or as included proteins.
Abstract: Human brain lipofuscin isolate was studied for its purity and physical and chemical properties. Purification of the impure material was achieved by gel permeation chromatography using Sephadex LH-20 and BioBeads S-X1 gels. The purified lipofuscin polymer represented ca. 12% of the starting material with the rest of the material being various mixed lipids. The mol wt of the purified lipofuscin was determined to be between 6000–7000 daltons. IR, UV-visible, NMR, and fluorometric spectra were obtained, all indicating the fundamentally lipid nature of lipofuscin. The NMR spectrum strongly resembled that of a typical long chain fatty acid. Numbers of fatty acids and several amino acids were present as a portion of the lipofuscin structure. The results obtained suggested that the brain lipofuscin employed in the present study consisted mainly of polymeric lipid and phospholipid structures along with amino acids either bound to the lipids or as included proteins.
TL;DR: An efficient procedure for preparing phytenic acid methyl ester, free of isomers, from phytol is reported, and the applicability of these methods to natural mixtures was demonstrated with wax esters from mosses which contained both types of isoprenoids.
Abstract: An efficient procedure for preparing phytenic acid methyl ester, free of isomers, from phytol is reported. Phytyl phytenate and other isoprenoid wax esters were synthesized. Gas liquid chromatography of these wax esters and other compounds related to phytol and phytenic acid is described. The alkyl constituents of isoprenoid wax esters can be analyzed after alkaline methanolysis and the acyl constituents after acidic methanolysis. The applicability of these methods to natural mixtures was demonstrated with wax esters from mosses which contained both types of isoprenoids and with wax esters from healthy and frost damaged grass which contained phytol, but not phytenic acid.
TL;DR: Linoleic acid hydroperoxide formed by soybean lipoxygenase was metabolized by the same enzyme in the presence of guaiacol to form hydroperoxydihydroxyoctadecenoic acids.
Abstract: Linoleic acid hydroperoxide formed by soybean lipoxygenase was metabolized by the same enzyme in the presence of guaiacol. The products of this reaction included trihydroxyoctadecenoic acids, hydroperoxydihydroxyoctadecenoic acids, hydroxyepoxyoctadecenoic acids, dihydroxyoctadecenoic acids, hydroxyoctadecadienoic acids, and oxooctadecadienoic acids.
TL;DR: The high pressure reverse chromatography resulted in better separations of polyenoic acids than can be accomplished by conventional argentation silicic acid column chromatography.
Abstract: High pressure reverse-phase liquid chromatography has been used to separate saturated fatty acids, their methyl esters, polyunsaturated fatty acids, and triglycerides. Rapid separation of fatty acids differing in chain length and number of double bonds has been accomplished. Analysis time was less than 10 min in most cases. The high pressure reverse chromatography resulted in better separations of polyenoic acids than can be accomplished by conventional argentation silicic acid column chromatography. The analyses were carried out on a chemically bonded reverse phase packing, VYDAC reverse phase.
TL;DR: Nine diets, each containing different levels of linoleic acid and linolenic were fed to duplicate groups of rainbow trout for 14 weeks, and their conversion to more unsaturated fatty acids typical of fish lipids was investigated.
Abstract: Nine diets, each containing different levels of linoleic acid (18∶2ω6) and linolenic (18∶3ω3) were fed to duplicate groups of rainbow trout for 14 weeks. The growth rate, feed efficiency, accumulated mortality, and fatty acid composition of neutral fat and phospholipids of these groups of fish were determined. The growth was slow in the groups of fish receiving diets containing (A) low concentration of 18∶3ω3 and (B) high concentration (5%) of 18∶2ω6. The accumulated mortality was high in these groups of fish. The diet containing 1% 18∶3ω3 alone supported rapid fish growth with low mortality. The feed efficiency of this diet was also high. The metabolism of 18∶2ω6 and 18∶3ω3 in fish and their conversion to more unsaturated fatty acids typical of fish lipids was investigated.
TL;DR: The excitation and emission maxima of the model fluorescent compounds, together with the characteristic reductions in fluorescence intensity caused by alkaline pH or heavy metal coordination, provide criteria with which to examine lipid peroxidation products for the presence of the conjugated Schiff base fluorophore.
Abstract: The fluorescence excitation spectrum of model conjugated Schiff base compounds that arise from the reaction of malonaldehyde with amino acids was shown to contain a maximum at 260–280 nm in addition to the previously observed maximum at 350–390 nm. Excitation at either maximum results in emission at a single maximum at 440–480 nm. The excitation and emission maxima of the model fluorescent compounds, together with the characteristic reductions in fluorescence intensity caused by alkaline pH or heavy metal coordination, provide criteria with which to examine lipid peroxidation products for the presence of the conjugated Schiff base fluorophore. Silicic acid column chromatography and silica gel thin layer chromatography were employed to fractionate the fluorescent products of model lipid peroxidation systems and of rat testicular lipid soluble extracts. These products contained large families of compounds whose fluorescence characteristics were the same as those of the Schiff base floorophores. The fractionation methods used enabled more thorough fluorescence characterization of many of the products of lipid peroxidation, but the fluores-cence criteria available do not provide definitive proof of structure.
TL;DR: Localization of a methyl branch in a fatty acid molecule by mass spectrometry is facilitated by using the pyrrolidide rather than the methyl ester.
Abstract: Localization of a methyl branch in a fatty acid molecule by mass spectrometry is facilitated by using the pyrrolidide rather than the methyl ester. Branched fatty acid methyl esters are converted to pyrrolidides and are than analyzed by gas chromatography and mass spectrometry. The diagnostic fragments indicate position of the methyl branch.
TL;DR: The thiobarbituric acid test for lipid peroxidation, when applied to a mixture of acetaldehyde and sucrose, produces a 532 nm aborbing chromogen which is indistinguishable from that formed by malonaldehyde and thi Barsic acid.
Abstract: The thiobarbituric acid test for lipid peroxidation, when applied to a mixture of acetaldehyde and sucrose, produces a 532 nm aborbing chromogen which is indistinguishable from that formed by malonaldehyde and thiobarbituric acid. Unless special procedures are adopted to correct for this effect, the combined action of acetaldehyde and sucrose interferes seriously with the assay of lipid peroxidation reactions, notably those implicated in alcohol-induced liver injuries. However, this unusual thiobarbituric acid effect also can be used as a sensitive method for the detection of acetaldehyde.
TL;DR: The American oyster,Crassostrea virginica, was found to contain structurally homologous nonmethylene-interrupted dienoic (NMID) fatty acids and a combination of analytical procedures was required for conclusive structure determination.
Abstract: The American oyster, Crassostrea virginica, was found to contain structurally homologous nonmethylene-interrupted dienoic (NMID) fatty acids. The major C20 and C22 nonmethylene-interrupted dienoic fatty acid isomers were shown to occur as two pairs of homologues 5,13-20:2 with 7,15-22:2 and 5,11-20:2 with 7,13-22:2. A combination of analytical procedures was required for conclusive structure determination.
TL;DR: The lack of equilibration of the triacylglycerols among the lipoprotein classes under normal conditions and in choline deficiency demonstrates an as yet unrecognized source of compartmentation of plasma lipids.
Abstract: Three major density classes of lipoproteins and a residual protein (d>1.21) were isolated by ultracentrifugation from plasma of fasted, fed normal, and choline-deficient rats. Lipid extracts were obtained from total plasma and the various density classes of lipoproteins, and each extract was examined in detail by thin layer and gas chromatographies. The results indicated essentially identical compositions of molecular species of phosphatidyl choline, which suggested their rapid equilibration among the different plasma lipoprotein classes. In contrast, the molecular species of the triacylglycerols and cholesteryl esters showed significant differences among the chylomicrons, very low and low, and high density lipoproteins, which excluded the possibility of their ready equilibration in vivo. Omission of choline from diet resulted in a sharp and statistically significant decrease in all lipid components of the very low and low density lipoproteins within 2 days. After 10 days of choline deficiency, the lipid levels of chylomicrons and very low and low density lipoproteins were ca. one-half the levels found in the choline supplemented animals, and there were discernible distortions in their lipid composition. Reintroduction of choline led to a prompt return to normal levels and lipid composition of both chylomicron and very low and low density lipoprotein fractions. The lack of equilibration of the triacylglycerols among the lipoprotein classes under normal conditions and in choline deficiency demonstrates an as yet unrecognized source of compartmentation of plasma lipids.
TL;DR: Individual phospholipid classes derived from hepatoma, host liver, and normal liver of rats maintained on chow and fat free diets were examined in detail and the sphingomyelin and phosphoglyceride structures compared.
Abstract: Individual phospholipid classes derived from hepatoma, host liver, and normal liver of rats maintained on chow and fat free diets were examined in detail and the sphingomyelin and phosphoglyceride structures compared. The concentration of hepatoma sphingomyelin was higher while phosphatidylcholine, phosphatidylethanolamine, phosphatidylinositol, phosphatidylserine, and diphosphatidylglycerol were only one-fourth to one-half normal liver concentrations, irrespective of diet. Hepatoma phosphatidylcholine, phosphatidylethanolamine, phosphatidylserine, and phosphatidylinositol contained higher percentages of 18∶1 and, except phosphatidylinositol, much lower percentages of most polyunsaturated fatty acids than liver. The 1-position of host liver phosphatidylcholine and phosphatidylethanolamine, normal liver phosphatidylcholine and phosphatidylethanolamine, and hepatoma phosphatidylcholine from animals on both diets had the same approximate fatty acid composition, but the percentage of 16∶0 in hepatoma phosphatidylethanolamine was reduced dramatically. The low percentage of 16∶0 at the 1-position of both phosphatidylethanolamine and triglycerides suggests that the 1-position fatty acids of these two classes may have a similar origin. The fat free diet reduced the percentage of 18∶2 in liver diphosphatidylglycerol 3-fold and the decrease was offset by increased percentages of 16∶1 and 18∶1; whereas the very low percentage of 18∶2 in hepatoma diphosphatidylglycerol was offset by increased percentages of 18∶0 and 16∶0. Liver phosphatidylinositol and phosphatidylcholine from the animals fed the fat free diet contained the highest percentage of 20∶3, which replaced 20∶4. Hepatoma sphingomyelin contained a much higher concentration of 24∶0 and 24∶1 than liver. The hepatoma sphingomyelin also contained a C-24 dienoic acid, which was not detected in host and normal liver. Host liver contained a higher percentage of 22∶6 than normal liver. The diglycerides derived from host liver PC contained a significantly higher percentage of carbon number 38 than normal liver. Diglycerides derived from hepatoma phosphatidylcholine and phosphatidylethanolamine exhibited a 1-random-2-random distribution of fatty acids, whereas diglycerides from liver phosphatidylcholine and phosphatidylethanolamine showed pairing of specific fatty acids.
TL;DR: The inverse relationship between lipid droplets and prostaglandin content in the inner medulla suggested a significant role of lipid droplet triglycerides as storage pools for prostaglandsin precursors.
Abstract: Lipid droplets isolated from rabbit renal medullary tissue were analyzed and found to be composed of triglyceride and free fatty acids in a ratio of 2.9∶1. These triglycerides were unique when compared to triglycerides of other rabbit tissues examined, in that they contained high percentages of octadecanoic acid (stearic acid, 9.8%), 5,8,11,14-eicosatetraenoic acid (arachidonic acid, 6.8%), and 7,10,13,16-docosatetraenoic acid (adrenic acid, 10%). Lipid droplet triglycerides were found to increase during experimental hydronephrosis and after administration of indomethacin, a prostaglandin synthetase and phosphodiesterase inhibitor. From gas liquid chromatography of fatty acid methyl esters of these triglycerides, it was determined that they were enriched further in their percent composition of 9,12-octadecadienoic acid (linoleic acid) and arachidonic acid, a prostaglandin precursor. The inverse relationship between lipid droplets and prostaglandin content in the inner medulla suggested a significant role of lipid droplet triglycerides as storage pools for prostaglandin precursors.
TL;DR: From a parent population of 774, a subpopulation of 160 normal adults ages 27–66 was randomly selected, 20 from each decade and sex and the reading procedure allowed the identification and quantification of floating β and sinking pre-β.
Abstract: From a parent population of 774, a subpopulation of 160 normal adults ages 27–66 was randomly selected, 20 from each decade and sex. A detailed comparison was made by analytic ultracentrifugation and complete agarose gel electrophoresis on serum and the 1.006 g/ml top and bottom preparative ultracentrifuge lipoprotein fractions. The latter was internally standardized by total lipid and plasma total cholesterol and triglyceride determinations giving normal reference lipoprotein values. The reading procedure allowed the identification and quantification of floating β and sinking pre-β. In the subpopulation, there were two of the former and 13 of the latter. For large scale clinical application of such quantitative lipoprotein electrophoresis full automation of the microdensitometry and calculations will be required.
TL;DR: It appeared that the hypophysis was involved in the functions of essential fatty acids in liver mitochondria as well as the neutral and phospholipid composition of the normal animals.
Abstract: Studies are reported on the effects of diets containing fatty supplements with (A) a high concentration of arachidonate (46% concentrate of ethyl arachidonate), (B) a high concentration of linoleate (corn oil), and (C) an essential fatty acid deficient, fully saturated fat (hydrogenated coconut oil) upon lipid composition, membrane permeability, and enzyme activities of liver mitochondria of normal and hypophysectomized rats. The fatty supplements produced differences in the fatty acid composition of the liver mitochondria; hypophysectomy, in addition, influenced the neutral and phospholipid composition. Permeability, indicated by swelling properties, correlated generally with the degree of unsaturation and essential fatty acid content of the lipid of the mitochondria of the normal animals. The fatty supplements also influenced the enzyme acitivites of the mitochondria of the normal animals. The mitochondria of the hypophysectomized animals were less responsive to the differences in the dietary fat in both their swelling properties and enzyme activities. Although the relationship was complex, it appeared that the hypophysis was involved in the functions of essential fatty acids in liver mitochondria.
TL;DR: In in vivo experiments, the lymphatic absorption rate of 6 esters, acetate, palmitate, acid succinate, nicotinate, o-hydroxybenzoate, and pivalate, was measured on thoracic duct fistula rats and suggested that hydrolysis of α-tocopheryl esters was not necessarily a prerequisite for intestinal absorption.
Abstract: Twelve d,1-3,4-3H2-α-tocopheryl esters were synthesized from d,1-3,4-3H2-α-tocopherol. They were acetate, propionate, butyrate, isobutyrate, caprylate, palmitate, acid succinate, benzoate, nicotinate, o-hydroxybenzoate, o-acetoxybenzoate, and pivalate. The hydrolysis of these esters with bile-pancreatic juice and with 9,000 × g supernatant of small intestine and liver homogenates of rats was examined. When these esters were incubated in small intestine or liver supernatants, hydrolysis occurred at a similar rate. In the incubation experiments, α-tocopheryl acetate, propionate, butyrate, isobutyrate, caprylate, palmitate, and acid succinate were classified as an easily hydrolyzable group. α-Tocopheryl benzoate and nicotinate were in a moderately hydrolyzable group. o-Hydroxybenzoate and pivalate, which resisted hydrolysis, were in a scarcely hydrolyzable group. o-Acetoxybenzoate was easily hydrolyzed to the o-hydroxybenzoate. Hydrolysis on straight chain fatty acid esters of α-tocopherol easily occurred in bile-pancreatic juice. In in vivo experiments, the lymphatic absorption rate of 6 esters, acetate, palmitate, acid succinate, nicotinate, o-hydroxybenzoate, and pivalate, was measured on thoracic duct fistula rats. Easily hydrolyzable esters were recovered mostly in lymph as α-tocopherol, whereas, an ester which strongly resisted hydrolysis, such as pivalate, appeared mainly unchanged. This fact suggested that hydrolysis of α-tocopheryl esters was not necessarily a prerequisite for intestinal absorption. The percentage of absorption of slowly hydrolyzed esters in lymph was relatively lower than that of moderately or easily hydrolyzable esters.
TL;DR: Rats were fed cholesterol, cacao butter, or olive oil diets to determine the effect of dietary lipids on the rate of drug biotransformation in the liver and duodenum, and lipid diets decreased the activities of drug hydroxylation and glucuronidation.
Abstract: Rats were fed cholesterol, cacao butter, or olive oil diets to determine the effect of dietary lipids on the rate of drug biotransformation in the liver and duodenum. The cholesterol rich diet maintained the hepatic aryl hydrocarbon hydroxylase activity at the same level as did the standard diet. Rats fed olive oil and cacao butter diets showed lower hepatic aryl hydrocarbon hydrorylase activity. The p-nitroanisole 0-demethylase activity was doubled in hepatic microsomes of rats fed the high cholesterol diet when compared to rats fed the standard diet. The hepatic uridine diphosphate glucoronosyltransferase activity showed different patterns depending on the in vitro treatment of the microsomal membranes. If the enzyme activity was assayed from the native, untreated microsomes, an increase in the measurable uridine diphosphate glucuronosyl transferase activity was found in rats having cholesterol rich diet. After the in vitro activation of membrane-bound uridine diphosphate glucuronosyltransferase by trypsin, the increase in measurable activity was 10 fold in the group fed the standard diet, 6 fold in group fed cholesterol, 4 fold in group fed cacao butter, and 3 fold in group fed olive oil. Trypsin digestion of microsomes increased the measurable uridine diphosphate glucuronosyltransferase activity less in rats fed diets rich in neutral fats than those fed the standard diet. In the duodenal mucosa, lipid diets decreased the activities of drug hydroxylation and glucuronidation.
TL;DR: Initial oxidation of linolenate and sparing of the linolenic acid complexed with polar lipids are discussed, and radioactivity was found neither in 18∶3 nor its endproduct, 22∶6, and palmitate was the most highly radioactive component.
Abstract: Twelve-thirteen day old rats were given 1-(14)C linolenic acid by intraperitoneal injection. Fatty acids were isolated from the brains of animals sacrificed at the end of 8 and 48 hr and 15 and 45 days. Eight hr after the tracer, radioactivity was found neither in 18∶3 nor its endproduct, 22∶6, and palmitate was the most highly radioactive component. At longer intervals, 22∶6 seemed to retain much of the radioactivity, whereas palmitate showed a precipitous decline in radioactivity. Initial oxidation of linolenate and sparing of the linolenate complexed with polar lipids are discussed.
TL;DR: The mass spectra oft-butyldimethylsilyl fatty acid esters all display a pronounced (M−C4H9)+ ion, and the proportion of the total ionization carried by this fragment facilitates their qualitative analysis at the subanogram level by mass fragmentography.
Abstract: The mass spectra oft-butyldimethylsilyl fatty acid esters all display a pronounced (M−C4H9)+ ion. The proportion of the total ionization carried by this fragment, particularly for saturated and mono-, di-, and tri-unsaturated acid derivatives, facilitates their qualitative analysis at the subanogram level by mass fragmentography.