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R Wood

Publications and source records attributed to R Wood.

At least 217 records · Page 12Linked to original sources
PubMed1977

Incorporation of dietary cis and trans isomers of octadecenoate in lipid classes of liver and hepatoma.

Groups of rats bearing Morris minimal deviation hepatoma 7288CTC were fed a fat-free diet supplemented with either 0.5% safflower oil (diet A), 15% safflower oil or free acids (diets Band C), or 15% safflower oil or free safflower fatty acids (diet D) for 4 weeks. A group of normal rats was also fed diet D. Triglycerides, cholesteryl esters, phosphatidylcholines, and phosphatidylethanolamines isolated from livers and hepatomas of animals on each diet were analyzed quantitatively for positional isomers in the cis- and trans-octadecenoate fractions. When sufficient samples could be obtained, the cis- and trans-hexadecenoate fractions were also analyzed. Plasma from normal rats on diet D was analyzed in the same manner. The octadecenoate fractions of all hepatoma and liver lipid classes from animals fed diets A, B, and C were greater than 95% the cis isomers. Trans isomers accounted for approximately 15, 30, 50, and 70% of the octadecenoate fractions isolated from liver triglycerides, cholesteryl esters, phosphatidylcholines, and phosphatidylethanolamines, respectively, of animals fed diet D. In contrast, all hepatoma lipid classes from animals on diet D contained the same approximate percentage of trans isomers (15 to 20%). Oleic and vaccenic acids were the major positional cis-octadecenoate isomers of all liver and hepatoma lipid classes from animals fed diets A, B, and C. The ratios of oleic to vaccenic, unaffected by diets A, B, and C, differed for each lipid class in liver, but the ratios were similar for the two hepatoma neutral lipid classes and for the two phospholipid classes. The cis-octadecenoate fractions from all liver and hepatoma lipid classes of animals fed diet D consisted predominantly of the delta9, delta11, and delta12 isomers. The cis delta10 isomer, which was a major isomer of the diet, was almost excluded from liver, hepatoma, and plasma lipids. The positional isomers of the trans-octadecenoate fractions from liver and hepatoma triglycerides and cholesteryl esters exhibited the same approximate distribution as the trans fatty acids of diet D. In contrast, the 10-trans-octadecenoate, like 10-cis-octadecenoate, was almost excluded from the phospholipids of liver and plasma. Unlike liver, the hepatoma phospholipids contained 10-trans-octadecenoate at approximately half the percentage of neutral lipids. Because diet D contained no hexadecenoic fatty acids, the occurrence of trans-hexadecenoate isomers in liver and plasma lipids indicated a chain shortening process. Predominance of the 8-trans-hexadecenoate isomer indicated a preference of the 10-trans-octadecenoate isomer for chain shortening.

Animals↗
PubMed1977

Lipids of cultured hepatoma cells: VIII. Utilization of D-[1-14C] glucose for lipid biosynthesis.

Minimal deviation hepatoma 7288C cells (HTC) were incubated in serum-supplemented and serum-free Swim's 77 medium in the presence of D-[1-14C] glucose for 1, 2, 4, 8, 12 and 24 hr. Glucose oxidation to CO2, incorporation into total cell mass, and incorporation into cell and medium lipids were determined. The percentage distribution of total cell lipid radioactivity in individual neutral and polar lipid classes was followed as a function of time. Degradation studies of individual lipid classes were performed to ascertain the percentage of radioactivity in acyl and glycerol moieties. The percentage of D-[1-14C] glucose oxidized to 14CO2, incorporated into cell matter and cell lipids was elevated in cells incubated in serum-free medium as opposed to serum-supplemented medium. The percentage distribution of total cell lipid radioactivity into individual neutral lipid classes from both serum-free and serum-supplemented cultures was as follows: sterols greater than triglycerides greater than free fatty acids greater than sterol esters. The percentage distribution of total cell lipid radioactivity into individual polar lipid classes of serum-supplemented cultures was as follows: phosphatidylcholine greater than phosphatidylinositol greater than sphingomyelin greater than phosphatidylethanolamine greater than phosphatidylserine. The distribution of glucose radiolabel into individual polar lipid classes of serum-free HTC cells was different from their serum-supplemented counterparts: sphingomyelin greater than phosphatidylcholine greater than phosphatidylinositol greater than phosphatidylethanolamine greater than phosphatidylserine. Glycerol from glyceride classes contained a higher percentage of radioactivity than the acyl moieties, with this percentage significantly elevated in serum-free cultures. The data indicate that, although glucose is a substrate for HTC cell lipids, other precursors present in the culture system also contribute to the lipid constituency of this hepatoma cell line.

Blood↗
PubMed1976

Oleic and vaccenic acid levels in lipid clases of tumors.

The isomeric octadecenoate composition of triglyceride, phosphatidyicholine, and phosphatidylethanolamine classes from a variety of rat and mouse tumors was examined. Phosphatidylethanolamine from the tumors contained a higher percentage of octadecenoate than reported for many normal tissues. The octadecenoate fractions of the three lipid classes from various tumors consisted of ca. 75% or greater oleate, with vaccenate making up the balance. These data indicate that the loss of lipid class specificity for isomeric octadecenoates reported in hepatomas (Lipids 10:746, 1975, and Lipids 9:987, 1974) also occurs in other tumors.

Animals↗
PubMed1975

Hepatoma, host liver, and normal rat liver phospholipids as affected by diet.

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 spingomyelin 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, phosphatidyl-serine, 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.

Animals↗
PubMed1975

Hepatoma, host liver, and normal rat liver lipids: distribution of isomeric monoene fatty acids in individual lipid classes.

Monoenoic acid fractions were isolated from phosphatidycholine, phosphatidylethanolamine, triglycerides, and cholesteryl esters of hepatoma 7288CTC, host liver, and normal liver from animals maintained on chow and fat free diets. Hexadecanoate (16:1), octadecenoate (18:1), and eisosenoate (20:1) fractions were analyzed quantitatively for their isomeric composition. The fat free diet had little or no effect relative to the chow diet on the isomeric composition of 16:1, 18:1, and 20:1 from any lipid class in either heptoma, host liver, or normal liver. Host livers were reduced in palmitoleic acid, and oleic and eicos-11-enoic acids were increased relative to normal liver. The 16:1 fraction from triglyceride of normal liver, host liver, and hepatoma contained 90, 80, and 75% palmitoleic acid, respectively. The 20:1 fraction from triglycerides of normal liver, host liver, and hepatoma contained ca. 55, 70, and 60% eicos-11-enoic acid, respectively, with the remainder consisting of eicos-13-enoic acid. The proportion of vaccenic acid in the 18:1 fraction was 60, 50, 20, and 25% for phosphatidylethanolamine, phosphatidylcholine, triglycerides, and cholesteryl esters, respectively, with oleic acid making up the balance. In contrast, all hepatoma lipid classes exhibited the same proportion of oleic (70%) and vaccenic (30%) acids. These data appear to be the first to demonstrate lipid class specificity for isomeric octadecenoic acids in normal liver and the loss of this specificity in a neoplasm.

Carcinoma, Hepatocellular↗
PubMed1975

Lipids of cultured hepatoma cells: VII. Structural analyses of glycerolipids in minimal deviation hepatoma 7288C.

Phosphatidylcholine. phosphatidylethanolamine, and triglycerides were isolated from minimal deviation hepatoma 7288C cells cultured as monolayers to confluency in roller flasks containing Swim's 77 medium supplemented with 5% fetal calf serum, plus 20%, 10%, or 5% bovine serum. Fatty acid distribution at each position of glycerol was determined for the 3 glycerolipid classes, and carbon number distributions of triglycerides and diglycerides derived from phosphatidylcholine and phosphatidylethanolamine were quantitated by high temperature gas liquid chromatography. Fatty acid composition was only marginally affected by the level of bovine serum in the culture medium. Percentage composition of fatty acids esterified at each position of the 3 glycerolipids was different, indicating a nonrandom distribution of acyl groups in triglycerides and the 2 diacyl phosphatides. The carbon number distribution of diglycerides derived from phosphatidylcholine and phosphatidylethanolamine was different, and neither carbon number distribution agreed with the calculated 1-random, 2-random diacyl distribution, thus indicating pairing of certain acids in the diglycerides derived from these phospholipd classes. The determined triglyceride carbon number distributions did not show complete agreement with those calculated, assuming a 1-random, 2-random, 3-random type of fatty acyl distribution, suggesting preferential pairing of some acids in this lipid class. The 1-, 2-diglycerides derived from phosphatidylcholine, phosphatidylethanolamine, and triglycerides differed, indicating either selectivity in utilization of diglyceride species in biosynthesis of these glycerolipids, or modification of glycerolipids after their initial synthesis.

Carcinoma, Hepatocellular↗
PubMed1975

Sterospecific analysis of hepatoma, host liver, and normal rat liver triglycerides from animals on chow and fat free diets.

Triglycerides from normal liver, host liver, and heptoma of rats maintained on chow and fat-free diets were subjected to sterospecific analysis. Normal and host liver triglycerides from animals on the same diet did not exhibit significant differences. Fat-free diet reduced polyunsaturated fatty acids in normal and in host liver triglycerides. Each position of hepatoma and liver triglyceride glycerol exhibited a characteristic fatty acid composition. Palmitate concentrations were reduced dramatically and stearate levels were increased significantly at the 1 position of hepatoma triglycerides, relative to the corresponding position of liver triglycerides which were affected little by diet ot tumor. Except for higher percentages of C-20 and higher fatty acids, common to all three positions, the composition of hepatoma triglycerides at the 2 position appeared normal. The 3 position of hepatoma triglycerides contained significantly higher percentages of stearate than liver. Data obtained previously for Ehrlich ascites cell triglycerides were in good agreement with this hepatoma. Data from these two neoplasms suggest that the metabolic system that regulates or controls the fatty acid composition at the 1 and 3 positions of normal tissue triglycerides does not function normally in neoplasms.

Animals↗
PubMed1975

Lipids of cultured hepatoma cells. VI. Glycerolipid and monoenoic fatty acid biosynthesis in minimal deviation hepatoma 7288C-1.

1-14C-Acetic, 1-14C-palmitic, or 1-14C-stearic acid was incubated with minimal deviation hepatoma 7288C cells grown in culture to assess: de novo fatty acid synthesis, oxidation, desaturation, and elongation of saturated fatty acids, as well as the ability of media fatty acids to serve as precursors of cellular glycerolipids. Distribution of radioactivity in the individual lipid classes and the various fatty acids of triglyceride, phosphatidyl choline, and phosphatidyl ethanolamine was determined. The radioactivity among the monoenoic acid isomers derived from triglyceride, phosphatidyl choline, and phosphatidyl ethanolamine was analyzed by reductive ozonolysis. Only small amounts of the labeled substrates were oxidized to carbon dioxide. Except for labeled stearic acid, which also was incorporated heavily into phosphatidyl inositol and phosphatidyl serine, most radioactivity was recovered in triglyceride, phosphatidyl choline, and phosphatidyl ethanolamine. Synthesis of cholesterol and long chain fatty acids from labeled acetic acid demonstrated that these cells can perform de novo synthesis of fatty acids and cholesterol. Both labeled palmitic and stearic acids were desaturated to the corresponding delta9 monoenes, and palmitic and palmitoleic acids were elongated. The nexadecenoic acid fraction isolated from triglyceride, phosphatidyl choline, and phosphatidyl ethanolamine, when acetic or palmitic acid was the labeled substrate, showed that greater than 70 percent of the labeled acids were the delta9 isomer. Radioactivity of the octadecenoic acid fraction derived from labeled acetic or palmitic acids was nearly equally divided between the delta9 isomer, oleic acid, and the delta11 isomer, vaccenic acid. Desaturation of labeled stearic acid produced only oleic acid. These data demonstrate that the biosynthesis of vaccenic acid in these cultured neoplastic cells proceeds via the elongation of palmitoleic acid. The relatively high level of vaccenic acid synthesis in these cells suggests that the reported elevation of "oleic acid" in many neoplasms may result from increased concentration of vaccenic acid.

Acetates↗
PubMed1975

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.

Animals↗