EFFECTS OF DIET ON INCORPORATION OF ACETATE-1-C14 INTO CHOLESTEROL BY RAT LIVER SLICES

1960 ◽  
Vol 38 (7) ◽  
pp. 649-656 ◽  
Author(s):  
K. K. Carroll
Keyword(s):  
Fatty Acids ◽  
Oleic Acid ◽  
Rat Liver ◽  
Liver Cholesterol ◽  
Chow Diet ◽  
Acetate Incorporation ◽  
Test Diet ◽  
Semisynthetic Diet ◽  
Liver Slices ◽  
Fat Soluble Vitamins

The rate of incorporation of acetate-1-C14 into cholesterol by rat liver slices decreased when animals were transferred from a commercial chow diet to semisynthetic diets. A greater decrease was observed when the test diet contained oleic acid or olive oil than when it contained higher homologues of oleic acid, or preparations of cerebrosides. The decrease was not affected by the presence or absence of fat-soluble vitamins in the test diet containing oleic acid. Amphenone B affected acetate incorporation into liver cholesterol differently depending on whether it was fed in a chow diet or a semisynthetic diet. The incorporation of acetate into liver fatty acids of rats fed various diets usually increased or decreased with incorporation into cholesterol but differences between groups were less marked. Incorporation of acetate into cholesterol by intestinal mucosa was relatively insensitive to changes in diet.

EFFECTS OF DIET ON INCORPORATION OF ACETATE-1-C14 INTO CHOLESTEROL BY RAT LIVER SLICES

1960 ◽  
Vol 38 (1) ◽  
pp. 649-656
Author(s):  
K. K. Carroll
Keyword(s):  
Fatty Acids ◽  
Oleic Acid ◽  
Rat Liver ◽  
Liver Cholesterol ◽  
Chow Diet ◽  
Acetate Incorporation ◽  
Test Diet ◽  
Semisynthetic Diet ◽  
Liver Slices ◽  
Fat Soluble Vitamins

The rate of incorporation of acetate-1-C14 into cholesterol by rat liver slices decreased when animals were transferred from a commercial chow diet to semisynthetic diets. A greater decrease was observed when the test diet contained oleic acid or olive oil than when it contained higher homologues of oleic acid, or preparations of cerebrosides. The decrease was not affected by the presence or absence of fat-soluble vitamins in the test diet containing oleic acid. Amphenone B affected acetate incorporation into liver cholesterol differently depending on whether it was fed in a chow diet or a semisynthetic diet. The incorporation of acetate into liver fatty acids of rats fed various diets usually increased or decreased with incorporation into cholesterol but differences between groups were less marked. Incorporation of acetate into cholesterol by intestinal mucosa was relatively insensitive to changes in diet.

ACETATE INCORPORATION INTO CHOLESTEROL AND FATTY ACIDS BY LIVERS OF FETAL, SUCKLING, AND WEANED RATS

1964 ◽  
Vol 42 (1) ◽  
pp. 79-86 ◽  
Author(s):  
K. K. Carroll
Keyword(s):  
Fatty Acids ◽  
Mevalonic Acid ◽  
Liver Cholesterol ◽  
Acetate Incorporation ◽  
Suckling Rats ◽  
Commercial Diet ◽  
Liver Slices ◽  
Fetal Rats ◽  
Liver Homogenates ◽  
Intact Rats

Liver homogenates from fetal rats gave good incorporation of labelled acetate into cholesterol and fatty acids, but liver slices or homogenates from suckling rats gave very little incorporation. The amount of acetate incorporated increased greatly as soon as the suckling rats began to eat a commercial diet. Mevalonic acid was incorporated into cholesterol equally well by liver slices from suckling and weaned rats. Acetate given orally or intraperitoneally to intact rats was incorporated into liver cholesterol and fatty acids to a lesser extent in suckling rats than in rats weaned to a commercial diet. Plasma cholesterols were elevated in suckling rats and dropped to normal adult levels at weaning. Liver cholesterols tended to be slightly higher in suckling rats.

Effect of saturated fat diets on rat liver NADP-linked enzymes

1965 ◽  
Vol 209 (4) ◽  
pp. 773-780 ◽  
Author(s):  
Helen M. Tepperman ◽  
Jay Tepperman
Keyword(s):  
Fatty Acids ◽  
Enzyme Activity ◽  
Rat Liver ◽  
Corn Oil ◽  
Saturated Fat ◽  
Coconut Oil ◽  
Liver Slices ◽  
Fat Diets ◽  
Effect Of Feeding

The aggregate hexosemonophosphate dehydrogenase (HMPD) activity was found to be higher in livers of rats fed a diet containing saturated fat (hydrogenated coconut oil = H) for 7 days and fasted for 48 hr than it was in similarly prepared animals fed a corn oil (CO) diet. Later, a liver HMPD-increasing effect of feeding H was found in nonfasted animals. Lipogenesis (i.e., the incorporation of acetate-1-C14 into fatty acids by liver slices) was shown to be as low or lower in the H group as in the CO. Liver slices prepared from H and CO diet adapted rats were incubated with either acetate-1-C14 or palmitate-1-C14 and the extent of incorporation of C14 into individual fatty acids was measured. With both substrates more radioactivity was found in 16:1, 18:0, and 18:1 in the case of H-fed animals. It is proposed that a component of the signal for eliciting increased NADP-linked enzyme activity in the H rats was an increased rate of oxidation of NADPH attendant on monoene formation and chain lengthening.

EFFECTS OF HYPOGLYCIN A ON THE METABOLISM OF AMINO ACIDS BY LIVER SLICES

1964 ◽  
Vol 42 (1) ◽  
pp. 139-142 ◽  
Author(s):  
S. J. Patrick ◽  
L. C. Stewart
Keyword(s):  
Amino Acids ◽  
Fatty Acids ◽  
Fatty Acid ◽  
Glutamic Acid ◽  
Rat Liver ◽  
Inhibitory Effects ◽  
Liver Slices

The effects of hypoglycin A on the metabolism of L-leucine-C14, L-alanine-C14, and L-glutamic-acid-C14 by rat liver slices have been investigated. Hypoglycin exerted markedly inhibitory effects on the conversion of leucine-C14 to fatty acid, cholesterol, and CO2. Conversion of alanine-C14 and glutamic acid-C14 to fatty acids was also inhibited by hypoglycin. No effects of hypoglycin on the conversion of C14-amino acids into protein or glycogen were demonstrated.

scholarly journals High rates of [1-14C]acetate incorporation into the lipid of isolated spinach chloroplasts

1976 ◽  
Vol 158 (3) ◽  
pp. 593-601 ◽  
Author(s):  
P G Roughan ◽  
C R Slack ◽  
R Holland
Keyword(s):  
Fatty Acids ◽  
Oleic Acid ◽  
Fatty Acid ◽  
Palmitic Acid ◽  
Free Fatty Acids ◽  
Acid Synthesis ◽  
Polar Lipids ◽  
Acetate Incorporation ◽  
Spinach Chloroplasts ◽  
Triton X

Spinach chloroplasts, isolated by techniques yielding preparations with high O2- evolving activity, showed rates of light-dependent acetate incorporation into lipids 3-4 fold higher than any previously reported. Incorporation rates as high as 500 nmol of acetate/h per mg of chlorophyll were measured in buffered sorbitol solutions containing only NaHCO3 and [1-14C]acetate, and as high as 800 nmol/h per mg of chlorophyll when 0.13 mM-Triton X-100 was also included in the reaction media. The fatty acids synthesized were predominantly oleic (70-80% of the total fatty acid radioactivity) and palmitic (20-25%) with only minor amounts (1-5%) of linoleic acid. Linolenic acid synthesis was not detected in the system in vitro. Free fatty acids accounted for 70-90% of the radioactivity incorporated and the remainder was shared fairly evenly between 1,2-diacylglycerols and polar lipids. Oleic acid constituted 80-90% of the free fatty acids synthesized, but the diacylglycerols and polar lipids contained slightly more palmitic acid than oleic acid. Triton X-100 stimulated the synthesis of diacylglycerols 3-6 fold, but stimulated free fatty acid synthesis only 1-1.5-fold. Added glycerol 1-phosphate stimulated both the synthesis of diacylglycerols and palmitic acid relative to oleic acid, but did not increase acetate incorporation into total chloroplast lipids. CoA and ATP, when added separately, stimulated acetate incorporation into chloroplast lipids to variable extents and had no effect on the types of lipid synthesized, but when added together resulted in 34% of the incorporated acetate appearing in long-chain acyl-CoA. Pyruvate was a much less effective precursor of chloroplast fatty acids than was acetate.

THE EFFECTS OF SOME DIETARY DERIVED LIPIDS AND FAT SOLUBLE VITAMINS ON RAT SERUM TRIBUTYRINASE AND ALKALINE PHOSPHATASE

1952 ◽  
Vol 30 (4) ◽  
pp. 308-313
Author(s):  
Jack D. Taylor ◽  
Neil B. Madsen ◽  
Jules Tuba
Keyword(s):  
Fatty Acids ◽  
Alkaline Phosphatase ◽  
Oleic Acid ◽  
Stearic Acid ◽  
Serum Alkaline Phosphatase ◽  
Adult Rats ◽  
Rat Serum ◽  
Low Levels ◽  
Fat Soluble Vitamins ◽  
Increased Activity

Synthetic diets were fed to adult rats for four weeks to determine the effects of dietary stearic acid, oleic acid, glycerol, Crisco, and vitamins, A, D, and E on the activity of serum alkaline phosphatase and serum tributyrinase. On a diet devoid of fats or fatty acids, the rats manifested abnormally low enzyme levels, which for serum alkaline phosphatase fell to values characteristic of starvation. Basal levels of the two enzymes, obtained with a fat free diet, were not altered by the ingestion of glycerol or vitamins A, D, and E. Dietary stearic acid, oleic acid, and Crisco, each significantly increased activity of phosphatase and tributyrinase and it would appear that both enzymes are concerned with intestinal absorption of fatty acids. The effect of oleic acid was most pronounced with both enzymes. The rats all gained weight during the tests so none of the variations in enzyme levels can be attributed to inanition. After the dietary test periods, all groups were starved for one week. Serum phosphatase values fell to the same constant low levels for all animals. Tributyrinase values rose towards levels which suggest that the enzyme is concerned with mobilization of depot fats during periods of fasting.

EFFECT OF ERUCIC ACID ON INCORPORATION OF ACETATE-1-C14 INTO CHOLESTEROL AND FATTY ACIDS

1959 ◽  
Vol 37 (7) ◽  
pp. 803-810 ◽  
Author(s):  
K. K. Carroll
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Erucic Acid ◽  
Cholesterol Metabolism ◽  
Young Male ◽  
Male Rats ◽  
Acetate Incorporation ◽  
Acid Incorporation ◽  
Liver Slices ◽  
Fatty Acid Incorporation

Young male rats were fed synthetic diets containing either no fat or various individual fatty acids for 3 to 4 weeks. They were then killed and the incorporation of acetate-1-C14 into cholesterol and fatty acids was measured in liver slices and in scrapings of intestinal mucosa. Acetate incorporation into cholesterol by liver slices was much greater in animals fed erucic acid than in those fed no fat, palmitic, stearic, oleic, or linoleic acids. A marked differential was not observed in fatty acid incorporation but values tended to be higher on the fat-free and erucic acid diets. Erucic acid did not stimulate acetate incorporation into cholesterol by mucosa and in general mucosa seemed to be less sensitive to changes in diet. The results are discussed in relation to previously observed effects of erucic acid on cholesterol metabolism.

scholarly journals The sensitivity of acetyl-coenzyme A carboxylase to citrate stimulation in a homogenate of rat liver containing subcellular particles

1970 ◽  
Vol 117 (2) ◽  
pp. 385-395 ◽  
Author(s):  
Jill Iliffe ◽  
N. B. Myant
Keyword(s):  
Fatty Acids ◽  
Rat Liver ◽  
Specific Radioactivity ◽  
Acid Synthesis ◽  
Acetate Incorporation ◽  
Acetyl Coa Carboxylase ◽  
Acetyl Coa ◽  
Carboxylase Activity ◽  
Highly Sensitive ◽  
Activated State

1. Although citrate is known to activate purified preparations of acetyl-CoA carboxylase, it had no stimulatory effect on the incorporation of [14C]acetate into long-chain fatty acids in a whole homogenate of rat liver (S0.7) under conditions in which the activity of acetyl-CoA carboxylase was rate-limiting for fatty acid synthesis. 2. The rate of incorporation of acetyl carbon into fatty acids was estimated in S0.7 preparations incubated with [14C]acetate, by measuring the specific radioactivity of the acetyl carbon of acetyl-CoA and the incorporation of 14C into fatty acids. These estimates were compared with estimates of acetyl-CoA carboxylase activity in the S0.7 preparation obtained by direct assay in conditions in which the enzyme was in the fully activated state. 3. In the absence of citrate, incorporation of acetyl carbon into fatty acids was about 75% of the value expected if the acetyl-CoA carboxylase in the S0.7 preparation were in the fully activated state. 4. Incorporation of acetyl carbon into fatty acids in the S0.7 preparation was stimulated by citrate, but the effect was many times less than the stimulation of [14C]acetate incorporation by citrate in particle-free preparations. 5. When the mitochondria and microsomes were removed from the S0.7 preparation, [14C]acetate incorporation into fatty acids fell to a negligible value and the preparation became highly sensitive to stimulation by citrate. 6. It is suggested that in the presence of mitochondria and microsomes, and in the intact liver cell, the degree of activation of acetyl-CoA carboxylase is such that citrate activation may not be of physiological significance.

Effect of Adrenalectomy on the Incorporation of Acetate Into Fatty Acids, Cholesterol and Acetoacetic Acid by Rat Liver Slices

1955 ◽  
Vol 184 (1) ◽  
pp. 59-62 ◽  
Author(s):  
W. F. Perry ◽  
Helen F. Bowen
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Rat Liver ◽  
Acid Formation ◽  
Acetoacetic Acid ◽  
Adrenalectomized Animal ◽  
Liver Slices ◽  
Adrenalectomized Rats

The incorporation of C14 acetate into fatty acids, cholesterol, acetoacetic acid and CO2 by liver slices of intact and adrenalectomized rats was studied, the slices being incubated in bicarbonate and phosphate buffers. It was found that in both buffer systems incorporation into fatty acids and cholesterol was depressed while incorporation into acetoacetic acid was unaffected by adrenalectomy. However, total acetoacetic acid formation by the slices tended to be higher in preparations from adrenalectomized animals. The amount of acetate carbon appearing as CO2 was similar with slices from both types of animals. Bicarbonate was found to be a more favorable medium than PO4 for fatty acid formation, while PO4 was the more favorable medium for cholesterogenesis, though the differences between adrenalectomized and intact animals persisted in either buffer. Forced feeding with glucose increased the incorporation of acetate into fat and cholesterol in both buffer systems in adrenalectomized as well as in intact animals. However, the adrenalectomized preparation still incorporated acetate to a lesser extent than the controls. It was concluded that while the depressed incorporation of acetate into fatty acid and cholesterol by adrenalectomized liver slices was consistent with a depressed synthesis of these lipids, there was also the possibility that it reflected an increased turnover of lipids in the liver of the adrenalectomized animal.

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