ACETATE INCORPORATION INTO CHOLESTEROL AND FATTY ACIDS BY LIVER SLICES FROM RATS FED COMMERCIAL OR SEMISYNTHETIC DIETS: THE EFFECT OF DIETARY FATS

1964 ◽  
Vol 42 (1) ◽  
pp. 71-78 ◽  
Author(s):  
K. K. Carroll
Keyword(s):  
Fatty Acids ◽  
Mevalonic Acid ◽  
Dietary Fats ◽  
Acetate Incorporation ◽  
Commercial Diet ◽  
Rate Limiting Step ◽  
Liver Slices ◽  
Cholesterol Biosynthetic Pathway ◽  
Rate Limiting ◽  
Insoluble Portion

Liver slices from rats fed a commercial diet incorporated more acetate-1-C14 into cholesterol than did slices from rats fed semisynthetic diets. The stimulatory effect of the commercial diet was due in part to a saponifiable component of the ether-soluble portion of the diet, possibly linoleic acid; and in part to the ether-insoluble portion of the diet. Dietary fats stimulated acetate incorporation into cholesterol more when mixed with the ether-insoluble portion of commercial diet than when mixed with semisynthetic diet. With either diet, unsaturated fats stimulated incorporation more than saturated fats. The rate-limiting step in these experiments was prior to mevalonic acid in the cholesterol biosynthetic pathway. Acetate incorporation into fatty acids was little affected by the nature of the dietary fat or the diet in which it was fed.

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 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.

Metabolic development and mitochondrial changes during cyclopiazonic acid production in Penicillium cyclopium

1977 ◽  
Vol 23 (7) ◽  
pp. 856-872 ◽  
Author(s):  
Dianne C. Neethling ◽  
Robert M. McGrath
Keyword(s):  
Secondary Metabolism ◽  
Mevalonic Acid ◽  
Cyclopiazonic Acid ◽  
Electron Microscopic Examination ◽  
Electron Microscopic ◽  
Rate Limiting Step ◽  
Penicillium Cyclopium ◽  
Intermediate Time ◽  
Atp Generation ◽  
Rate Limiting

During a study of cyclopiazonic acid (total α- and β-cyclopiazonic acids, CA) production by Penicillium cyclopium Westling, it was found that nitrogen depletion controlled the advent of secondary metabolism and that nitrate reduction was not rate-limiting. In concert with N depletion both tryptophan (Trp) biosynthesis and glucose catabolism fell. The rate of Trp production dropped to match the rate of CA biosynthesis. Glucose utilization varied between an early and late preference for the pentose cycle, with a mixture of pentose and Emden–Meyerhof pathways at an intermediate time. This pattern may well reflect the need for erythrose-4-phosphate in Trp biosynthesis. Additions of Trp caused a drop in CA production possibly because of repression of Trp synthetase. Exogeneous dimethylallylpyrophosphate (DMAPP) increased CA biosynthesis, while mevalonic acid had no effect which suggested a rate-limiting step between these two metabolites. These changes probably best fit Bu'Lock's hypothesis that secondary metabolism links fermentative and aerobic metabolism (ATP generation). In this case protein and polyisoprenoid biosynthesis, sugar utilization, and energy requirements would all be interlocked with the advent of secondary metabolism. The possible relationship between the observed metabolic changes and energy control were supported by electron-microscopic examination of the mitochondria in situ, when these ATP-generating organelles underwent major changes. Addition of ATP to the culture depressed CA production, as did excessive aeration. The metabolic regulator cAMP had no effect other than to increase autocatalysis.

In Vitro Metabolism of Fatty Acids by Adipose and Liver Tissue of the Adrenalectomized Rat

1957 ◽  
Vol 189 (3) ◽  
pp. 433-436 ◽  
Author(s):  
W. F. Perry ◽  
Helen F. Bowen
Keyword(s):  
Fatty Acids ◽  
Adipose Tissue ◽  
Octanoic Acid ◽  
Normal Liver ◽  
Liver Slice ◽  
Acetate Incorporation ◽  
Slice Preparation ◽  
Progressive Loss ◽  
Liver Slices

The utilization of acetate and octanoate by adipose tissue from rats 1 and 2 weeks postadrenalectomy has been studied. In addition, acetate incorporation into liver fatty acids and ketogenesis by liver slices from 2-week postoperative animals has been measured. Adrenalectomy resulted in a progressive loss of fat from adipose tissue. At 1-week postadrenalectomy the incorporation of acetate into fatty acids by adipose tissue did not differ from the control preparations but was much increased 2 weeks after adrenalectomy. At this time there was no increase in utilization of added octanoic acid by the adipose tissue and neither at 1 nor at 2 weeks was the production of CO2 from either acetate or octanoic significantly different from normal. Liver slices from 2-week adrenalectomized animals had a markedly defective ability to incorporate acetate into liver fatty acids similar to that previously noted in 1-week animals. However, liver slice preparation from 2-week adrenalectomized rats showed increased ketone body formation, indicating increased fatty acid utilization by the liver. It is suggested that there is a gradual mobilization of fat from the depots to the liver in the adrenalectomized rat with increased utilization of fat by the liver.

The effects of tunicamycin, mevinolin and mevalonic acid on HMG-CoA reductase activity and nuclear division in the myxomycete Physarum polycephalum

1989 ◽  
Vol 92 (3) ◽  
pp. 341-344
Author(s):  
W. Engstrom ◽  
O. Larsson ◽  
W. Sachsenmaier
Keyword(s):  
Physarum Polycephalum ◽  
Nuclear Division ◽  
Reductase Activity ◽  
Mevalonic Acid ◽  
Minor Effect ◽  
Hmg Coa Reductase ◽  
Rate Limiting Step ◽  
Coa Reductase ◽  
A Minor ◽  
Rate Limiting

The effects of two inhibitors of 3-hydroxy 3-methyl glutaryl-coenzyme A reductase (tunicamycin and mevinolin) on nuclear division in the myxomycete Physarum polycephalum were examined. Tunicamycin exerted a minor effect on division in synchronized cultures, whereas mevinolin delayed the second, third and fourth nuclear divisions with increasing efficiency. Mevinolin also appeared to be the more potent inhibitor of HMG-CoA reductase, which catalyses the rate-limiting step in the biosynthesis of cholesterol and other isoprene derivatives. These effects of mevinolin could be partially reversed by the addition of mevalonate, suggesting that mevinolin exerts its inhibitory effects on Physarum nuclear division by decreasing the activity of HMG-CoA reductase.

Anaerobic batch degradation of solid poultry slaughterhouse waste

2000 ◽  
Vol 41 (3) ◽  
pp. 33-41 ◽  
Author(s):  
E. Salminen ◽  
J. Rintala ◽  
L.Ya. Lokshina ◽  
V.A. Vavilin
Keyword(s):  
Fatty Acids ◽  
Methane Production ◽  
Long Chain Fatty Acids ◽  
Rate Limiting Step ◽  
Limiting Step ◽  
Propionate Degradation ◽  
Waste Degradation ◽  
New Generation ◽  
Rate Limiting ◽  
Long Chain

We studied anaerobic batch degradation of solid poultry slaughterhouse wastes with different initial waste and inoculum concentrations and waste-to-inoculum ratios and simulated the dynamics of the process with a new generation <METHANE> model. Our modelling results suggest that inhibited propionate degradation by long-chain fatty acids (LCFA) and inhibited hydrolysis by a high propionate concentration constituted the rate-limiting step in the waste degradation. Palmitate was the most abundant LCFA in the assays. Within 27 days of incubation, up to 0.55 to 0.67 m3 of methane (STP)/kg VS added was produced under the studied conditions. Lower waste-to-inoculum ratios exhibited a faster onset and rate of specific methane production. In all the assays, ammonification occurred within 3 to 6 days and accounted for 50 to 60% of total nitrogen.

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.

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

1959 ◽  
Vol 37 (1) ◽  
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.

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