Effect of carbon tetrachloride ingestion on liver and plasma triglyceride turnover rates

The half-life times of plasma phospholipid and nonphospholipid fatty acids were determined in postabsorptive dogs using C14-carboxyl-labeled palmitic acid. Labeled plasma lipids were introduced into the blood of a recipient dog by cross-circulation with a donor dog that had been fed the radioactive palmitic acid 24 hours previously. Blood samples were taken at various time intervals after the cross-circulation was completed. When the specific activity of the nonphospholipid fatty acids was plotted against time, a semilogarithmic curve was obtained that was resolved into two exponential components with mean half-life times of 22.3 ± 21.9 (S.D.) and 905 ± 182 (S.D.) minutes. A half-life time of 327 ± 81 (S.D.) minutes was found for the phospholipid fatty acids. In one experiment the nonphospholipid fat was further fractionated chromatographically into triglycerides and cholesterol esters. The half-life times of the fatty acids of these two fractions were comparable to the values obtained for the fast and slow components, respectively, found in the preceding experiments. The turnover rate of the triglyceride fatty acids was 1502 ± 505 (S.D.) mg/hr. The rate of appearance of the cholesterol ester fatty acids into the plasma was 29.0 ± 32.7 (S.D.) mg/hr.; the rate of disappearance, 63.4 ± 38.0 (S.D.) mg/hr. A turnover rate of 125.2 ± 49.2 (S.D.) mg/hr. was found for the phospholipid fatty acids in the earlier experiments. The large turnover rate of the plasma triglyceride fatty acids strongly suggests that this fraction is important in the transport of fatty acids in the postabsorptive dog.

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Metabolism of Palmitic and Linoleic Acids in Man: Differences in Turnover and Conversion to Glycerides

Clinical Science ◽

10.1042/cs0400345 ◽

1971 ◽

Vol 40 (4) ◽

pp. 345-350 ◽

Cited By ~ 35

Author(s):

P. J. Nestel ◽

P. Barter

Keyword(s):

Fatty Acids ◽

Fatty Acid ◽

Linoleic Acid ◽

Palmitic Acid ◽

Free Fatty Acids ◽

Plasma Triglyceride ◽

Turnover Rates ◽

Polyunsaturated Fat ◽

Total Turnover ◽

Fat Diets

1. The metabolism of palmitic acid (a saturated fatty acid) and linoleic acid (a polyunsaturated fatty acid) was compared in seven subjects during constant infusions of the radioactive tracers. 2. The studies were repeated in some subjects after the turnover of the free fatty acids and the size of the fatty acid and glyceride pools had been altered with sucrose or polyunsaturated fat diets. 3. The fractional turnover of linoleic acid was nearly always greater than that of palmitic acid, though its total turnover rate was less. 4. A lesser proportion of the turnover of linoleate than of palmitate was incorporated into plasma triglyceride over a range of turnover rates of free fatty acids and glyceride fatty acid pools. This may be a factor in the lowering of plasma triglyceride concentrations with diets rich in polyunsaturated fatty acids.

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Changes in Turnover Rates of Some Enzymes Involved in Nitrogen Metabolism in the Rat Liver after Administration of Carbon Tetrachloride

The Journal of Biochemistry ◽

10.1093/oxfordjournals.jbchem.a129418 ◽

1970 ◽

Vol 68 (6) ◽

pp. 811-820 ◽

Cited By ~ 2

Author(s):

Motohiro MARUYAMA ◽

Yoshihiro SATO ◽

Yasuo UCHIDA

Keyword(s):

Carbon Tetrachloride ◽

Nitrogen Metabolism ◽

Rat Liver ◽

Turnover Rates

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Colloidal systems in soils

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100168050 ◽

1994 ◽

Vol 52 ◽

pp. 64-65

Author(s):

J. Thieme ◽

J. Niemeyer ◽

P. Guttman

Keyword(s):

Clay Minerals ◽

Polymeric Materials ◽

Spatial Arrangement ◽

High Specific Surface Area ◽

Turnover Rates ◽

Colloidal Systems ◽

Chemical Conditions ◽

Aggregation Phenomena ◽

Iron And Manganese ◽

Soil Colloids

In soil science the fraction of colloids in soils is understood as particles with diameters smaller than 2μm. Clay minerals, aquoxides of iron and manganese, humic substances, and other polymeric materials are found in this fraction. The spatial arrangement (microstructure) is controlled by the substantial structure of the colloids, by the chemical composition of the soil solution, and by thesoil biota. This microstructure determines among other things the diffusive mass flow within the soils and as a result the availability of substances for chemical and microbiological reactions. The turnover of nutrients, the adsorption of toxicants and the weathering of soil clay minerals are examples of these surface mediated reactions. Due to their high specific surface area, the soil colloids are the most reactive species in this respect. Under the chemical conditions in soils, these minerals are associated in larger aggregates. The accessibility of reactive sites for these reactions on the surface of the colloids is reduced by this aggregation. To determine the turnover rates of chemicals within these aggregates it is highly desirable to visualize directly these aggregation phenomena.

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