Tissue lipid content

Distribution. Generally the highest concentration of PCB residues in fish are in tissues of high lipid content. In Table V juvenile coho salmon were fed equal amounts of three chlorobi-phenyls for 117 days. Fish were then killed and lipid content and PCB concentration of various tissues determined (33). Tissues are arranged from top to bottom in order of increasing PCB concentration. For most tissues, but not all, as lipid content increases so does PCB concentration. Lipid content and PCB concentration are low in liver and white muscle, intermediate in spinal column and lateral line muscle, and high in adipose tissue. Lipid content cannot be the sole determinant of PCB concentration in fish tissues because a discrepancy exists between lipid content of brain, heart and spleen and PCB concentration. 

Neschen, S., Moore, I., Regittnig, W., Yu, C. L., Wang, Y., Pypaert, M., Petersen, K. F., and Shulman, G. I. (2002). Contrasting effects of fish oil and safflower oil on hepatic peroxisomal and tissue lipid content. Am. J. Physiol. Endocrinol. Metab. 282, E395-E401. 

Shchepkina, A.M. (1980b). The influence of helminths on the tissue lipid content of Black Sea anchovy and bullhead during the annual cycle. Technical Reports National Marine Fisheries Service, NOAA 25,49-51. 

Forsythe, W.A., Miller, E.R., Hill, G.M., Romsos, D.R., and Simpson, R.C. 1980. Effects of dietary protein and fat sources on plasma cholesterol parameters, LCAT activity and amino acid levels and on tissue lipid content of growing pigs. J. Nutr. 110(12), 2467-2479. 

Bertelsen, S.L., A.D. Hoffman, C.A. Gallinat, C.M. Elonen and J.W. Nichols. Evaluation of log Kow and tissue lipid content as predictors of chemical partitioning into fish tissues. Environ. Toxicol. Chem. 17 ... 

Sultatos (2002). For fenitrothion, equilibrium was achieved by 60 min and was clearly stable during 120 min of dialysis (37 C). Based on these results, it was feasible to experimentally determine both tissue blood and tissue buffer partitioning and calculate a Uver blood PC. Poulin and Krishnan (1995, 1996) also developed an algorithm-based approach for determining PCs using the chemical s octanobwater partitioning and the tissue lipid content. This approach was utilized to calculate PCs for chlorpyrifos, diazinon, and their oxen metabolites, and these are presented in Table 2. 

We thank Kelly Hall for secretarial and illustration assistance and Mark Lowe for technical assistance with characterization of tissue lipid content. This work was supported by NIH grant DK45416 and American Heart Association grant GIA 9750199N. D. P. Kelly is an Established Investigator of the American Heart Association. F. Djouadi receives support from the Scientific Programs of N. A. T. O. and the Fondation pour la Recherche Medicale. 

Bioconcentration, Bio accumulation and Biomagnification. These aspects are determined by the physicochemical properties of a chemical, an organism s ability to excrete the chemical, the organism s lipid content and its trophic level. Bioconcentration relates to the difference between the environmental concentration and that of the body tissues. A high bioconcentration factor (BCF) predisposes to bioaccnmulation. The upper limit of bioaccnmulation is determined by lipid levels in the organism s tissues. Whether the resultant body burden causes biomagnification in the food chain depends upon the metabolic capabilities of the exposed organism. 

This outcome was consistent with a hypothesis that structural deterioration could have been a byproduct of microorganism activity. The higher lipid content in the poorly preserved tissue suggests that those lipids are primarily extrinsic, that is, that they were produced by bacteria and/or fungi. As the food source for such microorganisms, the protein within the bone may have been substantially altered in concert with the microstructure deterioration. The quantification of the changes to the organic fraction became our next focus of research. 

Most commonly, the lipid metabolism pathology is manifest as hyperlipemia (elevated concentration of lipids in blood) and tissue lipidoses (excessive lipid de-position in tissues). Normally, the lipid contents in the blood plasma are total lipids, 4-8 g/litre triglycerides, 0.5-2.1 mmol/litre total phospholipids, 2.0-3.5 mmol/litre total cholesterol, 4.0-8.0 mmol/litre (esterified cholesterol accounts for 2/3 of total cholesterol). 

High antioxidative activity carvedilol has been shown in isolated rat heart mitochondria [297] and in the protection against myocardial injury in postischemic rat hearts [281]. Carvedilol also preserved tissue GSL content and diminished peroxynitrite-induced tissue injury in hypercholesterolemic rabbits [298]. Habon et al. [299] showed that carvedilol significantly decreased the ischemia-reperfusion-stimulated free radical formation and lipid peroxidation in rat hearts. Very small I50 values have been obtained for the metabolite of carvedilol SB 211475 in the iron-ascorbate-initiated lipid peroxidation of brain homogenate (0.28 pmol D1), mouse macrophage-stimulated LDL oxidation (0.043 pmol I 1), the hydroxyl-initiated lipid peroxidation of bovine pulmonary artery endothelial cells (0.15 pmol U1), the cell damage measured by LDL release (0.16 pmol l-1), and the promotion of cell survival (0.13 pmol l-1) [300]. SB 211475 also inhibited superoxide production by PMA-stimulated human neutrophils. 

Lipid Content and Concentration of PCB Residues in Tissues of Juvenile Coho Salmon3... 

Using PCB levels in five species of freshwater finfish, collected over a course of 20 years. Stow (1995) failed to find a significant relationship between residue concentrations and percent lipid. The finding of Randall et al. (1991) may explain part of the problem. They found that using different extraction solvents for tissues, lipid concentrations can vary by 3.5 fold and that laboratories vary widely in the type of solvents used for the extraction of HOC residues in tissues. Whole body lipid levels across BMO species typically vary from about 1 to 15% (based on wet tissue weights). Thus, the lipid mediated differences in BMO tissue concentrations may be as high as 15 fold. Unlike BMOs, Standard SPMDs have a uniform lipid content, which precludes any need for lipid normalization, and the extraction or dialysis solvent is standardized. 

Due to its lipophilic character, chloroform accumulates to a greater extent in tissues of high lipid content. As shown by the results presented above, the relative concentrations of chloroform in various tissues decreased as follows adipose tissue > brain > liver > kidney > blood. 

---