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- Nilsson, Åke, et al.
(författare)
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Adaptive regulation of lipoprotein lipase and salt-resistant lipase activities in essential fatty acid deficiency. An experimental study in the rat.
- 1990
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Ingår i: Metabolism. ; 39:12, s. 1305-1308
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Tidskriftsartikel (refereegranskat)abstract
- Lipoprotein lipase (LPL) activities of postheparin plasma, heart, lungs, and adipose tissue, and salt-resistant lipase (hepatic lipase, SRL) activities of postheparin plasma, liver, and adrenals were examined in essential fatty acid deficient (EFAD) rats and in age-matched controls. The LPL activity of heart was higher in the deficient than in the control rats, but did not differ in the other tissues. The SRL activity of postheparin plasma was twofold higher, and that of liver and adrenals approximately 50% higher in the group with EFA deficiency. It is suggested that SRL exhibits an adaptive up-regulation in EFA deficiency. This up-regulation may be linked to a role for the enzyme in the transport of polyenoic fatty acids.
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| 2. |
- Nilsson, Åke, et al.
(författare)
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Incorporation of dietary 14Carachidonic and 3Heicosapentaenoic acid into tissue lipids during absorption of a fisk oil emulsion
- 1992
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Ingår i: Journal of Lipid Research. - 1539-7262. ; 33:9, s. 1295-1305
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Tidskriftsartikel (refereegranskat)abstract
- A preferential incorporation of dietary arachidonic acid (20:4, n-6) into chyle lipoprotein phospholipids, a relative resistance of 20:4 esters of chyle triacylglycerol (TG) to hydrolysis by lipoprotein lipase, a preferential utilization of 20:4 for phospholipid acylation, and a low rate of oxidation of 20:4 are factors that may contribute to the differences seen in the incorporation into tissue lipids between absorbed 20:4 and the predominant dietary 16-18 carbon fatty acids. In this study we fed [14C]20:4 and [3H]eicosapentaenoic acid (20:5, n-3) as free fatty acids in a fish oil emulsion to rats and analyzed the radioactivity in different tissue lipids after 1, 2, and 4 h. The purpose was to examine the degree of similarity in the fate of the two major eicosanoid precursors during the absorption of a fish oil meal. The recovery after 2 and 4 h of 14C exceeded that of 3H in lipids of small intestine, serum, liver, heart, kidneys, and spleen. The differences increased with time, e.g., the liver contained 9.7 (+/- 0.7)% 3H and 17.9 (+/- 1.4)% of the 14C (P less than 0.001), and the upper half of the small intestine 10.0 (+/- 0.8)% of the 3H and 22.8 (+/- 1.1)% of the 14C (P less than 0.001) after 4 h. The 14C and 3H radioactivity per g tissue after 4 h ranked as follows: liver and brown adipose tissue greater than kidneys greater than heart, lungs, spleen, and serum greater than colon greater than white adipose tissue and testes, the differences between tissues being up to 50-fold. There were up to fourfold variations in the 14C/3H ratios between tissues after 4 h, the highest value being observed in the heart and the lowest in white adipose tissue. Of the radioactivity retained in liver and intestine, more 14C and 3H was in phospholipids and less in triacylglycerol (TG), the differences being largest in the liver, e.g., after 4 h 57.6 (+/- 0.8)% of the 14C and 29.9 (+/- 0.9)% of the 3H (P less than 0.001) in the liver was in phosphatidylcholine (PC). In both intestine and liver the highest 14C/3H ratios were found in phosphatidylinositiol (PI). Also phosphatidylethanolamine (PE) contained more 14C than 3H but the quantitative differences were relatively small after 4 h. In heart the proportions of 3H and 14C found in PE and PI did not differ, whereas more of the 14C was in PC and more of the 3H was in cardiolipin and phosphatidylserine.(ABSTRACT TRUNCATED AT 400 WORDS).
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