The lecithin–cholesterol acyl transferase activity of rat intestinal lymph
The lecithin-cholesterol acyl transferase (LCAT) activity in rat mesenteric lymph was examined as a possible source of chylomicron cholesteryl ester. Lymph activity was only 2–3% of rat serum activity. Removal of d < 1.006 lipoproteins increased lymph LCAT activity, but only to 6–8% of that of se...
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doaj-8d1207cfe5104390abfaf86b80fcf1672021-04-24T05:53:55ZengElsevierJournal of Lipid Research0022-22751977-05-01183293300The lecithin–cholesterol acyl transferase activity of rat intestinal lymphS B Clark0K R Norum1Gastrointestinal Research Division, St. Luke's Hospital Center, New York, NY 10025; Institute for Nutrition Research, School of Medicine, University of Oslo, Oslo 3, Norway; Address all correspondence to Dr. S. Bennett Clark.Gastrointestinal Research Division, St. Luke's Hospital Center, New York, NY 10025; Institute for Nutrition Research, School of Medicine, University of Oslo, Oslo 3, NorwayThe lecithin-cholesterol acyl transferase (LCAT) activity in rat mesenteric lymph was examined as a possible source of chylomicron cholesteryl ester. Lymph activity was only 2–3% of rat serum activity. Removal of d < 1.006 lipoproteins increased lymph LCAT activity, but only to 6–8% of that of serum. Relative to total cholesterol in the d < 1.08 g/ml fractions, lymph LCAT activity in lymph from fasting rats was less than serum, but in lymph from nonfasting rats the ratio LCAT/HDL-cholesterol reached levels greater than serum, suggesting a contribution of enzyme from the gut. Both LCAT activity and HDL concentration in mesenteric lymph increased during feeding.Subfractions of lymph that inhibited serum LCAT were: chylomicrons, VLDL, chylomicron lipid, VLDL apoprotein, and HDL apoprotein. In the rat, the low LCAT activity of mesenteric lymph was in part due to the low enzyme concentration present, and the activity was apparently lowered further by lipid-rich lipoproteins that inhibited the reaction. Enzyme inhibition due to the apoprotein fractions of lipoproteins is probably minor in the rat in vivo.http://www.sciencedirect.com/science/article/pii/S0022227520416785cholesterol metabolismintestinal enzymeslipoproteins |
collection |
DOAJ |
language |
English |
format |
Article |
sources |
DOAJ |
author |
S B Clark K R Norum |
spellingShingle |
S B Clark K R Norum The lecithin–cholesterol acyl transferase activity of rat intestinal lymph Journal of Lipid Research cholesterol metabolism intestinal enzymes lipoproteins |
author_facet |
S B Clark K R Norum |
author_sort |
S B Clark |
title |
The lecithin–cholesterol acyl transferase activity of rat intestinal lymph |
title_short |
The lecithin–cholesterol acyl transferase activity of rat intestinal lymph |
title_full |
The lecithin–cholesterol acyl transferase activity of rat intestinal lymph |
title_fullStr |
The lecithin–cholesterol acyl transferase activity of rat intestinal lymph |
title_full_unstemmed |
The lecithin–cholesterol acyl transferase activity of rat intestinal lymph |
title_sort |
lecithin–cholesterol acyl transferase activity of rat intestinal lymph |
publisher |
Elsevier |
series |
Journal of Lipid Research |
issn |
0022-2275 |
publishDate |
1977-05-01 |
description |
The lecithin-cholesterol acyl transferase (LCAT) activity in rat mesenteric lymph was examined as a possible source of chylomicron cholesteryl ester. Lymph activity was only 2–3% of rat serum activity. Removal of d < 1.006 lipoproteins increased lymph LCAT activity, but only to 6–8% of that of serum. Relative to total cholesterol in the d < 1.08 g/ml fractions, lymph LCAT activity in lymph from fasting rats was less than serum, but in lymph from nonfasting rats the ratio LCAT/HDL-cholesterol reached levels greater than serum, suggesting a contribution of enzyme from the gut. Both LCAT activity and HDL concentration in mesenteric lymph increased during feeding.Subfractions of lymph that inhibited serum LCAT were: chylomicrons, VLDL, chylomicron lipid, VLDL apoprotein, and HDL apoprotein. In the rat, the low LCAT activity of mesenteric lymph was in part due to the low enzyme concentration present, and the activity was apparently lowered further by lipid-rich lipoproteins that inhibited the reaction. Enzyme inhibition due to the apoprotein fractions of lipoproteins is probably minor in the rat in vivo. |
topic |
cholesterol metabolism intestinal enzymes lipoproteins |
url |
http://www.sciencedirect.com/science/article/pii/S0022227520416785 |
work_keys_str_mv |
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