Search results for "acids"
showing 10 items of 3520 documents
Characterization of choline efflux from the perfused heart at rest and after muscarine receptor activation.
1986
The resting efflux of choline from perfused chicken hearts varied from 0.4 to 2.6 nmol/g min, but was constant for at least 80 min in the individual experiments. The rate of choline efflux was found to be equal to the rate of choline formation in the heart, which, from the following reasons, was essentially due to hydrolysis of choline phospholipids. Cardiac content of choline phospholipids (7,200 nmol/g) was much higher than that of acetylcholine (5.5 nmol/g). Resting release of acetylcholine was 0.016 nmol/g min and, after inhibition of cholinesterase, only about 0.1 nmol/g min. Resting efflux of choline was reduced by mepacrine, a phospholipase A2 inhibitor, by perfusion with a Ca2+-free…
Sox17 regulates liver lipid metabolism and adaptation to fasting.
2014
Liver is a major regulator of lipid metabolism and adaptation to fasting, a process involving PPARalpha activation. We recently showed that the Vnn1 gene is a PPARalpha target gene in liver and that release of the Vanin-1 pantetheinase in serum is a biomarker of PPARalpha activation. Here we set up a screen to identify new regulators of adaptation to fasting using the serum Vanin-1 as a marker of PPARalpha activation. Mutagenized mice were screened for low serum Vanin-1 expression. Functional interactions with PPARalpha were investigated by combining transcriptomic, biochemical and metabolic approaches. We characterized a new mutant mouse in which hepatic and serum expression of Vanin-1 is …
Behaviour influences cholesterol plasma levels in a pig model
2012
Little is known about the relationship between feed intake behaviour and cholesterol levels in humans. This can be attributed to the fact that feed intake behaviour in humans is difficult to assess. The relationships between feed intake, feed efficiency and feed intake behaviour, and cholesterol and triglyceride levels were investigated at an average age of 187 days, in a pig model consisting of 202 Duroc barrows. Feed intake and feed intake behaviour were recorded individually and daily by means of an electronic identification system. Animals with high levels of total cholesterol also had high levels of high-density lipoprotein (HDL), low-density lipoprotein (LDL) cholesterol and triglycer…
Role of the cyclic AMP-dependent pathway in free radical-induced cholesterol accumulation in vascular smooth muscle cells.
2000
We have previously reported that free radical-treated vascular smooth muscle cells (SMC) lead to cholesterol accumulation in vitro. In the current study, we investigated the effects of oxidative stress on cyclic AMP concentration and cAMP-dependent enzymes involved in cholesterol homeostasis in A7r5 cells. Under our conditions of a mild oxidative stress, namely with no change in cell viability, we found that free radicals, initiated using azobis-amidinopropane dihydrochloride (AAPH), resulted in a dose-dependent decrease in cellular cAMP which was opposed by vitamin E preincubation. Although the addition of adenylate cyclase activators (carbacyclin and forskolin) increased cAMP levels it di…
Oxidative stress leads to cholesterol accumulation in vascular smooth muscle cells.
1999
The transformation of macrophages and smooth muscle cells into foam cells by modified low-density lipoproteins (LDL) is one of the key events of atherogenesis. Effects of free radicals have mainly been studied in LDL, and other than toxicity, data dealing with direct action of free radicals on cells are scarce. This study focused on the direct effects of free radicals on cholesterol metabolism of smooth muscle cells. A free radical generator, azobis-amidinopropane dihydrochloride, was used, and conditions for a standardized oxidative stress were set up in vascular smooth muscle cells. After free radical action, the cells presented an accumulation of cholesterol that appeared to be the resul…
Changes in serum lipid and lipoprotein concentrations and compositions at birth and after 1 month of life in macrosomic infants of insulin-dependent …
1999
The aim of this study was to determine whether macrosomia related to maternal diabetes alters lipoprotein metabolism and whether these abnormalities still persist or regress after 1 month of life. Serum lipoprotein compositions and concentrations as well as serum lipid fatty acid compositions were investigated in macrosomic infants (birth weight = 4840 +/- 105 g at term) of insulin-dependent diabetic mothers at birth and after 1 month of life, and were compared to those of control infants (birth weight = 3400 +/- 198 g at term) of healthy mothers. Compared to controls, at birth, macrosomic newborns had higher serum lipids, apolipoprotein A-I and B-100, and lipoprotein (very low density lipo…
A targeted apoB38.9 mutation in mice is associated with reduced hepatic cholesterol synthesis and enhanced lipid peroxidation.
2006
Familial hypobetalipoproteinemia (FHBL) due to truncation-specifying mutations of apolipoprotein B (apoB), which impair hepatic lipid export in very low-density lipoprotein (VLDL) particles, is associated with fatty liver. In an FHBL-like mouse with the apoB38.9 mutation, fatty liver develops despite reduced hepatic fatty acid synthesis. However, hepatic cholesterol contents in apoB38.9 mice are normal. We found that cholesterogenic enzymes (3-hydroxy-3-methylglutaryl-coenzyme A reductase, sterol-C5-desaturase, and 7-dehydrocholesterol reductase) were consistently downregulated in two separate expression-profiling experiments using a total of 19 mice ( n = 7 each for apob+/+and apob+/38.9, …
Platelet sensitivity to prostacyclin and thromboxane production in hyperlipidemic patients
1982
SummaryIn 13 type II hyperlipidemics (10 males and 3 females; mean age 50.2 ± 10.6 years), in 10 type IV hyperlipidemics (7 males and 3 females; mean age 51 ± 13.3 years) and in 23 healthy age-and sex-matched controls, the following parameters were measured: plasma cholesterol; plasma TG; plasma C-HDL; VLDL, separated in a preparative ultracentrifuge; C-LDL; Apo B, with immunoelectrophoretic method; platelet sensitivity to prostacyclin; TXB2 formation in PRP; TXB2 in serum.This study provides evidence for: 1. Reduced platelet sensitivity to prostacyclin, more evident in type II hyperlipidemia that provides an additional mechanism involved in increased platelet aggregation found in type II h…
Polymorphisms at theSRBIlocus are associated with lipoprotein levels in subjects with heterozygous familial hypercholesterolemia
2002
Scavenger receptor, class B, type 1 (SRBI) is a promising candidate gene involved in the pathophysiology of atherosclerosis. We have examined the association of three common polymorphisms at the SRBI locus in 77 subjects who were heterozygous for familial hypercholesterolemia (FH). The alleles represented by polymorphisms in exon 1 and exon 8 were associated with variation in plasma concentrations of fasting triglyceride (TG). Mean plasma TG concentrations for homozygotes for the most common allele, and for heterozygotes and homozygotes for the less common allele were 85 +/- 6, 111 +/- 9 and 135 +/- 22 mg/dl (p = 0.011) for exon 1, and 96 +/- 11, 86 +/- 6 and 134 +/- 13 mg/dl (p = 0.007) fo…
In vivo metabolism of LDL subfractions in patients with heterozygous FH on statin therapy
2004
LDL can be subfractionated into buoyant (1.020-1.029 g/ml(-1)), intermediate (1.030-1.040 g/ml(-1)), and dense (1.041-1.066 g/ml(-1)) LDLs. We studied the rebound of these LDL-subfractions after LDL apheresis in seven patients with heterozygous familial hypercholesterolemia (FH) regularly treated by apheresis (58 +/- 9 years, LDL-cholesterol = 342 +/- 87 mg/dl(-1), triglycerides = 109 +/- 39 mg/dl(-1)) and high-dose statins. Apolipoprotein B (apoB) concentrations were measured in LDL subfractions immediately after and on days 1, 2, 3, 5, and 7 after apheresis. Compartmental models were developed to test three hypotheses: 1) that dense LDLs are derived from the delipidation of buoyant and in…