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At least 91 records · Page 5Linked to original sources
PubMed1999

Growth hormone (GH) therapy in GH-deficient adults influences the response to a dietary load of cholesterol and saturated fat in terms of cholesterol synthesis, but not serum low density lipoprotein cholesterol levels.

An increased dietary load of cholesterol (ch) and saturated fat increases serum low density lipoprotein ch (LDL-ch) levels. GH therapy in GH-deficient adults decreases serum LDL-ch levels. In the rat, GH is important for resistance to dietary cholesterol in terms of serum cholesterol levels. The aim of this study was to investigate the influence of GH on the effects of an increase in the intake of cholesterol and saturated fat on serum lipoproteins and markers for cholesterol synthesis in man. Six GH-deficient adults were given an isocaloric diet enriched in cholesterol and saturated fat for 17 days with and without GH therapy (1-1.5 U/day). Serum cholesterol, LDL-ch, apolipoprotein B (apoB), and apoA1 levels increased during the diet period with GH therapy and tended to increase during the diet period without GH. However, GH therapy did not influence the dietary effect on serum cholesterol, LDL-ch, apoA1, or apoB levels. Serum levels of triglycerides, very low density lipoprotein ch, high density lipoprotein ch, and apoE were not affected by diet or GH therapy. GH therapy increased serum lipoprotein(a) levels, but did not affect the response to diet. The serum total delta7-lathosterol/cholesterol ratio increased less during the diet period with GH therapy than during the diet period without GH. Serum 7alpha-hydroxy-4-cholesten-3-one levels tended to increase during both diet periods, but were not influenced by GH treatment. Serum plant sterol levels did not change. These results indicate that GH counteracts an increase in cholesterol synthesis induced by a high fat diet without affecting bile acid synthesis or sterol absorption. GH therapy did not have any major influence on the dietary effects on serum lipoprotein levels.

Adult↗
PubMed1989

Effect of a modified, well-tolerated niacin regimen on serum total cholesterol, high density lipoprotein cholesterol and the cholesterol to high density lipoprotein ratio.

One hundred one patients with coronary artery disease and pretreatment ratios of total cholesterol to high density lipoprotein (HDL) cholesterol greater than 4.0 were treated with niacin, commencing at low dosages (100 to 250 mg twice daily) and gradually increasing the dosage over 4 to 8 weeks to 1,000 mg twice daily. Dosage adjustments were made to minimize side effects. At a mean follow-up duration of 11 +/- 7 months, and a mean dosage of 1,415 +/- 698 mg/day, the group had a 13% reduction in total cholesterol, 31% increase in HDL and 32% decrease in the cholesterol to HDL ratio. A subgroup of 62 patients taking greater than 1,000 mg/day of niacin had an 18% reduction in total cholesterol, 32% increase in HDL and 36% improvement in the cholesterol to HDL ratio. A subgroup of 39 patients taking less than or equal to 1,000 mg/day of niacin had only a 5% reduction in total cholesterol, although a 29% increase in HDL and a 24% decrease in the cholesterol to HDL ratio were recorded. Side effects of niacin were reported in 38% of the patients, but led to discontinuation of therapy in only 4. Niacin can be administered in a fashion that is well tolerated, inexpensive and very effective in improving the cholesterol to HDL ratio.

Adult↗
PubMed1992

Non-cholesterol sterols, absorption and synthesis of cholesterol and apolipoprotein A-I kinetics in a Finnish lecithin-cholesterol acyltransferase deficient family.

We describe the first Finnish LCAT-deficient family with two affected, one questionably affected and one healthy family member. The affected family members presented stomatocytes in the peripheral blood, exhibited low serum levels of total, LDL and HDL cholesterol, triglycerides, phospholipids and apolipoprotein A-I and especially A-II. Apolipoprotein A-I catabolism was accelerated to moderately high and very high levels in the two affected subjects. Cholesterol esterification percentage was low in all lipoprotein fractions. The intestinal cholesterol absorption efficiency and cholesterol and bile acid synthesis were within normal limits. The esterification percentage of demethylated cholesterol precursor sterols, cholestanol and plant sterols resembled mostly that of cholesterol, while those of VLDL and LDL methostenols, precursor sterols esterified by acyl-CoA:cholesterol acyltransferase (ACAT), suggested normal ACAT activity. In HDL all sterols were poorly esterified. The observations on stomatocytes, normal absorption and synthesis of cholesterol and bile acids, abnormal kinetics of apolipoprotein A-I, evidence of normal ACAT activity and abnormal esterification of non-cholesterol sterols are findings presented for the first time in LCAT deficiency.

Absorption↗
PubMed2004

Dietary raw peas (Pisum sativum L.) reduce plasma total and LDL cholesterol and hepatic esterified cholesterol in intact and ileorectal anastomosed pigs fed cholesterol-rich diets.

Previous studies demonstrated the cholesterol-lowering effect of dietary legumes (mainly soybeans) in animals and humans, but the mechanisms by which they exert this effect are not completely understood. The contribution of the hindgut to this hypocholesterolemic effect is also not well documented. The present work was undertaken to investigate the effect of cholesterol-enriched (2.8 g/kg) casein (C) and raw pea seed (RP) diets on the cholesterol metabolism of intact (I) and ileorectal anastomosed (IRA) growing pigs. Four groups of 6 pigs were allocated to the treatments (C-I, C-IRA, RP-I, and RP-IRA pigs) for 3 wk. Plasma total cholesterol was lowered by the RP diet through a significant decrease in LDL cholesterol. The RP diet also decreased the hepatic concentration of esterified cholesterol and increased 3-hydroxy-3-methylglutaryl CoA reductase activity and LDL receptor synthesis. The biliary total cholesterol and bile acid concentrations were greater in RP- than in C-fed pigs. In addition, fecal bile acid output was higher in RP-fed pigs. The cecum-colon by-pass inhibited cholesterol and beta-sitosterol microbial transformation, lowered the bile acid output, and increased the primary to secondary bile acid output ratio, but its influence on cholesterolemia was negligible. These results suggest a hypocholesterolemic effect of the raw pea diet probably due to increased fecal bile acid output and an increased biliary bile acid concentration.

Anastomosis, Surgical↗
PubMed2004

Lateral distribution of cholesterol in dioleoylphosphatidylcholine lipid bilayers: cholesterol-phospholipid interactions at high cholesterol limit.

Lateral organization of cholesterol in dioleoyl-phosphatidylcholine (DOPC) lipid bilayers at high cholesterol concentration (>45 mol%) was investigated using steady-state fluorescence anisotropy and fluorescent resonance energy transfer techniques. The recently devised Low Temperature Trap method was used to prepare compositionally uniform cholesterol/DOPC liposomes to avoid the problem of lipid demixing. The fluorescence anisotropy of diphenylhexatrience chain-labeled phosphatidylcholine (DPH-PC) in these liposomes exhibited local maxima at cholesterol mol fractions of 0.50 and 0.57, and a sharp drop at 0.67. For the liposomes labeled with both dehydroergosterol and DPH-PC, the fluorescent resonance energy transfer efficiency from dehydroergosterol to DPH-PC displayed a steep jump at cholesterol mol fraction of 0.5, and dips at 0.57 and 0.68. These results indicate the presence of highly ordered cholesterol regular distribution domains at those observed critical compositions. The observed critical mol fraction at 0.67 agreed favorably with the solubility limit of cholesterol in DOPC bilayers as independently measured by light scattering and optical microscopy. The regular distribution at 0.57 was previously predicted from a Monte Carlo simulation based on the Umbrella model. The results strongly support the hypothesis that the primary requirement for cholesterol-phospholipid mixing is that the polar phospholipid headgroups need to cover the nonpolar body of cholesterol to avoid the exposure of cholesterol to water.

Cholesterol↗
PubMed1994

Effect of the acyl-CoA:cholesterol acyltransferase inhibitor DuP 128 on cholesterol absorption and serum cholesterol in humans.

Intestinal cholesterol esterification by the enzyme acyl-CoA:cholesterol acyltransferase (ACAT) is a presumed prerequisite for cholesterol absorption. We evaluated the effect of a potent, poorly absorbed ACAT inhibitor (DuP 128: N'-(2,4-difluorophenyl)-N-[5-(4,5-diphenyl-1H-imidazol-2-ylthio)pe ntyl]- N-heptylurea) on cholesterol absorption in a randomized trial. Thirty subjects received DuP 128 for 7 weeks, 10 each at 900 mg per day, 1800 mg per day, and 3600 mg per day; six subjects received placebo; and nine subjects received 1 gm neomycin twice a day. Cholesterol absorption determinations used a continuous dual isotope 14C-cholesterol and 3H-beta sitosterol method. DuP 128 (pooled doses) induced at 14.4% +/- 11.4% reduction in cholesterol absorption (p < 0.05 versus placebo): 17.6% +/- 8.4% at 900 mg, 9.1% +/- 11.4% at 1800 mg, and 17.1% +/- 12.9% at 3600 mg. Neomycin induced a 26.4% +/- 10.7% reduction (p < 0.01). After 6 weeks, neomycin reduced serum total and low-density lipoprotein cholesterol by 22.4% +/- 9.2% and 24.0% +/- 11.6%, respectively (p < 0.01 versus placebo). DuP 128 induced reductions of 3.9% +/- 11% (difference not significant) and 4.95% +/- 14.3% (p = 0.05). ACAT inhibitors limit cholesterol absorption in humans; however, the magnitude of the effect, as exemplified by DuP 128, is small.

Adult↗
PubMed2004

Hamsters fed diets high in saturated fat have increased cholesterol accumulation and cytokine production in the aortic arch compared with cholesterol-fed hamsters with moderately elevated plasma non-HDL cholesterol concentrations.

There is growing evidence that dietary fatty acids and/or dietary cholesterol could have a direct role on inflammatory diseases such as atherosclerosis. F(1)B Golden Syrian hamsters (Mesocricetus auratus), in 2 groups of 72, were fed for 10 wk a semipurified diet containing either 20 g/100 g hydrogenated coconut oil without cholesterol or cocoa butter (20 g/100 g) with cholesterol (0.15 g/100 g). After the 10-wk treatment period, plasma was collected from food-deprived hamsters (16 h) for plasma lipid measurements. Hamsters were then ranked according to their plasma VLDL and LDL cholesterol (non-HDL-C) concentrations with 1.86 mmol/L as the cut-off point between low (Low; n = 36) and medium (Med; n = 36) concentrations for each treatment. Hamsters in the Low and Medium groups fed cholesterol (Low-chol) had significantly lower plasma total cholesterol (TC) concentrations than hamsters in the Low group fed coconut oil (Low-CO). However, this difference for the Medium group was reflected in significantly lower plasma HDL cholesterol (HDL-C) concentrations. Hamsters in the Low-CO group had significantly higher aortic total and esterified cholesterol concentrations than hamsters in the Low-chol group. Hamsters in the Low-chol group had significantly higher aortic tumor necrosis factor-alpha concentrations than hamsters in the Low-CO group. Hamsters in the Med-CO group had significantly higher aortic interleukin-1beta concentrations than hamsters in the Med-chol group. In conclusion, the present study suggests that dietary cholesterol and saturated fatty acids could have an effect on atherosclerosis not only beyond their role in affecting plasma lipoproteins but also through increased production of inflammatory cytokines in the arterial wall.

Animals↗
PubMed1994

Pseudopregnancy-dependent accumulation of cholesterol sulfate due to up-regulation of cholesterol sulfotransferase and concurrent down-regulation of cholesterol sulfate sulfatase in the uterine endometria of rabbits.

The uterine endometria of rabbits induced into pseudopregnancy by intramuscular injection of 17 beta-estradiol, followed by intravenous injection of human chorionic gonadotropin, expressed cholesterol sulfate at a significantly high concentration. The highest concentration of cholesterol sulfate was observed 4 days after the injection of gonadotropin for formation of the corpus luteum, being 10 times higher than that in nonpregnant endometria, and 15.2% of the total cholesterol in the endometrium was converted to the sulfated form, whose percentage in nonpregnant endometrium was 3.2%. However, no significant change in the concentration of gangliosides was observed during the period of pseudopregnancy. In the pseudopregnant endometria, the activity of cholesterol sulfotransferase, a cytosolic thiol enzyme, was increased thirtyfold over that in the nonpregnant endometria, whereas cholesterol sulfate sulfatase, a microsomal enzyme, exhibited approximately one-tenth of the activity in nonpregnant endometria. Arylsulfatase C, but not arylsulfatases A and B, exhibited the same change in activity as cholesterol sulfate sulfatase. Thus, the striking increase in cholesterol sulfate after induction of pseudopregnancy was found to be due to the activation of cholesterol sulfotransferase and the simultaneous inhibition of cholesterol sulfate sulfatase.

Animals↗
PubMed1978

On the mechanism for the regulation of 3-hydroxy-3-methylglutaryl-coenzyme A reductase, of cholesterol 7alpha-hydroxylase and of acyl-coenzyme A:cholesterol acyltransferase by free cholesterol.

The administration of mevalonic acid to rats by intravenous injection resulted in a dose- and time-dependent increase in the activity of cholesterol 7alpha-hydroxylase in the liver microsomal fraction, a decrease in the microsomal activity of 3-hydroxy-3-methylglutaryl-coenzyme A reductase and no significant change in the activity of acyl-coenzyme A:cholesterol acyltransferase or in the concentration of free and of esterified cholesterol in the liver microsomal fraction. However, the increased hepatic cholesterogenesis that follows the injection of mevalonic acid resulted in an increase of the size of the intracellular pool of cholesterol that is in the environment of 3-hydroxy-3-methylglutaryl-coenzyme A reductase and acts as substrate for cholesterol 7alpha-hydroxylase. The administration of mevalonic acid to rats by stomach tube resulted in an increase in the activity of cholesterol 7alpha-hydroxylase and of acyl-coenzyme A:cholesterol acyltransferase and in the concentration of cholesterol esters in the liver microsomal fraction, while there was a considerable decrease in the activity of 3-hydroxy-3-methylglutaryl-coenzyme A reductase.

Acyltransferases↗
PubMed1999

Dietary taurine enhances cholesterol degradation and reduces serum and liver cholesterol concentrations in rats fed a high-cholesterol diet.

The effect of taurine on hypercholesterolemia induced by feeding a high-cholesterol (HC) diet (10g/kg) to rats was examined. When various amounts of taurine (0.25, 0.5, 1, 2.5, 5, 10, 20, 30, 40 or 50 g/kg diet) were supplemented to HC for 2 wk, serum total cholesterol gradually and significantly decreased in a dose-dependent manner and normalized at the dose of 10 g taurine/kg, compared with the control (cholesterol free) diet group. By contrast, serum HDL-cholesterol was elevated by taurine supplementation. The HC diet caused a significant decrease in the concentration of taurine in serum, liver and heart compared to that in the control group, and the effective dose of supplemental taurine to improve its reduction was 2.5 g/kg diet. In the hypercholesterolemic rats fed the HC diet, the excretion of fecal bile acids and hepatic cholesterol 7 alpha-hydroxylase (CYP7A1) activity and its mRNA level increased significantly, and the supplementation of taurine further enhanced these indexes, indicating an increase in cholesterol degradation. The abundance of mRNA for Apo A-I, one of the main components of HDL, was reduced by HC and recovered by taurine supplementation. Agarose gel electrophoresis revealed that, in hypercholesterolemic rats fed the HC diet, the serum level of the heavier VLDL increased significantly, but taurine repressed this increase and normalized this pattern. Significant correlations were observed between the time- and dose-dependent increases of CYP7A1 gene expression and the decrease of blood cholesterol concentration in rats fed the HC diet supplemented with taurine (time, r = -0.538, P < 0.01, n = 32; dose, r = -0.738, P < 0.001, n = 20). These results suggest that the hypocholesterolemic effects of taurine observed in the hypocholesterolemic rats fed the HC diet were mainly due to the enhancement of cholesterol degradation and the excretion of bile acid.

Animals↗
PubMed1998

Cholesterol-lowering effects of NTE-122, a novel acyl-CoA:cholesterol acyltransferase (ACAT) inhibitor, on cholesterol diet-fed rats and rabbits.

Pharmacological characterization of NTE-122 (trans-1,4-bis[[1-cyclohexyl-3-(4-dimethylamino phenyl)ureido]methyl]cyclohexane), a novel acyl-CoA:cholesterol acyltransferase (ACAT) inhibitor, was performed with both in vitro and in vivo assay systems. NTE-122 inhibited microsomal ACAT activities of various tissues (liver of rabbit and rat, small intestine of rabbit and rat, and aorta of rabbit) and cultured cells (HepG2 and CaCo-2), with IC50 values from 1.2 to 9.6 nM. The inhibition mode of NTE-122 was competitive for HepG2 ACAT. NTE-122 had no effect on other lipid metabolizing enzymes, such as 3-hydroxy-3-methylglutaryl-CoA reductase, acyl-CoA synthetase, cholesterol esterase, lecithin:cholesterol acyltransferase, acyl-CoA:sn-glycerol-3-phosphate acyltransferase and cholesterol 7alpha-hydroxylase up to 10 microM. When NTE-122 was administered to the cholesterol diet-fed rats, serum and liver cholesterol levels were markedly reduced with an ED50 of 0.12 and 0.44 mg/kg/day, respectively. In the cholesterol diet-fed rabbits, NTE-122 significantly lowered plasma and liver cholesterol levels at more than 2 mg/kg/day. These results indicate that NTE-122 is a potent, selective and competitive inhibitor of ACAT, making it a worth while therapeutic agent for hypercholesterolemia and atherosclerosis.

1-Acylglycerol-3-Phosphate O-Acyltransferase↗
PubMed1993

Rationale and design of the Department of Veterans Affairs High-Density Lipoprotein Cholesterol Intervention Trial (HIT) for secondary prevention of coronary artery disease in men with low high-density lipoprotein cholesterol and desirable low-density lipoprotein cholesterol.

Although a large body of epidemiologic evidence suggests that low levels of high-density lipoprotein (HDL) cholesterol are strongly associated with an increased risk of coronary artery disease (CAD), no large-scale clinical trials focusing on this association have been reported. This report describes the rationale and design of the Department of Veterans Affairs HDL Intervention Trial (HIT), a multicenter, randomized, controlled clinical trial designed to determine whether lipid therapy reduces the combined incidence of CAD death and nonfatal myocardial infarction in men with established CAD who have low levels of HDL cholesterol with "desirable" levels of low-density lipoprotein (LDL) cholesterol. Twenty-five hundred men with CAD and HDL cholesterol < or = 40 mg/dl, LDL cholesterol < or = 140 mg/dl, and triglycerides < or = 300 mg/dl are being recruited at 20 Department of Veterans Affairs medical centers, randomized to either gemfibrozil or placebo, and followed in a double-blind manner for an average of 6 years. In this population, gemfibrozil is expected to increase HDL cholesterol by 10 to 15%, have a negligible effect on LDL cholesterol, and lower triglycerides by 30 to 40%. Because an estimated 20 to 30% of patients with CAD have a low HDL cholesterol as their primary lipid abnormality, the results of this trial are expected to have far-reaching clinical implications.

Adult↗
PubMed1999

Amperometric determination of total cholesterol at gold electrodes covalently modified with cholesterol oxidase and cholesterol esterase with use of thionin as an electron mediator.

Immobilization of cholesterol oxidase (EC 1.1.3.6) (ChOx) on a gold electrode was attempted by cross-linking using glutaraldehyde between ChOx molecules and a self-assembled monolayer of 2-aminoethanethiolate. The resulting electrode (ChOx/Au) exhibits an amperometric response to free cholesterol in the presence of thionin as an electron mediator, and a steady-state response is obtained approximately 60 s after injection of cholesterol into the electrolyte solution. Coimmobilization of cholesterol esterase (EC 3.1.1.13) (ChE) and ChOx (ChE/ChOx/Au) allows the amperometric determination of both esterified cholesterol and free cholesterol. Cyclic voltammetry of the ChE/ChOx/Au and the dependence of the amperometric response to cholesterol on the concentration of thionin suggest that thionin is encapsulated in the enzyme film on the electrode surface. Apparent Michaelis constants of the ChOx/Au and the ChE/ChOx/Au electrodes suggest that the amperometric response was controlled by penetration of the reaction substrate into the films of the enzyme(s). The concentration of total (free and esterified) cholesterol in human serum samples, determined by using the techniques developed in the present study, is in good agreement with that determined by the well-established technique using colorimetry.

Cholesterol↗
PubMed1994

ACAT inhibition decreases LDL cholesterol in rabbits fed a cholesterol-free diet. Marked changes in LDL cholesterol without changes in LDL receptor mRNA abundance.

Rabbits fed low-fat, cholesterol-free diets containing casein as the sole protein source develop endogenous hypercholesterolemia (EH). To test the hypothesis that lipoprotein cholesteryl esters in EH rabbits are acyl coenzyme A:cholesterol acyltransferase (ACAT) derived, we treated EH rabbits with CI-976, a potent and selective ACAT inhibitor. In addition, since cholesterol and bile acid synthesis as well as low-density lipoprotein (LDL) receptor activity are reduced in EH rabbits, we determined whether changes in gene expression for 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase, 7 alpha-hydroxylase, and the LDL receptor might be associated with the efficacy due to ACAT inhibition. Compared with EH controls, CI-976-treated rabbits (50 mg/kg per day for 5 weeks) had decreased plasma total cholesterol (-43%), very-low-density lipoprotein (VLDL) cholesterol (-62%), LDL cholesterol (-43%), plasma apolipoprotein B (-23%), liver cholesteryl esters (-39%), LDL size, VLDL and LDL cholesteryl ester content (percent of total lipids), cholesteryl oleate/cholesteryl linoleate ratios in VLDL and LDL (25% to 30%), and ex vivo liver ACAT activity. The triglyceride/cholesteryl ester ratio increased twofold to fourfold in these apolipoprotein B-containing lipoproteins. Endogenous cholesterol absorption appeared to be unaffected by drug treatment. CI-976 failed to alter specific hepatic mRNAs involved in cholesterol metabolism, but comparisons among dietary control groups revealed a marked reduction in 7 alpha-hydroxylase mRNA, no change in LDL receptor mRNA, and an increase in HMG-CoA reductase mRNA in EH rabbits compared with normal chow-fed controls.(ABSTRACT TRUNCATED AT 250 WORDS)

Anilides↗
PubMed1987

The effects of polyoxyethylated cholesterol feeding on hepatic cholesterol synthesis and intestinal cholesterol absorption in rats.

Adduction of ethylene glycol moieties to the 3-hydroxy position of cholesterol produces polyoxyethylated cholesterol (POEC), a water-soluble compound that suppresses cholesterol synthesis and esterification in cultured human fibroblasts. Feeding Sprague-Dawley rats a diet containing 2% (wt/wt) POEC with 10 ethoxy groups resulted in a 3-fold increase in hepatic 3-hydroxy-3-methylglutaryl-CoA reductase activity compared to activity in rats pair-fed a diet of standard rat chow. POEC with an average of 20 ethoxy groups (POEC-20) caused comparable changes in hepatic [2-14C]acetate incorporation into non-saponifiable lipids under ad libitum feeding conditions, significantly reduced cholesterol absorption (18% vs 57%), and increased fecal excretion of neutral steroids (5.1 vs 2.0 mg/g food intake). POEC-20 also reduced cholesterol absorption in rats fed a diet enriched with 2% cholesterol (11% vs 31%). Histologic studies of intestinal mucosa and hepatic tissues from rats fed POEC showed no pathologic changes. These experiments indicate that POEC reduces cholesterol absorption and causes compensatory increases in hepatic cholesterol synthesis.

Animals↗
PubMed1985

Utilization of intramitochondrial membrane cholesterol by cytochrome P-450-dependent cholesterol side-chain cleavage reaction in bovine adrenocortical mitochondria: steroidogenic and non-steroidogenic pools of cholesterol in the mitochondrial inner membranes.

Inner and outer submitochondrial membranes were prepared after disruption of malate-treated bovine adrenocortical mitochondria. It was found that a part of the endogenous cholesterol in the inner membrane (approx. 50%) was rapidly utilized by the cholesterol side-chain cleavage reaction. The utilization of cholesterol in the outer membrane, on the other hand, was inefficient and slow in spite of the fact that cholesterol concentration is higher in the outer than in the inner membrane. When the inner membrane prepared from untreated mitochondria was incubated for 20 min in the presence of a reconstituted cytochrome P-450-reducing system, the inner membrane cholesterol was depleted by approximately 70%. The half-life of the depletion reaction was 2-3 min. In addition, when the outer membrane plus the soluble fraction from the untreated mitochondria were added as a source of cholesterol to the inner membrane fraction, a marginal increase in the production of steroids was observed. From these results it is concluded that a portion of the inner membrane cholesterol can be steroidogenic, whereas the rest of the cholesterol is non-steroidogenic.

Adrenal Cortex↗
PubMed2002

Dietary taurine enhances cholesterol degradation and reduces serum and liver cholesterol concentrations in rats fed a high-cholesterol diet.

The effect of taurine on hypercholesterolemia induced by feeding a high-cholesterol (HC) diet (10 g/kg) to rats was examined. When taurine was supplemented to HC for 2 wk, serum total cholesterol significantly decreased and serum HDL-cholesterol increased compared with the HC diet group. In the hypercholesterolemic rats fed the HC diet, the excretion of fecal bile acids and hepatic cholesterol 7 alpha-hydroxylase (CYP7A1) activity and its mRNA level increased significantly, and the supplementation of taurine further enhanced these indexes, indicating an increase in cholesterol degradation. Agarose gel electrophoresis revealed that, in hypercholesterolemic rats fed the HC diet, the serum level of the heavier VLDL increased significantly, but taurine repressed this increase and normalized this pattern. Significant correlations were observed between the time-dependent increase of CYP7A1 gene expression and the decrease of blood cholesterol concentration in rats fed the HC diet supplemented with taurine. These results suggest that the hypocholesterolemic effects of taurine observed in the hypocholesterolemic rats fed the HC diet were mainly due to the enhancement of cholesterol degradation and the excretion of bile acid.

Animals↗