Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0020473 (hyperlipidemia)
 15,891 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Lipoprotein metabolism was studied in eleven patients with Type III hyperlipoproteinaemia, one with normolipidaemic dysbetalipoproteinaemia and eight controls. Apolipoprotein B kinetics in very low density, intermediate density and low density lipoproteins (VLDL, IDL and LDL) was investigated. Fractional catabolic rates (FCRs) of VLDL-apo B and IDL-apo B were lower (P less than 0.005 and P less than 0.001) in the patients: 0.064 +/- 0.018 and 0.059 +/- 0.006 h-1 respectively, (mean +/- SEM), compared with 0.219 +/- 0.035 and 0.243 +/- 0.028 h-1. Synthetic rates (SRs) of IDL-apo B varied widely from 1.5 mg kg-1 day-1 in the subject with normolipidaemic dysbetalipoproteinaemia to 2.8-25.2 mg kg-1 day-1 in Type III. The mean time for conversion of IDL-apo B to LDL-apo B was prolonged, 18.7 h compared with 3.8 h in the controls (P less than 0.001). LDL-apo B pool size and SR were lower in the patients (P less than 0.05 for both). Two patients treated with gemfibrozil showed reduced hyperlipidaemia and decreased SR of VLDL-apo B and IDL-apo B. Dysbetalipoproteinaemia is associated with pronounced impairment of IDL and VLDL-remnant catabolism, lipoprotein levels reflecting an interaction between this defect and SR of these lipoproteins.
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PMID:Plasma apolipoprotein B metabolism in familial type III dysbetalipoproteinaemia. 392 66

The release of histaminase activity in plasma after small intravenous of heparin was studied in 85 normal subjects and patients. In normal subjects, plasma histaminase activity (basal level, 1.7+/-0.1 U/ml, mean +/-SEM) increased 1.6+/-0.2 U/ml after 10 U of heparin/kg, 8.5+/-2.4 U/ml after 20 U/kg, and 33+/-4.9 U/ml after 75 U/kg. The extent of the increase varied widely among individuals but in a particular individual the response was constant and dose-dependent. Histaminase activity rose to peak levels within 7-15 min and then declined exponentially with a half-life of 40-120 min. This pattern of response was also observed in two patients with the histaminase-producing tumor, medullary carcinoma of the thyroid. A significantly reduced response was observed, however, in 14 patients with type I hyperlipoproteinemia, a disorder in which high plasma triglyceride levels are associated with low postheparin plasma lipolytic activity. After 10 U heparin/kg, plasma histamine activity increased 0.5+/-0.2 U/ml, and after 75 U heparin/kg, 10.9+/-5.6 U/ml. In contrast, in 27 patients with other types of hyperlipoproteinemia in whom postheparin lipolytic activity was normal, the increase (2.4+/-0.6 U/ml) in plasma histaminase activity after 10 U heparin/kg was not significantly different from that of normal subjects. The reduced response of the plasma histaminase activity to heparin in patients with type I hyperlipoproteinemia did not appear to be due to the presence of lipemia or to an inhibitor of the enzyme in plasma. These findings suggest that many patients with type I hyperlipoproteinemia may have deficient release of both lipolytic and histaminase activities into plasma after heparin administration.
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PMID:Response of plasma histaminase activity to small doses of heparin in normal subjects and patients with hyperlipoproteinemia. 419 95

We have previously reported that normal Wistar rats fed an isocaloric, sucrose-rich (63%) diet (SRD) developed glucose intolerance and elevated triglyceride levels in plasma as well as in heart and liver tissue. This metabolic state was accompanied by hyperinsulinism both in vivo and in vitro, suggesting that a state of insulin resistance has developed. The aim of this study was to gather information on the various plasma post-heparin lipolytic activities in rats fed a SRD. Hepatic triglyceride lipase (H-TGL) was evaluated by both, protamine sulfate inhibition (PSI) of extrahepatic lipoprotein lipase (LPL) and heparin-Sepharose affinity chromatography (H-SAC). Both methods rendered comparable results. Total triglyceride lipase (T-TGL) was measured after Krauss et al. and monoglyceride hydrolase (MGH) after Vogel et al. Our results have shown a significant decline of plasma T-TGL (5.32 +/- 0.34 means +/- SEM vs. 7.48 +/- 0.64 mumol glycerol ml-1 h-1; p less than 0.01), H-TGL (3.71 +/- 0.28 vs. 5.05 +/- 0.69; p less than 0.05), LPL (1.61 +/- 0.26 vs. 2.42 +/- 0.41; p less than 0.05) and MGH (558 +/- 108 mumol glycerol l-1 min-1 vs. 1,165 +/- 45; p less than 0.001) activities. Thus, feeding a sucrose-rich diet induced a state of hyperlipemia and insulin resistance in which not only plasma T-TGL but also H-TGL and MGH activities were significantly decreased. This suggests that the latter two enzymes are also under nutritional and/or hormonal control.
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PMID:Post-heparin plasma hepatic triglyceride lipase and monoglyceride hydrolase activities in hyperlipemia induced by a sucrose rich diet. 661 28

Three healthy male and three female inpatient volunteers consumed isocaloric diets for 4 wk. At weekly intervals, a fatty meal (100 g fat) was consumed by each fasting subject and blood drawn at 2 h intervals for 12 h. Of the four oral fat loads, two contained saturated fat (polyunsaturated/saturated fat ratio = 0.34) and two contained unsaturated fat (polyunsaturated/saturated fat = 2.21). The magnitude of alimentary lipemia, expressed as area under the plasma triglyceride curve, was 3- to 4-fold higher in males than females. Alimentary lipemia was inversely related to the subjects' fasting plasma high-density lipoprotein (HDL)-cholesterol, HDL apolipoprotein (apo) CIII and directly related to plasma triglycerides. The P/S ratios of the daily diet or the fat meal did not significantly influence the plasma triglyceride curve. After fat intake, mean (+/- SEM) plasma total apoCII and CIII fell to 54 +/- 20% and 73 +/- 5% of base-line, respectively, at 12 h in five of six subjects. After oral fat, an initial fall and a subsequent rise in apoCII and CIII in HDL was associated with reciprocal changes in apoC concentrations in very low-density lipoproteins. We speculate from the data that 1) plasma HDL and their apoC concentrations are important determinants of chylomicron clearance and 2) transfer of apoCs from HDL to triglyceride-rich lipoproteins in the early phase of fat absorption does not result in the total recycling of apoCs from these lipoproteins to HDL during the late phase of alimentary lipemia.
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PMID:Alimentary lipemia: plasma high-density lipoproteins and apolipoproteins CII and CIII in healthy subjects. 682 85

Endothelin-1 (ET-1) is a potent vasoconstrictor whose serum concentration increases with the development of atherosclerosis. Coronary artery-vein bypass grafts are susceptible to vasospasm and to the development of accelerated atherosclerosis. Although ET-1 is thought to play a role in coronary vasospasm, the effect of ET-1 in atherosclerotic vein grafts is unknown. The responses of veins, arteries, and vein bypass grafts from normolipidemic and hyperlipidemic animals to ET-1 were therefore investigated. Vein bypass grafts were placed in the carotid position of 12 New Zealand White rabbits. Seven were fed a 1% cholesterol diet for 4 weeks before surgery and thereafter until harvest (hyperlipidemia), and five were fed a normal diet (normolipidemia). Vein grafts, contralateral common carotid arteries, and jugular veins were harvested 4 weeks after surgery. Whereas there were no histologic changes in veins or carotids, normolipidemic vein grafts developed intimal hyperplasia and hyperlipidemic vein grafts developed atherosclerosis. Isometric tension studies with ET-1 (10(-12) to 10(-6) M) showed that hyperlipidemia increased the maximal tension generated to ET-1 in the veins (660 +/- 80 to 1,110 +/- 140 mg, mean +/- SEM; p < 0.05), carotids (150 +/- 30 mg to 540 +/- 120 mg; p < 0.05), and vein grafts (180 +/- 20 to 450 +/- 60 mg; p < 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Endothelin and vein bypass grafts in experimental atherosclerosis. 750 84

Lipid abnormalities are seen frequently in renal transplant patients. Cardiovascular disease is an important cause of morbidity and mortality in these patients. We assessed the efficacy and safety of the lipid-lowering drugs, nicotinic acid (short acting) and lovastatin, the 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor. Twelve renal transplant patients who had persistent hyperlipidemia despite 6 weeks of dietary treatment participated in this prospective, randomized, open-labeled crossover trial. At 16 weeks, when compared with control values, nicotinic acid (> or = 1.5 g twice a day) significantly reduced the total cholesterol (from 312 +/- 18 [+/- SEM] mg/dL to 229 +/- 19 mg/dL; P = 0.03) and the low-density lipoprotein cholesterol (from 218 +/- 15 mg/dL to 142 +/- 13 mg/dL; P = 0.03) and significantly increased the high-density lipoprotein cholesterol (from 44 +/- 3 mg/dL to 58 +/- 5 mg/dL; P = 0.03). The triglyceride level was reduced from 255 +/- 40 mg/dL to 150 +/- 23 mg/dL (P = 0.09). At 16 weeks, lovastatin therapy (40 mg/d) significantly reduced the total cholesterol (from 285 +/- 13 mg/dL to 233 +/- 10 mg/dL; P = 0.005) and the low-density lipoprotein cholesterol (from 201 +/- 11 mg/dL to 147 +/- 7 mg/dL; P = 0.001). There were no significant changes in the triglyceride and high-density lipoprotein cholesterol levels. Although flushing developed in 67% of patients treated with nicotinic acid, this was not a reason for any of the study dropouts. During this short-term study period no adverse biochemical effects were noted with either of the drugs.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Effects of nicotinic acid and lovastatin in renal transplant patients: a prospective, randomized, open-labeled crossover trial. 770 60

A model of early atherosclerosis in hamsters with moderate hypercholesterolemia (217 to 271 mg/dL) was established that was highly responsive to exogenous antioxidants. A key feature of this model was elevation of vascular oxidative stress by use of a diet deficient in nutritional antioxidants and supplemented with corn oil (10%) and cholesterol (0.2%, 0.4%, or 0.8%). After 10 weeks on the 0.4% cholesterol diet, mean plasma alpha-tocopherol levels declined from 5.68 +/- 0.30 to 1.27 +/- 0.15 micrograms/mL, while monocyte-macrophage foam cell lesions in the aortic arch, as assayed by video microscopy/image analysis of oil red O-stained histological specimens, increased from undetectable at week 0 to 60,900 +/- 5400 microns 2 per specimen at week 10 (mean +/- SEM, n = 36). alpha-Tocopherol or probucol administered for 10 weeks markedly suppressed LDL oxidation ex vivo and profoundly inhibited aortic foam cell formation. However, the effects of antioxidants on aortic lesions were attenuated at higher plasma cholesterol levels, although LDL oxidation ex vivo was effectively inhibited. With a plasma cholesterol level at approximately 250 mg/dL, the maximum effect of alpha-tocopherol on lesion size reached approximately 36% of control value, and the dose for half-maximal effect was approximately 10 mg.kg-1.d-1, which resulted in a plasma alpha-tocopherol value of approximately 20 micrograms/mL. Under these conditions a linear, inverse correlation of aortic lesion size and plasma alpha-tocopherol concentration was observed (n = 68, r = -0.581, P < .001). The data demonstrate that LDL oxidation is a significant component of early atherogenesis in this model but suggest that hyperlipidemia can outweigh the therapeutic effectiveness of antioxidants. The high sensitivity of aortic lesion initiation to alpha-tocopherol in hamsters maintained on moderately hypercholesterolemic diets depleted of endogenous antioxidants demonstrates that vascular oxidative stress can be isolated from other causative factors in an in vivo model of atherosclerosis.
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PMID:Relation of vascular oxidative stress, alpha-tocopherol, and hypercholesterolemia to early atherosclerosis in hamsters. 774 45

To investigate the potential use of apoE in gene therapy of hyperlipidemias, an adenoviral vector was constructed that contained the human apoE3 cDNA under the control of the RSV promoter (Av1RE). Transduction of HepG2 cells resulted in the overexpression of human apoE secreted into the culture medium. Intravenous injection of 5 x 10(11) Av1RE vector particles into apoE-deficient mice resulted in expression of human apoE3 in mouse plasma at levels of 1.2 +/- 0.4 micrograms/L (mean +/- SEM, n = 5) 7 days after injection. Mice injected with the control vector Av1Lacz4 did not express detectable levels of human apoE. Average plasma cholesterol concentrations were reduced approximately eightfold from 737.5 +/- 118 mg/dL (mean +/- SEM, n = 6) to 98.2 +/- 4.4 mg/dL (mean +/- SEM, n = 5) and were unaffected in the control vector group. Expression of human apoE resulted in a shift in the plasma lipoprotein distribution from primarily VLDL and LDL in the control mice to predominantly HDL in the Av1RE-treated group. Western blot analysis of fast protein liquid chromatography-fractionated mouse plasma showed that the human apoE protein was associated with VLDL, LDL, and HDL. Correction of the hyperlipidemic condition found in the apoE-knockout mouse strain by direct in vivo gene transfer establishes the potential of this approach for treatment of hyperlipidemia caused by apoE deficiency or malfunction in human disease.
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PMID:Phenotypic correction of hypercholesterolemia in apoE-deficient mice by adenovirus-mediated in vivo gene transfer. 774 59

Hepatic VLDL overproduction in familial combined hyperlipidaemia (FCH) may delay the clearance of atherogenic apolipoprotein (apo) B containing particles. We investigated if normalization of fasting plasma triglycerides (TG) by hypolipidaemic treatment results in improved metabolism of apo B48 and apo B100 in six male subjects with FCH and compared them to six normolipidaemic controls. The FCH patients were studied before (TG, 5.2 +/- 1.2 mmol l-1; mean +/- SEM) and after therapy (TG, 2.1 +/- 0.3 mmol l-1) with either simvastatin (n = 4) or combined therapy with gemfibrozil (n = 2). The postprandial changes of apo B100 and apo B48 were studied after a single oral fat meal (24 h; 50 gram fat m-2). Changes in triglyceride rich particles (TRP; d < 1.006 g ml-1) and remnant fractions (REM; d:1.006-1.019 g ml-1) of apo B were quantitated by scanning silverstained SDS-PAGE (4-15%). Apo B48 in fasting TRP in untreated and treated FCH was 15% and 14% of total apo B, and 6% in controls (P < 0.05). In controls, postprandial B48 increased maximally at 4 h by 81% in TRP and by 137% in REM compared to baseline. In treated FCH, the postprandial apo B48 pattern normalized in TRP compared to the untreated state. Postprandial apo B100 in controls decreased in TRP and REM by 33% and 18% (P < 0.05). In untreated and treated FCH, postprandial apo B100 remained unchanged vs. baseline in TRP and in REM suggesting hypersecretion of VLDL. The elimination of B100--assessed as area under the curve--in TRP (32.5 +/- 3.6 au.h; mean +/- SEM) and REM fractions (33.2 +/- 3.1 au.h), improved significantly after treatment (21.0 +/- 2.8 and 20.4 +/- 3.3 au.h, respectively). The apo B48 clearance in TRP fractions was improved after treatment (4.3 +/- 1.4 au.h vs. 2.9 +/- 1.2 au.h; P = 0.06), but not in REM fractions (2.8 +/- 1.0 au.h vs. 1.8 +/- 0.5 au.h; NS). In conclusion, in FCH subjects with apo B100 hypersecretion and increased fasting plasma apo B48 levels, reduction of fasting plasma TG improved, but did not normalize, TRP apo B48 and B100 metabolism. However, therapy normalized postprandial apo B100 remnant metabolism. Impaired postprandial apo B metabolism may be instrumental in the development of premature atherosclerosis in FCH subjects.
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PMID:Postprandial apolipoprotein B100 and B48 metabolism in familial combined hyperlipidaemia before and after reduction of fasting plasma triglycerides. 785 67

The purpose of this study was to examine the influence of brisk walking on postprandial lipemia in 26 sedentary women aged 41 to 55 years. The lipemic response to a high-fat meal (mean +/- SEM: 73.8 +/- 1.3 g fat, 66% energy; 81.8 +/- 1.4 g carbohydrate) was determined pretraining and posttraining. Blood samples were obtained in the fasted state and hourly for 6 hours after the meal. Serum was analyzed for triacylglycerol (TAG), total cholesterol, high-density lipoprotein (HDL) and HDL2 cholesterol, apolipoproteins (apos) A-I and B, nonesterified fatty acids (NEFA), glucose, and insulin. Subjects were randomly assigned to one of two groups: walkers (n = 13) followed a program of brisk walking (average of 21 +/- 1 [range, 17 to 27] min.d-1 at 1.76 +/- 0.02 m.s-1), whereas controls (n = 13) maintained their habitual life-style. Procedures were repeated 12 weeks later, with 48 hours between the last training session and determination of postprandial lipemia. Eleven walkers and 13 controls completed the study. Responses over time were compared between groups (Mann-Whitney U, P < .05). Brisk walking improved endurance fitness and decreased body fatness, but had no influence on peak TAG concentration (walkers, 1.6 +/- 0.2 v 1.6 +/- 0.2 mmol.L-1; controls, 1.9 +/- 0.3 v 2.1 +/- 0.3) or the area under the TAG/time curve after the test meal. The area under the insulin/time curve decreased in walkers relative to controls. These results suggest that in sedentary women aged 41 to 55, brisk walking attenuates the serum insulin response, but not the lipemic response, to consumption of a high-fat mixed meal when these responses are determined 48 hours after the last exercise bout.
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PMID:Influence of 12 weeks of training by brisk walking on postprandial lipemia and insulinemia in sedentary middle-aged women. 788 87


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