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)

We have studied the lipoproteins, apolipoproteins, and postheparin lipase activities in an extended pedigree with familial hepatic lipase deficiency. A deficiency of hepatic lipase was found in three of five brothers and in one of their children. Triglyceride enrichment of low density and high density lipoproteins was identified as the constitutive phenotype. beta-very low density lipoprotein was observed in hepatic lipase-deficient subjects, but it was absent when the plasma triglyceride concentration was less than 1 mM/l. The hepatic lipase-deficient subjects had normal or elevated low density lipoprotein cholesterol and high density lipoprotein cholesterol concentrations. Hyperprebetalipoproteinemia, hyperbetalipoproteinemia, and hyperalphalipoproteinemia were observed in both affected and unaffected family members. Compared with the unaffected family members, the hepatic lipase-deficient subjects had no significant differences in very low density lipoprotein cholesterol, very low density lipoprotein triglyceride, or low density lipoprotein cholesterol. These observations are consistent with the presence of additional genes causing hyperlipidemia in this family, independent of the deficiency of hepatic lipase.
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PMID:Plasma lipoproteins in familial hepatic lipase deficiency. 229 46

It has been established previously that nephrotic hyperlipidemia is characterized by both an increase in lipid synthesis and a defect in removal of lipoproteins. The relationship between these defects and altered albumin metabolism is uncertain. One hypothesis is that hepatic lipogenesis increases in parallel with albumin synthesis. To test this hypothesis, albumin synthesis was increased in nephrotic rats fed an 8.5% protein diet (LPN) by increasing dietary protein to 40% (HPN). Proteinuria was modulated in half of the rats fed 40% protein by enalapril (HPE). Albumin synthesis was the same in both HPN and HPE, but proteinuria was reduced in HPE compared to HPN, and so were serum cholesterol and triglycerides (TG). To examine the effect of serum albumin on lipid clearance in the absence of proteinuria, plasma clearance of chylomicrons (CM) and VLDL was measured in Nagase analbuminemic rats (NAR) and found to be no different than in normal SD rats. When proteinuria was induced in NAR and in SD rats, a severe and identical defect in both CM and VLDL clearance was acquired in both groups and blood lipid levels were increased to a similar degree in both groups. Neither hyperlipidemia nor defective removal of lipoproteins from the circulation are linked to albumin synthesis or serum albumin concentration but result, at least in part, from proteinuria. Postheparin lipoprotein lipase (LPL) activity was reduced slightly in nephrotic animals compared to nonnephrotic controls, but the most striking finding was a highly significant decrease in postheraprin LPL activity in normal NAR compared to SD rats (P less than 0.001), suggesting that reduced LPL activity is not responsible for reduced clearance of CM and VLDL in nephrotic rats.
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PMID:Proteinuria, not altered albumin metabolism, affects hyperlipidemia in the nephrotic rat. 238 6

In an attempt to elucidate the mechanisms underlying retinoid-induced hyperlipidemia, the effects of etretinate (Tigason) and isotretinoin (Roaccutane) on two different plasma fat elimination variables and on the plasma fatty acid composition were studied. Twelve patients with various hyperkeratotic disorders participated in a double-blind cross-over study of etretinate and isotretinoin. Each drug was given for 8 weeks with an 8-week intermission. On five occasions an intravenous fat tolerance test (IVFTT) was performed and the lipoprotein lipase activity (LPLA) in adipose tissue and skeletal muscle was measured. Isotretinoin significantly reduced the fat elimination rate as measured by IVFTT (p less than 0.001) and also decreased the muscle LPLA (p less than 0.05). The etretinate-induced depression of these variables was not statistically significant. The LPLA of adipose tissue and the plasma fatty acid composition were not markedly altered by any of the drugs. The observed changes are probably not sufficient to entirely explain retinoid-induced hyperlipidemia but the results strengthen the opinion that plasma lipid metabolism is more unfavourably affected by isotretinoin than etretinate.
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PMID:Plasma fat elimination tissue lipoprotein lipase activity and plasma fatty acid composition during sequential treatment with etretinate and isotretinoin. 243 78

The JCR:LA-corpulent rat is an obese, hyperlipidemic, hyperinsulinemic strain that is atherosclerosis-prone and develops myocardial lesions. The hyperlipidemia is due to elevated plasma levels of a large relatively triglyceride-rich very low density lipoprotein (VLDL). Both corpulent and lean male and female rats were studied. Postheparin lipid clearance and apparent hepatic secretion rate after Triton WR1339 inhibition of lipoprotein lipase were determined. The concentrations of cholesterol and cholesteryl esters were not significantly altered by either treatment. Triglycerides showed rapid postheparin clearance in corpulent rats. The apparent hepatic secretion rate was markedly higher in corpulent male rats than in lean male rats, and the rate in corpulent females was again higher, reflecting the higher serum triglyceride concentrations in corpulent female rats. The relative secretion rate of C:48 triglyceride molecular species was lower than that of the C:50 to C:56 species, while the postheparin clearance of C:48 triglyceride molecular species was impaired compared to the C:50 species and those with higher carbon numbers. This effect was more marked in the male than in the female corpulent rats. The results indicate that VLDL hyperlipidemia in the corpulent rat is due to hepatic hypersecretion of VLDL and not to a defect in lipoprotein lipase. Further, the atherogenesis that is characteristic of the corpulent male rat may be related to the differential metabolism of fatty acids.
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PMID:Plasma lipid secretion and clearance in hyperlipidemic JCR:LA-corpulent rats. 259 65

Hyperlipidaemia is implicated in vascular complications of uraemic patients on haemodialysis. In this work serum lipids, serum lipoprotein lipase (LPL) and insulin levels were measured in 45 chronic uraemic patients on haemodialysis and 44 healthy volunteers. A significant rise in total lipids (TL), cholesterol and triglycerides (TG) was detected in the haemodialysis patients, but no changes were found in either serum phospholipids or high density lipoprotein cholesterol (HDL-chol.). The rise in TL, TG and cholesterol was positively correlated with the duration of dialysis but not with age or sex. On the other hand, a significant rise was also observed in serum LPL and insulin levels but with no correlation between any of them and the lipid levels. From this study it may be apparent that other factors rather than LPL abnormalities may be implicated in hyperlipidaemia in uraemic patients under haemodialysis.
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PMID:Hyperlipidaemia in uraemic patients under chronic haemodialysis. Correlation with serum lipoprotein lipase and insulin levels. 270 Jan 87

The administration of a single injection of tumor necrosis factor (TNF) produces a variety of acute and sustained biological effects, including hyperlipidemia, stimulation of hepatic lipogenesis, decreases in adipose tissue lipoprotein lipase activity, and anorexia with weight loss. Chronic administration of a fixed dose of TNF produces tachyphylaxis to the anorectic/cachectic effects of TNF. We now report that the hyperlipidemic effect of TNF persists during chronic TNF administration in the absence of any cachectic effect of TNF. Sprague-Dawley rats injected with TNF (250 micrograms/kg) show a significant decrease in weight over the next 24 h which can be accounted for by decreases in food and water intake accompanied by an increase in urine output. With subsequent daily injections of TNF, treated rats begin eating and rapidly regain weight. Hypertriglyceridemia persists for up to 10 days of daily injections of TNF. After three daily injections of TNF, no decreases were seen in lipoprotein lipase activity in a wide variety of tissues. De novo hepatic lipogenesis remained increased in TNF-treated animals after four daily injections, but by the fifth day hepatic lipogenesis returned to normal. After 5 days of TNF treatment the acute incorporation of labeled glycerol into serum triglycerides remained elevated. These data indicate that hyperlipidemia persists during multiple daily injections of TNF and that TNF induced hypertriglyceridemia is not inevitably linked to the syndrome of cachexia.
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PMID:Persistence of the hypertriglyceridemic effect of tumor necrosis factor despite development of tachyphylaxis to its anorectic/cachectic effects in rats. 271 42

Because there are no characteristic clinical or biochemical manifestations, the heterozygote state for lipoprotein lipase (LPL) deficiency has been difficult to detect. Measurements of postheparin plasma LPL activity and of LPL mass were performed in six families of probands with LPL deficiency to characterize the heterozygote state. LPL mass was measured in a sandwich enzyme-linked immunosorbent assay (ELISA) using a monoclonal antibody (5D2) that had been produced against bovine milk LPL. Thirteen obligate heterozygotes from these families had reduced LPL activity and mass below the 95th percent confidence limits of 34 normal controls, while one obligate heterozygote had LPL activity and mass between the 90th and 95th percent confidence limits. Potential heterozygotes in these families were identified as normal (n = 8) or heterozygotes (n = 6) by comparison to the 95th percent confidence limits of the controls. Some relatives in four of the six families exhibited mild hyperlipidemia, similar to the pattern seen in familial combined hyperlipidemia (FCHL). The hyperlipidemia segregated with the heterozygote state for LPL deficiency in these families (p less than 0.03). High density lipoprotein (HDL) cholesterol was significantly reduced in the heterozygotes for LPL deficiency (p less than 0.01). The measurement of LPL activity and mass allows identification of the heterozygote state for LPL deficiency, which is characterized by variable expressions of hyperlipidemia and reduced HDL cholesterol. These results suggest that the heterozygote state for LPL deficiency may form one subset of FCHL.
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PMID:Detection and characterization of the heterozygote state for lipoprotein lipase deficiency. 271 95

The aim of this study was to characterize the plasma lipoprotein pattern and some aspects of cholesterol metabolism in a line of hyperlipemic male rats. Plasma cholesterol and triglycerides were increased about 3-fold as compared to control animals (238 vs. 75 and 185 vs. 59 mg/dl respectively). The plasma lipoprotein distribution and the chemical composition of the isolated lipoproteins was unaffected. Plasma triglyceride production rate was increased (40%, P less than 0.01) and post-heparin lipoprotein lipase activity in plasma decreased (-28%, P less than 0.01) in the hyperlipemic rat. The activity of 3 enzymes involved in cholesterol metabolism (HMG-CoA reductase, cholesterol 7 alpha-hydroxylase, and acyl-CoA cholesterol-acyltransferase) did not differ from control values. 3H2O incorporation into digitonin-precipitable sterols, however, was significantly higher than in controls. This finding was due, in part, to an increased liver weight in the hyperlipemic animals. Furthermore kinetic data using 125I-LDL showed that the fractional catabolic rate of lipoprotein was within the normal range, while the synthetic rate of LDL protein was increased (0.67 vs. 0.3 mg/kg/h, P less than 0.01) in the hyperlipemic rat. These observations suggest that multiple metabolic defects underline the hyperlipemia observed in this animal model.
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PMID:Plasma lipoproteins and cholesterol metabolism in spontaneously hyperlipemic rats. 273 Jul 13

Hyperlipidemia of initially Type V and finally of Type III was observed in a patient with Weber-Christian disease. The lipoprotein lipase (LpL) and hepatic triglyceride lipase (HTGL) activities of the post-heparin plasma were low, but detectable. Both lipase activities were higher when assayed with 20 microliters of post-heparin plasma than with more than 30 microliters, indicating the presence of some inhibitory factor in the plasma. This plasma inhibited purified LpL and HTGL from human post-heparin plasma. Zonal ultracentrifugation studies showed that the inhibitor of hepatic lipase was associated with the middle fraction of intermediate lipoprotein and low density lipoproteins (1.020 less than d less than 1.040). These results are consistent with the idea that dyslipoproteinemia in this patient was partially due to dysfunction of the catabolic system caused with an inhibitor of lipolytic enzymes.
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PMID:Dyslipoproteinemia and an inhibitor of lipolytic enzymes in Weber-Christian disease. 273 46

Apoprotein, lipoprotein and lipid parameters of 36 normolipidemic subjects (23 males, mean age 22.7 +/- 7.6 years; 13 females, mean age 26.2 +/- 9.8 years) receiving oral isotretinoin (mean daily dose 0.73 +/- 0.26 mg/kg body weight) for nodulocystic acne (n = 18), severe acne papulopustulosa (n = 15), gram-negative folliculitis (n = 2) and papulopustular rosacea (n = 1) were monitored before and during isotretinoin therapy at biweekly intervals over a period of 14.6 +/- 5.6 weeks. Pretreatment values of mean plasma triglycerides increased significantly (p less than 0.001) from 81.8 +/- 31.9 mg/dl to 112.4 +/- 38.7 mg/dl (47.4%) during isotretinoin treatment. With respect to the mean percent increase of plasma triglycerides from pretreatment levels, patients were classified as nonresponders (less than 10% triglyceride increase), responders (greater than 10% less than 50% triglyceride increase) and hyperresponders (greater than 50% triglyceride increase), revealing a distribution of 25.0, 36.1 and 38.9%, respectively. Isotretinoin treatment had no influence on the isoelectric focusing pattern of apoprotein E isoforms and C apoproteins. In particular, apoprotein C-II, the cofactor of lipoprotein lipase, was not affected. No correlation between apoprotein E phenotypes (2/3, 3/3, 3/4) and the mean plasma triglyceride increase could be demonstrated. Apoprotein B-48, a marker of chylomicrons and atherogenic chylomicron remnants, could not be detected by SDS-PAGE. On the other hand in 21.0% of patients with preexisting mean lipoprotein Lp(a) levels of 18.1 +/- 12.9 mg/dl a moderate increase of atherogenic Lp(a) to mean levels of 37.0 +/- 22.0 mg/dl was observed. Pretreatment values of very-low-density lipoprotein (VLDL) apoprotein (apo) B (7.5 +/- 2.0 mg/dl), low-density lipoprotein apo B (67.3 +/- 17.5 mg/dl) and total plasma apo B (76.6 +/- 19.0 mg/dl) increased significantly to levels of 10.3 +/- 2.4 mg/dl (p less than 0.001), 75.7 +/- 15.8 mg/dl (p less than 0.10) and 85.9 +/- 17.7 mg/dl (p less than 0.05), respectively. As lipoprotein lipase and hepatic lipase activities have been shown to be unaffected by isotretinoin treatment, our data support the hypothesis that isotretinoin induces hepatic oversecretion of VLDL, a condition resembling type IV hyperlipidemia in diabetics, familial hypertriglyceridemia of familial combined hyperlipidemia.
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PMID:Characterization of apoprotein metabolism and atherogenic lipoproteins during oral isotretinoin treatment. 296 29


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