Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.1.1.34 (lipoprotein lipase)
 7,025 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The lipid metabolic disorders in chronic renal insufficiency (CRI) are related to increased hepatic lipid synthesis, reduced triglyceride removal coupled with insulin insensitivity and impaired lipoprotein lipase activity. Growth hormone is lipolytic, and the effects of recombinant human growth hormone (rhGH) on the hypercholesterolemia of CRI are unsettled. To test this question, we gave rhGH for 14 days at a dosage of 3 units/day intraperitoneally to two-stage, 5/6 nephrectomized, male Sprague-Dawley rats (n = 18) compared to sex- and age-matched control (n = 27) and CRI (n = 40) rats. At the end of the study, CRI rats and those treated with rhGH had a similar degree of renal impairment, as assessed by serum concentrations (mean +/- SEM) of urea nitrogen (49 +/- 3 vs. 54 +/- 4 mg/dl), creatinine (0.9 +/- 0.0 vs. 1.0 +/- 0.1 mg/dl) and cumulative food intake (311 +/- 8 vs. 290 +/- 12 g). Serum urea nitrogen (16 +/- 4 mg/dl) and creatinine (0.4 +/- 0.1 mg/dl) concentrations as well as food intake (412 +/- 9 g) of control rats were significantly (p < 0.0001) different. Serum cholesterol concentration of CRI rats treated with rhGH (87 +/- 3 mg/dl) was not higher than those of CRI rats (81 +/- 2 mg/dl, p < 0.1338) but was significantly higher than in control rats (55 +/- 3 mg/dl, p < 0.0001). CRI rats treated with rhGH showed a similar serum albumin concentration and lower serum glucose than CRI rats (0.9 +/- 0.1 vs. 0.9 +/- 0.0 g/dl and 144 +/- 4 vs. 163 +/- 3 mg/dl, p < 0.0001).(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Hypercholesterolemia in rats with chronic renal insufficiency not aggravated by recombinant human growth hormone. 147 89

Lipid and lipoprotein levels were measured in 118 clinically stable patients who had received a kidney transplant more than 1 year earlier. Seventy-one were treated with ciclosporin (CS), 47 were not. The CS group had significantly higher mean cholesterol (6.54 versus 6.00 mmol/l) and triglyceride (1.83 versus 1.34 mmol/l) concentrations than the non-CS group. LDL/HDL cholesterol ratios were similar in the two groups. The CS patients had higher creatinine and prednisolone doses and used beta-blockers and loop diuretics more frequently. Multiple regression analysis did not show an independent correlation between lipid levels and treatment with CS. On the other hand, there was an independent correlation between cholesterol levels and treatment with loop diuretics, suggesting that such treatment contributes to the higher cholesterol levels in kidney transplant recipients. The diabetics had a more favorable lipoprotein profile than the nondiabetics, especially in triglycerides and HDL cholesterol levels. The marked difference in triglyceride levels between the treatment groups prompted us to evaluate the lipoprotein lipase and hepatic lipase activities in 20 hyperlipidemic, nondiabetic patients. Both enzyme activities were moderately reduced with no difference between the treatment groups, suggesting that factors other than CS interfere with the lipase activities in kidney transplant recipients.
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PMID:Lipoprotein levels and post-heparin lipase activities in kidney transplant recipients: ciclosporin- versus non-ciclosporin-treated patients. 180 36

Twenty six preterm infants were studied at the age of 2, 7, and 26 days. The activities of lipoprotein and hepatic lipase in plasma taken 15 minutes after a heparin bolus of 100 IU/kg had been given and the concentrations of carnitine in serum and urine were measured. The mean gestational age was 31 weeks (range 26-35 weeks) and birth weight 1580 g (range 840-2280 g). Thirteen infants weighed under 1500 g at birth (very low birth weight), 20 were of appropriate weight for gestational age and six were small for gestational age. Lipoprotein lipase activity was higher in the preterm infants of appropriate weight than in the infants of very low birth weight and those who were small for gestational age. At the age of 2 or 7 days the activity of lipoprotein lipase in the preterm infants (mean (SEM) 46.2 (4.3) mumol free fatty acid/ml/hour) was, however, higher than in term infants and adults. Multivariate regression analyses showed that weight and relative birth weight together explained 58% of the variance of lipoprotein lipase activity but only 3% of the variance of hepatic lipase activity. Serum carnitine concentration was lower in the preterm infants than in term infants. Urinary excretion of carnitine increased progressively with age but was independent of serum concentration and carnitine intake. Urinary excretion of total carnitine was significantly greater in the infants who were small for gestational age (mean (SEM) 754 (203) nmol/mg of creatinine, n = 6) than in the infants of appropriate weight (161 (22.0) nmol/mg of creatinine, n = 12) but acyl/free carnitine ratio was smaller in the infants who were small for gestational age than in infants of appropriate weight (0.56 v 5.5). The results indicate that the slow elimination of fat from the circulation in preterm infants less mature than 32 weeks of gestation can hardly be explained by low lipoprotein lipase activity.
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PMID:Lipoprotein lipase, hepatic lipase, and carnitine in premature infants. 334 61

To elucidate the pathogenesis of hyperlipidemia in chronic renal disease in children and adolescents, we have measured serum triglyceride, total cholesterol, high density lipoprotein cholesterol (HDL-C) and activities of postheparin plasma lipoprotein lipase and hepatic triglyceride lipase (EC 3.1.1.3) in nine patients with transplants, and nine hemodialyzed and 18 conservatively treated patients with chronic renal failure. In 29 of 36 patients, serum insulin levels both in fasting and in response to oral glucose load were measured. The lipase activities were measured separately, utilizing antiserum against hepatic triglyceride lipase. All groups of patients had hypertriglyceridemia. The patients with endogenous creatinine clearance less than 20 ml/min/m2 had a low HDL-C level. The HDL-C level was correlated inversely with serum triglyceride level and positively with glomerular filtration rate. The lipoprotein lipase activities were low in patients with endogenous creatinine clearance less than 20 ml/min/m2. Although hepatic triglyceride lipase activities were not significantly low in any groups of patients, they were correlated with glomerular filtration rates in the conservatively treated patients with chronic renal failure. A defective triglyceride removal due to low lipase activities may contribute to uremic hypertriglyceridemia in these patients. On the other hand, patients with transplants had almost normal lipase activities and exhibited hyperinsulinemia; overproduction of triglyceride due to hyperinsulinemia may contribute to their hypertriglyceridemia.
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PMID:Lipid profiles and lipase activities in children and adolescents with chronic renal failure treated conservatively or with hemodialysis or transplantation. 638 39

In two separate trials male and female Wistar rats, 12 weeks of age, were either killed as a preliminary control group, ad lib.-fed or undernourished for 4 weeks until one-third of their 12-week body-weight was lost. Food intakes, urinary and faecal collections and measurements of standard metabolic rate were made at one-weekly intervals on both the ad lib.-fed and undernourished animals of both sexes. The bodies of the preliminary controls, the ad lib.-fed and the undernourished animals of both sexes were analysed for protein and fat, and the weights of four fat depots, two muscles and the major organs of all groups were determined. Measurements of lipid synthesis rate (LSR) and lipoprotein lipase (EC 3.1.1.34) (LPL) activity in the four fat depots and measurements of whole-body protein synthesis rates were carried out on animals of both sexes in each group. Although both sexes lost the same proportion of body-weight the females required more food on a body-weight basis than the males during the undernutrition period. The females absorbed significantly more energy on a body-weight basis during undernutrition and so were less efficient than the males at withstanding nutritional stress. There were no significant differences between males and females, on a body-weight basis, in the excretion of nitrogenous waste products (urinary nitrogen, creatinine, hydroxyproline or NT-methylhistidine) suggesting that there were no differences between the sexes in protein sparing during undernutrition.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Response of male and female rats to undernutrition. 1. Changes in energy utilization, body composition and tissue turnover during undernutrition. 647 63

1. Lipoprotein lipase was separated from normal human post-heparin plasma by affinity chromatography and assayed with a 14C-labelled triolein emulsion. No enzyme activity was detected unless whole serum was included in the assay as a source of cofactor, apolipoprotein C-II. 2. After a 10 h fast, serum obtained from 46 normal subjects, eight patients with hypertriglyceridaemia but normal renal function, patients with chronic renal failure (24 undialysed, 20 haemodialysed) and 14 recipients of renal allografts, was added to incubation medium for the assay of lipoprotein lipase to determine the maximum activation of the enzyme. 3. When serum was obtained from normal subjects, maximum activation of the enzyme correlated positively with the concentration of triacylglycerol in the sample. Neither sex nor age had a significant effect on the maximum activation achieved by serum from control subjects. 4. The maximum lipoprotein lipase-activating capacity of serum from uraemic and transplant patients was significantly reduced when compared with serum from healthy controls or from the non-uraemic hypertriglyceridaemic patients. 5. Maximum enzyme activation correlated positively with high-density lipoprotein cholesterol in serum from undialysed patients, but did not correlate positively with total serum triacylglycerols in any of the patient groups. Only in transplant recipients was there a significant inverse relationship between serum creatinine concentrations and maximum enzyme activation. 6. Although lipoprotein lipase activation was impaired in uraemic subjects and renal transplant recipients, this appeared to be due more to the presence of an inhibitor than to cofactor deficiency.
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PMID:Impaired lipoprotein lipase activation by uraemic and post-transplant sera. 701 1

Disturbances in lipid metabolism and accelerated atherosclerosis are well-known phenomena of chronic renal insufficiency. The disturbance in lipid metabolism has been repeatedly described as secondary type IV hyperlipoproteinemia according to the classification of Fredrickson. The classification of Fredrickson, however, does not take into account the role of the alpha-lipoproteins (the HDL lipoproteins and HDL cholesterol). Hence, HDL cholesterol was determined and correlated to other routine parameters of lipid metabolism in 66 patients with different degrees of renal insufficiency. Furthermore, an intravenous fat tolerance test was performed in 14 patients with terminal renal insufficiency. Beside the well-known hypertriglyceridemia with cholesterol values near the upper limits of normal, a significant reduction in HDL cholesterol was found, showing a significant inverse correlation to plasma creatinine values. Patients with advanced or terminal renal insufficiency additionally showed a significant inverse correlation between HDL cholesterol and plasma triglycerides. The disappearance rate of intravenously administered fat emulsion (which corresponds to the clearance rate of chylomicrons and VLDL) was diminished in azotaemic patients, showing a significant inverse correlation between HDL cholesterol and disappearance rate in the intravenous FTT. Beside hypertriglyceridemia, the diminished HDL cholesterol values represent an additional risk factor for the genesis of accelerated atherosclerosis. The diminished k value demonstrates a diminished activity of lipoprotein lipase as cause of hypertriglyceridemia, whereby the positive correlation between the k value and HDL cholesterol and the inverse correlation between HDL cholesterol and triglycerides suggest a causal relationship between the decreased activity of lipoprotein lipase and diminished HDL cholesterol levels.
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PMID:[High-density-lipoprotein and renal insufficiency (author's transl)]. 708 Apr 95

Plasma lipoprotein and apoprotein (apo) A-I, A-II and B concentrations and post-heparin plasma lipoprotein lipase (LPL) activity and mass were measured in 13 children with congenital nephrotic syndrome of the Finnish type (CNF) six months after renal transplantation to determine whether the severe lipid abnormalities documented prior to and during peritoneal dialysis would normalize. Plasma total triglyceride decreased by 52% (p < 0.001), VLDL triglyceride by 55% (p < 0.01) and total cholesterol by 17% (p < 0.01). HDL cholesterol increased by 51% (p < 0.001), whereas no significant change was observed in LDL cholesterol. Despite these improvements, plasma lipoprotein concentrations were still abnormal after transplantation. Total (p < 0.01) and VLDL triglyceride (p < 0.05) as well as total (p < 0.01), VLDL (p < 0.01) and LDL cholesterol (p < 0.01) were higher than in control children. HDL cholesterol normalized. Plasma apo A-I and A-II concentrations were normal, but the apo B concentration remained high (p < 0.01). Post-heparin LPL activity and mass were normal (25.0 +/- 9.1 mumol FFA/ml/h and 227.2 +/- 88.4 ng/ml). The mean cyclosporine dose correlated positively with the serum creatinine concentration (r = +0.72, p < 0.01). Positive correlations were also observed between total (r = +0.68, p < 0.05) and VLDL triglyceride (r = +0.62, p < 0.05) and the serum creatinine concentrations. We conclude that renal transplantation substantially improves the triglyceride and cholesterol abnormalities in CNF but significant abnormalities still persist.
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PMID:Short-term effects of renal transplantation on plasma lipids and lipoprotein lipase in children with congenital nephrosis. 805 Feb 8

Disorders in lipoprotein metabolism (dyslipidemia) can result in premature atherosclerosis or pancreatitis. Dyslipidemias can be classified as hypercholesterolemia, hypertriglyceridemia, combined hyperlipidemia, and low levels of high density lipoprotein (HDL) cholesterol. All of the dyslipidemias can be primary or secondary. Both elevated levels of low density lipoprotein cholesterol and decreased levels of HDL cholesterol predispose to premature atherosclerosis. Triglyceride levels greater than 1,000 mg/dL increase the risk for pancreatitis. In the appraisal of the dyslipidemias, measurement of serum cholesterol, triglycerides, HDL-cholesterol and obtaining the LDL cholesterol by Friedewald equation is usually sufficient in the majority of patients. However, in some cases, such as the diagnosis of the Type III dyslipidemia and when triglycerides are > or = 400 mg/dL, ultracentrifugation is required to determine the VLDL or LDL cholesterol. Lipoprotein electrophoresis can be useful in the diagnosis of Type III dyslipidemia (broad beta band) and also to detect chylomicrons. In young subjects with coronary artery disease with a normal LDL cholesterol an apolipoprotein B-100 level may be a useful test. In children and young adults with severe hypertriglyceridemia, measurement of lipoprotein lipase activity or assaying apolipoprotein C-II levels can be useful in elucidating the cause. Also, laboratory tests are useful in excluding a secondary cause of dyslipidemia (urinalysis, plasma creatinine, TSH, glucose, protein electrophoresis, alkaline phosphatase and transaminases). Thus, laboratory investigations play an important role in the management of dyslipidemia.
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PMID:A practical approach to the laboratory diagnosis of dyslipidemia. 870 23

VLDL receptor (VLDL-R) is a novel member of the LDL receptor gene family with distinct tissue distribution and function. It binds and internalizes VLDL particles and is primarily expressed in skeletal muscle, heart, brain and adipose tissue, which use fatty acids for energy production or storage. CRF is associated with elevated serum triglyceride and VLDL concentrations and depressed VLDL and chylomicron clearance. We have recently shown marked down-regulation of lipoprotein lipase expression in CRF. This study was conducted to test the hypothesis that VLDL-R expression may be similarly depressed in CRF. To this end, VLDL-R mRNA (Northern blot) and protein mass (Western blot) of skeletal muscle (soleus) and heart were measured in male Sprague-Dawley rats six weeks after 5/6 nephrectomy (CRF group) or sham operation (NL group). A group of erythropoietin (EPO)-treated (150 U/kg twice weekly) CRF animals was included to determine the possible effect of EPO-deficiency anemia (EPO-CRF group). Subgroups of animals were studied at weeks 1, 3 and 6. The CRF group showed a fivefold increase in plasma triglyceride concentration. This was associated with an impressive fourfold reduction in heart and skeletal muscle VLDL-R mRNA and protein mass. VLDL-R mRNA levels in the heart and skeletal muscle were directly related to creatinine clearance and inversely related to serum triglyceride and VLDL concentrations. EPO therapy led to a mild improvement in CRF hypertriglyceridemia but failed to improve VLDL-R expression. Thus, the rise in plasma triglyceride and VLDL concentrations in CRF animals was associated with marked down-regulation of VLDL-R expression. Down-regulation of VLDL-R expression, shown here for the first time, reveals another facet of disturbed lipid metabolism in CRF.
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PMID:Down-regulation of VLDL receptor expression in chronic experimental renal failure. 906 30


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