Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: 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)

Eighteen healthy sedentary males took part in supervised bicycle training for 50 minutes three to five times a week. Twelve subjects (group A) trained for 6 weeks at heavy intensity, and six subjects (group B) trained for 12 weeks at moderate intensity. Maximal oxygen uptake increased by about 20% (P less than 0.01). Body weight and composition as well as diet remained unchanged. After 6 weeks plasma high-density lipoprotein (HDL) cholesterol concentrations had increased by 7% (P less than 0.05) in all subjects. The increase was most marked in group B at 14% (P less than 0.05) compared to 3% in group A (ns). Apolipoprotein AI (apo AI) increased by about 7% in both groups (P less than 0.01). After 12 weeks HDL cholesterol and apo AI levels had almost returned to initial values. Measurements of HDL components showed increases of 6% to 12% in free cholesterol, cholesteryl ester (P less than 0.05), and phospholipid (P less than 0.01); whereas, the minor triglyceride fraction decreased by 20% (P less than 0.01). Zonal ultracentrifugation in four subjects revealed a preferential rise of about 35% in the HDL2 subfraction, increasing the HDL2/HDL3 ratio by about 20%. In parallel, the composition of the lipoprotein classes changed. The protein moiety of all classes, except low-density lipoprotein (LDL), expanded at the expense of the core components cholesteryl ester and triglyceride. Hepatic lipase (HL) activity decreased by 6% (P less than 0.05), and lipoprotein lipase (LPL) activity in adipose tissue increased by about 50% (P less than 0.05) during the first 6 weeks of training, while LPL activity in postheparin plasma and skeletal muscle did not change. The transient rise in HDL cholesterol levels was correlated (P less than 0.05) to the elevation of adipose tissue LPL activity. The alterations in HDL concentration were also related to changes in body composition and diet, especially to an increase in fat intake.
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PMID:Plasma lipoproteins and lipolytic enzyme activities during endurance training in sedentary men: changes in high-density lipoprotein subfractions and composition. 641 47

Two progestins with different androgenic activity were compared for their effects on plasma high density lipoproteins and postheparin plasma lipase activities in premenopausal women. Levonorgestrel, a nortestosterone-derived steroid with androgenic activity reduced plasma HDL cholesterol by 17% (P less than 0.05) and HDL2 cholesterol by 30% (P less than 0.05), without changing the HDL3 cholesterol concentration. At the same time the postheparin plasma hepatic lipase activity was increased by 56% (P less than 0.01) whereas the lipoprotein lipase was not changed. None of these effects was reproduced during administration of medroxyprogesterone acetate, a progestin with low androgenic activity. The results suggest, first, that the decrease of HDL cholesterol observed during treatment with progestins is related to the androgenic activity of the steroid used, and, second, that the change in HDL (HDL2) is caused by androgen-induced increase of hepatic lipase activity.
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PMID:Different effects of two progestins on plasma high density lipoprotein (HDL2) and postheparin plasma hepatic lipase activity. 646 May 9

Familial chylomicronemia is a rare genetic disorder attributable to the absence of lipoprotein lipase activity or the absence of apo-CII, i.e., the cofactor for the same enzyme. Plasma lipoproteins were analyzed by zonal ultracentrifugation under rate flotation conditions in four patients with lipoprotein lipase deficiency and two patients with apo-CII deficiency. Lipoproteins of density less than 1.006 gm/ml, and particularly lipoproteins with Sf greater than 100, were present in very high concentrations. Low levels of density greater than 1.006 gm/ml lipoproteins were observed. This fraction was composed of some different and discrete lipoprotein populations: intermediate-density lipoproteins (in three of six patients, density = 1.006 to 1.019 gm/ml); low-density lipoprotein LDL2 (in all patients, density = 1.019 to 1.045 gm/ml); low-density lipoprotein LDL3 (in all patients, density = 1.045 to 1.063 gm/ml); high-density lipoprotein HDL2 (in four of six patients); and high-density lipoproteins HDL3 (in all patients). LDL3 was never observed in normal participants by means of zonal ultracentrifugation; this subclass of low-density lipoproteins seems to correspond to LDL particles of very low Sf (2 to 5) previously identified by analytical ultracentrifugation in patients with severe hypertriglyceridemia. LDL3 was isolated by means of zonal ultracentrifugation as a single and discrete peak in all patients. Lipoproteins of density greater than 1.006 gm/ml were rich in triglycerides and poor in cholesterol in comparison with normal lipoproteins. The heterogeneity of low-density lipoproteins (particularly the appearance of LDL3), low levels of total high-density lipoproteins, and lower HDL3 flotation rate than normal are typical aspects of serum lipoproteins in these patients. No significant differences in the lipoprotein profiles of the patients with lipoprotein lipase deficiency in comparison with patients with apo-CII deficiency were found. In both groups of patients, the plasma lipoproteins profile and the altered lipoprotein composition could be related to the impaired catabolism of triglyceride-rich lipoproteins caused by the absence of lipoprotein lipase activity.
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PMID:The plasma lipoproteins in familial chylomicronemia. Analysis by zonal ultracentrifugation. 649 71

In order to study the effects of chronic alcoholism, 3 groups of patients were investigated and compared to 10 healthy controls. Group I consisted of 9 heavy drinkers, who exhibited type V hyperlipidemia (HLP) under alcohol intake. Group II consisted of 7 patients, who previously had type V HLP under the influence of alcohol. At the time of the investigation, however, they had ceased alcohol drinking for at least 6 months and were normolipidemic. Group III consisted of 7 heavy drinkers without hyperlipidemia. Compared to controls, group I had significantly decreased plasma concentrations of high density lipoproteins2 (HDL2) and HDL3 (both P less than 0.01); activities of post-heparin lipoprotein lipase (LPL) and hepatic lipase (HTGL) as well were excessively decreased (both P less than 0.01). In group III LPL was also decreased (P less than 0.01), but HTGL was distinctly (P less than 0.01) higher than in controls. No such differences could be demonstrated for the patients of group II. Acute alcohol withdrawal from a patient suffering from alcoholism with HLP led to a sharp increase of LPL with a simultaneous decrease of VLDL within 2 days and a more delayed increase of LDL, HDL2 and HTGL, all reaching normal values within 12 days after cessation of alcohol drinking. With respect to the apolipoprotein (apo) composition of HDL2, patients of group I and group III exhibited a significantly lower percentual content of apo C-I at the expense of a significantly higher content of apo A-II as compared to controls and patients of group II. In group I and II, the percentual content of apo D in HDL2 was significantly higher than in controls and in group III. It is concluded that severe alcohol intake strongly impairs LPL in patients with HLP. The pronounced increase of HTGL in some patients (group III) may protect these individuals from HLP. The increased content of apo D in HDL2 may be a possible primary trait for alcohol-inducible HLP.
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PMID:Post-heparin lipolytic activities and alterations of the chemical composition of high density lipoproteins in alcohol-induced type V hyperlipidemia. 649 35

Chronic alcohol intake is associated with an increase in fasting plasma high density lipoproteins (HDL). To study alcohol's acute effects on plasma lipoproteins, we measured plasma lipoprotein concentrations and activities of postheparin plasma lipases in nine normolipemic males after ingestion of 40 g of ethanol (as whiskey). After alcohol there was no change in lipoprotein lipase activity but hepatic lipase was decreased to 67% of baseline at 6 hr. There were associated increases in HDL phospholipids (12 mg/dl) and cholesterol (10 mg/dl) resulting in prominence of larger, lipid-enriched HDL particles. Changes were most pronounced in the HDL3 and HDL2a subclasses. Very low density lipoprotein (VLDL) phospholipids and cholesterol were also increased by 13 and 9 mg/dl, respectively, with no significant change in triglycerides. Changes in lipoproteins and lipase were largely reversed 10 hr after alcohol intake. The transient increases in VLDL and HDL lipids after alcohol may result in part from acute inhibition of hepatic lipase activity. The results suggest a role of hepatic lipase in the catabolism of phospholipids of VLDL and possibly HDL.
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PMID:Acute inhibition of hepatic lipase and increase in plasma lipoproteins after alcohol intake. 654 Dec 37

Chronic renal disease with secondary hyperlipidemia is highly atherogenic. In uremia and patients on chronic hemodialysis there is a high incidence of atherosclerotic complications whereas the incidence of atherosclerotic disease is relatively low in the nephrotic syndrome. This is surprising, as nephrosis produces type-II hyperlipidemia, which is usually highly atherogenic. In this study 10 patients (5 male, 5 female) with a newly diagnosed nephrotic syndrome were compared to 10 controls (5 male, 5 female). As laboratory parameters, lipids, lipoproteins (VLDL, IDL, LDL, HDL2 and HDL3 by rate zonal centrifugation) and the percentage composition of the major apolipoproteins in VLDL, HDL2 and HDL3, as well as lipoprotein lipase (LPL), hepatic lipase (HTGL) and lecithin-cholesterol-acyl-transferase (LCAT) were measured. In nephrotic patients significantly higher plasma levels of cholesterol, triglycerides, phospholipids, VLDL, IDL and LDL were found, whereas HDL-chol, HDL2 and HDL3 were unchanged. LPL and HTGL were both significantly impaired, whereas LCAT was distinctly increased. The percentage composition of apolipoproteins in HDL2 and HDL3 was normal. In nephrotic VLDL, apo-AI was distinctly increased at the expense of a decrease in apo-CII, and increased LCAT was explained by the relative rise of apo-AI in nephrotic VLDL. The increase in apo-AI in VLDL is discussed as a possible reason for the low atherogenic risk of secondary hyperlipidemia in nephrotic syndrome.
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PMID:[Lipoproteins, apolipoproteins, lipoprotein lipase, hepatic triglyceride lipase and lecithin cholesterol acyltransferase in patients with nephrotic syndrome]. 661 72

Serum lipoproteins were measured during a single infusion of intralipid and during parenteral nutrition with intralipid and glucose. Postheparin plasma lipolytic enzymes and plasma LCAT activity were assayed before and after the parenteral nutrition. Both single and repeated infusions of intralipid were followed by a significant rise of HDL2 concentration (p less than 0.01), whereas the HDL3 decreased. The composition of HDL subclasses altered. The HDL2 triglyceride and phospholipids increased, while the HDL3 esterified cholesterol and protein decreased. In vitro incubation of serum with intralipid alone caused no changes in the zonal profile of HDL subclasses, but hydrolysis of intralipid by lipoprotein lipase was followed by conversion of HDL3 into lighter particles floating in the density range of HDL2. The present results provide additional evidence for a precursor-product relationship between the HDL2 and HDL3. During 4 days of parenteral nutrition with intralipid, the basal (morning) values of serum total and VLDL triglyceride did not change. The LDL phospholipids increased progressively (from 67 to 98 mg/dl, p less than 0.05). The total HDL cholesterol decreased and this change was due to the fall of HDL3 cholesterol esters (from 19 to 12 mg/dl, p less than 0.05). Also the basal values of apo A-I and A-II in HDL3 decreased. The basal level of the HDL2 remained constant. Postheparin plasma LPL activity increased by 52% (p less than 0.01) but hepatic lipase activity fell by 49% (p less than 0.05). These changes may account for the maintenance of plasma HDL2, whereas the progressive fall of the basal HDL3 is probably due to the lack of intestinal apoprotein synthesis during absent intestinal absorption.
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PMID:Changes of high density lipoprotein subfraction concentration and composition by intralipid in vivo and by lipolysis of intralipid in vitro. 665 16

Plasma lipids, lipoproteins, tissue lipoprotein lipase (LPL) and hepatic lipase (H-TGL) were studied in 7 patients with familial hyperchylomicronemia from four different families. Their first-degree relative were also studied. The patients were heterogeneous for the genetic defect; LPL activity was absent in five patients (LPL deficiency) but normal in two. However, these two did not have apo C-II, the physiological activator of LPL (C-II deficiency). There were no significant differences in the clinical picture between patients with LPL deficiency and C-II deficiency. In both mutants, marked hypertriglyceridemia was due to an accumulation of lipoproteins of density less than 1.006 g/ml. The LDL fraction was very reduced and abnormal in composition, presenting a CH/TG ratio of 0.5. The plasma apolipoprotein B (apo B) level was low (67 +/- 5.5 mg/dl) and was transported mainly in the VLDL fraction (26 +/- 3.2 mg/dl) rather than in the LDL fraction (15 +/- 1.4 mg/dl). Very low levels of cholesterol and apolipoprotein A-I in HDL subfractions HDL2 and HDL3 were also recorded. Only 3 out of the 24 first-degree relatives of patients with LPL deficiency showed even a small increase in plasma triglycerides, but 15 had low or low to normal LPL values. H-TGL levels were normal in all subjects. The 4 first-degree relatives of C-II deficiency patients showed normal levels of plasma lipids. LPL and H-TGL, and 2 children of 1 patient showed normal distribution of apo C peptides in their VLDL. A block in chylomicron catabolism, due to the absence of LPL or apo C-II, may lead to a massive accumulation of lipoproteins with a density less than 1.006 g/ml, and a drastic reduction in the LDL and HDL fractions. Low LPL values in the first-degree relatives of LPL deficiency patients might represent a biochemical marker for healthy carriers of LPL deficiency.
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PMID:Familial lipoprotein lipase and apolipoprotein C-II deficiency. Lipoprotein and apoprotein analysis, adipose tissue and hepatic lipoprotein lipase levels in seven patients and their first degree relatives. 665 13

The distinct increase in the highly atherogenic plasma low-density lipoproteins (LDL) caused by the wellknown LDL-receptor defect is considered to be responsible for the development of atherosclerosis in familial hypercholesterolemia (FH). In contrast to the atherogenic LDL, the high-density lipoproteins (HDL) are considered to have a protective effect against the development of atherosclerosis and have hitherto been insufficiently investigated in association with FH. HDL2 are assumed to be important in the removal of free cholesterol from the peripheral tissue to the liver, but this hypothesis needs to be supported by further experimental investigations. In this study 18 patients (7 men/11 women) with familial hypercholesterolemia (FH) were compared with 18 healthy controls (8 men/10 women). From fasting plasma the following parameters were determined: cholesterol, triglycerides, phospholipids, HDL-cholesterol, by rate zonal ultracentrifugation the lipoproteins VLDL (very low-density lipoproteins), IDL (intermediate-density lipoproteins), LDL (low-density lipoproteins), HDL2 and HDL3, as well as the activities of lipoprotein lipase (LPL) and hepatic lipase (HTGL). In addition, the percentage composition of the major apolipoproteins (apo) of HDL2 and HDL3 were determined by polyacrylamide disc-gel electrophoresis. In LDL of patients with FH the percentage amount of protein was significantly (p less than 0.01) smaller than in controls. Furthermore, in HDL2 of patients with FH, the percentage content of apo-A II and apo-D was significantly (both p less than 0.01) higher than in controls. In HDL3 of patients with FH a significantly smaller (p less than 0.02) amount of apo-E was revealed than in controls.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:[Atherosclerosis in familial hypercholesteremia possibly induced by defective HDL]. 671 Jan 13

Twenty-seven menopausal women were given the synthetic progestin levonorgestrel for two weeks. The mean plasma high-density lipoprotein (HDL) cholesterol concentration decreased from 1.32 mmol/l to 1.01 mmol/l (p less than 0.001) during treatment. This was due to the selective reduction in plasma HDL2 cholesterol from 0.73 mmol/l to 0.44 mmol/l, whereas the plasma HDL3 cholesterol was not changed. The mean hepatic lipase (HL) activity of postheparin plasma increased from 20.6 to 35.3 mumol.h-1.ml-1 (p less than 0.001) while the lipoprotein lipase (LPL) activity was not changed. A significant inverse correlation existed between the HDL2 cholesterol concentration and HL activity both before (r=-0.49, p less than 0.01) and after (r=-0.39, p less than 0.05) treatment, and a significant correlation was observed between the changes in these two variables (r=0.39, p less than 0.05). These results are compatible with the hypothesis that HL participates in the regulation of plasma HDL2 levels and they suggest that progestin treatment reduces plasma HDL2 cholesterol concentration by increasing the hepatic lipase activity. It is not known whether this type of HDL2 reduction is accompanied by increased atherogenesis but as long as the issue is unresolved some caution is needed in the long-term use of levonorgestrel, particularly in women who simultaneously are given some other drug depressing plasma HDL2 concentration.
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PMID:Reduction of plasma high-density lipoprotein cholesterol and increase of postheparin plasma hepatic lipase activity during progestin treatment. 679 Jan 99


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