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

---

Query: EC:3.1.1.34 (lipoprotein lipase)
7,025 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Report on a case of Tangier disease in a girl aged 4.11 m. Clinically the tonsils were hypertrophic and of a yellow color. Their stroma contained many cholesterinesters which produced the histologic picture of foam-cell xanthomatosis. The serum contained only traces of alpha-lipoprotein. The level of Cholesterin of the HDL fraction was reduced to one twelvth of the norm. The serum of her father also showed a clearly reduced content of HDL cholesterin. In the patient herself lipolytic enzymes like lecithin-cholesterin-acyltransferase, post-heparin plasma-lipoprotein lipase and hepatic triglycerid-lipase showed normal activity.
...
PMID:["Hypo-alpha-lipoproteinemia" (Tangier-disease) (author's transl)]. 17 1

In a 60-year-old patient with manifest diabetes mellitus and in his 63-year-old brother with latent diabetes mellitus hypobeta-lipoproteinaemia was diagnosed. Cholesterol values were around 1,8 mmol/1 in whole serum samples. The LDL-cholesterol fraction was 1,04 mmol/1. The beta-lipoprotein band in the lipoprotein electrophoresis was markedly reduced. Apolipoprotein B measured by radial immuno-diffusion was about 30% of the normal for age. The components of LDL were normal. Values of hepatic triglyceride lipase and lipoprotein lipase in heparinised plasma were within the normal range. The simultaneous occurrence of hypobetalipoproteinaemia and diabetes mellitus is described here for the first time.
...
PMID:[Familial hypobetalipoproteinaemia and diabetes mellitus (author's transl)]. 19 10

The monolayer technique has been used to study the interaction of lipids with plasma apolipoproteins. Apolipoprotein C-II and C-III from human very low density lipoproteins, apolipoprotein A-I from human high density lipoproteins and arginine-rich protein from swine very low density lipoproteins were studied. The injection of each apoprotein underneath a monolayer of egg phosphatidy[14C]choline at 20 mN/m caused an increase in surface pressure to approximately 30 mN/m. With apolipoprotein C-II and apolipoprotein C-III there was a decrease in surface radioactivity indicating that the apoproteins were removing phospholipid from the interface; the removal of phospholipid was specific for apolipoprotein C-II and apolipoprotein C-III. Although there was a removal of phospholipid from the monolayer, the surface pressure remained constant and was due to the accumulation of apoprotein at the interface. The rate of surface radioactivity decrease was a function of protein concentration, required lipid in a fluid state and, of the lipids tested, was specific for phosphatidylcholine. Cholesterol and phosphatidylinositol were not removed from the interface. The addition of 33 mol% cholesterol to the phosphatidylcholine monolayer did not affect the removal of phospholipids by apolipoprotein C-III. The addition of phospholipid liposomes to the subphase greatly facilitated the apolipoprotein C-II-mediated removal of phospholipid from the interface. Although apolipoprotein A-I and arginine-rich protein gave surface pressure increases, phospholipid was only slightly removed fromthe interface by the addition of liposomes. Based on these findings, we conclude that the apolipoproteins C interact specifically with phosphatidylcholine at the interface. This interaction is important as it relates to the transfer of the apolipoproteins C and phospholipids from very low density lipoproteins to other plasma lipoproteins. The addition of human plasma high density lipoproteins or very low density lipoproteins to the subphase increased the apolipoprotein C-mediated removal of phosphatidyl[14C]choline from the interface 3--4 fold. Low density lipoproteins did not affect the rate of decrease. During lipolysis of very low density lipoproteins to the subphase increased the apolipoprotein C-mediated removal of with the lipid monolayer. Lipolysis experiments were performed in a monolayer trough containing a surface film of egg phosphatidyl[14C]choline and a subphase of very low density lipoproteins and bovine serum albumin. Lipolysis was initiated by the addition of purified milk lipoprotein lipase to the subphase. As a result of lipolysis, there was a decrease in surface radioactivity of phosphatidylcholine. The pre-addition of high density lipoproteins decreased the rate of decrease in surface radioactivity...
...
PMID:Interaction of plasma apolipoproteins with lipid monolayers. 22 40

Eighteen adult diabetic patients were treated with methandrostenolone in daily doses of 15 mg for 3 weeks. Serum triglyceride and cholesterol levels and lipoprotein lipase activity were determined before and after treatment. In patients with intense hypertriglyceridaemia, triglyceride concentration decreased and, with the exception of a single patient, lipoprotein lipase activity returned to normal. Cholesterol concentration did not change characteristically.
...
PMID:Effect of methandrostenolone on serum triglyceride and cholesterol levels in diabetic patients. 123 59

Cholesterol ester hydrolase activity has been studied in mammary glands of rats. Subcellular fractionation of the glands obtained in mid-lactation indicated that around 80% of the recovered activity was associated with particulate fractions. Two distinct cholesterol ester hydrolase activities were identified, one with an optimum pH of 7.5-9.0 and the second (approximately 5% of the total activity) with a more acidic pH optimum. Although the neutral cholesterol ester hydrolase had some properties in common with the lipoprotein lipase in mammary tissue, it was shown to be a separate entity by several criteria. Its activity could be increased following treatment with Mg-ATP and cAMP-dependent protein kinase, suggesting identity with the hormone sensitive lipase of adipose tissue. The cholesterol ester hydrolase activity in mammary glands just after parturition was greater than in glands obtained either from late-pregnant or midlactating animals. The subcellular distribution of the neutral cholesterol ester hydrolase suggested that it may have a different function to the neutral cholesterol ester hydrolase of adrenals and other tissues. Nevertheless the fact that the activity of the enzyme can be modulated by cAMP-dependent protein kinase suggests the possibility that hormonal control of this enzyme may be involved in the regulation of cholesterol metabolism in the mammary gland.
...
PMID:Cholesterol ester hydrolase activity in mammary tissue of the lactating rat. 164 25

Apolipoprotein E (apoE) is an important constituent of plasma lipoproteins and a ligand for several lipoprotein receptors. It is produced mainly in the liver but also in several peripheral tissues like brain, adrenal glands, kidney, and macrophages. Some of these tissues also coexpress lipoprotein lipase (LPL), an important enzyme in the metabolism of lipids and lipoproteins. This suggested a possible coordinate expression of these genes and led us to analyze whether adipocytes, a major source of LPL, could also synthesize apoE. Northern blotting experiments showed that apoE mRNA is found in differentiated mouse 3T3-L1 adipocytes as well as biopsies of human adipose tissue maintained in organ culture but not in undifferentiated 3T3-L1 preadipocytes. [35S]Methionine pulse-labeling experiments revealed that apoE protein is produced in human adipose tissue and differentiated mouse 3T3-L1 adipocytes but not in preadipocytes. In biosynthetic labeling experiments, most apoE was found to be cell associated even after prolonged chase periods. Heparin treatment of the cultured cells did not enhance apoE secretion. During differentiation of 3T3-L1 cells, the onset of apoE gene expression was later than that of LPL. The apoE mRNA and intracellular apoE protein concentrations increased linearly with time of differentiation, at least through day 11, whereas LPL showed highest expression at day 7 and then declined. The increase in apoE mRNA correlated with the cellular lipid content. Inhibition of lipid accumulation in differentiated cells by biotin deprivation decreased apoE expression. Cholesterol-loading experiments suggested that apoE mRNA expression is regulated by the intracellular free cholesterol content of 3T3-L1 adipocytes. In contrast, the LPL mRNA level was not influenced by biotin deprivation or cholesterol loading. Human recombinant tumor necrosis factor, a potent inhibitor of LPL gene transcription, had no effect on adipocyte apoE mRNA levels. Therefore, although apoE and LPL are both expressed in adipocytes in a differentiation-dependent manner, the time course of their expression differs as do their responses to cellular lipid content and tumor necrosis factor. We conclude that these genes are not coordinately regulated in adipocytes.
...
PMID:Apolipoprotein E gene expression in mouse 3T3-L1 adipocytes and human adipose tissue and its regulation by differentiation and lipid content. 170 37

Serum lipid abnormalities are common in familial hemophagocytic lymphohistocytosis (FHL), a disorder also characterized by fever, hepatosplenomegaly, pancytopenia and a prominent lymphohistiocytic accumulation in the mononuclear phagocyte system. The lipoprotein pattern in nine children with FHL was studied with a quantitative method measuring cholesterol and triglycerides in each major class of lipoproteins. Triglycerides were markedly elevated during active FHL in serum, very low density lipoproteins, and low density lipoproteins. Cholesterol was increased in very low density lipoproteins whereas both triglycerides and cholesterol were extremely low in high density lipoproteins. These lipoprotein abnormalities, reversible on successful therapy, are compatible with a depressed lipolytic activity. Post-heparin levels of lipoprotein lipase and hepatic lipase in plasma were studied in four children and found to be markedly low during active FHL. We suggest that inflammatory cytokines, which may strongly suppress lipoprotein lipase activity, can be important mediators in the pathophysiology of FHL and that they may participate in the development of the lipid abnormalities.
...
PMID:Lipoprotein alterations and plasma lipoprotein lipase reduction in familial hemophagocytic lymphohistiocytosis. 186 86

Nephrotic syndrome, uremia, hemodialysis, peritoneal dialysis, and renal transplantation are accompanied by alterations in lipoprotein metabolism In nephrotic patients, total cholesterol, LDL, VLDL and triglycerides are elevated, while HDL may be increased, normal, or decreased. The pathophysiology includes increased hepatic synthesis of VLDL and cholesterol, decreased activity of lipoprotein lipase, and increased urinary excretion of HDL. The risk of coronary heart disease (CHD) is increased in nephrotic patients and elevated LDL-cholesterol may contribute to this risk. Cholesterol lowering diet and drugs are indicated. Presently, Lovastatin and Simvastatin are the most potent cholesterol lowering drugs in nephrotic patients with good evidence of long-term safety. Most patients with impaired renal function or on hemodialysis have moderate hypertriglyceridemia due to decreased lipoprotein lipase activity. HDL may be slightly decreased. Although the risk of CHD is increased in these patients, triglyceride lowering drugs are not indicated, since no benefit can be expected. Peritoneal dialysis is accompanied by elevated VLDL in addition to hypertriglyceridemia. Reabsorption of large amounts of glucose from peritoneal dialysis fluid increases the carbohydrate load and stimulates hepatic VLDL synthesis. Cholesterol lowering therapy may be advantageous, but the experience is very limited. Side effects of lipid lowering drugs may be aggravated in renal failure. Total cholesterol, LDL, VLDL, and triglycerides are elevated in 50% of patients following renal transplantation. Corticosteroids and cyclosporin are major causes of hyperlipidemia. Cholesterol lowering therapy is indicated since the incidence of CHD is increased.(ABSTRACT TRUNCATED AT 250 WORDS)
...
PMID:[Pathophysiology and therapy of lipid metabolism disorders in kidney diseases]. 192 Dec 28

We determined the effect of estrogen and progesterone on plasma cholesterol and lipoprotein cholesterol concentrations and on arterial lesions in 24 ovariectomized and hysterectomized baboons fed a high-cholesterol/high-saturated-fat diet. These baboons were divided into four groups: untreated control (C); estrogen, 100 micrograms/kg/week injected i.m. (E); progesterone, 3 mg/kg/day (P); and estrogen plus progesterone (E + P). The treatment regimen continued for 18 months. Cholesterol levels in plasma and lipoproteins were measured before hormone treatment and at 3, 10, and 18 months of treatment. Postheparin plasma lipoprotein lipase (LPL) activity was also measured during the treatment. After 18 months of hormone treatment, baboons were necropsied and arterial lesions were measured. Hormone treatment significantly influenced plasma cholesterol (P greater than C greater than [E + P] greater than E) and very low density lipoprotein plus low density lipoprotein (VLDL + LDL) cholesterol (P greater than C greater than [E + P] greater than E), with very little effect on high density lipoprotein (HDL) cholesterol concentration. The E + P group had a significantly higher HDL cholesterol concentration than did the P group. The (VLDL + LDL)/HDL cholesterol ratios in the E and E + P groups were significantly lower than those in the P and C groups. LPL activities were significantly lower in the E group compared with those in the E + P and P groups. Hormone treatment significantly influenced lesions in four (innominate, carotid, iliac, and abdominal aorta) of seven arteries. The P group had the most fatty streaks, and the E + P group had the least.(ABSTRACT TRUNCATED AT 250 WORDS)
...
PMID:Effects of estrogen and progesterone on plasma lipoproteins and experimental atherosclerosis in the baboon (Papio sp.). 198 1

Previous studies have provided evidence that Mg deficiency affects lipid metabolism. The present experiments were designed to assess whether the hypertriglyceridemia associated with Mg deficiency was related to alterations in post-heparin lipase activity (PHLA). Mg-deficient and control diets were pair-fed to weanling Wistar rats for eight days and plasma lipoproteins were separated into various density classes by sequential preparative ultracentrifugation. Triglycerides were significantly increased in chylomicrons and in the very low density lipoprotein, low density lipoprotein and high density lipoprotein (HDL) fractions. Cholesterol and phospholipid levels were significantly lower in the HDL fraction. PHLA in deficient rat was substantially lower than in control rats. The inverse correlation between plasma triglyceride concentration and PHLA strongly suggests that hypertriglyceridemia is the result of defective lipolysis of plasma triglycerides in Mg-deficient rats. Further examination of the PHLA was carried out by salt-mediated inhibition of lipoprotein lipase (LPL) and by heparin sepharose affinity chromatography and purified rat LPL antiserum. The results indicate that hepatic lipase is significantly decreased in Mg-deficient rats but the low PHLA is due mainly to a decline in LPL. However, total LPL activity, that is, both the intracellular and the extracellular pools of LPL in adipose tissue, heart and diaphragm, were unaffected by Mg deficiency. The results suggest that the decrease of LPL activity in the plasma of Mg-deficient rats may be due to a selective decrease in the heparin-releasable pool of enzyme.
...
PMID:Effect of magnesium deficiency on post-heparin lipase activity and tissue lipoprotein lipase in the rat. 204 84


1 2 3 4 5 6 7 Next >>

---