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)

This study was initiated to compare lipoprotein lipase activity in isolated heart myocytes and the heparin residual compartment of perfused hearts from adult rats. Heart lipoprotein lipase activity was divided into two fractions by 1 min of heparin perfusion. Heparin-residual and myocyte lipoprotein lipase activity were lower in hearts obtained from fasted compared to fed rats. In each case, the myocyte enzyme activity was 55 to 60% of heparin-residual levels. The difference between myocyte and heparin-residual activity may be a consequence of the time and treatment required to isolate cells in that long-term in vitro exposure of heart tissue to heparin also reduces residual activity. In vivo treatment with endotoxin decreased both heparin-residual and myocyte lipoprotein lipase activities; whereas, colchicine administration increased both activities compared to saline injected rats. In this latter experiment heart heparin-residual and myocyte lipoprotein lipase activities were positively correlated (r = 0.90). The results indicate that in the mature heart intracellular lipoprotein lipase activity is primarily associated with myocytes.
J Mol Cell Cardiol 1989 Mar
PMID:Comparison of lipoprotein lipase activity in heart myocytes and perfused hearts. 274 52

Tumor Necrosis Factor (TNF) inhibits lipoprotein lipase activity in cultured myocytes and in the Langendorff rat heart after 3 h perfusion with TNF of glucocorticoid-pretreated rats. TNF acutely stimulates glyc(ogen)olysis and concomitantly endogenous lipolysis. The latter was significantly increased only when rats had been pretreated with glucocorticoid or fed a trierucate-rich diet. Under these conditions, contractile activity of the Langendorff hearts was acutely increased by TNF. The mechanism of the acute increase of contractile function and the accompanying increased glycolytic and lipolytic activities, by TNF, may be explained by increased cytosolic Ca2+ and cAMP levels.
Mol Cell Biochem 1988 Feb
PMID:Effects of tumor necrosis factor (TNF) on lipolytic activities of rat heart. 284 May 63

The effects of angiotensin II (AII) on prolactin release and arachidonate liberation were studied in anterior pituitary cells preincubated with [3H]arachidonate to label the cellular phospholipids. AII increased prolactin release and [3H]arachidonate liberation over similar concentration ranges with the dynamics of these two events proving identical. Dopamine attenuated both prolactin release and [3H]arachidonate liberation. The diacylglycerol lipase inhibitor RHC80267 decreased AII-stimulated prolactin release and arachidonate liberation. Further evidence that AII-induced release of arachidonate is mediated by a diacylglycerol lipase is suggested by the finding that AII increased [14C]stearate liberation from cells prelabeled with the fatty acid. Although arachidonate itself may have some role in prolactin secretion, it is likely that arachidonate metabolites are more directly involved because BW755c and AA861, inhibitors of arachidonate metabolite formation, increased AII-stimulated arachidonate liberation, but decreased prolactin release.
Mol Cell Endocrinol 1988 May
PMID:Angiotensin II increases pituitary cell prolactin release and arachidonate liberation. 313 14

Lipopolysaccharide (LPS), the active principle of certain endotoxins, protein-free perfused in rat hearts leads in 3 h to a considerable loss of lipoprotein lipase (LPL) activity. In the presence of albumin LPS has virtually no effect. Tumor necrosis factor (TNF) added instead of LPS had no effects on LPL activity during 3 h in vitro perfusion. LPS injected into rats intravenously leads within 3 h to severe toxic phenomena amongst which increased capillary permeability. This was visualized as increased rate of interstitial fluid formation in Langendorff hearts mounted 3 h after rats had been treated with LPS. LPL activity did not decline in 3 h lasting endotoxemia. Six hours after LPS injection, however, cardiac LPL activity was considerably lowered, although immunoblotting and immunohistochemistry still showed LPL protein to be present. These date indicate the presence of a considerable pool of inactive LPL protein in addition to active LPL, that can be released in the presence of heparin. The LPL activity is lowered by LPS injection after a lag phase of at least 3 h, while capillary endothelial cells are influenced more rapidly. The relatively late expression of TNF toxicity in cardiomyocytes of the intact heart is discussed.
Mol Cell Biochem 1988 Feb
PMID:Cardiac lipoprotein lipase: effects of lipopolysaccharide and tumor necrosis factor. 339 37

The lipase activity of the adult rat heart consists of at least two components; a lipoprotein lipase and a "hormone-sensitive" or triglyceride lipase. The control of the triglyceride lipase by intermediates of lipid metabolism was studied in rat heart homogenates. Perfusion of hearts with fatty acids, glucose or no exogenous substrate did not alter lipase activity. Bovine serum albumin (BSA) stimulated the in vitro lipase activity whereas palmityl-coenzyme A (CoA) was a potent inhibitor. Other fatty acid intermediates such as acetyl-CoA, acetyl-carnitine, palmityl-carnitine and palmitate had little or no effect. Long-chain acyl CoA may be an important intermediate for matching triglyceride hydrolysis with the supply of extracellular fatty acids and the rates of fatty acid oxidation.
J Mol Cell Cardiol 1988 Mar
PMID:Inhibition of myocardial lipase by palmityl CoA. 341 15

Removal of litters from young lactating rats for 24 or 48 h or treatment of lactating rats with bromocriptine increased the rate of fatty acid synthesis and the activities of lipoprotein lipase and fatty acid synthetase in adipose tissue, decreased the lipoprotein lipase and fatty acid synthetase activities of mammary gland and lowered the serum-prolactin concentration. Concurrent injections of prolactin prevented the effects of bromocriptine and 24 h of litter removal on most of these changes in adipose tissue, but did not prevent the effects of 48 h of litter removal. The results suggest that effects of prolactin on adipose-tissue metabolism are dependent on a functional mammary gland. Most of the responses of adipose tissue to litter removal were reduced in older rats.
Mol Cell Endocrinol 1981 May
PMID:Prolactin and the regulation of adipose-tissue metabolism during lactation in rats. 701 33

Membrane phospholipid degradation has been proposed to play a key role in hypoxic-ischemic brain injury. We tested the hypotheses that both nordihydroguaiaretic acid, a phospholipase A2 and lipoxygenase inhibitor, and RHC 80267, a diacylglycerol lipase inhibitor, would decrease the release of [3H]arachidonic acid metabolites from prelabeled cultures of astroglia subjected to combined glucose-oxygen deprivation and that these inhibitors would also decrease astroglial injury during combined glucose-oxygen deprivation. Both nordihydroguaiaretic acid and RHC 80267 significantly inhibited the release of [3H]arachidonic acid metabolites during combined glucose-oxygen deprivation. This suggests that two separate enzymic pathways, the phospholipase A2 pathway and the phospholipase C/diacylglycerol lipase pathway, contribute to the release of astroglial [3H]arachidonic acid metabolites during combined glucose-oxygen deprivation. However, both of these lipase inhibitors increased astroglial cell death during combined glucose-oxygen deprivation, probably due to inhibition of arachidonic acid release. We speculate that arachidonic acid release may be a mechanism of astroglial self-preservation during combined glucose-oxygen deprivation.
Mol Chem Neuropathol 1995 May
PMID:Nordihydroguaiaretic acid and RHC 80267 potentiate astroglial injury during combined glucose-oxygen deprivation. 754 17

Incubation of equine very low density lipoproteins with lipoprotein lipase isolated from horse postheparin plasma resulted in the formation of lipoproteins of a higher density. Lipoproteins isolated after incubation and plasma lipoproteins had a different chemical composition and triacylglycerol fatty acid pattern. In vitro-obtained low density lipoproteins contained substantially more phospholipids and triacylglycerols but significantly less cholesteryl esters than native low density lipoproteins. Comparing the triacylglycerol fatty acid pattern of plasma very low density lipoproteins and in vitro--obtained low density lipoproteins, a drastic decrease in the proportion of linolenic acid was observed with increasing density.
Comp Biochem Physiol B Biochem Mol Biol 1995 Sep
PMID:In vitro Catabolism of very low density lipoproteins from horse (Equus caballus) by the action of autologous lipoprotein lipase. 758 41

In the present study, we investigated possible mechanisms behind exogenous phospholipase C-induced glycerol production in irreversibly damaged myocytes. Rat ventricular myocytes were preincubated for 60 min in substrate-free Krebs-Henseleit bicarbonate buffer equilibrated with 95% N2-5% CO2 (37 degrees C, pH = 7.4), resulting in exhaustion of cellular high energy phosphates and loss of rod-shaped morphology. At the end of the preincubation period, the incubation vials were divided into two groups; one receiving 10 mU/ml phospholipase C (PC-PLC), whereas the other received an equivalent volume of buffer (control incubations). Incubation was then continued for another 60 min under 95% air-5% CO2 atmosphere. Samples for measurement of metabolite levels were taken immediately after cell isolation, at the end of the preincubation period and at the end of the normoxic incubation period. During the 60 min incubation period following reoxygenation, glycerol output was markedly higher from PC-PLC treated than from control myocytes. However, the elevated glycerol output from these cells was not accompanied by a simultaneous rise in glycerol-3-phosphate, nor was it inhibited by inclusion of pyruvate in the incubation buffer. On the other hand, glycerol output from PC-PLC treated myocytes was effectively inhibited by a diacylglycerol lipase inhibitor (U-57908, The Upjohn Company). Analysis of cellular lipids revealed a 22% reduction of phospholipid in PC-PLC treated myocytes (P < 0.02), while the content of triacylglycerol, diacylglycerol and unesterified fatty acids increased by 76, 261 and 103%, respectively (P < 0.02). No significant changes were observed for these parameters in control myocytes.(ABSTRACT TRUNCATED AT 250 WORDS)
J Mol Cell Cardiol 1995 Mar
PMID:Phospholipid degradation in hypoxic/reoxygenated cardiomyocytes in response to phospholipase C from Bacillus cereus. 760 7

By aligning nucleotide and amino acid sequences of lipoprotein lipase in eight species (man, pig, cow, sheep, mouse, rat, guinea-pig and chicken), we found that the main domains (catalytic, N-glycosylation and putative heparin binding sites) are well conserved. The longest identical amino acid chain was encoded by a sequence between the end of exon 2 and the beginning of exon 3, emphasizing the importance of this region which encodes the beta 5-loop of the active site, among other domains. Exon 10 is entirely untranslated in the seven mammals studied here and contains species-characteristic deletions, insertions or elements rich in A or A + T. In chicken, the beginning of exon 10 is translated. These eight previously unreported alignments could be a useful tool for further studies on LPL function.
Comp Biochem Physiol B Biochem Mol Biol 1995 Jul
PMID:Comparison of the cDNA and amino acid sequences of lipoprotein lipase in eight species. 761 63


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