Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0004153 (atherosclerosis)
 77,401 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Effect of dexamethasone administration on aortic morphology, cholesterol content and synthesis of prostaglandins from (14C)-arachidonic acid in aorta of spontaneously atherosclerosis susceptible pigeons was examined. Dexamethasone markedly inhibited the synthesis of prostaglandin E2 and stimulated the synthesis of prostaglandin I2 in aorta. In aorta of glucocortocoid treated animals, endothelial abnormalities noted in control birds were decreased and numerous surface protrusions or 'microvilli' were noted. The possibility that glucocorticoid induced inhibition of PGE2 synthesis in pigeon aorta may contribute to improved aortic morphology is discussed.
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PMID:Effect of glucocorticoid administration early in life on aortic prostaglandin synthesis and morphology in atherosclerosis-susceptible pigeons. 392 21

The synthesis of prostaglandin I2 (PGI2) was found to decrease with age in cultured, porcine aortic endothelial cells. Arachidonic acid (AA)-induced PGI2 synthesis per cell at low cell density was higher than that at high cell density. PGI2 synthesis by cultured porcine aortic smooth muscle cells, without exogenous AA, was higher than that by cultured porcine aortic endothelial cells, while AA-induced PGI2 synthesis by cultured porcine aortic medial smooth muscle cells was lower than that by cultured endothelial cells. PGI2 synthesis by cultured smooth muscle cells incubated with fibrinogen degradation products (FDPs) for 24 h decreased. After incubation with FDPs for 24 h, AA-induced PGI2 synthesis by endothelial cells also diminished. These data suggest that PGI2 synthesis in the vascular wall is affected by FDPs, and that FDPs probably play an important role in the initiation of atherosclerosis.
Atherosclerosis
PMID:Fibrinogen degradation products influence PGI2 synthesis by cultured porcine aortic endothelial and smooth muscle cells. 643 Mar 6

There is an abundance of information suggesting that prostaglandins are involved in the development and clinical expression of atherosclerosis. Many studies demonstrate a relationship between prostaglandins and the risk factors for peripheral and coronary artery disease. Thus, part of the mechanism by which hyperlipidemia, diabetes mellitus, smoking, hypertension, sex hormones, age, heredity, emotional stress and diet contribute to the development and progression of atherosclerosis may be through an imbalance between thromboxane A2 and prostaglandin I2. Recent studies show a temporal relationship between acute ischemic events (specifically, unstable angina) and a transcardiac increase in thromboxane B2, while others demonstrate a salutary effect of disaggregatory and vasodilatory prostaglandins in such patients. If prostaglandins and thromboxane prove important in ischemic vascular disease, attention will be directed at the correction of their pathologic imbalance. This may be accomplished by dietary manipulation as well as by the development of prostaglandin receptor antagonists or inhibitors of specific prostaglandin pathways.
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PMID:Prostaglandins and ischemic heart disease. 703 86

The lipid-lowering profile of ethyl 10,11-dihydro-4-methoxydibenz[b,f]-(1,4)oxazepine-8-carboxylate (AZ-1355) has been evaluated using clofibrate as a reference compound. This compound is structurally unrelated to any other hypolipidemic agent. AZ-1355 was selected not only for its effect in reducing serum lipids, but also because it inhibits platelet aggregation in vivo and elevates the prostaglandin I2/thromboxane A2 ratio in vitro. It lowers serum total cholesterol in Triton-treated hyperlipidemic mice, and also lowers serum total cholesterol and triglyceride in dietary hyperlipidemic rats. In golden hamsters chosen for further evaluation, AZ-1355 reduced serum, liver and cardiac lipids, improved the beta/alpha-lipoprotein ratio and increased the HDL cholesterol. Thus, it is apparent that the lipid-lowering profile of AZ-1355 differs from that of clofibrate.
Atherosclerosis
PMID:The lipid-lowering profile in rodents. AZ-1355, a new dibenzoxazepine derivative. 733 5

We examined the effect of beraprost sodium (BPS), a stable prostaglandin I2 (PGI2) analogue, on restenosis after balloon angioplasty in the atherosclerotic artery in rabbits. Regional atherosclerosis was induced in the femoral artery of New Zealand white rabbits by balloon deendothelialization and 2% cholesterol diet. After establishment of atheroma in the femoral artery, angioplasty was performed. In all, 65 rabbits were assigned to the following six subcutaneous drug treatment groups: control group (n = 13, saline 0.25 ml/kg); BPS low-dose group (n = 11, BPS 50 micrograms/kg twice daily); BPS high-dose group (n = 12, BPS 100 micrograms/kg twice daily); 2-day BPS high-dose group (n = 11, BPS 100 micrograms/kg twice daily for 2 days after angioplasty); aspirin (ASA) group (n = 10, ASA 30 mg once daily); and BPS+ASA group (n = 8, BPS 50 micrograms/kg twice daily plus ASA 30 mg once daily). Administration of each drug was started 30 min before balloon angioplasty and was continued until 4 weeks thereafter, except in the 2-day BPS high-dose group. Re-examination 4 weeks after the angioplasty showed significant (p < 0.05) preservation of the luminal diameter in the BPS high-dose and 2-day BPS high-dose groups (1.30 +/- 0.15 and 1.25 +/- 0.09 mm, respectively) as compared with that in the control group (0.83 +/- 0.10 mm); however, the luminal diameter in the BPS low-dose, ASA, and BPS+ASA groups (0.94 +/- 0.18, 1.06 +/- 0.11, and 1.05 +/- 0.15 mm, respectively) was not significantly different from that in the control group.
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PMID:Inhibition of restenosis by beraprost sodium (a prostaglandin I2 analogue) in the atherosclerotic rabbit artery after angioplasty. 756 40

Embryonic data and ultrastructural analyses suggest that the primitive endothelium signals undifferentiated mesenchymal cells to migrate to the forming blood vessel and subsequently regulates mural cell growth and behavior. Upon maturation of the blood vessel, chemotactic and mitogenic signals are apparently diminished and differentiated smooth muscle cells normally remain quiescent. This homeostasis is seemingly upset in conditions which lead to pathologies characterized by smooth muscle cell hyperplasia such as atherosclerosis. By culturing endothelial cells at different densities, we attempted to re-create the various stages of vascular development. Whereas media conditioned by sparse endothelial cells stimulate smooth muscle cells, media conditioned by dense endothelial cell cultures are inhibitory. Culture of sparse smooth muscle cells in media conditioned for 3 days by postconfluent endothelial cell cultures leads to dose-dependent and reversible smooth muscle cell inhibition. Furthermore, in the presence of the endothelial cell-derived inhibitor, smooth muscle cells are rendered refractory to mitogens such as fibroblast growth factor and platelet-derived growth factor. The inhibitory activity is not attributable to the well-characterized inhibitors of smooth muscle cell growth, transforming growth factor type-beta, prostaglandin I2, or heparan sulfate proteoglycan. Partial characterization of the inhibitory conditioned media suggests that the active molecule is smaller than 1,000 da, and stable to boiling as well as proteinase K and heparinase digestion. These findings support the concept that there is intercellular communication between endothelial cells and smooth muscle cells and provide evidence for a novel endothelial cell-derived smooth muscle cell growth inhibitor.
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PMID:Density-dependent endothelial cell production of an inhibitor of smooth muscle cell growth. 822 80

Cellular calcium modulates enzyme activity, cell proliferation, and differentiation. In vascular smooth muscle cells (VSMC), calcium may contribute to increased vascular contractility and structural alterations in both hypertension and atherosclerosis. We investigated the role of calcium in angiotensin II (AII)-induced prostaglandin release and DNA synthesis in VSMC. Prostaglandin levels were determined by radioimmunoassay, and DNA synthesis was determined by the incorporation of [3H]thymidine. AII dose-dependently stimulated the release of prostaglandin E2 and prostaglandin I2, and this effect was synergistically enhanced by the Ca2+ ionophore A23187. Conversely, the AII response was inhibited by EGTA, a chelator of Ca2+ ions and by verapamil and nifedipine, two Ca2+ channel blockers or by incubation of the cells without exogenous Ca2+. TMB-8, an inhibitor of calcium mobilization, also strongly reduced angiotensin response. Similar results were obtained for angiotensin III (AIII) and vasopressin, two other agonists of prostaglandin production. AII- or serum-stimulated DNA synthesis was almost abolished by EGTA, whereas TMB-8, verapamil, and nifedipine had little or no effect. The production of prostaglandins triggered by angiotensins and vasopressin in VSMC is dependent on both intracellular and extracellular calcium, with calcium entering through L-type Ca2+ channels. Extracellular calcium is important for AII and serum mitogenic activity, but L-type Ca2+ channels do not appear to be implicated.
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PMID:Role of calcium in angiotensin II-induced prostaglandin release and DNA synthesis in rat vascular smooth muscle cells. 872 Apr 17

Prostaglandins, thromboxanes, and other eicosanoids represent a widespread lipid-mediator system for intercellular signalling, and, hence, have multiple cellular actions. Thus it is not surprising that numerous events in the pathogenesis of atherosclerosis are associated with an altered formation of eicosanoids. To reconsider the availability of eiconsanoid precursors as one possible cause of atherogenesis, the dietary intake and the serum concentrations of arachidonic acid (AA) and eicosapentaenoic acid (EPA) were determined in patients with high risk for atherosclerosis on continuous ambulatory peritoneal dialysis (CAPD) with and without diabetes in comparison to healthy controls and diabetic patients without late complications. The factor AA/EPA in serum was created as a marker for the atherosclerosis risk. The setting was in a CAPD unit in one city hospital. There were 26 CAPD patients [9 with insulin-dependent diabetes mellitus (IDDM), 9 with noninsulin-dependent diabetes mellitus (NIDDM), and 8 without diabetes], 27 IDDM without late complications, and 41 healthy control persons. The AA levels in serum were significantly higher in all of the CAPD groups. In contrast, the EPA concentrations in serum were significantly lower in the CAPD groups, with the lowest EPA levels found in the CAPD-IDDM group. Therefore, the factors AA/EPA in serum were significantly higher in all of the CAPD groups, and again significantly higher in the CAPD-IDDM group than in the other CAPD groups. No differences in the amount of dietary intake of AA existed between the groups. The daily intake of EPA was significantly highest in the control group. Higher concentrations of AA and a lack of n-3 fatty acids lead in the presence of a reduced prostaglandin I2 biosynthesis, to a higher formation rate of potentially proatherogenic metabolites such as thromboxane A2, a vasoconstricting and platelet aggregating agent. Thus, the quotient AA/EPA could possibly be used as a marker of atherogenicity in the future.
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PMID:Eicosanoid precursors: potential factors for atherogenesis in diabetic CAPD patients? 872 2

Statins inhibit 3-hydroxy-3-methylglutaryl (HMG-CoA) reductase, the rate limiting step in cholesterol synthesis. They are, therefore, used clinically to lower cholesterol and prevent atherosclerosis. Statins have beneficial effects on multiple organ systems. Some of these effects are found in the absence of significant changes in cholesterol levels. Polyunsaturated fatty acids also inhibit HMG-CoA reductase and have many of the same beneficial effects of statins. Four statins (mevastatin, lovastatin, simvastatin and atorvastatin) have been tested in rat liver cells for their effect on arachidonic acid (AA) release and prostaglandin I2 production induced in the presence of lactacystin and 12-O-tetradecanoylphorbol-13-acetate. Each statin stimulated release of AA and induced prostaglandin I2 production. Mevalonate, the product of HMG-CoA reductase, did not reduce the stimulation observed in the presence of simvastatin indicating that HMG-CoA reductase activity is not involved. In view of the multiple biologic properties of AA, the AA released as a result of the action of the statins may play a role in some of the pharmacological effects attributed to these drugs.
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PMID:Statins stimulate arachidonic acid release and prostaglandin I2 production in rat liver cells. 1268 40

Hyaluronic acid (HA) is a prominent constituent of the extracellular matrix of atherosclerotic vascular lesions in humans known to modulate vascular smooth muscle phenotype. The regulation of HA synthesis by vasodilatory prostaglandins was analyzed in human arterial smooth muscle cells (SMCs). The prostacyclin analogue, iloprost (100 nmol/L), markedly increased pericellular formation of HA coats and HA secretion into the cell culture medium in human arterial SMCs (8.7+/-1.6-fold). Expression of HA synthase 2 (HAS2) was determined by semiquantitative RT-PCR and found to be strongly upregulated at concentrations of iloprost between 1 and 100 nmol/L after 3 hours. Furthermore, endogenous cyclooxygenase-2 (COX2) activity was required for basal expression of HAS2 mRNA in SMCs in vitro. Total HA secretion in response to iloprost was markedly decreased by RNA interference (RNAi), specific for HAS2. In addition, siRNA targeting HAS2 strongly increased the spreading of human SMCs compared with mock-transfected cells. HAS2 mRNA levels were also stimulated by a selective prostacyclin receptor (IP) agonist, cicaprost (10 nmol/L), prostaglandin E(2) (10 nmol/L), and the EP(2) receptor agonist, butaprost (1 micromol/L). Induction of HAS2 mRNA and HA synthesis by prostaglandins was mimicked by stable cAMP analogues and forskolin. In human atherectomy specimens from the internal carotid artery, HA deposits and COX2 expression colocalized frequently. In addition, strong EP(2) receptor expression was detected in SMCs in HA-rich areas. Therefore, upregulation of HAS2 expression via EP(2) and IP receptors might contribute to the accumulation of HA during human atherosclerosis, thereby mediating proatherosclerotic functions of COX2.
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PMID:Induction of hyaluronic acid synthase 2 (HAS2) in human vascular smooth muscle cells by vasodilatory prostaglandins. 1475 26


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