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Heterozygous familial hypercholesterolaemia is associated with pathological exercise-induced leakage of muscle proteins, which is not aggravated by simvastatin therapy.

The objective of this study was to assess the relationship between therapy with the HMG-CoA reductase inhibitor simvastatin and muscle damage and the possible causal role of hypercholesterolaemia. The exercise-induced release of muscle proteins as a parameter of muscle damage was studied in two equicholesterolaemic groups of male patients with heterozygous familial hypercholesterolaemia (FH); one group without treatment, the second group on simvastatin. To assess the role of cholesterol, a third group of healthy male volunteers was studied as well. The study took place at the Lipid Clinic of an 800-bed University Hospital. One group of 21 male patients with heterozygous FH did not receive treatment, except for a lipid-lowering diet. A second group of 13 male FH patients were treated with 40 mg simvastatin day-1 for at least 1 year and matched for cholesterol levels with the first group. A third group consisted of 25 normocholesterolaemic male controls. All subjects underwent a 45 min lean body mass (LBM) standardized ergometer muscle provocation test (2 Watt/kg LBM). Levels of creatine kinase (CK) and myoglobin (Mb) were assessed before and 1 and 8 h after exercise and compared with baseline levels. The exercise-induced release of muscle proteins is reflected by peak CK and Mb levels expressed as a percentage of baseline levels. The exercise-induced increase in Mb and CK levels did not differ between untreated and simvastatin-treated FH patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Simvastatin decreases the hepatic secretion of very-low-density lipoprotein apolipoprotein B-100 in heterozygous familial hypercholesterolaemia: pathophysiological and therapeutic implications.

We studied six patients with heterozygous familial hypercholesterolaemia (FH) before and after 8 weeks of treatment with simvastatin (40 mg day-1), an inhibitor of 3-hydroxy-3-methyl-glutaryl-Coenzyme A. Simvastatin decreased plasma low-density lipoprotein (LDL) cholesterol by 43% (P = 0.002), triglycerides by 15% [corrected] (P = 0.05) and mevalonic acid (a measure of in vivo cholesterol synthesis) by 20% (P = 0.002); high-density lipoprotein cholesterol increased by 17% (P = 0.02). The hepatic secretion rate of very-low-density lipoprotein apolipoprotein B-100 (VLDL apoB) was measured directly using a primed, constant intravenous infusion of 1-[13C]-leucine with monitoring of the isotopic enrichment of apoB by gas chromatography-mass spectrometry; fractional secretion rate (FSR) was derived using a monoexponential function. Simvastatin decreased the FSR, ASR and pool size of VLDL apoB by 17% (14.3 (SEM 3.6)) vs. (11.9 (SEM 3.5) pools day-1, P = 0.10), 83% (51.4 (SEM 17.9) vs. (8.6 (SEM 1.4), P = 0.007 mg kg-1 day-1) and 65% (234.2 (SEM 30.4) vs. 82.6 (SEM 24.0) mg, P = 0.02), respectively. The change in the ASR of VLDL apoB was significantly correlated with the change in plasma LDL cholesterol concentration (P = 0.04), but not with the change of triglyceride or mevalonic acid. We conclude that the hepatic secretion of VLDL apoB in FH is decreased by simvastatin, which may partly explain the fall in plasma cholesterol.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Dual bezafibrate-simvastatin therapy for combined hyperlipidaemia.

Statins and fibrates are both effective in the treatment of hyperlipidaemias but are not recommended in combination because episodes of rhabdomyolysis have followed combined lovastatin-gemfibrozil therapy. We assessed treatment with dual bezafibrate-simvastatin therapy in routine clinical practice. In 22 patients, total cholesterol, LDL-cholesterol and triglycerides fell by 20.1% (P < 0.0001), 35.1% (P < 0.001) and 31% (P < 0.05) respectively, and HDL-cholesterol rose by 18.4% (P < 0.05) on combination therapy. The reduction in cholesterol followed the introduction of simvastatin, while the decrease in triglycerides followed treatment with bezafibrate. No patient developed myopathy. We conclude that dual simvastatin-bezafibrate therapy is well tolerated and may reduce triglyceride concentrations, but offers no advantage in cholesterol reduction over treatment with simvastatin alone.

Adult↗

Long-term effects of simvastatin in familial dysbetalipoproteinaemia.

The long-term effects (66 weeks) of simvastatin (40 mg in one or two doses per day), an inhibitor of HMG CoA-reductase, were evaluated in 12 patients with familial dysbetalipoproteinaemia (type III hyperlipoproteinaemia). Simvastatin had a persistent hypolipidaemic effect; the mean reduction in serum cholesterol was 36-51%, and the mean reduction in serum triglycerides was 32-55%. The decrease in serum lipids was caused by a decline in VLDL-cholesterol and LDL-cholesterol levels; the mean ratio between VLDL-cholesterol and serum triglycerides decreased significantly from 1.06 to 0.73. There was no significant difference between the once-a-day and twice-a-day regimens. Simvastatin was well tolerated; no serious side-effects were observed. These data demonstrate the usefulness of simvastatin in the therapy of familial dysbetalipoproteinaemia.

Adult↗

Treatment of primary hypercholesterolaemia. Short-term efficacy and safety of increasing doses of simvastatin and pravastatin: a double-blind comparative study.

OBJECTIVES: To compare the efficacy and safety of increasing doses (0, 10, 20 and 40 mg day-1, each dose for 6 weeks) of the inhibitors of 3-hydroxy-3-methylglutaryl coenzyme A reductase, simvastatin and pravastatin, in the treatment of primary hypercholesterolaemia. DESIGN: Randomized, double-blind study with two parallel groups. SETTING: Two specialist lipid clinics in the Netherlands. SUBJECTS: Forty-eight patients aged 25-66 years with primary hypercholesterolaemia (mean serum cholesterol 10.2 mmol-1). MAIN OUTCOME MEASURES: Total serum cholesterol, triglycerides, lipoproteins, apolipoproteins A-I and B, laboratory safety parameters and sleep questionnaires. RESULTS: Both drugs induced a dose-dependent reduction in the mean total and low-density lipoprotein cholesterol concentration (P < 0.001); low-density lipoprotein cholesterol decreased from 32 to 43% by simvastatin and from 23 to 33% by pravastatin. There was an overall difference in the mean relative change from baseline in favour of simvastatin (total cholesterol, P < 0.01; LDL cholesterol P < 0.001). Both drugs reduced serum triglycerides by 10-15%. The changes in apolipoprotein B and the differences in efficacy between the two drugs paralleled those of total and low-density lipoprotein cholesterol. Adverse experiences were mild and did not differ between treatment groups; in each group, one subject discontinued medication because of complaints of dizziness. Sleep questionnaires revealed different degrees of sleep problems, unaffected by active treatment. CONCLUSIONS: Simvastatin appeared to be more potent than pravastatin in lowering total cholesterol, low-density lipoprotein cholesterol and apolipoprotein B, whereas both drugs had the same short-term safety profile.

Adult↗

Simvastatin (MK 733): an effective treatment for hypercholesterolemia.

This study describes the efficacy of the drug simvastatin. It is likely to be the first HMG CoA reductase inhibitor in Australia and New Zealand available for the treatment of hyperlipidemia. Twenty-four patients, 12 men and 12 women with primary hypercholesterolemia were randomly allocated to treatment by cholestyramine (eight patients) or to simvastatin (16 patients) for a 12-week period. With simvastatin, total cholesterol levels decreased by 37.5% from a baseline mean of 10.33 mmol/L to 6.4 mmol/L after 12 weeks. Low density lipoprotein (LDL) cholesterol concentration decreased by 48.2% from 8.40 mmol/L to 4.39 mmol/L. These effects were better than observed for cholestyramine alone where cholesterol and LDL-cholesterol reductions were 24.9% and 33.1% respectively. Thirteen patients, however, did not achieve target LDL levels of 3.62 mmol/L, or below, and therefore were treated with a combination of cholestyramine and simvastatin, resulting in a decrease of total cholesterol and LDL-cholesterol by 45.5% and 53.5% of baseline values studied over an eight-week period. No major clinical side-effects were encountered. One patient appeared to have had a change in colour vision at the end of the study at 20 weeks, without loss of visual acuity.

Adult↗

Biochemical changes and morphological alterations of liver and kidney in hamsters after administration of the HMG-coenzyme A reductase inhibitor, simvastatin: prevention and reversibility by mevalonate.

The present study analyses the effects of simvastatin, a specific inhibitor of the 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA reductase) in male Syrian hamsters fed a standard diet or a diet supplemented with 0.12% cholesterol and 20% coconut oil. In hamsters fed the standard diet, gastric administration of simvastatin (10 mg/kg/day) during 12 days was found to be lethal and to have hepatotoxic and nephrotoxic effects. This toxicity was exacerbated in hamsters fed a hyperlipidaemic diet and was preceded by a progressive anorexia and loss of body weight. Marked elevations in serum aspartate and alanine aminotransferase activities were associated with the organ lesions. All elevated biochemical changes and morphological alterations were prevented or reversed by coadministration of mevalonate, the product of the HMG-CoA reductase. It is suggested that the dramatic effect of simvastatin could result from depletion of a non-sterol metabolite of mevalonate in spite of a lack of protective effects of farnesol and geranylgeraniol in the following study. The toxicity of simvastatin could indeed result from the low basal activity of HMG-CoA reductase in hamster liver coupled with a prolonged inhibition of mevalonate synthesis.

Administration, Oral↗

Antioxidant properties of carnosine re-evaluated with oxidizing systems involving iron and copper ions.

Carnosine has antioxidant properties and is efficient in the treatment of chemically-induced inflammatory lesions in animals. However, some studies question its biological significance as antioxidant and show lack of protection and even pro-oxidant effect of carnosine in systems containing nickel and iron ions. The ability of carnosine to: (1) reduce Fe(3+) into Fe(2+) ions; (2) protect deoxyribose from oxidation by Fe(2+)-, Fe(3+)-, and Cu(2+)-H(2)O(2)-EDTA systems; (3) protect DNA from damage caused by Cu(2+)-, and Fe(2+)-H(2)O(2)-ascorbate systems; (4) inhibit HClO- and H(2)O(2)-peroxidase-induced luminol dependent chemiluminescence was tested in vitro. At concentration 10 mM carnosine reduced 16.6+/-0.5 nmoles of Fe(3+) into Fe(2+) ions during 20 min. incubation and added to plasma significantly increased its ferric reducing ability. Inhibition of deoxyribose oxidation by 10 mM carnosine reached 56+/-5, 40+/-11 and 30+/-11% for systems containing Fe(2+), Fe(3+) and Cu(2+) ions, respectively. The damage to DNA was decreased by 84+/-9 and 61+/-14% when Cu(2+)-, and Fe(2+)-H(2)O(2)-ascorbate systems were applied. Combination of 10 mM histidine with alanine or histidine alone (but not alanine) enhanced 1.3 and 2.3 times (P<0.05) the DNA damage induced by Fe(2+)-H(2)O(2)-ascorbate. These amino acids added to 10 mM carnosine decreased 3.1-fold (P<0.05) its protective effect on DNA. Carnosine at 10 and 20 mM decreased by more than 90% light emission from both chemiluminescent systems. It is concluded that carnosine has significant antioxidant activity especially in the presence of transition metal ions. However, hydrolysis of carnosine with subsequent histidine release may be responsible for some pro-oxidant effects.

Animals↗

Simvastatin inhibits leptin-induced hypertrophy in cultured neonatal rat cardiomyocytes.

AIM: To test the hypothesis that statins inhibit leptin-induced hypertrophy in cultured neonatal rat cardiomyocytes. METHODS: Cultured neonatal rat cardiomyocytes were used to evaluate the effects of simvastatin on leptin-induced hypertrophy. Intracellular reactive oxygen species (ROS) levels were determined by using 2',7'-dichlorofluorescein diacetate (DCF-DA) fluorescence. Total intracellular RNA and cell protein content, which serve as cell proliferative markers, were assayed by using propidium iodide (PI) fluorescence and the Bio-Rad DC protein assay, respectively. The cell surface area, an indicator of cell hypertrophy, was quantified by using Leica image analysis software. RESULTS: After 72 h treatment, leptin markedly increased RNA levels, cell surface area, and total cell protein levels in cardiomyocytes, which were significantly inhibited by simvastatin or catalase treatment. ROS levels were significantly elevated in cardiomyocytes treated with leptin for 4 h compared with those cells without leptin treatment. The increase in ROS levels in cardiomyocytes induced by leptin was reversed by treatment with simvastatin and catalase. CONCLUSION: Simvastatin inhibits leptin-induced ROS-mediated hypertrophy in cultured neonatal rat cardiac myocytes. Statin therapy may provide an effective means of improving cardiac dysfunction in obese humans.

Animals↗

Acyl-coenzyme a formation of simvastatin in mouse liver preparations.

Formation of an acyl-CoA thioester has been proposed, but not directly demonstrated, to be a key step in mediating both lactonization and atypical beta-oxidation of 3-hydroxy-3-methylglutaryl-CoA reductase inhibitors. Here, we describe studies to characterize formation of acyl-CoA thioesters in vitro in mouse liver preparations using the hydroxy acid form of simvastatin (SVA) as a model substrate. With an optimized chromatography method, three new products were detected in addition to the dehydration product (P1) and the lactone form of simvastatin, which have been characterized previously (Prueksaritanont et al., 2001). Based on high-pressure liquid chromatography analysis, UV spectroscopy, mass spectrometry, and NMR spectral characterization, two metabolites were identified as acyl-CoA thioester conjugates of SVA and P1, respectively, whereas the third metabolite (M1) was confirmed to be the L-beta-hydroxy isomer of simvastatin. M1 was probably formed by stereospecific hydration, a previously reported reaction, and subsequent lactonization of P1-S-acyl CoA. Among all the mouse liver subcellular fractions, microsomes exhibited the highest capacity to catalyze the CoASH-dependent metabolism of SVA, whereas such activity was totally absent in cytosol. Together, these results provide direct experimental evidence that SVA (and conceivably other statins as well) is able to form an acyl-CoA thioester, possibly by microsomal long-chain acyl-CoA synthetase(s), leading to formation of two parallel metabolic pathways, one resulting in the two diastereomers of statin lactones (simvastatin and M1) and the other to the beta-oxidation pathway of statin hydroxy acids.

Acetyl-CoA C-Acyltransferase↗

In nasopharyngeal carcinoma cells, Epstein-Barr virus LMP1 interacts with galectin 9 in membrane raft elements resistant to simvastatin.

Nasopharyngeal carcinomas (NPC) are etiologically related to the Epstein-Barr virus (EBV), and malignant NPC cells have consistent although heterogeneous expression of the EBV latent membrane protein 1 (LMP1). LMP1 trafficking and signaling require its incorporation into membrane rafts. Conversely, raft environment is likely to modulate LMP1 activity. In order to investigate NPC-specific raft partners of LMP1, rafts derived from the C15 NPC xenograft were submitted to preparative immunoprecipitation of LMP1 combined with mass spectrometry analysis of coimmunoprecipitated proteins. Through this procedure, galectin 9, a beta-galactoside binding lectin and Hodgkin tumor antigen, was identified as a novel LMP1 partner. LMP1 interaction with galectin 9 was confirmed by coimmunoprecipitation and Western blotting in whole-cell extracts of NPC and EBV-transformed B cells (lymphoblastoid cell lines [LCLs]). Using mutant proteins expressed in HeLa cells, LMP1 was shown to bind galectin 9 in a TRAF3-independent manner. Galectin 9 is abundant in NPC biopsies as well as in LCLs, whereas it is absent in Burkitt lymphoma cells. In subsequent experiments, NPC cells were treated with Simvastatin, a drug reported to dissociate LMP1 from membrane rafts in EBV-transformed B cells. We found no significant effects of Simvastatin on the distribution of LMP1 and galectin 9 in NPC cell rafts. However, Simvastatin was highly cytotoxic for NPC cells, regardless of the presence or absence of LMP1. This suggests that Simvastatin is a potentially useful agent for the treatment of NPCs although it has distinct mechanisms of action in NPC and LCL cells.

Blotting, Western↗

Lifetime cost effectiveness of simvastatin in a range of risk groups and age groups derived from a randomised trial of 20,536 people.

OBJECTIVES: To evaluate the cost effectiveness of 40 mg simvastatin daily continued for life in people of different ages with differing risks of vascular disease. DESIGN: A model developed from a randomised trial was used to estimate lifetime risks of vascular events and costs of treatment and hospital admissions in the United Kingdom. SETTING: 69 hospitals in the UK. PARTICIPANTS: 20,536 men and women (aged 40-80) with coronary disease, other occlusive arterial disease, or diabetes. INTERVENTIONS: 40 mg simvastatin daily versus placebo for an average of 5 years. MAIN OUTCOME MEASURES: Cost effectiveness of 40 mg simvastatin daily expressed as additional cost per life year gained. Major vascular event defined as non-fatal myocardial infarction or death from coronary disease, any stroke, or revascularisation procedure. Results were extrapolated to younger and older age groups at lower risk of vascular disease than were studied directly, as well as to lifetime treatment. RESULTS: At the April 2005 UK price of 4.87 pounds sterling (7 euros; 9 dollars) per 28 day pack of generic 40 mg simvastatin, lifetime treatment was cost saving in most age groups and vascular disease risk groups studied directly. Gains in life expectancy and cost savings decreased with increasing age and with decreasing risk of vascular disease. People aged 40-49 with 5 year risks of major vascular events of 42% and 12% at start of treatment gained 2.49 and 1.67 life years, respectively. Treatment with statins remained cost saving or cost less than 2500 pounds sterling per life year gained in people as young as 35 years or as old as 85 with 5 year risks of a major vascular event as low as 5% at the start of treatment. CONCLUSIONS: Treatment with statins is cost effective in a wider population than is routinely treated at present.

Adult↗

An omega-3 polyunsaturated fatty acid concentrate administered for one year decreased triglycerides in simvastatin treated patients with coronary heart disease and persisting hypertriglyceridaemia.

BACKGROUND: Omega-3 fatty acids, such as those present in fish oil, have been reported to prolong life in myocardial infarction survivors. These fatty acids can decrease serum triglyceride concentrations, but so far the doses used in trials examining their effects on coronary end points have had only minimal triglyceride lowering effects. OBJECTIVE: To examine the triglyceride lowering effectiveness, safety, and tolerability of Omacor, a concentrate of omega-3, long chain, polyunsaturated fatty acids from fish oil (84% of the total as opposed to an average of 35% in fish oil) over one year in patients with established coronary heart disease (CHD) and persisting hypertriglyceridaemia, despite receiving simvastatin in doses similar to those employed in the Scandinavian simvastatin survival study. SUBJECTS AND METHODS: 59 patients with CHD, receiving simvastatin 10-40 mg daily with serum triglycerides > 2.3 mmol/l, were randomised to receive Omacor 2 g twice a day or placebo for 24 weeks in a double blind trial. Forty six patients accepted the offer of active treatment for a further 24 weeks in an open phase of the trial. RESULTS: There was a sustained significant decrease in serum triglycerides by 20-30% (p < 0.005) and in very low density lipoprotein (VLDL) cholesterol by 30-40% (p < 0.005) in patients receiving active Omacor at three, six, and 12 months compared either to baseline or placebo. Omacor did not have any deleterious effect on low density or high density lipoprotein cholesterol or on biochemical and haematological safety tests. There was no adverse effect on glycaemic control in patients with diabetes, who showed a decrease in serum triglyceride, which was at least as great as in non-diabetic patients. One patient receiving placebo died of acute myocardial infarction. Three patients withdrew from the trial (two on placebo and one on active treatment). Omacor was generally well tolerated. CONCLUSION: Omacor was found to be a safe and effective means of lowering serum triglycerides over one year in patients with CHD and combined hyperlipidaemia, whose triglycerides remained elevated despite simvastatin treatment.

Adult↗

Simvastatin induces death of multiple myeloma cell lines.

BACKGROUND: Accumulating reports indicate that statins widely prescribed for hypercholesteromia have antineoplastic activity. We hypothesized that because statins inhibit farnesylation of Ras that is often mutated in multiple myeloma (MM), as well as the production of interleukin (IL)-6, a key cytokine in MM, they may have antiproliferative and/or proapoptotic effects in this malignancy. METHODS: U266, RPMI 8226, and ARH77 were treated with simvastatin (0-30 microM) for 5 days. The following aspects were evaluated: viability (IC50), cell cycle, cell death, cytoplasmic calcium ion levels, supernatant IL-6 levels, and tyrosine kinase activity. RESULTS: Exposure of all cell lines to simvastatin resulted in reduced viability with IC50s of 4.5 microM for ARH77, 8 microM for RPMI 8226, and 13 microM for U266. The decreased viability is attributed to cell-cycle arrest (U266, G1; RPMI 8226, G2M) and cell death. ARH77 underwent apoptosis, whereas U266 and RPMI 8226 displayed a more necrotic form of death. Cytoplasmic calcium levels decreased significantly in all treated cell lines. IL-6 secretion from U266 cells was abrogated on treatment with simvastatin, whereas total tyrosine phosphorylation was unaffected. CONCLUSIONS: Simvastatin displays significant antimyeloma activity in vitro. Further research is warranted for elucidation of the modulated molecular pathways and clinical relevance.

Anticholesteremic Agents↗

One year experience in the treatment of familial hypercholesterolaemia with simvastatin.

Patients with heterozygous familial hypercholesterolaemia (FH) have a substantially increased risk of atherosclerosis due to very high plasma levels of cholesterol. Recent evidence has shown that coronary heart disease in these patients may regress with lipid-lowering therapy. In this study the efficacy and safety of simvastatin, an inhibitor of the enzyme 3-hydroxy-3-methylglutaryl coenzyme A, was investigated in 30 patients with FH over a period of one year. Substantial reductions in the plasma concentrations of total cholesterol (-28%), low-density lipoprotein (LDL) cholesterol (-32%), intermediate-density lipoprotein (IDL) cholesterol and apolipoprotein (apo) B (-33%) were achieved with 20 mg/day of simvastatin; there were no significant changes in triglycerides high-density lipoprotein cholesterol or apo A. In contrast to previous studies, 40 mg/day of simvastatin did not result in a further statistically significant fall in LDL cholesterol, IDL cholesterol or apo B in the group as a whole. The drug was well tolerated and no adverse clinical or laboratory events were recorded. In particular, no ophthalmological, hepatic or renal disorders were observed and there were no sleep disturbances. We conclude that simvastatin is an efficacious and safe drug to treat patients with heterozygous FH and that rarely will the dose need to be increased above 20 mg/day.

Adult↗

Effects of simvastatin and pravastatin on peroxidation of erythrocyte plasma membrane lipids in patients with type 2 hypercholesterolemia.

Since hypercholesterolemia directly modifies the composition of erythrocytes plasma membrane, the influence of statins on erythrocytes has been researched. The beneficial effects of statins on clinical events may involve mechanisms that modify endothelial dysfunction, plaque stability, thrombus formation and inflammatory responses. The aim of the study was to evaluate the hypolipemic efficacy and effects of pravastatin and simvastatin on erythrocyte membrane fluidity and damage of erythrocytes in patients with type 2 hypercholesterolemia in comparison with a control group of healthy subjects. The study involved 53 patients affected by type 2 hypercholesterolemia (mean age, 53.3 +/- 10.3) with initial total serum cholesterol (TC) levels > 250 mg/dL, LDL-cholesterol (LDL-C) levels > 170 mg/dL, and triglycerides (TG) levels < 400 mg/dL. The control group consisted of 30 healthy individuals (mean age 56.9 +/- 6.3). Statins were given for 12 weeks. The dosages for oral administration of simvastatin and pravastatin were 20 mg/day. Laboratory tests were carried out before and after 4 and 12 weeks of the pharmacological treatment. The damage to plasma membrane of erythrocytes was measured on the basis of lipid peroxidation. The fluidity of plasma membrane of erythrocytes was determined by electron paramagnetic resonance (EPR) spectroscopy, using two spin labels: 5-DSA and 16-DSA. The cholesterol level in the membrane of red blood cells was estimated. Simvastatin and pravastatin reduced the total cholesterol concentration and LDL-cholesterol in plasma, as well as the cholesterol concentration in erythrocytes membranes. Hypercholesterolemia induced changes in the basic properties of human erythrocyte plasma membrane, including its fluidity and the intensity of lipid peroxidation. These results indicate that the simvastatin and pravastatin therapy reverses the alteration in the erythrocyte plasma membrane properties.

Adult↗

Simvastatin upregulates coronary vascular endothelial nitric oxide production in conscious dogs.

Statin drugs can upregulate endothelial nitric oxide (NO) synthase (eNOS) in isolated endothelial cells independent of lipid-lowering effects. We investigated the effect of short-term simvastatin administration on coronary vascular eNOS and NO production in conscious dogs and canine tissues. Mongrel dogs were instrumented under general anesthesia to measure coronary blood flow (CBF). Simvastatin (20 mg. kg(-1). day(-1)) was administered orally for 2 wk; afterward, resting CBF was found to be higher compared with control (P < 0.05) and veratrine- (activator of reflex cholinergic NO-dependent coronary vasodilation) and ACh-mediated coronary vasodilation were enhanced (P < 0.05). Response to endothelium-independent vasodilators, adenosine and nitroglycerin, was not potentiated. After simvastatin administration, plasma nitrate and nitrite (NO(x)) levels increased from 5.22 +/- 1.2 to 7. 79 +/- 1.3 microM (P < 0.05); baseline and agonist-stimulated NO production in isolated coronary microvessels were augmented (P < 0.05); resting in vivo myocardial oxygen consumption (MVO(2)) decreased from 6.8 +/- 0.6 to 5.9 +/- 0.4 ml/min (P < 0.05); NO-dependent regulation of MVO(2) in response to NO agonists was augmented in isolated myocardial segments (P < 0.05); and eNOS protein increased 29% and eNOS mRNA decreased 50% in aortas and coronary vascular endothelium. Short-term administration of simvastatin in dogs increases coronary endothelial NO production to enhance NO-dependent coronary vasodilation and NO-mediated regulation of MVO(2).

Acetylcholine↗

Limitation of heart growth in neonatal piglets by simvastatin and atorvastatin: comparison with pravastatin.

The pig heart grows rapidly in the first few days after birth. We examined the effects of simvastatin, atorvastatin, and pravastatin on heart growth in piglets. After vehicle, 2 mg x kg(-1) x day(-1) simvastatin, 2 mg x kg(-1) x day(-1) atorvastatin, or 4 mg x kg(-1) x day(-1) pravastatin were administered orally for 6 days, the thoracic cavity was opened, and the heart was removed under pentobarbital sodium (30 mg/kg ip) anesthesia. The heart was perfused to remove residual blood. After the heart was blotted dry, the right and left ventricular free walls were dissected. Each free wall was weighed and used for determination of DNA, RNA, and protein concentrations and mitogen-activated protein (MAP) kinase activity. Simvastatin and atorvastatin resulted in smaller increases with age in the weight, concentrations of RNA and protein, and activity of MAP kinase in the left ventricular free wall, whereas pravastatin did not. The parameters of heart growth in the right ventricular free wall were not appreciably affected by either drug. The blood pressure and heart rate were not changed by the treatments. These results suggest that simvastatin and atorvastatin interfere with heart growth in neonatal piglets after birth, especially in the left ventricular free wall.

Administration, Oral↗