Rapid improvement of nitric oxide bioavailability after lipid-lowering therapy with cerivastatin within two weeks

Statins reduce vascular inflammation in atherogenesis: A review of underlying molecular mechanisms

Chronic inflammation enhances the detrimental role of dyslipidaemia during atherogenesis. Statins are among the most effective anti-atherosclerotic medications, being able to impact on both cardiovascular morbidity and mortality. Although these molecules have been first described as lipid-lowering medications, several lines of evidence suggest additional benefits through their "pleiotropic" anti-atherosclerotic activities. Specifically, statins can modulate vascular atherosclerotic inflammation by directly improving functions of endothelial cells, vascular smooth muscle cells, platelets, and immune cells. Here, we discuss basic and clinical evidence to provide an update on the molecular mechanisms underlying the protective anti-inflammatory role of statins in atherogenesis.

Biocatalyzed Synthesis of Statins: A Sustainable Strategy for the Preparation of Valuable Drugs

Statins, inhibitors of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase, are the largest selling class of drugs prescribed for the pharmacological treatment of hypercholesterolemia and dyslipidaemia. Statins also possess other therapeutic effects, called pleiotropic, because the blockade of the conversion of HMG-CoA to (R)-mevalonate produces a concomitant inhibition of the biosynthesis of numerous isoprenoid metabolites (e.g., geranylgeranyl pyrophosphate (GGPP) or farnesyl pyrophosphate (FPP)). Thus, the prenylation of several cell signalling proteins (small GTPase family members: Ras, Rac, and Rho) is hampered, so that these molecular switches, controlling multiple pathways and cell functions (maintenance of cell shape, motility, factor secretion, differentiation, and proliferation) are regulated, leading to beneficial effects in cardiovascular health, regulation of the immune system, anti-inflammatory and immunosuppressive properties, prevention and treatment of sepsis, treatment of autoimmune diseases, osteoporosis, kidney and neurological disorders, or even in cancer therapy. Thus, there is a growing interest in developing more sustainable protocols for preparation of statins, and the introduction of biocatalyzed steps into the synthetic pathways is highly advantageous—synthetic routes are conducted under mild reaction conditions, at ambient temperature, and can use water as a reaction medium in many cases. Furthermore, their high selectivity avoids the need for functional group activation and protection/deprotection steps usually required in traditional organic synthesis. Therefore, biocatalysis provides shorter processes, produces less waste, and reduces manufacturing costs and environmental impact. In this review, we will comment on the pleiotropic effects of statins and will illustrate some biotransformations nowadays implemented for statin synthesis.

Cerivastatin Nanoliposome as a Potential Disease Modifying Approach for the Treatment of Pulmonary Arterial Hypertension

In this study we investigated nanoliposome as an approach to tailoring the pharmacology of cerivastatin as a disease-modifying drug for pulmonary arterial hypertension (PAH). Cerivastatin encapsulated liposomes with an average diameter of 98 ± 27 nm were generated by a thin film and freeze-thaw process. The nanoliposomes demonstrated sustained drug-release kinetics in vitro and inhibited proliferation of pulmonary artery (PA) smooth muscle cells with significantly less cellular cytotoxicity as compared with free cerivastatin. When delivered by inhalation to a rat model of monocrotaline-induced PAH, cerivastatin significantly reduced PA pressure from 55.13 ± 9.82 to 35.56 ± 6.59 mm Hg (P < 0.001) and diminished PA wall thickening. Echocardiography showed that cerivastatin significantly reduced right ventricle thickening (monocrotaline: 0.34 ± 0.02 cm vs. cerivastatin: 0.26 ± 0.02 cm; P < 0.001) and increased PA acceleration time (monocrotaline: 13.98 ± 1.14 milliseconds vs. cerivastatin: 21.07 ± 2.80 milliseconds; P < 0.001). Nanoliposomal cerivastatin was equally effective or slightly better than cerivastatin in reducing PA pressure (monocrotaline: 67.06 ± 13.64 mm Hg; cerivastatin: 46.31 ± 7.64 mm Hg vs. liposomal cerivastatin: 37.32 ± 9.50 mm Hg) and improving parameters of right ventricular function as measured by increasing PA acceleration time (monocrotaline: 24.68 ± 3.92 milliseconds; cerivastatin: 32.59 ± 6.10 milliseconds vs. liposomal cerivastatin: 34.96 ± 7.51 milliseconds). More importantly, the rate and magnitude of toxic cerivastatin metabolite lactone generation from the intratracheally administered nanoliposomes was significantly lower as compared with intravenously administered free cerivastatin. These studies show that nanoliposome encapsulation improved in vitro and in vivo pharmacologic and safety profile of cerivastatin and may represent a safer approach as a disease-modifying therapy for PAH.

Early Effects of Simvastatin versus Atorvastatin on Oxidative Stress and Proinflammatory Cytokines in Hyperlipidemic Subjects

The authors investigated the time-dependent action of atorvastatin and simvastatin on oxidative stress and cytokine levels immediately after the start of treatment. These factors play a role in endothelial dysfunction. Hyperlipidemic patients (n=132) were assigned to treatment with 40 mg atorvastatin, 40 mg simvastatin, or placebo. Blood samples were taken before, 2 hours, 24 hours, 7 days, and 3 weeks after the administration of the statin or placebo to evaluate serum concentrations of total peroxides (TP), interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-a) and soluble intercellular vascular adhesion molecule 1 (sICAM 1). In the atorvastatin group the TP changes were significantly different at 2 hours and 24 hours (p=0.005), whereas in the simvastatin group there was a gradual, more or less linear decline in TP until 7 days (p=0.006) and then a plateau. Simvastatin exhibited a faster statistically significant decrease over time in IL-6 and sICAM 1 levels (at 7 days, p=0.014 and p=0.001, respectively). TNF-a demonstrated a faster linear trend in the simvastatin group, but the significant effect appeared late (p=0.006). Both simvastatin and atorvastatin exerted early beneficial effects on oxidative stress, proinflammatory cytokines, and endothelial activation in hyperlipidemic subjects. These effects became significant 2 hours following the initiation of therapy.

Endothelial Dysfunction After ST-segment Elevation Myocardial Infarction and Long-term Outcome: A Study With Reactive Hyperemia Peripheral Artery Tonometry

INTRODUCTION AND OBJECTIVES

Long-term data on the relationship between endothelial dysfunction after ST-segment elevation myocardial infarction and future adverse clinical events are scarce. The aim of this study was to noninvasively assess whether endothelial dysfunction 4 weeks to 6 weeks after primary percutaneous coronary intervention for acute ST-segment elevation myocardial infarction predicts future clinical events.

METHODS

This prospective cohort study was performed in 70 patients of the RESPONSE randomized trial, who underwent noninvasive assessment of endothelial function 4 weeks to 6 weeks after primary percutaneous coronary intervention. Endothelial function was measured by the reactive hyperemia peripheral artery tonometry method; an index<1.67 identified endothelial dysfunction.

RESULTS

The reactive hyperemia peripheral artery tonometry index measured on average 1.90±0.58. A total of 35 (50%) patients had endothelial dysfunction and 35 (50%) patients had normal endothelial function. Periprocedural "complications" (eg, cardiogenic shock, total atrioventricular block) were more common in patients with endothelial dysfunction than in those without (25.7% vs 2.9%; P<.01). During 4.0±1.7 years of follow-up, 20 (28.6%) patients had major adverse cardiovascular events: events occurred in 9 (25.7%) patients with endothelial dysfunction and in 11 (31.5%) patients with normal endothelial function (P=.52). There was an association between the prevalence of diabetes mellitus at baseline and the occurrence of major adverse cardiovascular events during follow-up (univariate analysis: hazard ratio=2.8; 95% confidence interval, 1.0-7.8; P<.05), and even in multivariate analyses the risk appeared to be increased, although not significantly (multivariate analysis: hazard ratio=2.5; 95% confidence interval, 0.8-7.5).

CONCLUSIONS

In this series of patients who survived an ST-segment elevation myocardial infarction, endothelial dysfunction, as assessed by reactive hyperemia peripheral artery tonometry 4 weeks to 6 weeks after myocardial infarction, did not predict future clinical events during a mean follow-up of 4 years.

Effects of atorvastatin on systemic and renal NO dependency in patients with non-diabetic stage II-III chronic kidney disease

AIMS

Clinical trials suggest that statins have beneficial effects on the cardiovascular system independent from their cholesterol lowering properties. In patients with chronic kidney disease stage II-III, we tested the hypothesis that atorvastatin increased systemic and renal nitric oxide (NO) availability using L-N(G) -monomethyl arginine (L-NMMA) as an inhibitor of NO production.

METHODS

In a randomized, placebo-controlled, crossover study patients were treated with atorvastatin for 5 days with standardized diet and fluid intake. Glomerular filtration reate (GFR), fractional excretions of sodium (FENa ), urinary excretion of aquaporin-2 (u-AQP2) and epithelial sodium channels (u-ENaCγ ), vasoactive hormones (renin, angiotensin II, aldosterone, arginine vasopressin, endothelin-1 and brain natriuretic peptide) and central blood pressure (BP) estimated by applanation tonometry were measured before and after systemic administration of the NO inhibitor L-NMMA.

RESULTS

Atorvastatin caused a significant reduction in U-ENaCγ , but sodium excretion, C H 2 O , FENa and u-AQP2 were not changed by atorvastatin. L-NMMA reduced renal effect variables, including GFR, FENa and u-ENaCγ and increased brachial BP and central BP to a similar extent during both treatments. Vasoactive hormones were changed in the same way by L-NMMA during atorvastatin and placebo treatment.

CONCLUSION

During, atorvastatin and placebo treatment, inhibition of nitric oxide synthesis induced the same response in brachial and central blood pressure, GFR, renal tubular function and vasoactive hormones. Thus, the data do not support that atorvastatin changes nitric oxide availability in patients with mild nephropathy. The reduced u-ENaC may reflect changes in sodium absorption in the nephron induced by atorvastatin.

Dietary supplementation with essential amino acids boosts the beneficial effects of rosuvastatin on mouse kidney

The effects of high-potency statins on renal function are controversial. To address the impact of statins on renal morpho-functional aspects, normotensive young mice were treated with rosuvastatin (Rvs). Moreover, because statins may impair mitochondrial function, mice received either dietary supplementation with an amino acid mixture enriched in essential amino acids (EAAm), which we previously demonstrated to increase mitochondrial biogenesis in muscle or an unsupplemented control diet for 1 month. Mitochondrial biogenesis and function, apoptosis, and insulin signaling pathway events were studied, primarily in cortical proximal tubules. By electron microscopy analysis, mitochondria were more abundant and more heterogeneous in size, with dense granules in the inner matrix, in Rvs- and Rvs plus EAAm-treated animals. Rvs administration increased protein kinase B and endothelial nitric oxide synthase phosphorylation, but the mammalian target of rapamycin signaling pathway was not affected. Rvs increased the expression of sirtuin 1, peroxisome proliferator-activated receptor γ coactivator-1α, cytochrome oxidase type IV, cytochrome c, and mitochondrial biogenesis markers. Levels of glucose-regulated protein 75 (Grp75), B-cell lymphoma 2, and cyclin-dependent kinase inhibitor 1 were increased in cortical proximal tubules, and expression of the endoplasmic reticulum-mitochondrial chaperone Grp78 was decreased. EAAm supplementation maintained or enhanced these changes. Rvs promotes mitochondrial biogenesis, with a probable anti-apoptotic effect. EAAm boosts these processes and may contribute to the efficient control of cellular energetics and survival in the mouse kidney. This suggests that appropriate nutritional interventions may enhance the beneficial actions of Rvs, and could potentially prevent chronic renal side effects.

Simvastatin induces a central hypotensive effect via Ras-mediated signalling to cause eNOS up-regulation

BACKGROUND AND PURPOSE

Clinical studies indicate that statins have a BP-lowering effect in hypercholesterolemic individuals with hypertension. Specifically, statins modulate BP through the up-regulation of endothelial NOS (eNOS) activation in the brain. However, the signalling mechanisms through which statins enhance eNOS activation remain unclear. Therefore, we examined the possible signalling pathways involved in statin-mediated BP regulation in the nucleus tractus solitarii (NTS).

EXPERIMENTAL APPROACH

To investigate the involvement of Ras and other signalling pathways in simvastatin-induced effects on BP, BP and renal sympathetic nerve activity (RSNA) were determined in spontaneously hypertensive rats (SHRs) before and after i.c.v. administration of simvastatin in the absence and presence of a Ras-specific inhibitor (farnesyl thiosalicylic acid, FTS), a geranylgeranyltransferase inhibitor (GGTI-2133), a PI3K inhibitor (LY294002) or a MAPK-ERK kinase (MEK) inhibitor (PD98059).

KEY RESULTS

FTS significantly attenuated the decrease in BP and increased NO evoked by simvastatin and reversed the decrease in basal RSNA induced by simvastatin. Immunoblotting and pharmacological studies showed that inhibition of Ras activity by FTS significantly abolished simvastatin-induced phosphorylation of ERK1/2, ribosomal protein S6 kinase (RSK), Akt and decreased eNOS phosphorylation. Likewise, administration of Akt and ERK1/2 signalling inhibitors, LY294002 and PD98059, attenuated the reduction in BP evoked by simvastatin. Furthermore, i.c.v. simvastatin decreased Rac1 activation and the number of ROS-positive cells in the NTS.

CONCLUSIONS AND IMPLICATIONS

Simvastatin modulates central BP control in the NTS of SHRs by increasing Ras-mediated activation of the PI3K-Akt and ERK1/2-RSK signalling pathways, which then up-regulates eNOS activation.

Nitric oxide, oxidative stress, and p66Shc interplay in diabetic endothelial dysfunction

Increased oxidative stress and reduced nitric oxide (NO) bioavailability play a causal role in endothelial cell dysfunction occurring in the vasculature of diabetic patients. In this review, we summarized the molecular mechanisms underpinning diabetic endothelial and vascular dysfunction. In particular, we focused our attention on the complex interplay existing among NO, reactive oxygen species (ROS), and one crucial regulator of intracellular ROS production, p66Shc protein.

Effects of atorvastatin on systemic and renal nitric oxide in healthy man

Statin treatment improves endothelial function but the effects of statins on renal nitric oxide have not been clarified. In this crossover study, 26 healthy subjects received atorvastatin 80 mg per day or placebo for 5 days. After 5 days of treatment, L-N(G)-monomethyl arginine caused a similar increase in blood pressure and decrease in urine output and glomerular filtration rate. The decrease in fractional excretion of sodium to L-N(G)-monomethyl arginine was more pronounced after atorvastatin treatment. Atorvastatin did not change the response to several vasoactive hormones. The results indicate that atorvastatin increase renal nitric oxide, which may explain a part of the pleiotropic effects of statins.

Chronic administration of atorvastatin induced anti-convulsant effects in mice: the role of nitric oxide

Atorvastatin has neuroprotective effects, and there is some evidence that nitric oxide is involved in atorvastatin effects. In this study, we evaluated whether the nitrergic system is involved in the anticonvulsant effects of chronic atorvastatin administration. Intravenous and intraperitoneal pentylenetetrazol were used to induce seizures in mice. Chronic atorvastatin treatment significantly increased the seizure threshold which is induced by both intravenous and intraperitoneal pentylenetetrazol. Intraperitoneal pentylenetetrazol also decreased the incidence of tonic seizure and death in atorvastatin-treated groups. Chronic co-administration of a non-selective nitric oxide synthase inhibitor, l-NAME, or a selective inducible nitric oxide synthase inhibitor, aminoguanidine, with atorvastatin inhibited atorvastatin-induced anticonvulsant effects in intravenous model of pentylenetetrazol. Acute injection of l-NAME or aminoguanidine inhibited the anticonvulsant effects of atorvastatin in both models of intravenous- and intraperitoneal-pentylenetetrazol-induced seizures. In conclusion, we demonstrated that nitric oxide signaling probably through inducible nitric oxide synthase could be involved in the anticonvulsant effects of atorvastatin.

Effects of statin treatment on endothelial function, oxidative stress and inflammation in patients with arterial hypertension and normal cholesterol levels

OBJECTIVE

Patients with arterial hypertension are characterized by impaired endothelial function and increased cardiovascular risk. Statins have been proposed as a potential treatment option in hypertension, even in those with normal low-density lipoprotein (LDL)-cholesterol levels. We tested whether fluvastatin reduces oxidative stress and inflammation, and improves endothelial function in patients with arterial hypertension and normal LDL-cholesterol.

METHODS

In a cross-over designed, double-blind randomized trial, 26 patients with arterial hypertension and LDL-cholesterol below 160 mg/dl were treated for 2 weeks with either placebo or fluvastatin 80 mg/day. Endothelium-dependent vasodilation (EDV) was assessed as the forearm blood flow (FBF) response to intra-arterial infusion of acetylcholine (ACH, 12 and 48 μg/min), and endothelium-independent vasodilation (EIV) as the FBF response to nitroprusside (3.2 and 12.8 μg/min). Furthermore, we measured reduced to oxidized glutathione (GSH/GSSG) ratio in red blood cells, total antioxidant capacity in plasma (TAC) and high-sensitivity C-reactive protein (hs-CRP) levels.

RESULTS

Fluvastatin lowered LDL-cholesterol from 118 ± 16 to 90 ± 25 mg/dl (P < 0.0001), but had no effect on blood pressure, high-density lipoprotein (HDL)-cholesterol or triglycerides. EDV and EIV were unaffected by fluvastatin treatment (e.g. increase of FBF 48 μg/min: 339 ± 285% during placebo versus 268 ± 194% during fluvastatin, n.s.). Finally, GSH/GSSG ratio, TAC and hs-CRP levels were similar between fluvastatin and placebo treatment.

CONCLUSION

Fluvastatin treatment did not improve endothelial function, oxidative stress or inflammation in patients with arterial hypertension and normal LDL-cholesterol levels. These data argue against the usefulness of statins in patients with arterial hypertension in the absence of hypercholesterolemia or other additional risk factors.

The Fcγ receptor IIA R131H gene polymorphism is associated with endothelial function in patients with hypercholesterolaemia

OBJECTIVE

A gene polymorphism substituting arginine (R) for histidine (H) at position 131 has been described within the Fcγ receptor IIa (FcγRIIa). The R allele is associated with increased binding of CRP and enhanced activation of monocytes. FcγRIIa is also expressed on endothelial cells, and we hypothesized this polymorphism would be associated with alterations of endothelial function.

METHODS

Genomic DNA was extracted and allele-specific PCR reactions were used to determine the FcγRIIa H131R polymorphism in 78 hypercholesterolaemic subjects. Using strain gauge plethysmography, forearm blood flow (FBF) responses were determined to intra-arterial infusion of acetylcholine (ACH), for endothelium-dependent vasodilatation (EDV), to nitroprusside (NP), for endothelium-independent vasodilatation (EIV), to NG-monomethyl-l-arginine (l-NMMA), for basal NO activity, and to ACH in the presence of l-NMMA, to assess the contribution of NO release to EDV.

RESULTS

Homozygous carriers of the H allele (n=30) had significantly better EDV than homozygous carriers of the R allele (n=15), while heterozygotes showed an intermediate phenotype (n=33) (e.g. % increase of FBF to ACH 48μg/min: 527±359% in H/H versus 452±262% in H/R versus 332±413% in R/R, p=0.0012 by 2-way ANOVA). EIV and basal NO activity were not affected by genotype, and co-infusion of l-NMMA abolished the differences in EDV.

CONCLUSIONS

The R allele of the FcγRIIa polymorphism is associated with impaired EDV and reduced NO activity during endothelial cell stimulation. These data suggest that the functional effects of the FcγRIIa H131R gene polymorphism previously observed in vitro translate into clinically relevant alterations of endothelial function in vivo.

Urinary proteomics in cardiovascular disease: Achievements, limits and hopes

Cardiovascular disease (CVD) is the major cause of mortality and morbidity worldwide. Diagnosis of CVD and risk stratification of patients with CVD remains challenging despite the availability of a wealth of non-invasive and invasive tests. Clinical proteomics analyses a large number of peptides and proteins in biofluids. For clinical applications, the urinary proteome appears particularly attractive due to the relative low complexity compared with the plasma proteome and the noninvasive collection of urine. In this article, we review the results from pilot studies into urinary proteomics of coronary artery disease and discuss the potential of urinary proteomics in the context of pathogenesis of CVD.

Is oxidative stress a therapeutic target in cardiovascular disease?

An abnormal production of reactive oxygen species (ROS) and the subsequent decrease in vascular bioavailability of nitric oxide (NO) have long been proposed to be the common pathogenetic mechanism of the endothelial dysfunction, resulting from diverse cardiovascular risk factors such as hypercholesterolaemia, diabetes mellitus, chronic smoking, metabolic syndrome, and hypertension. Superoxide produced by the nicotinamide dinucleotide phosphate (NADPH) oxidase, mitochondrial sources, or the xanthine oxidase may react with NO, thereby resulting in excessive formation of peroxynitrite, a reactive nitrogen species that has been demonstrated to accelerate the atherosclerotic process by causing direct structural damage and by causing further ROS production. Despite this sound biological rationale and a number of pre-clinical and clinical lines of evidence, studies testing the effects of classical antioxidants such as vitamin C, vitamin E, or folic acid in combination with vitamin E have been disappointing. Rather, substances such as statins, angiotensin-converting enzyme inhibitors, or AT1-receptor blockers, which possess indirect antioxidant properties mediated by the stimulation of NO production and simultaneous inhibition of superoxide production (e.g. from the NADPH oxidase), have been shown to improve vascular function in pre-clinical and clinical studies and to reduce the incidence of cardiovascular events in patients with cardiovascular disease. Today, oxidative stress remains an attractive target for cardiovascular prevention and therapy. However, a deeper understanding of its source, and of its role in vascular pathology, is necessary before new trials are attempted.

Impact of chronic anticholesterol therapy on development of microvascular rarefaction in the metabolic syndrome

OBJECTIVE

The obese Zucker rat (OZR) model of the metabolic syndrome is partly characterized by moderate hypercholesterolemia, in addition to other contributing comorbidities. Previous results suggest that vascular dysfunction in OZR is associated with chronic reduction in vascular nitric-oxide (NO) bioavailability and chronic inflammation, both frequently associated with hypercholesterolemia. As such, we evaluated the impact of chronic cholesterol-reducing therapy on the development of impaired skeletal muscle arteriolar reactivity and microvessel density in OZR and its impact on chronic inflammation and NO bioavailability.

MATERIALS AND METHODS

Beginning at seven weeks of age, male OZR were treated with gemfibrozil, probucol, atorvastatin, or simvastatin (in chow) for 10 weeks. Subsequently, plasma and vascular samples were collected for biochemical/molecular analyses, while arteriolar reactivity and microvessel network structure were assessed by using established methodologies after 3, 6, and 10 weeks of drug therapy.

RESULTS

All interventions were equally effective at reducing total cholesterol, although only the statins also blunted the progressive reductions to vascular NO bioavailability, evidenced by greater maintenance of acetylcholine-induced dilator responses, an attenuation of adrenergic constrictor reactivity, and an improvement in agonist-induced NO production. Comparably, while minimal improvements to arteriolar wall mechanics were identified with any of the interventions, chronic statin treatment reduced the rate of microvessel rarefaction in OZR. Associated with these improvements was a striking statin-induced reduction in inflammation in OZR, such that numerous markers of inflammation were correlated with improved microvascular reactivity and density. However, using multivariate discriminant analyses, plasma RANTES (regulated on activation, normal T-cell expressed and secreted), interleukin-10, monocyte chemoattractant protein-1, and tumor necrosis factor alpha were determined to be the strongest contributors to differences between groups, although their relative importance varied with time.

CONCLUSIONS

While the positive impact of chronic statin treatment on vascular outcomes in the metabolic syndrome are independent of changes to total cholesterol, and are more strongly associated with improvements to vascular NO bioavailability and attenuated inflammation, these results provide both a spatial and temporal framework for targeted investigation into mechanistic determinants of vasculopathy in the metabolic syndrome.

Reduced LDL-cholesterol levels in patients with coronary artery disease are paralleled by improved endothelial function: An observational study in patients from 2003 and 2007

Objective

Recent guidelines recommend more aggressive lipid-lowering in secondary prevention protocols. We examined whether this resulted in improved endothelial function.

Methods

We studied saphenous vein specimens of patients undergoing surgical coronary revascularisation in 2007 and compared results with those of patients examined in 2003. Endothelium-dependent vasodilation was assessed by relaxation to calcium ionophore A23187, and vascular superoxide production by lucigenin enhanced chemiluminescence.

Results

Statin dose increased from 26 ± 16 mg/d in 2003 to 37 ± 17 mg/d in 2007 (P < 0.001), and total (4.0 ± 0.9 mmol/L vs 4.8 ± 1.0 mmol/L) and LDL-cholesterol levels (2.0 ± 0.7 mmol/L vs 3.0 ± 0.9 mmol/L) were lower in 2007 compared to 2003 (P < 0.001; n = 90 each). Endothelium-dependent vasodilation was greater in 2007 (44 ± 15%) compared to 2003 (28 ± 12%; n = 36 each; P < 0.001). Vascular superoxide derived from endothelial NO synthase (eNOS) was lower in 2007 than in 2003 (reduction by N^G-nitro-l-arginine-methyl ester, 0.29 ± 0.21 nmol/(mg min) vs 0.09 ± 0.20 nmol/(mg min); P = 0.002). In linear regression analysis, LDL-cholesterol levels have been shown to be the major determinant of endothelial function in the combined 2003 and 2007 cohort.

Conclusion

Intensive lipid-lowering is associated with improved endothelial function and reduced superoxide production from eNOS. Further improvement in vascular function could be achieved by targeting other sources of superoxide including xanthine oxidase.

[Correlation of depression with stroke. Pathophysiological mechanisms]

Stroke is the third leading cause of death, just after heart disease and cancer. Its incidence will probably increase dramatically in the coming decades. For prevention it is urgently necessary to gain fundamental knowledge about the risk factors and pathophysiological mechanisms. It is now widely accepted that depression and stroke are correlated with each other. There is little knowledge, however, about the links that might connect both diseases. This review discusses different mechanisms that lead to an increased stroke risk and can be influenced by depression as well thus possibly linking depression and stroke.

Statins and angiogenesis: is it about connections?

Statins, inhibitors of 3-hydroxy-3-methyl-glutaryl-coenzyme A reductase, have been shown to induce both angiogenic and angiostatic responses. We attempted to resolve this controversy by studying the effects of two different statins, rosuvastatin and simvastatin, in two different assay systems. In the matrigel angiogenesis assay, both statins enhanced tube formation by human umbilical vein endothelial cells (HUVECs, p<0.01 vs. control). In the ex vivo mouse aortic ring sprouting assay, both statins virtually abolished new vessel formation (p<0.01). As a basic difference between the two models of angiogenesis is dispersed state of endothelial cells vs. compact monolayer, we analyzed influence of statins on endothelial junction proteins. RT-PCR analysis and cytoimmunostaining of HUVECs treated with simvastatin revealed increased expression of VE-cadherin (p<0.05). The blockade of VE-cadherin with a specific antibody reversed simvastatin-induced tube formation (p<0.002). These data suggest that statins through VE-cadherin stimulation modulate cell-cell adhesion and diminish the ability of cells to proliferate and migrate. The observations of reduced angiogenesis in the intact vessel may relate to anti-atherosclerotic and anti-cancer effects of statins, and provide a feasible explanation for conflicting data under different experimental conditions.

Impact of the endothelial nitric oxide synthase gene G894T polymorphism on renal endothelial function in patients with type 2 diabetes

OBJECTIVE

Endothelial dysfunction and increased oxidative stress contribute to the progression of diabetic nephropathy. To analyze the functional significance of the G894T polymorphism of NOS3, the gene encoding endothelial nitric oxide synthase (NOS), we assessed basal nitric oxide activity and the amount of oxidative stress in the renal circulation of patients with type 2 diabetes.

METHODS

Renal plasma flow (RPF) was assessed by steady-state input clearance technique with sodium para-aminohippurate in 84 patients with type 2 diabetes and 84 patients without diabetes. RPF was measured at baseline and after the infusion of the NOS inhibitor N-monomethyl-L-arginine (4.25 mg/kg); the substrate of NOS L-arginine (100 mg/kg); and coinfusion of vitamin C (3 g) with L-arginine (100 mg/kg).

RESULTS

The decrease of RPF to N-monomethyl-L-arginine was similar between carriers of the T allele and homozygous carriers of the G allele in patients with diabetes (-56+/-40 vs. -68.1+/-74 ml/min/1.73 m, P=0.342) and patients without diabetes (-66.7+/-81 vs. -58.3+/-63 ml/min/1.73 m, P=0.606). In patients with diabetes, however, carriers of the T allele revealed a more pronounced increase of RPF to coinfusion of vitamin C with L-arginine than homozygous carriers of the G allele (61.8+/-75 vs. 22.3+/-73 ml/min/1.73 m, P=0.021), whereas in patients without diabetes the response of RPF to coinfusion of vitamin C with L-arginine was similar between both groups (46.2+/-80 vs. 70.7+/-86 ml/min/1.73 m, P=0.217). Gene-environment interaction between disease (diabetes) and genotype (genotype GG vs. genotype GT/TT) was observed for increase of RPF to coinfusion of vitamin C with L-arginine (P=0.020).

CONCLUSION

G894T polymorphism of NOS3 has no impact on the basal nitric oxide activity of renal circulation. In contrast, the T allele is associated with increased oxidative stress in the renal circulation in patients with diabetes suggesting a specific role of the G894T polymorphism in the pathogenesis of diabetic nephropathy.

Glutathione S-transferase variants and hypertension

OBJECTIVES

Glutathione S-transferases are involved in defences against oxidative stress. We have recently demonstrated reduced expression of glutathione S-transferase mu type 1 (Gstm1) in a rat model of hypertension. Here, we examine the association between GSTM variants and hypertension in human.

METHODS

We screened 83 patients with hypertension and 46 controls for single nucleotide polymorphisms in GSTM genes by TaqMan single nucleotide polymorphism genotyping assays and DNA sequencing. We then genotyped 753 trios from the Medical Research Council British Genetics of Hypertension Study transmission disequilibrium test cohort for 10 single nucleotide polymorphisms and the GSTM1 deletion and examined renal GSTM expression in a cohort of 27 hypertensive and 18 normotensive subjects. Finally, we attempted to replicate our findings in 1675 cases and 1654 controls from the Medical Research Council British Genetics of Hypertension Study case-control cohort.

RESULTS

We identified two major linkage disequilibrium blocks including GSTM4/GSTM2 and GSTM5/GSTM3 separated by the GSTM1 gene. In the British Genetics of Hypertension transmission disequilibrium test resource, a single nucleotide polymorphism in the 3' region of GSTM5 (rs11807) was found to be associated with hypertension (P = 0.01) with the T-allele being over-transmitted to hypertensive offspring. GSTM5 mRNA expression was found to be reduced in kidney tissue of subjects homozygous for the T-allele of rs11807 as compared to C-allele homozygous and CT heterozygous subjects (P = 0.02). Nevertheless, rs11807 was not associated with hypertension in the British Genetics of Hypertension case-control cohort (P = 0.61).

CONCLUSION

Our studies do not provide an evidence of an association of GSTM gene variants with hypertension in humans. They, however, illustrate the essential role of replication of initial results in a second cohort.

Antioxidative effects of statins

HMG CoA reductase inhibitors (statins) have been shown to be effective lipid lowering agents and are beneficial in the primary and secondary prevention of coronary heart disease. However, the overall benefits observed with statins appear to be greater than what might be expected from changes in lipid levels alone and the positive effects have only partially been reproduced with other lipid lowering drugs, suggesting effects in addition to cholesterol lowering. In experimental models, many of the cholesterol-independent effects of statins are mediated by inhibition of isoprenoids, which serve as lipid attachments for intracellular signalling molecules such as small Rho guanosine triphosphate-binding proteins, whose membrane localization and function are dependent on isoprenylation. This review summarizes the effects of statins on endothelial function and oxidative stress.

Potential therapeutic role of statins in neurological disorders

Statins, the inhibitors of HMG-CoA reductase, are currently among the most commonly prescribed agents for the prevention of cardiovascular disease. It is well established that statins reduce cholesterol levels and prevent coronary heart disease. Moreover, evidence suggests that statins have additional properties such as endothelial protection via actions on the nitric oxide synthetase system as well as antioxidant, anti-inflammatory and antiplatelet effects. There is evidence that all these actions might have potential therapeutic implications not only in stroke, but also in various neurological disorders, such as Alzheimer's disease, Parkinson's disease, multiple sclerosis and primary brain tumors. In this review, we summarize the protective effects of statins on various neurological diseases. Currently available data suggest that statins are safe and effective in the treatment of these neurological disorders, although further experiments and new data are required.

Targeting reactive oxygen species in hypertension

Oxidative stress plays an important role in the pathogenesis of hypertension. A number of sources of reactive oxygen species have been identified including NADPH oxidase, endothelial NO synthase, and xanthine oxidase. Inhibitors of these systems reduce blood pressure in experimental models. Targeted overexpression of antioxidant systems and interference with expression of oxidant systems has also been successfully used in animal models of hypertension. It is expected that these strategies will eventually be translated to human disease, but currently, the specificity and toxicity of such measures are not yet fulfilling quality criteria for treatment of humans. In the meantime, presumably nontoxic measures, such as administration of antioxidant vitamins, are the only available treatments for oxidative stress in humans. In this review, we discuss strategies to target oxidative stress both in experimental models and in humans. We also discuss how patients could be selected who particularly benefit from antioxidant treatment. In clinical practice, diagnostic procedures beyond measurement of blood pressure will be necessary to predict the response to antioxidants; these procedures will include measurement of antioxidant status and detailed assessment of vascular structure and function.

Gender differences in short-term effects of atorvastatin on lipid profile, fibrinolytic parameters, and endothelial function

BACKGROUND AND AIM

Little is known about the impact of gender on short-term effects of atorvastatin. We investigated the gender differences in the short-term lipid-lowering and pleiotropic effects of atorvastatin therapy.

METHODS AND RESULTS

Seventy-two consecutive patients including 48 women with primary hypercholesterolemia, were assigned prospectively to treatment with atorvastatin (10mg/day) for 3 months. We measured fasting lipid concentrations, thiobarbituric acid reactive substances (TBARS) as marker of lipid peroxide, fibrinolytic parameters, and endothelial function by flow-mediated vasodilation of the brachial artery (FMD), at baseline and after 3 months of therapy. We assessed the impact of gender on temporal differences in these parameters. In men, atorvastatin decreased total, low-density lipoprotein (LDL), and small, dense LDL-cholesterol concentrations, and increased FMD after 3 months. In women, atorvastatin decreased TBARS, triglyceride, and total, LDL, small, dense LDL, and remnant-like lipoprotein particle-cholesterol concentrations, and increased FMD after 3 months. Fibrinolytic parameters did not change significantly in either men or women. With respect to the percent change in those parameters after 3 months, TBARS (-17.6+/-12.4 vs. -0.4+/-18.8%, p<0.01) and small, dense LDL-cholesterol (-96.7+/-8.3 vs. -68.6+/-29.7%, p<0.01) decreased to a greater degree in women, although the relative changes in other parameters were similar between men and women.

CONCLUSIONS

We found gender differences in some of the lipid altering changes, including TBARS and small, dense LDL-cholesterol concentrations, after short-term atorvastatin therapy, which were greater in women. However, short-term atorvastatin therapy may be beneficial in improving endothelial function equally in both men and women.

Rosuvastatin improves basal nitric oxide activity of the renal vasculature in patients with hypercholesterolemia

OBJECTIVE

Impaired endothelium-dependent vasodilation represents an early manifestation of atherosclerosis. Prospective studies have demonstrated that impaired endothelial function in the peripheral circulation of hypercholesterolemic patients predicts CV events and can be restored by statin treatment. Whether this also holds true in the renal circulation has not yet been adequately addressed.

METHODS

In a double-blind, randomized, placebo-controlled cross-over trial, 40 hypercholesterolemic patients were randomly assigned to receive rosuvastatin (10mg/day) and matching placebo. The primary objective of the study was to assess the effect of 6-week treatment with rosuvastatin on basal NOS activity of the renal vasculature, as assessed by measuring renal plasma flow (RPF) both before and after blockade of NOS with systemic infusion of N(G)-monomethyl-L-arginine (L-NMMA). In a subgroup of 20 patients we also studied the effects of a 3-day treatment regimen.

RESULTS

Compared to placebo treatment, rosuvastatin decreased LDL-cholesterol levels both after 3 days and 6 weeks of treatment. The decrease in RPF in response to L-NMMA was significantly more pronounced after 6-week therapy with rosuvastatin compared to placebo (-13.7+/-1.0% versus -11.3+/-0.7%; p=0.046), indicating increased basal NOS activity with rosuvastatin treatment. A trend towards improved basal NOS activity was already evident after 3-day treatment.

CONCLUSION

Treatment with rosuvastatin improved basal NOS activity in the renal circulation of hypercholesterolemic patients, suggestive of a nephroprotective effect. In view of the close relation between altered renal function and cardiovascular events, these nephroprotective effects may contribute to the improved CV prognosis associated with statin treatment.

Effects of perhexiline and nitroglycerin on vascular, neutrophil and platelet function in patients with stable angina pectoris

Perhexiline, a "metabolic" anti-anginal agent currently under investigation in management of congestive heart failure and acute coronary syndromes improves platelet nitric oxide responsiveness in patients with impaired responsiveness. The current study investigated possible interactions between perhexiline and the nitric oxide donor nitroglycerin on arterial stiffness, neutrophil superoxide release and on platelet nitric oxide responsiveness. Patients (n=39) with stable angina pectoris, awaiting cardiac catheterization were randomized to additional perhexiline or unchanged drug therapy; all patients received nitroglycerin infusion for 2 h. Vasomotor responses to perhexiline and combined perhexiline/nitroglycerin were examined using changes in augmentation index, measured via applanation tonometry. Neutrophil superoxide release was measured ex vivo utilizing lucigenin mediated chemiluminescence and effect of perhexiline on inhibition of platelet aggregation by sodium nitroprusside was also measured. Perhexiline alone did not affect augmentation index, neutrophil superoxide release, or ex vivo platelet sodium nitroprusside response. Nitroglycerin decreased augmentation index (P<0.01) and superoxide release (P<0.05). Magnitude of inhibition of superoxide release was significantly enhanced by perhexiline pre-treatment (P<0.05); however perhexiline had no effect on magnitude of vasomotor response to nitroglycerin. In conclusion, perhexiline exerts no effects on arterial stiffness and does not potentiate nitroglycerin induced dilatation. In patients with normal platelet function perhexiline does not affect platelet nitric oxide responsiveness. In vivo low dose nitroglycerin inhibits neutrophil superoxide release; this effect is potentiated by pre-treatment with perhexiline. These "anti-inflammatory" effects of nitroglycerin may contribute to utility in acute coronary syndromes and congestive heart failure.

Short-term statin treatment improves endothelial function and neurohormonal imbalance in normocholesterolaemic patients with non-ischaemic heart failure

OBJECTIVES

To investigate the effect of short-term statin treatment on impaired endothelium-dependent vasodilatation and haemodynamic abnormalities typically occurring in chronic heart failure (CHF).

METHODS

In a double-blind, crossover study endothelium-dependent vasodilatation was measured in conduit and resistance vessels of 23 patients with non-ischaemic CHF after 6 weeks of placebo and 40 mg atorvastatin. The haemodynamic impact was assessed by cardioendocrine hormones, echocardiography and clinical indicators of CHF.

RESULTS

Cholesterol concentrations were population average (low density lipoprotein 3.56 (SEM 0.16) mmol/l, triglycerides 1.70 (0.20) mmol/l and high density lipoprotein 1.17 (0.07) mmol/l). In resistance vessels, the area under the curve ratio during acetylcholine infusion increased from 9.2 (1.9) with placebo to 12.2 (2.1) with statin (p < 0.01). This improvement was reversed during co-infusion with the nitric oxide antagonist N(G)-monomethyl-L-arginine. In conduit arteries, flow-mediated dilatation increased from 5.64 (SEM 0.88)% with placebo to 6.83 (0.97)% with statin (p < 0.05). Endothelium-independent vasodilatation did not change (p = 0.68 for conduit and p = 0.45 for resistance vessels). Endothelin 1 and atrial natriuretic peptide (ANP) decreased from 1.57 (0.08) and 51.3 (1.0) with placebo to 1.42 (0.09) pg/ml (p < 0.05) and 42.1 (7.5) pmol/l (p < 0.05), respectively, with statin.

CONCLUSIONS

In patients with non-ischaemic CHF and population-average cholesterol concentrations, short-term statin treatment improves endothelial function in conduit and resistance vessels and lowers plasma endothelin 1 and ANP concentrations.

The nonlipid effects of statins on endothelial function

Hydroxymethylglutaryl-coenzyme A reductase inhibitors or statins constitute one of the wonder drugs of the last 2 decades. Use of this hypolipidemic medication class reduces morbidity and mortality in patients with a wide variety of cholesterol levels. Beneficial effects of the medication are seen in advance of changes in lipids suggesting nonlipid mechanisms may play a role in mediating these benefits of statins. One important nonlipid mechanism by which statins may improve vascular outcomes is restoration of normal endothelial cell function. This review will discuss the nonlipid effects of statins on endothelial cell function to highlight other avenues of benefit conferred by these medications.

Review article: The role of statins in reducing perioperative cardiac risk: physiologic and clinical perspectives

PURPOSE

To review the pathobiology and clinical implications of coronary vulnerable atherosclerotic plaques (VAPs), to discuss the role of statin therapy in VAP stabilization, and the potential benefits of perioperative statin therapy (PST) in reducing perioperative risk of acute coronary syndromes (ACSs).

SOURCE

MEDLINE search using "perioperative", "cardiac morbidity", "atherosclerosis", "vulnerable plaque", "statins" and combinations of these terms as keywords. The reference lists of relevant articles were further reviewed to identify additional citations.

PRINCIPAL FINDINGS

The nonstenotic, yet rupture-prone VAP causes most myocardial infarctions (MIs) and other ACSs, both in the nonsurgical and surgical patients. Large clinical trials in both primary and secondary prevention and in patients with ACSs have demonstrated that statin therapy will reduce cardiovascular morbidity and mortality across a broad spectrum of patient subgroups. These trials also suggest, and laboratory investigations establish, that statins possess favourable vascular effects independent of cholesterol reduction. Statins appear to interfere specifically with the pathophysiologic mechanisms implicated in atherothrombotic disease. Statins reduce vascular inflammation, improve endothelial function, stabilize VAPs, and reduce platelet aggregability and thrombus formation. Recent studies have shown that PST is associated with a reduced incidence of perioperative and long-term cardiovascular complications in high-risk patients. Combined therapy with statins and ss-blockers is a conceptually valid strategy targeting critical steps in the pathogenesis of an ACS.

CONCLUSION

Emerging evidence for the efficacy and safety of PST is promising, especially when combined with ss-blocker therapy in patients at highest risk. Confirmation of this early evidence awaits the results of ongoing and future prospective randomized controlled trials.

Single administration of cerivastatin, an HMG-CoA reductase inhibitor, improves the coronary flow velocity reserve: a transthoracic Doppler echocardiography study

HMG-CoA reductase inhibitors (statins) have been shown to improve the endothelial function by lowering lipids. Recent studies also suggest a direct impact of statins on the vascular wall. We assessed the rapid effect of cerivastatin on the coronary flow velocity reserve (CFVR) using transthoracic Doppler echocardiography (TTDE). The coronary flow velocity from the distal left anterior descending artery was measured in 16 healthy subjects (all male, age 24-38 years) using a 5-MHz transducer, on the day before, just before, and 3 h after administering 0.3 mg of cerivastatin. Hyperemia was achieved by the intravenous administration of adenosine, and the CFVR was calculated as the radio of the mean diastolic hyperemic coronary flow velocity to the basal flow velocity. The serum lipid profile and high-sensitivity C-reactive protein (hsCRP) were measured. The CFVR following the single administration of cerivastatin increased from 2.93+/-0.58 to 3.91+/-0.86, P=0.003, and was significantly higher than the CFVR measured at the same time on the previous day (3.91+/-0.86 vs 3.37+/-0.48, P=0.009). Neither the serum lipid profile nor hsCRP exhibited a remarkable change after cerivastatin administration. We concluded that a single-dose administration of cerivastatin, an HMG-CoA reductase inhibitor, improves the coronary flow velocity reserve without modifying the serum lipid profile.

Impaired basal NO activity in patients with glomerular disease and the influence of oxidative stress

Endothelial dysfunction has been found to be linked to and predictive of cardiovascular events. Whether endothelial function of the renal vasculature is impaired in patients with chronic glomerular disease and whether oxidative stress is of importance in this setting has not yet been determined. In this study, endothelial function of the renal vasculature was investigated in 25 patients with chronic glomerular disease and 50 control subjects matched for age and blood pressure. Renal plasma flow (RPF) and glomerular filtration rate were measured by constant infusion input clearance technique at baseline and following infusions of the nitric oxide synthase (NOS) inhibitor N(G)-monomethyl-L-arginine (L-NMMA, 4.25 mg/kg), the substrate of NOS L-arginine (100 mg/kg) and the antioxidant vitamin C (3 g co-infused with L-arginine 100 mg/kg). At baseline, RPF was similar in the two groups. The reduction in RPF in response to L-NMMA was less pronounced in patients with chronic glomerular disease compared to control subjects (-4.6+/-12 vs -9.8+/-9%; P=0.040), indicating reduced basal nitric oxide (NO) activity in chronic glomerular disease. Co-infusion of the antioxidant vitamin C on top of L-arginine induced a more pronounced increase in RPF in patients with chronic glomerular disease than in control subjects (21.7+/-17 vs 10.9+/-22%; P=0.036). Our findings suggest that basal NO activity of the renal vasculature is reduced in patients with chronic glomerular disease compared to age- and blood pressure-matched control subjects. This might be in part related to increased oxidative stress.

ORIGINAL RESEARCH—ED PHARMACOTHERAPY: Can Atorvastatin Improve the Response to Sildenafil in Men with Erectile Dysfunction Not Initially Responsive to Sildenafil? Hypothesis and Pilot Trial Results

BACKGROUND

Erectile dysfunction (ED) may be one manifestation of a generalized vascular disorder characterized by endothelial dysfunction. Statin drugs may improve endothelial function, even before altering the lipid profile.

OBJECTIVE

We sought to determine whether the addition of a statin with sildenafil would improve ED in men who initially responded poorly to sildenafil.

METHODS

Men with moderate-to-severe ED despite an adequate sildenafil trial were enrolled in this randomized, double-blind, placebo-controlled pilot study. ED was defined using a validated self-administered questionnaire as a score of <or=16 on the International Index of Erectile Function (erectile function domain score range of 6-30). Improvement in ED score with sildenafil was reassessed at 6 and 12 weeks of treatment with atorvastatin (80 mg daily) or matching placebo.

RESULTS

Twelve men (mean age 58 +/- 13 years) with a mean domain score of 8.2 +/- 6.9 and a mean duration of ED of 3.7 years were enrolled in the study. Treatment with atorvastatin decreased mean low-density lipoprotein cholesterol by 43% and resulted in an improvement with sildenafil in domain score of 7.8 (P = 0.036); an effect was apparent by 6 weeks. The increase in domain score in placebo patients was not statistically significant.

CONCLUSIONS

Treatment with atorvastatin improved sexual function and the response to oral sildenafil in men who did not initially respond to treatment with sildenafil. The results of this pilot study support the hypothesis that vascular endothelial dysfunction contributes to ED in sildenafil nonresponders and deserves further testing in a large clinical trial.

Short- and long-term influence of diet and simvastatin on brachial artery endothelial function

BACKGROUND

Endothelium-dependent dilation (EDD) has often been studied in patients with hypercholesterolemia without overt coronary atherosclerosis where an improvement after statin treatment has been documented within few weeks. The aim of the study was to assess the short-term effect of diet as well as short- and long-term effect of simvastatin on EDD in patients with hypercholesterolemia and ischemic heart disease.

METHODS

In 43 male patients with hypercholesterolemia and ischemic heart disease, EDD of the brachial artery was measured at baseline, after 3 months on a lipid-lowering diet, and after another 1, 3 and 12 months on simvastatin at 40 mg/day.

RESULTS

Three months changes in EDD were neither influenced by diet nor short-term simvastatin therapy (4.9% vs. 4.9% vs. 4.8%, p=ns). Twelve months simvastatin treatment, however, significantly improved EDD by 32.7% (4.9% vs. 6.5%, p=0.007). By regression analysis an individual adjusted increase in EDD during the simvastatin treatment period was seen (coefficient 0.132 a month, p=0.002). A significant reduction in total cholesterol of 31.0% (6.1+/-0.8 vs. 4.2+/-0.7, p<0.001) and LDL cholesterol of 42.6% (4.0+/-0.8 vs. 2.2+/-0.6, p<0.001) was observed.

CONCLUSION

EDD is improved after long-term simvastatin therapy; however, neither did 3 months diet or 3 months simvastatin therapy has influence on the EDD.

Anti-angiogenic and anti-inflammatory effects of statins: relevance to anti-cancer therapy

Angiogenesis is indispensable for the growth of solid tumors and angiogenic factors are also involved in the progression of hematological malignancies. Targeting the formation of blood vessels is therefore regarded as a promising strategy in cancer therapy. Interestingly, besides demonstration of some beneficial effects of novel anti-angiogenic compounds, recent data on the activity of already available drugs point to their potential application in anti-angiogenic therapy. Among these are the statins, the inhibitors of 3-hydroxy-3-methylglutaryl-coenzyme A reductase. Statins are very efficient in the treatment of hypercholesterolemia in cardiovascular disorders; however, their effects are pleiotropic and some are not directly related to the inhibition of cholesterol synthesis. Some reports particularly highlight the pro-angiogenic effects of statins, which are caused by low, nanomolar concentrations and are regarded as beneficial for the treatment of cardiovascular diseases. On the other hand, the anti-angiogenic activities, observed at micromolar concentrations of statins, may be of special significance for cancer therapy. Those effects are caused by the inhibition of both proliferation and migration and induction of apoptosis in endothelial cells. Moreover, the statin-mediated inhibition of vascular endothelial growth factor synthesis, the major angiogenic mediator, may contribute to the attenuation of angiogenesis. It has been suggested that the anti-cancer effect of statins can be potentially exploited for the cancer therapy. However, several clinical trials aimed at the inhibition of tumor growth by treatment with very high doses of statins did not provide conclusive data. Herein, the reasons for those outcomes are discussed and the rationale for further studies is presented.

Anti-Inflammatory Effects of Statins: Clinical Evidence and Basic Mechanisms

Chronic inflammation is a key feature of vascular disease states such as atherosclerosis. Multiple clinical studies have shown that a class of medications termed statins lower cardiovascular morbidity and mortality. Originally developed to lower serum cholesterol, increasing evidence suggests that these medications have potent anti-inflammatory effects that contribute to their beneficial effects in patients. Here, we discuss the clinical and experimental evidence underlying the anti-inflammatory effects of these agents.

Acute Effect of Cerivastatin on Cardiac Regional Ischemia in a Rat Model Mimicking Off-Pump Coronary Surgery

BACKGROUND

Although the off-pump technique is becoming widely used in coronary bypass surgery, there has been no experimental rat heart model of regional reversible ischemia. The aims of this study were to investigate the optimal duration of coronary occlusion for making reversible ischemia and to examine whether cerivastatin increases myocardial tolerance against prolonged coronary occlusion.

METHODS

Study 1--Male Sprague-Dawley rats (350 to 450 g) underwent temporary occlusion of either left anterior descending artery (LAD; for 3, 5, 7.5, 10, 12.5, 15, or 20 min) or circumflex artery (CX; for 5, 10, or 15 min). Study 2--Rats were divided into two groups, control and cerivastatin groups, which had 0.1 mg/kg cerivastatin intravenously after anesthesia. LAD was occluded for 10, 15, or 20 minutes. In the both studies, hearts were stained to determine the area at risk (AR) and infarcted (IF) area 24 hours after reperfusion.

RESULTS

In LAD occlusion, IF/AR increased in a time dependent manner: 4.5 +/- 3.2%, 9.7 +/- 5.2%, 17.2 +/- 3.0%, 16.8 +/- 2.7%, 23.9 +/- 9.5% (p < 0.01 vs. 3 min), 62.4 +/- 2.9% (p < 0.0001), and 63.4 +/- 2.9% (p < 0.0001) at 3, 5, 7.5, 10, 12.5, 15, and 20 min, respectively. Also in CX, IF/AR increased with time: 14.3 +/- 2.3%, 25.9 +/- 2.1%, and 40.9 +/- 6.2% (p < 0.001 vs. 5 min) at 5, 10, and 15 min, respectively. Cerivastatin significantly reduced IF/AR at 15 minutes (43.7 +/- 6.2%) and at 20 minutes (44.6 +/- 5.3%) compared to control (62.4 +/- 2.9% and 60.6 +/- 2.5%, respectively, p < 0.05).

CONCLUSION

Cerivastatin increased myocardial tolerance after prolonged coronary occlusion over 10 minutes, which was considered to be the upper limit for creating a regional reversible ischemia in rats.

Clinical impact of vasomotor function assessment and the role of ACE-inhibitors and statins

Impaired endothelial function is recognised as one of the earliest events of atherogenesis. Endothelium-dependent vasomotion has been the principal method to assess endothelial function. In this article, we will discuss the clinical value of the different techniques to evaluate endothelium-dependent vasomotion. To date, there seems not to be a simple and reliably endothelial function test to identify asymptomatic subjects at increased risk for cardiovascular disease in clinical practice. Recent studies indicate that pharmacological interventions, in particular with ACE-inhibitors and statins, might improve endothelial function. However, there is no solid evidence that improvement of endothelial function is a necessity for the observed reduction in cardiovascular events by these compounds. Overall, at this moment, there is no place in clinical practice for the use of endothelial function as a method for risk assessment or target of pharmacological interventions.

Lipid-independent effects of statins on endothelial function and bioavailability of nitric oxide in hypercholesterolemic patients

BACKGROUND

Experimental evidence suggests a lipid-independent effect of statins on endothelial function and nitric oxide (NO) availability in humans. We investigated whether improvement in NO availability in hypercholesterolemia can be achieved rapidly with statins before lipid-lowering therapy is complete.

METHODS

We studied 41 patients (52 +/- 11 years) with low-density lipoprotein (LDL) cholesterol > or = 130 mg/dL (179 +/- 45 mg/dL) randomly assigned to treatment either with atorvastatin (20 mg/day) or cerivastatin (0.4 mg/day). Endothelium-dependent vasodilation of the forearm vasculature was measured by plethysmography and intra-arterial infusion of acetylcholine (ACh) after 3 days (n = 18) and 14 days (n = 39) of treatment. NO availability and oxidative stress were assessed by coinfusion of l-NMMA and vitamin C.

RESULTS

After 3 days of treatment, LDL-cholesterol decreased by 11.9% with a further decrease to 29.6% after 14 days ( P < .001). Endothelium-dependent vasodilation improved by +46.7% after 3 days of statin therapy compared with before therapy (ACh 48 microg/min: +15.7 +/- 10.6 vs +10.7 +/- 10.8 mL/min per 100 mL, P < .05). No further improvement in endothelium-dependent vasodilation (+42.7% compared with before therapy) could be demonstrated after 14 days of treatment (ACh 48 microg/min: +17.7 +/- 10.3 vs +12.4 +/- 9.3 mL/min per 100 mL before therapy, P < .001). Coinfusion of ACh plus vitamin C was able to improve endothelium-dependent vasodilation before but not after 3 or 14 days of statin therapy either. The improvement in endothelium-dependent vasodilation after therapy was no longer observed when the NO-synthase inhibitor l-NMMA was coinfused together with ACh.

CONCLUSIONS

Short-term lipid-lowering therapy with statins is able to improve endothelial function and NO availability almost completely after 3 days in hypercholesterolemic patients probably by decreasing oxidative stress. This improvement seems to be more rapid than the accompanying decline in LDL-cholesterol and not related to these lipid changes. This finding can support the concept of lipid-independent effects of statins in humans.

Differential Effect of Cerivastatin and L-Arginine on the Vascular Function of Human Radial and Left Internal Thoracic Arteries

BACKGROUND

There are a number of strategies to restore/preserve endothelial function. We have compared the effects of Cerivastatin (CS) to those of L-arginine (L-ARG) supplementation on the endothelial function of human arterial grafts.

METHODS

During coronary artery bypass grafting, specimens of radial artery (RA) and left internal thoracic artery (LITA) were obtained. Specimens were divided into vascular rings, which were incubated with either 10(-6) mol/L CS, 10(-3) mol/L L-ARG, or vehicle (control) for 2 or 24 hours. Endothelial function was examined with acethylcholine (10(-9) to 10(-5) mol/L) following contraction by 3 x 10(-8) mol/L endothelin-1.

RESULTS

Although no significant differences were observed in the RA at 2 hours, after 24 hours incubation, endothelium-dependent vasodilatation was significantly higher in CS group (68.4 +/- 5.0%; n = 6) compared to L-ARG group (49.9 +/- 5.4%; n = 7, p < 0.05) and control group (33.8 +/- 2.9%; n = 13, p < 0.0001). In addition, there was a significant increase in L-ARG group compared to control (p < 0.01). After 2 hours incubation of the LITA, CS failed to enhance endothelium-dependent vasodilatation compared to control (44.1 +/- 4.9%; n = 9, vs. 40.0 +/- 5.2%; n = 16, respectively, NS), while L-ARG increased it (64.7 +/- 4.9%; n = 7, p < 0.05 vs. CS and p < 0.01 vs. control). However, this increase disappeared at 24 hours although there was a higher trend of endothelium-dependent vasodilatation in CS group (30.3 +/- 3.7%; n = 8 in L-ARG, 56.5 +/- 8.8%; n = 9 in CS and 41.0 +/- 5.5%; n = 18 in control).

CONCLUSIONS

CS preserved endothelium-dependent vasodilatation of RA greater than L-ARG. These findings suggest that the use of statins may be an effective therapeutic strategy to preserve endothelial function in the RA grafts, and could have important implications in the clinical practice.