Rapamycin Combined with α-Cyanoacrylate Contributes to Inhibiting Intimal Hyperplasia in Rat Models / Rapamicina em Combinação com α-Cianoacrilato Contribui à Inibição de Hiperplasia Intimal em Modelos em Ratos

Abstract Background: Vein graft restenosis has an adverse impact on bridge vessel circulation and patient prognosis after coronary artery bypass grafting. Objectives: We used the extravascular supporter α-cyanoacrylate (α-CA), the local application rapamycin/sirolimus (RPM), and a combination of the two (α-CA-RPM) in rat models of autogenous vein graft to stimulate vein graft change. The aim of our study was to observe the effect of α-CA, RPM, and α-CA-RPM on vein hyperplasia. Methods: Fifty healthy Sprague Dawley (SD) rats were randomized into the following 5 groups: sham, control, α-CA, RPM, and α-CA-RPM. Operating procedure as subsequently described was used to build models of grafted rat jugular vein on carotid artery on one side. The level of endothelin-1 (ET-1) was determined by enzyme-linked immunosorbent assay (ELISA). Grafted veins were observed via naked eye 4 weeks later; fresh veins were observed via microscope and image-processing software in hematoxylin-eosin (HE) staining and immunohistochemistry after having been fixed and stored" (i.e. First they were fixed and stored, and second they were observed); α-Smooth Muscle Actin (αSMA) and von Willebrand factor (vWF) were measured with reverse transcription-polymerase chain reaction (RT-PCR). Comparisons were made with single-factor analysis of variance and Fisher's least significant difference test, with p < 0.05 considered significant. Results: We found that intimal thickness of the α-CA, RPM, and α-CA-RPM groups was lower than that of the control group (p < 0.01), and the thickness of the α-CA-RPM group was notably lower than that of the α-CA and RPM groups (p < 0.05). Conclusion: RPM combined with α-CA contributes to inhibiting intimal hyperplasia in rat models and is more effective for vascular patency than individual use of either α-CA or RPM.

Resumo Fundamento: Reestenose de enxertos venosos tem um impacto adverso na circulação de pontagens e no prognóstico de pacientes após a cirurgia de revascularização miocárdica. Objetivos: Nós utilizamos α-cianoacrilato (α-CA) como suporte extravascular, rapamicina/sirolimus (RPM) como aplicação local e a combinação dos dois (α-CA-RPM) em modelos de enxerto venoso autógeno em ratos para estimular mudança no enxerto venoso. O objetivo do nosso estudo foi observar o efeito de α-CA, RPM e α-CA-RPM na hiperplasia venosa. Métodos: Cinquenta ratos Sprague Dawley (SD) saudáveis foram randomizados nos 5 grupos seguintes: sham, controle, α-CA, RPM e α-CA-RPM. O procedimento operacional descrito subsequentemente foi utilizado para construir modelos de enxertos da veia jugular na artéria carótida em ratos, em um lado. O nível de endotelina-1 (ET-1) foi determinado por ensaio de imunoabsorção enzimática (ELISA). As veias enxertadas foram observadas a olho nu 4 semanas após; as veias frescas foram observadas via microscópio e software de processamento de imagem com coloração hematoxilina-eosina (HE) e imuno-histoquímica depois de serem fixadas e armazenadas; α-actina do músculo liso (αSMA) e o fator de von Willebrand (vWF) foram medidos com reação em cadeia da polimerase-transcriptase reversa (RT-PCR). Realizaram-se as comparações com análise de variância de fator único (ANOVA) e o teste de diferença mínima significativa (LSD) de Fisher, com p < 0,05 sendo considerado estatisticamente significante. Resultados: Nós achamos que a espessura intimal nos grupos α-CA, RPM e α-CA-RPM era menor que no grupo controle (p < 0,01) e a espessura no grupo α-CA-RPM era notavelmente menor que nos grupos α-CA e RPM (p < 0,05). Conclusão: A combinação de RPM e α-CA contribui à inibição de hiperplasia em modelos em ratos e é mais efetivo para patência vascular que uso individual de α-CA ou RPM.

Rapamycin Combined with α-Cyanoacrylate Contributes to Inhibiting Intimal Hyperplasia in Rat Models.

BACKGROUND: Vein graft restenosis has an adverse impact on bridge vessel circulation and patient prognosis after coronary artery bypass grafting. OBJECTIVES: We used the extravascular supporter α-cyanoacrylate (α-CA), the local application rapamycin/sirolimus (RPM), and a combination of the two (α-CA-RPM) in rat models of autogenous vein graft to stimulate vein graft change. The aim of our study was to observe the effect of α-CA, RPM, and α-CA-RPM on vein hyperplasia. METHODS: Fifty healthy Sprague Dawley (SD) rats were randomized into the following 5 groups: sham, control, α-CA, RPM, and α-CA-RPM. Operating procedure as subsequently described was used to build models of grafted rat jugular vein on carotid artery on one side. The level of endothelin-1 (ET-1) was determined by enzyme-linked immunosorbent assay (ELISA). Grafted veins were observed via naked eye 4 weeks later; fresh veins were observed via microscope and image-processing software in hematoxylin-eosin (HE) staining and immunohistochemistry after having been fixed and stored" (i.e. First they were fixed and stored, and second they were observed); α-Smooth Muscle Actin (αSMA) and von Willebrand factor (vWF) were measured with reverse transcription-polymerase chain reaction (RT-PCR). Comparisons were made with single-factor analysis of variance and Fisher's least significant difference test, with p < 0.05 considered significant. RESULTS: We found that intimal thickness of the α-CA, RPM, and α-CA-RPM groups was lower than that of the control group (p < 0.01), and the thickness of the α-CA-RPM group was notably lower than that of the α-CA and RPM groups (p < 0.05). CONCLUSION: RPM combined with α-CA contributes to inhibiting intimal hyperplasia in rat models and is more effective for vascular patency than individual use of either α-CA or RPM.

Effects of Rosuvastatin on Apolipoprotein J in Balloon-Injured Carotid Artery in Rats.

BACKGROUND: Restenosis after percutaneous coronary intervention in coronary heart disease remains an unsolved problem. Clusterin (CLU) (or Apolipoprotein [Apo] J) levels have been reported to be elevated during the progression of postangioplasty restenosis and atherosclerosis. However, its role in neointimal hyperplasia is still controversial. OBJECTIVE: To elucidate the role Apo J in neointimal hyperplasia in a rat carotid artery model in vivo with or without rosuvastatin administration. METHODS: Male Wistar rats were randomly divided into three groups: the control group (n = 20), the model group (n = 20) and the statin intervention group (n = 32). The rats in the intervention group were given 10mg /kg dose of rosuvastatin. A 2F Fogarty catheter was introduced to induce vascular injury. Neointima formation was analyzed 1, 2, 3 and 4 weeks after balloon injury. The level of Apo J was measured by real-time PCR, immunohistochemistry and western blotting. RESULTS: Intimal/medial area ratio (intimal/medial, I/M) was increased after balloon-injury and reached the maximum value at 4weeks in the model group; I/M was slightly increased at 2 weeks and stopped increasing after rosuvastatin administration. The mRNA and protein levels of Apo J in carotid arteries were significantly upregulated after rosuvastatin administration as compared with the model group, and reached maximum values at 2 weeks, which was earlier than in the model group (3 weeks). CONCLUSION: Apo J served as an acute phase reactant after balloon injury in rat carotid arteries. Rosuvastatin may reduce the neointima formation through up-regulation of Apo J. Our results suggest that Apo J exerts a protective role in the restenosis after balloon-injury in rats.

Effects of Rosuvastatin on Apolipoprotein J in Balloon-Injured Carotid Artery in Rats / Efeitos da Rosuvastatina sobre Apolipoproteína J em Artérias de Ratos Lesionadas com Balão

Abstract Background: Restenosis after percutaneous coronary intervention in coronary heart disease remains an unsolved problem. Clusterin (CLU) (or Apolipoprotein [Apo] J) levels have been reported to be elevated during the progression of postangioplasty restenosis and atherosclerosis. However, its role in neointimal hyperplasia is still controversial. Objective: To elucidate the role Apo J in neointimal hyperplasia in a rat carotid artery model in vivo with or without rosuvastatin administration. Methods: Male Wistar rats were randomly divided into three groups: the control group (n = 20), the model group (n = 20) and the statin intervention group (n = 32). The rats in the intervention group were given 10mg /kg dose of rosuvastatin. A 2F Fogarty catheter was introduced to induce vascular injury. Neointima formation was analyzed 1, 2, 3 and 4 weeks after balloon injury. The level of Apo J was measured by real-time PCR, immunohistochemistry and western blotting. Results: Intimal/medial area ratio (intimal/medial, I/M) was increased after balloon-injury and reached the maximum value at 4weeks in the model group; I/M was slightly increased at 2 weeks and stopped increasing after rosuvastatin administration. The mRNA and protein levels of Apo J in carotid arteries were significantly upregulated after rosuvastatin administration as compared with the model group, and reached maximum values at 2 weeks, which was earlier than in the model group (3 weeks). Conclusion: Apo J served as an acute phase reactant after balloon injury in rat carotid arteries. Rosuvastatin may reduce the neointima formation through up-regulation of Apo J. Our results suggest that Apo J exerts a protective role in the restenosis after balloon-injury in rats.

Resumo Fundamento: A reestenose após intervenção coronária percutânea (ICP) após doença coronariana continua um problema não solucionado. Estudos relataram que os níveis de clusterina (CLU), também chamada de apolipoproteína (Apo) J, encontram-se elevados na progressão da reestenose pós-angioplastia e na aterosclerose. Contudo, seu papel na hihperplasia neointimal ainda é controverso. Objetivo: Elucidar o papel da Apo J na hiperplasia neointimal na artéria carótida utilizando um modelo experimental com ratos in vivo, com e sem intervenção com rosuvastatina. Métodos: ratos Wistar machos foram divididos aleatoriamente em três grupos - grupo controle (n = 20), grupo modelo (n = 20), e grupo intervenção com estatina (n = 32). Os ratos no grupo intervenção receberam 10 mg/kg de rosuvastatina. Um cateter Fogarty 2 F foi introduzido para induzir lesão vascular. A formação de neoíntima foi analisada 1, 2, 3 e 4 semanas após lesão com balão. Concentrações de Apo J foram medidas por PCR em tempo real, imuno-histoquímica e western blotting. Resultados: A razão área íntima/média (I/M) aumentou após a lesão com balão e atingiu o valor máximo 4 semanas pós-lesão no grupo modelo; observou-se um pequeno aumento na I/M na semana 2, que cessou após a administração de rosuvastatina. Os níveis de mRNA e proteína da Apo J nas artérias carótidas aumentaram significativamente após administração de rosuvastatina em comparação ao grupo modelo, atingindo o máximo na semana 2, mais cedo em comparação ao grupo modelo (semana 3). Conclusão: A Apo J atuou como reagente de fase aguda após lesão com balão nas artérias carótidas de ratos. A rosuvastatina pode reduzir a formação de neoíntoma por aumento de Apo J. Nossos resultados sugerem que a Apo J exerce um papel protetor na reestenose após lesão com balão em ratos.

Reduced Progression of Cardiac Allograft Vasculopathy with Routine Use of Induction Therapy with Basiliximab / Redução da Progressão da Doença Vascular do Enxerto Cardíaco com o Uso Rotineiro da Terapia de Indução com Basiliximab

AbstractIntroduction:Cardiac allograft vasculopathy (CAV) is a major limitation for long-term survival of patients undergoing heart transplantation (HT). Some immunosuppressants can reduce the risk of CAV.Objectives:The primary objective was to evaluate the variation in the volumetric growth of the intimal layer measured by intracoronary ultrasound (IVUS) after 1 year in patients who received basiliximab compared with that in a control group.Methods:Thirteen patients treated at a single center between 2007 and 2009 were analyzed retrospectively. Evaluations were performed with IVUS, measuring the volume of a coronary segment within the first 30 days and 1 year after HT. Vasculopathy was characterized by the volume of the intima of the vessel.Results:Thirteen patients included (7 in the basiliximab group and 6 in the control group). On IVUS assessment, the control group was found to have greater vessel volume (120–185.43 mm3 vs. 127.77–131.32 mm3; p = 0.051). Intimal layer growth (i.e., CAV) was also higher in the control group (27.30–49.15 mm3 [∆80%] vs. 20.23–26.69 mm3[∆33%]; p = 0.015). Univariate regression analysis revealed that plaque volume and prior atherosclerosis of the donor were not related to intima growth (r = 0.15, p = 0.96), whereas positive remodeling was directly proportional to the volumetric growth of the intima (r = 0.85, p < 0.001).Conclusion:Routine induction therapy with basiliximab was associated with reduced growth of the intima of the vessel during the first year after HT.

ResumoFundamento:A doença vascular do enxerto (DVE) constitui uma grande limitação de sobrevida a longo prazo de pacientes submetidos a transplante cardíaco (TxC). Alguns imunossupressores diminuem o aparecimento da DVE.Objetivos:O principal objetivo foi avaliar, através de ultrassonografia intracoronária (USIC), a variação do crescimento volumétrico da camada íntima e comparar, após um ano, o grupo que recebeu basiliximab com um grupo de controle.Métodos:Treze pacientes de um único centro foram analisados retrospectivamente de 2007 a 2009. As análises foram feitas através de USIC, medindo-se o volume de um segmento coronariano nos primeiros 30 dias e um ano após o TxC. A vasculopatia foi caracterizada pelo volume da camada íntima do vaso.Resultados:O estudo incluiu 13 pacientes (7 no grupo com o basiliximab e 6 no grupo de controle). A análise por USIC revelou que o grupo de controle apresentou maior crescimento volumétrico do vaso (131,32 a 127,77 mm3 x 120 a 185,43 mm3 p = 0,051). O crescimento da camada íntima (CCI) também foi maior no grupo de controle [Basiliximab: 20,23 a 26,69 mm3 (∆ 33%); Controle: 27,30 a 49,15 mm3(∆ 80% p = 0,015)]. De acordo com a regressão univariada, o volume da placa aterosclerótica prévia do doador não teve relação com o crescimento da íntima (r = 0,15, p = 0,96), enquanto que o remodelamento positivo do vaso foi diretamente proporcional ao crescimento da íntima (r = 0,85, p < 0,001).Conclusão:A terapia de indução de rotina com basiliximab está associada à redução do crescimento da camada íntima do vaso no primeiro ano após o transplante cardíaco.

Reduced progression of cardiac allograft vasculopathy with routine use of induction therapy with basiliximab.

INTRODUCTION: Cardiac allograft vasculopathy (CAV) is a major limitation for long-term survival of patients undergoing heart transplantation (HT). Some immunosuppressants can reduce the risk of CAV. OBJECTIVES: The primary objective was to evaluate the variation in the volumetric growth of the intimal layer measured by intracoronary ultrasound (IVUS) after 1 year in patients who received basiliximab compared with that in a control group. METHODS: Thirteen patients treated at a single center between 2007 and 2009 were analyzed retrospectively. Evaluations were performed with IVUS, measuring the volume of a coronary segment within the first 30 days and 1 year after HT. Vasculopathy was characterized by the volume of the intima of the vessel. RESULTS: Thirteen patients included (7 in the basiliximab group and 6 in the control group). On IVUS assessment, the control group was found to have greater vessel volume (120-185.43 mm3 vs. 127.77-131.32 mm3; p = 0.051). Intimal layer growth (i.e., CAV) was also higher in the control group (27.30-49.15 mm3 [∆80%] vs. 20.23-26.69 mm3[∆33%]; p = 0.015). Univariate regression analysis revealed that plaque volume and prior atherosclerosis of the donor were not related to intima growth (r = 0.15, p = 0.96), whereas positive remodeling was directly proportional to the volumetric growth of the intima (r = 0.85, p < 0.001). CONCLUSION: Routine induction therapy with basiliximab was associated with reduced growth of the intima of the vessel during the first year after HT.

The antiatherogenic effect of bixin in hypercholesterolemic rabbits is associated to the improvement of lipid profile and to its antioxidant and anti-inflammatory effects.

Hypercholesterolemia and oxidative stress have been implicated in the pathophysiology of atherosclerosis and coronary artery disease. We investigated whether the carotenoid bixin (BIX) may reduce oxidative damage, inflammatory response, and the atherosclerotic lesion induced by hypercholesterolemia in rabbits. Rabbits received regular chow (control) or a hypercholesterolemic diet (0.5% cholesterol) alone or supplemented with BIX (10, 30 or 100 mg/kg body weight, b.w.) or simvastatin (15 mg/kg b.w.) for 60 days. Treatment with BIX or simvastatin reduced the atherosclerotic lesions in cholesterol-fed rabbits (up to 55 and 96% reduction, respectively). This protective effect of BIX was accompanied by decrease in the levels of tumor necrosis factor alpha by 15%, interleukin 6 by 19%, lipid peroxidation by 60%, non-high-density lipoprotein cholesterol (non-HDL-C) by 37%, and triglycerides by 41%. BIX increased by 160% the HDL-C levels and decreased by 67% the atherogenic index of hypercholesterolemic rabbits. In atherosclerotic rabbits, the non-protein thiol groups content and the activity of the antioxidant enzymes superoxide dismutase, catalase, glutathione reductase, and thioredoxin reductase were increased in the aortic tissue, whereas paraoxonase activity was reduced in the serum. All these changes were completely prevented by BIX or simvastatin treatment. These results demonstrate that BIX reduces the extent of atherosclerotic lesions and this effect was associated with the decrease in oxidative stress, inflammatory response, and improvement of dyslipidemia, which were most effectively controlled after treatment with 10-30 mg BIX/kg b.w. BIX consumption may, therefore, be an adjuvant to prevent atherosclerosis reducing risk factors for coronary diseases.

Sildenafil stimulates and dexamethasone inhibits pulmonary vascular development in congenital diaphragmatic hernia rat lungs.

BACKGROUND: A predictor of neonatal mortality in infants with congenital diaphragmatic hernia (CDH) is disrupted pulmonary vascular development, clinically expressed as pulmonary hypertension. OBJECTIVE: To determine if prenatal corticosteroids and phosphodiesterase-5 (PDE-5) inhibitors have a beneficial effect on pulmonary vascular development in CDH lungs. METHODS: We induced CDH in fetal rats by giving nitrofen. We then exposed them to dexamethasone or to sildenafil. We separated them into three groups: (1) DEX, 4 pregnant rats received dexamethasone at days E16, E18 and E20; (2) SILD, 4 pregnant rats received sildenafil and L-arginine between E14 and E22, and (3) placebo. We then analyzed the lung of each fetus with CDH at E22. We examined the number of arterioles and arteries, and their percent of medial wall thickness (%MWT). RESULTS: We obtained 30 CDH-positive fetuses. We analyzed 3,560 arterioles and 211 arteries. SILD showed a significant increase in the number of arterioles, but no significant increase in the number of arteries. No change was noted in the arteriolar %MWT. In contrast, DEX showed significant decreases in the number of arterioles and arteries and a significant increase in %MWT. CONCLUSIONS: PDE-5 inhibitors may improve pulmonary arteriolar development in fetuses with CDH. In contrast, prenatal corticosteroids could have deleterious effects on arteriolar and arterial development in CDH lungs.

Carotid intima-media thickness and plasma asymmetric dimethylarginine in Mexican children exposed to inorganic arsenic.

BACKGROUND: Arsenic exposure is a risk factor for atherosclerosis in adults, but there is little information on arsenic and early risk biomarkers for atherosclerosis in children. Carotid intima-media thickness (cIMT) is an indicator of subclinical atherosclerotic burden that has been associated with plasma asymmetric dimethylarginine (ADMA), a predictor of cardiovascular disease risk. OBJECTIVES: The aim of this study was to investigate associations of arsenic exposure with cIMT, ADMA, and endothelial adhesion molecules [soluble intercellular cell adhesion molecule-1 (sICAM-1); soluble vascular cell adhesion molecule-1 (sVCAM-1)] in children who had been exposed to environmental inorganic arsenic (iAs). METHODS: We conducted a cross-sectional study in 199 children 3-14 years of age who were residents of Zimapan, México. We evaluated cIMT using ultrasonography, and plasma lipid profiles by standard methods. We analyzed ADMA, sICAM-1, and sVCAM-1 by ELISA, and measured the concentrations of total speciated arsenic (tAs) in urine using hydride generation cryotrapping atomic absorption spectrometry. RESULTS: In the multiple linear regression model for cIMT, tAs categories were positively associated with cIMT increase. The estimated cIMT diameter was greater in 35- to 70-ng/mL and > 70-ng/mL groups (0.035 mm and 0.058 mm per 1-ng/mL increase in urinary tAs, respectively), compared with the < 35-ng/mL group. In addition to tAs level, plasma ADMA was a significant predictor of cIMT. In the adjusted regression model, cIMT, percent iAs, and plasma sVCAM-1 were significant predictors of ADMA levels (e.g., 0.419-µmol/L increase in ADMA per 1-mm increase in cIMT). CONCLUSIONS: Arsenic exposure and plasma ADMA levels were positively associated with cIMT in a population of Mexican children with environmental arsenic exposure through drinking water.

Beneficial effects of rosuvastatin on aortic adverse remodeling in nitric oxide-deficient rats.

This study aimed to evaluate the effect of rosuvastatin upon structural and ultrastructural aortic remodeling in a rat model of hypertension induced by NO synthase blockade. Wistar rats were divided into 4 groups: Control group (C); control treated with rosuvastatin 20mg/kg/day (CR); L-NAME group 40 mg/kg/day (LN) and L-NAME treated with rosuvastatin (LNR) (same doses). Body mass and blood pressure were measured weekly; the experiment lasted 5 weeks. L-NAME administration augmented blood pressure (BP) in the LN group in comparison to the C group (123.3 vs. 180.5 mm Hg at week 5). In LNR rats, rosuvastatin slightly attenuated BP rise, but it had no effect on the BP of CR group. Intima and media thickening of the thoracic aorta were observed in the LN group, and increased elastic fiber content as well. Rosuvastatin prevented all these alterations as seen in the LNR group. Ultrastructural changes due to L-NAME intake (intracellular vesicles and altered membrane morphology in endothelial cells, extracellular matrix deposition, and cytoplasmatic projections from smooth muscle cells toward the internal elastic lamina) were also prevented by rosuvastatin. All in all, rosuvastatin administration is capable of attenuating ultrastructural aortic wall remodeling in NO-deficient rats despite small changes in blood pressure.

Efecto del sulodexide sobre la capacidad de relajación y alteraciones estructurales de la arteria aorta en ratas diabéticas por estreptozotocina / Effect of sulodexide on aortic vasodilation capacity and associated morphological changes in rats with streptozotocin-induced diabetes

La disfunción endotelial (DE) se presenta en pacientes con hipercolesterolemia, hipertensión arterial, obesidad y diabetes mellitus. Evidencias sugieren un papel de los glicosaminoglicanos en la DE. Evaluamos el efecto del sulodexide (SLD), un glicosaminoglicano utilizado en el tratamiento de la albuminuria y la enfermedad isquémica en pacientes diabéticos, sobre la relajación arterial y los cambios morfológicos en un modelo experimental de diabetes tipo 1. La diabetes se indujo a ratas Sprague Dawley administrando estreptozotocina (STZ), 60 mg/kg, i.v. Los animales fueron distribuidos en los siguientes grupos: I= control, II= diabéticas, III: control + sulodexide, IV= diabéticas + sulodexide (15 mg/kg/día s.c). A los 3 meses fueron sacrificados, las aortas extraídas para evaluar la relajación vascular inducida por acetilcolina (Ach) y nitroprusiato de sodio en anillos precontraídos con fenilefrina. Fueron evaluadas histológicamente mediante microscopía de luz y coloraciones diversas. El SLD in vitro no modificó la tensión basal de los anillos arteriales en reposo o precontraídos con fenilefrina. La diabetes disminuyó la capacidad de relajación arterial en respuesta a la Ach en un 28,8-35,1% vs control, efecto que fue prevenido por SLD. No se observó diferencia significativa en la relajación inducida por nitroprusiato sódico entre los grupos. El estudio histológico en los animales diabéticos mostró alteraciones estructurales, particularmente en la íntima y la adventicia, cambios que fueron prevenidos por el tratamiento con SLD. Nuestros resultados apoyan la potencial utilidad terapéutica del SLD en el tratamiento de la disfunción endotelial.

Endothelial dysfunction (ED) is observed in patients with hypercholesterolemia, arterial hypertension, obesity and diabetes mellitus. Recent evidences suggest the involvement of glycosaminoglycans(GSG) in ED. We evaluated the effect of sulodexide (SLD), a natural GSG used in albuminuria and ischemic diabetes treatment, on arterial relaxation and vascular morphological changes in a diabetic type I model. Diabetes was induced, in Sprague-Dawley rats by streptozotocine (STZ) administration, 60 mg, iv. Rats were divided into four groups; I: control, II: diabetics, III: control + SLD, IV: diabetics treated with SLD (15 mg/day). After three months, phenylephrine precontracted aortic rings were used to evaluate acetylcholine (ACh) and sodium nitroprusside (NPS) relaxation capacities. Light microscopy of aorta was done with several staining procedures. In vitro, SLD did not change smooth muscle tone in resting or phenylephrine precontracted aortic rings. In diabetic rats, ACh relaxation was 28.8-35.1% lower than in control rats. Diabetic rats treated with SLD showed aortic ACh relaxation similar to control rats. No significative statistical difference was found in endothelium-independent NPS relaxation, between the different groups. Light microscopy histological studies revealed important morphological alterations, particularly in intima and adventitia layers of aortic artery; those changes were dramatically reversed in SLD treated rats. Our experiments support the conclusion that SLD is a potential drug for improving endothelial dysfunction in diabetes.

A randomized, double-blind, placebo-controlled trial of spironolactone on carotid intima-media thickness in nondiabetic hemodialysis patients.

BACKGROUND AND OBJECTIVES: Hemodialysis patients (HD) display high rates of cardiac diseases and mortality. In chronic kidney disease, vascular injury leads to coronary artery disease, heart failure, and stroke. Carotid intima-media thickness (CIMT) measurements are currently widely used in randomized controlled trials (RCTs) to study the efficacy of interventions. An RCT was designed for the assessment of the safety and effectiveness of spironolactone to inhibit the progression of CIMT in HD patients as a primary outcome. Secondary outcomes included measurements of plasma potassium. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: HD patients were randomly assigned to receive 50 mg spironolactone or placebo thrice weekly after dialysis. In between dialysis sessions, plasma potassium concentrations were measured every month. Ultrasonographic measurements of CIMT were done at the beginning of the study and after 2 years. RESULTS: Fifty-three age- and sex-adjusted patients (30 with drug and 23 with placebo) successfully completed the trial. There were no significant differences between the two groups in all profiles studied at baseline. Measurements of CIMT after 2 years showed a progression in the placebo group, whereas in the spironolactone group a significant decrease or even reversed CIMT was observed. Progression rates (mm/yr) were: common carotid, placebo: 0.06 +/- 0.07, spironolactone: 0.01 +/- 0.04; carotid bifurcation, placebo: 0.15 +/- 0.27, spironolactone: 0.0001 +/- 0.01; internal carotid, placebo: 0.10 +/- 0.12, spironolactone: -0.10 +/- 0.15. No episodes of hyperkalemia were observed, but a slight increase in plasma potassium was found in the spironolactone group. CONCLUSIONS: Fifty milligrams of spironolactone thrice weekly significantly reduced the progression of CIMT in HD patients.

Effectiveness of thalidomide and tamoxifen in preventing neointimal hyperplasia in experimental vascular injury in rats.

INTRODUCTION: Chronic allograft vasculopathy is an important cause of graft loss. Considering the inflammatory response in the development of chronic vascular lesions, therapeutic approaches to target the inflammatory process may be useful. We sought to investigate the possible protective effects on balloon catheter-induced vascular injury of thalidomide and tamoxifen, 2 drugs with powerful anti-inflammatory, immunomodulatory, and antifibrotic effects, using an animal model that mimics the morphologic features of chronic allograft vasculopathy. METHODS: Male Wistar rats subjected to balloon catheter carotid injury (INJ) were treated with thalidomide (100 mg/kg), or tamoxifen (10 mg/kg), or vehicle. Contralateral right carotid arteries were used as uninjured controls. Morphometric and immunohistochemical analyses were performed at 14 days postinjury. RESULTS: Injured carotid arteries showed marked neointimal hyperplasia, which was significantly inhibited among animals treated with thalidomide or tamoxifen: neointimal/media ratios of 1.4 +/- 0.4 versus 0.2 +/- 0.1 versus 0.4 +/- 0.2, for INJ, INJ + Thalid, and INJ + Tamox; respectively (P < .001). The endothelial cell loss was significantly less pronounced among animals subjected to carotid balloon injury that were treated with thalidomide (24 +/- 14 vs 1 +/- 1 cells per section in INJ, respectively (P < .05). Therapy with either thalidomide or tamoxifen effectively maintained alpha-smooth muscle actin expression in the media, similar to uninjured arteries. In this setting, tamoxifen was additionally effective to prevent the migration of myofibroblasts in to the intima. CONCLUSION: Thalidomide and tamoxifen were effective to reduce neointimal hyperplasia secondary to vascular damage. The vasculoprotective effects of thalidomide were more pronounced to preserve endothelial cells, whereas tamoxifen inhibited smooth muscle cell migration and proliferation. A possible beneficial effect of combined therapy with thalidomide plus tamoxifen should be addressed in future studies.

[Effect of sulodexide on aortic vasodilation capacity and associated morphological changes in rats with streptozotocin-induced diabetes]. / Efecto del sulodexide sobre la capacidad de relajación y alteraciones estructurales de la arteria aorta en ratas diabéticas por estreptozotocina.

Endothelial dysfunction (ED) is observed in patients with hypercholesterolemia, arterial hypertension, obesity and diabetes mellitus. Recent evidences suggest the involvement of glycosaminoglycans (GSG) in ED. We evaluated the effect of sulodexide (SLD), a natural GSG used in albuminuria and ischemic diabetes treatment, on arterial relaxation and vascular morphological changes in a diabetic type I model. Diabetes was induced, in Sprague-Dawley rats by streptozotocine (STZ) administration, 60 mg, i.v. Rats were divided into four groups; I: control, II: diabetics, III: control + SLD, IV: diabetics treated with SLD (15 mg/day). After three months, phenylephrine precontracted aortic rings were used to evaluate acetylcholine (ACh) and sodium nitroprusside (NPS) relaxation capacities. Light microscopy of aorta was done with several staining procedures. In vitro, SLD did not change smooth muscle tone in resting or phenylephrine precontracted aortic rings. In diabetic rats, ACh relaxation was 28.8-35.1% lower than in control rats. Diabetic rats treated with SLD showed aortic ACh relaxation similar to control rats. No significative statistical difference was found in endothelium-independent NPS relaxation, between the different groups. Light microscopy histological studies revealed important morphological alterations, particularly in intima and adventitia layers of aortic artery; those changes were dramatically reversed in SLD treated rats. Our experiments support the conclusion that SLD is a potential drug for improving endothelial dysfunction in diabetes.

The VYtorin on Carotid intima-media thickness and overall arterial rigidity (VYCTOR) study.

This study assessed the effect of 3 lipid-lowering therapies on the reduction of the carotid intima-media thickness (IMT) in high-risk coronary Mexican patients. The study was a randomized, comparative, and open clinical trial. Ninety high-risk coronary patients were allocated to 3 groups: pravastatin 40 mg, simvastatin 40 mg, and simvastatin 20 mg and ezetimibe 10 mg initially. If the therapeutic goals were not attained (<100 mg/dL of low-density lipoprotein cholesterol [LDL-C] for type C and <70 mg for type D), patients in group 1 received pravastatin 40 mg and ezetimibe 10 mg, group 2 received simvastatin 80 mg, and group 3 received simvastatin 40 mg and ezetimibe 10 mg. The primary endpoint was the change of IMT over the course of 1 year. The secondary endpoints were changes in LDL-C and in high sensitive C-reactive protein (CRPhs). The overall baseline IMTs generated by combining measurements in the internal carotid artery were 1.33+/-0.32 mm, 1.30+/-0.11 mm, and 1.23+/-0.28 mm for groups 1, 2, and 3, respectively. After 1 year, IMT values were 0.93+/-0.13 mm, 0.90+/-0.11 mm, and 0.92+/-0.01 mm for groups 1, 2, and 3, respectively. At the end of the study, LDL-C levels were 48+/-41, 45+/-37, and 48+/-31 in groups 1, 2, and 3, respectively. No significant differences were observed in CRP, high-density lipoprotein cholesterol, triglycerides, blood pressure, and body mass index, among the groups. This study is one of the first providing evidence that dual therapy has a beneficial effect on a surrogate marker of atherosclerosis.

Cuff-induced vascular intima thickening is influenced by titration of the Ace gene in mice.

We tested the hypothesis that small changes in angiotensin I-converting enzyme (ACE) expression can alter the vascular response to injury. Male mice containing one, two, three, and four copies of the Ace gene with no detectable vascular abnormality or changes in blood pressure were submitted to cuff-induced femoral artery injury. Femoral thickening was higher in 3- and 4-copy mice (42.4 +/- 4.3% and 45.7 +/- 6.5%, respectively) compared with 1- and 2-copy mice (8.3 +/- 1.3% and 8.5 +/- 0.9%, respectively). Femoral ACE levels from control and injured vessels were assessed in 1- and 3-copy Ace mice, which represent the extremes of the observed response. ACE vascular activity was higher in 3- vs. 1-copy Ace mice (2.4-fold, P < 0.05) in the control uninjured vessel. Upon injury, ACE activity significantly increased in both groups [2.41-fold and 2.14-fold (P < 0.05) for 1- and 3-copy groups, respectively] but reached higher levels in 3- vs. 1-copy Ace mice (P < 0.05). Pharmacological interventions were then used as a counterproof and to indirectly assess the role of angiotensin II (ANG II) on this response. Interestingly, ACE inhibition (enalapril) and ANG II AT(1) receptor blocker (losartan) reduced intima thickening in 3-copy mice to 1-copy mouse values (P < 0.05) while ANG II treatment significantly increased intima thickening in 1-copy mice to 3-copy mouse levels (P < 0.05). Together, these data indicate that small physiologically relevant changes in ACE, not associated with basal vascular abnormalities or blood pressure levels, do influence the magnitude of cuff-induced neointima thickening in mice.

Sonographic evaluation of endothelial function in letrozole and tamoxifen users.

OBJECTIVES: Studies have shown that women previously treated for breast cancer present fewer cardiovascular events, indicating a possible protective effect of tamoxifen treatment. The effects of these aromatase inhibitors on cardiovascular protection remain controversial. The aim of this study was to compare some cardiovascular risk markers among breast cancer survivors following treatment with tamoxifen group (TMXg), letrozole group (LTZg) or no endocrine treatment group (NETg). METHODS: A total of 103 breast cancer survivors: 35 using TMXg, 34 using letrozole group (LTZg) and 34 using no endocrine treatment group (NETg) were evaluated. Ultrasonographic evaluation of brachial artery flow-mediated dilation (FMD), carotid intima-media thickness (IMT) and stiffness index (beta); blood total cholesterol, HDL and triglycerides were assessed. RESULTS: All three groups presented similar values of HDL and IMT. TMXg showed the lowest total cholesterol (219.29+/-36.31mg/dL vs. 250.59+/-38.37mg/dL vs. 245.09+/-35.35mg/dL; TMXg vs. LTZg vs. NETg, respectively; p<0.01-ANOVA), the highest triglycerides (139.34+/-41.82mg/dL vs. 111.35+/-28.22mg/dL vs. 122.09+/-33.42mg/dL; p<0.01), the highest FMD (6.32+/-2.33% vs. 4.10+/-2.06% vs. 4.66+/-2.52%; p<0.01) and the lowest stiffness index (beta) (5.08+/-1.68 vs. 6.28+/-1.75 vs. 5.99+/-1.86; p=0.01). LTZg did not differ significantly from NETg on any evaluated parameter. CONCLUSIONS: We did not observe any effect of LTZg on the evaluated cardiovascular risk parameters compared to NETg. As such, the observed difference on lipid values, stiffness index (beta) and FMD between women receiving tamoxifen and letrozole might be best attributed to the beneficial effect of tamoxifen than to a detrimental effect of letrozole.

Gremlin promotes vascular smooth muscle cell proliferation and migration.

Recent reports highlight the importance of BMP in the vasculature. We investigated the expression pattern and role of the BMP antagonist gremlin in VSMC. We detected gremlin mRNA constitutive expression in adult and embryonic rat aortic VSMC, and in rat carotids. In vitro analysis demonstrated that angiotensin II, TGF-beta1 and PDGF induced significant changes in gremlin mRNA expression. Gremlin stable overexpression in A7r5 cells blocked BMP signaling. BMP-induced reduction in VSMC DNA synthesis was markedly inhibited by gremlin overexpression. In fact, gremlin overexpression increased DNA synthesis and cell counts, and accelerated cell cycle progression of VSMC, through mechanisms that include p27(kip1) down-regulation. Gremlin also led to marked increments in VSMC migration. In addition, gremlin gene silencing promoted a significant blockade on cell proliferation and migration. In vivo studies disclosed increased gremlin protein expression in the neointima of balloon-injured carotid arteries. In summary, the BMP antagonist gremlin is constitutively expressed in the normal vasculature. Gremlin induces VSMC proliferation and migration and is significantly regulated by growth factors and injury. We postulate that gremlin plays a part in the development of pathological phenotypic changes of adult VSMC.

Cardiovascular effects of tibolone: a selective tissue estrogenic activity regulator.

Traditionally, it was accepted that long-term hormone replacement therapy (HRT) has a cardiovascular beneficial effect in postmenopausal women with and without coronary artery disease (CAD). However, randomized trials in postmenopausal women have not shown any benefit in either primary or secondary prevention of cardiovascular events. Therefore, these findings have raised the question of whether traditional HRT (i.e., estrogen and progesterone) has a cardioprotective effect in women at risk for or with established CAD. Concerns about the use of conventional HRT have led to a search for alternatives. Tibolone is a synthetic compound with estrogenic, androgenic, and progestogenic properties that relieves climacteric symptoms and prevents postmenopausal bone loss. Tibolone possesses a tissue-selective mechanism of action that differs from that of estrogen and/or progestogen. Unlike these compounds, tibolone's metabolites play a central role in its mode of action. Tibolone is widely used for HRT. However, its clinical impact on cardiovascular disease is still under study. The current review focuses on the effects of tibolone on the cardiovascular system and discusses clinical investigations with this compound in postmenopausal women.

The effect of L-arginine on neointimal proliferation and artery remodeling on an iliac artery lesion caused by a balloon catheter in hypercholesterolemic rabbits.

OBJECTIVE: It has been implied that neointimal proliferation and remodeling are the major causes of restenosis. The objective of this study is to assess the effect of orally administered L-arginine on these two factors in hypercholesterolemic rabbits that had suffered an injury to their iliac arteries caused by a catheter balloon. METHODS: The study included nineteen rabbits that were divided in two groups: control (CG) and arginine (AG). There were 19 arteries studied from the control group and 17 in the arginine group. The animals were placed on a 2% hypercholesterolemic diet for 15 days and then submitted to a balloon angioplasty in order to produce a lesion in their iliac arteries. Next, the AG animals were given a 1g/kg/day oral dose of a L-arginine solution. The animals were sacrificed 15 days after the angioplasty procedure and histological artery sections were prepared, stained and fixed. The ratio between the neointimal area (in mm(2)) and the media layer (in mm(2)) was used to represent lesion development. In order to determine remodeling, the ratio between the total area of the medial portion of the vessel (greater balloon contact) and the total area of the reference segment of the vessel (less balloon contact) was used. RESULTS: Mean neointimal thickness (NI/M) was 0.8151+/-0.2201 in CG and 0.3296+/-0.1133 in AG. Remodeling patterns for the two groups studied were similar. CONCLUSION: In the experimental model used, L-arginine was able to reduce intimal tissue thickness in hypercholesterolemic rabbits but did not act on artery remodeling.