Role Of MMP-2 and MMP-9 in resistance to drug therapy in patients with resistant hypertension

A despeito da crescente evidência do importante papel das metaloproteinases da matriz extracelular (MMP-9 e MMP-2) na fisiopatologia da hipertensão, o perfil dessas moléculas na hipertensão arterial resistente (HAR) permanece desconhecido. Comparar os níveis plasmáticos de MMP-9 e MMP-2 e seus inibidores teciduais (TIMP-1 e TIMP-2, respectivamente), assim como as suas razões MMP-9/TIMP-1 e MMP-2/TIMP-2, entre pacientes com HAR controlada (HARC, n = 41) e HAR não controlada (HARNC, n = 35). Além disso, a associação desses parâmetros com as características clínicas, pressão arterial (PA) de consultório e rigidez arterial (determinada pela velocidade da onda de pulso) foi avaliada nesses subgrupos. Este estudo incluiu 76 indivíduos com HAR submetidos a exame físico, eletrocardiografia e exames laboratoriais para a avaliação de parâmetros bioquímicos. Valores semelhantes de MMP-9, MMP-2, TIMP-1, TIMP-2, e razões MMP-9/TIMP-1 e MMP-2/TIMP-2 foram encontrados nos subgrupos HARNC e HARC (p > 0,05). Observou-se uma correlação significativa entre PA diastólica (PAD) e razão MMP-9/TIMP-1 (r = 0,37; p = 0,02) e PAD e MMP-2 (r = -0,40; p = 0,02) no subgrupo HARNC. Por outro lado, não se observou correlação no subgrupo HARC. Os modelos de regressão logística demonstraram que MMP-9, MMP-2, TIMP-1, TIMP-2 e suas razões não se associaram com a falta de controle da PA. Esses achados sugerem que MMP-2 e MMP-9 não afetem o controle da PA em indivíduos com HAR.1052168174CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE MINAS GERAIS - FAPEMIGFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESPSem informaçãoSem informaçãoSem informaçãoDespite the increased evidence of the important role of matrix metalloproteinases (MMP-9 and MMP‑2) in the pathophysiology of hypertension, the profile of these molecules in resistant hypertension (RHTN) remains unknown. To compare the plasma levels of MMP-9 and MMP-2 and of their tissue inhibitors (TIMP-1 and TIMP-2, respectively), as well as their MMP-9/TIMP-1 and MMP-2/TIMP-2 ratios, between patients with controlled RHTN (CRHTN, n=41) and uncontrolled RHTN (UCRHTN, n=35). In addition, the association of those parameters with clinical characteristics, office blood pressure (BP) and arterial stiffness (determined by pulse wave velocity) was evaluate in those subgroups. This study included 76 individuals diagnosed with RHTN and submitted to physical examination, electrocardiogram, and laboratory tests to assess biochemical parameters. Similar values of MMP-9, MMP-2, TIMP-1, TIMP-2, and MMP-9/TIMP-1 and MMP-2/TIMP-2 ratios were found in the UCRHTN and CRHTN subgroups (P>0.05). A significant correlation was found between diastolic BP (DBP) and MMP-9/TIMP-1 ratio (r=0.37; P=0.02) and DPB and MMP-2 (r=-0.40; P=0.02) in the UCRHTN subgroup. On the other hand, no correlation was observed in the CRHTN subgroup. Logistic regression models demonstrated that MMP-9, MMP-2, TIMP-1, TIMP-2 and their ratios were not associated with the lack of BP control. These findings suggest that neither MMP-2 nor MMP-9 affect BP control in RHTN subjects

Sildenafil Preserves Diastolic Relaxation After Reduction By L-name And Increases Phosphodiesterase-5 In The Intercalated Discs Of Cardiac Myocytes And Arterioles.

We investigated the influence of sildenafil on cardiac contractility and diastolic relaxation and examined the distribution of phosphodiesterase-5 in the hearts of hypertensive rats that were treated with by NG-nitro-L-arginine methyl ester (L-NAME). Male Wistar rats were treated with L-NAME and/or sildenafil for eight weeks. The Langendorff method was used to examine the effects of sildenafil on cardiac contractility and diastolic relaxation. The presence and location of phosphodiesterase-5 and phosphodiesterase-3 were assessed by immunohistochemistry, and cGMP plasma levels were measured by ELISA. In isolated hearts, sildenafil prevented the reduction of diastolic relaxation (dP/dt) that was induced by L-NAME. In addition, phosphodiesterase-5 immunoreactivity was localized in the intercalated discs between the myocardial cells. The staining intensity was reduced by L-NAME, and sildenafil treatment abolished this reduction. Consistent with these results, the plasma levels of cGMP were decreased in the L-NAME-treated rats but not in rats that were treated with L-NAME + sildenafil. The sildenafil-induced attenuation of the deleterious hemodynamic and cardiac morphological effects of L-NAME in cardiac myocytes is mediated (at least in part) by the inhibition of phosphodiesterase-5.661253-

Sildenafil preserves diastolic relaxation after reduction by L-NAME and increases phosphodiesterase-5 in the intercalated discs of cardiac myocytes and arterioles

OBJECTIVES: We investigated the influence of sildenafil on cardiac contractility and diastolic relaxation and examined the distribution of phosphodiesterase-5 in the hearts of hypertensive rats that were treated with by NG-nitro-L-arginine methyl ester (L-NAME). METHODS: Male Wistar rats were treated with L-NAME and/or sildenafil for eight weeks. The Langendorff method was used to examine the effects of sildenafil on cardiac contractility and diastolic relaxation. The presence and location of phosphodiesterase-5 and phosphodiesterase-3 were assessed by immunohistochemistry, and cGMP plasma levels were measured by ELISA. RESULTS: In isolated hearts, sildenafil prevented the reduction of diastolic relaxation (dP/dt) that was induced by L-NAME. In addition, phosphodiesterase-5 immunoreactivity was localized in the intercalated discs between the myocardial cells. The staining intensity was reduced by L-NAME, and sildenafil treatment abolished this reduction. Consistent with these results, the plasma levels of cGMP were decreased in the L-NAME-treated rats but not in rats that were treated with L-NAME + sildenafil. CONCLUSION: The sildenafil-induced attenuation of the deleterious hemodynamic and cardiac morphological effects of L-NAME in cardiac myocytes is mediated (at least in part) by the inhibition of phosphodiesterase-5

Vascular damage in resistant hypertension: Tnf-alpha inhibition effects on endothelial cells

Inflammatory cytokines have been associated with the pathophysiology of hypertension and target organ damage (TOD). Resistant hypertensive patients (RHTN) are characterized by poor blood pressure control and higher prevalence of TOD. This study evaluated the relationship between plasma levels of TNF-alpha and arterial stiffness (pulse wave velocity-PWV) in 32 RHTN and 19 normotensive subjects. Moreover, we investigated the effect of TNF-alpha inhibition on human endothelial cells (HUVECs) incubated with serum from RHTN and normotensive subjects. HUVECs containing serum obtained from normotensive (n = 8) and hypertensive (n = 8) individuals were treated with TNF-alpha inhibitor (infliximab). Cell suspensions were used for measurement of DNA fragmentation and reactive oxygen species (ROS) content. RHTN patients showed higher levels of TNF-alpha compared to normotensive subjects, as well as higher PWV. Positive correlation was found between TNF-alpha levels and PWV measures in the whole group. HUVECs incubated with serum from RHTN showed increased cell apoptosis and higher ROS content compared to normotensive subjects. Infliximab attenuated the apoptosis of HUVECs incubated with serum from RHTN, but no effect in ROS production was observed. Our findings suggest that TNF-alpha might mediate, at least in part, vascular damage in resistant hypertension2015CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQCOORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPESFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPES

Cardiac Magnetic Resonance Assessment of Interstitial Myocardial Fibrosis and Cardiomyocyte Hypertrophy in Hypertensive Mice Treated With Spironolactone

Background: Nearly 50% of patients with heart failure (HF) have preserved LV ejection fraction, with interstitial fibrosis and cardiomyocyte hypertrophy as early manifestations of pressure overload. However, methods to assess both tissue characteristics dynamically and noninvasively with therapy are lacking. We measured the effects of mineralocorticoid receptor blockade on tissue phenotypes in LV pressure overload using cardiac magnetic resonance (CMR). Methods and Results: Mice were randomized to l‐nitro‐ω‐methyl ester (l‐NAME, 3 mg/mL in water; n=22), or l‐NAME with spironolactone (50 mg/kg/day in subcutaneous pellets; n=21). Myocardial extracellular volume (ECV; marker of diffuse interstitial fibrosis) and the intracellular lifetime of water (τic; marker of cardiomyocyte hypertrophy) were determined by CMR T1 imaging at baseline and after 7 weeks of therapy alongside histological assessments. Administration of l‐NAME induced hypertensive heart disease in mice, with increases in mean arterial pressure, LV mass, ECV, and τic compared with placebo‐treated controls, while LV ejection fraction was preserved (>50%). In comparison, animals receiving both spironolactone and l‐NAME (“l‐NAME+S”) showed less concentric remodeling, and a lower myocardial ECV and τic, indicating decreased interstitial fibrosis and cardiomyocyte hypertrophy (ECV: 0.43±0.09 for l‐NAME versus 0.25±0.03 for l‐NAME+S, P<0.001; τic: 0.42±0.11 for l‐NAME groups versus 0.12±0.05 for l‐NAME+S group). Mice treated with a combination of l‐NAME and spironolactone were similar to placebo‐treated controls at 7 weeks. Conclusions: Spironolactone attenuates interstitial fibrosis and cardiomyocyte hypertrophy in hypertensive heart disease. CMR can phenotype myocardial tissue remodeling in pressure‐overload, furthering our understanding of HF progression

Delineation of management zones using mobile measurements of soil apparent electrical conductivity and multivariate geostatistical techniques

Site-specific management promotes the identification and management of areas within the field, which represent subfield regions with homogeneous characteristics (management zones). However, determination of subfield areas is difficult because of the complex combination of factors which could affect crop yield. One possibility to capture yield variability is the use of soil physical properties to define the management zones as they are related to plant available water. With the aim of characterizing the spatial variability of the main soil physical variables and using this information to determine potential management zones, soil samples were taken from 70 locations in a 33-ha field in Badajoz, southwestern Spain. Firstly, accurate spatial distribution maps of the soil attributes were generated by using regression kriging as the most suitable algorithm in which exhaustive secondary information on soil apparent electrical conductivity (ECa) was incorporated. ECa measurements were carried out with a Veris 3100 operating in both shallow (0–30 cm), ECs, and deep (0–90 cm), ECd,mode. Clay, coarse sand and fine sand were the soil physical properties which exhibited higher correlation with ECa (positively correlated with the finer texture component, clay, and negatively correlated with the coarser ones, coarse and fine sands), particularly with ECs. Thus, this was the secondary variable used to obtain the kriged maps. Later, principal component analysis and fuzzy cluster classification were performed to delineate management zones, resulting in two subfields to be managed separately. This number of subfields was determined using the fuzzy performance index and normalized classification entropy as the way to optimize the classification algorithm

Efeito de um anticoncepcional hormonal oral de baixa dose na função endotelial venosa em mulheres jovens saudáveis: resultados preliminares

BACKGROUND: A possible increase in the incidence of venous thromboembolic events has been reported among users of third generation oral contraceptives. The objective of this study was to evaluate the effect of a low dose oral contraceptive (15 µg ethinyl estradiol/60 µg gestodene) on the venous endothelial function of healthy young women. METHODS: Prospective case control study using the dorsal hand vein technique. Venous endothelial function was evaluated at baseline and after 4 months in the oral contraceptive users group (11 women) and in a control group (9 women). After preconstriction of the vein with phenylephrine, dose-response curves for acetylcholine and sodium nitroprusside were constructed. RESULTS: In the contraceptive users group, a reduction occurred in the maximum venodilation response to acetylcholine and sodium nitroprusside after 4 months of oral contraceptive use, but this difference was not statistically significant (P >; 0.05). No significant changes were detected in maximum venodilation responses to acetylcholine and sodium nitroprusside at the 4-month time point in the control group. CONCLUSION: This study found no significant impairment of endothelium-dependent or independent venodilation in healthy young women following oral contraceptive use. Further studies are necessary using the same methodology in a larger sample over a longer follow-up period.Um aumento no risco de tromboembolismo venoso têm sido descrito em usuárias de anticoncepcionais hormonais oral de terceira geração. OBJETIVO: Avaliar o efeito de um anticoncepcional combinado hormonal oral de baixa dose (15 µg etinil estradiol/60 µg gestodeno) na função endotelial venosa de mulheres jovens saudáveis. MÉTODOS: Realizou-se um estudo caso-controle prospectivo em vinte mulheres jovens saudáveis que foram avaliadas pela técnica da complascência venosa. A função endotelial venosa foi avaliada em um momento basal e após 4 meses no grupo das usuárias de anticoncepcional oral (11 mulheres) e em um grupo controle (9 mulheres). Foram construídas curvas dose resposta para acetilcolina e nitroprussiato de sódio após a pré-constrição da veia com fenilefrina. RESULTADOS: No grupo de usuárias de anticoncepcional combinado hormonal oral houve diminuição da venodilatação máxima em resposta a acetilcolina e nitroprussiato de sódio, porém esta mudança não foi estatisticamente significante (p>; 0,05). No grupo controle não foram detectadas mudanças significantes na venodilatação máxima, em resposta a acetilcolina e nitroprussiato de sódio no intervalo de 4 meses. CONCLUSÃO: Este estudo não observou redução significante da venodilatação endotélio dependente e independente após os uso de anticoncepcional combinado hormonal oral. Mais estudos são necessários utilizando a mesma metodologia em uma amostra maior e com maior tempo de seguimento