Early rather than delayed administration of lisinopril protects the heart after myocardial infarction in rats

Background: ACE inhibitors have shown beneficial results in several studies after myocardial infarction (MI). However, these studies have shown conflicting results about the ideal starting time of the ACE inhibitors administration after MI and the importance of infarct size.Objectives: This study was designed to assess the long-term effects of lisinopril on mortality, cardiac function, and ventricular fibrosis after MI, in rats.Methods: Lisinopril (20 mg/kg/day) was given on day 1 or 21 days after coronary occlusion in small or large infarctions.Results: the mortality rate was reduced by 39% in early treatment and 30% in delayed treatment in comparison to the untreated rats. Early treatment reduced cardiac dysfunction in small MIs; however, delayed treatment did not. No statistical difference was observed among the groups for large MIs. No statistical difference was observed among the groups with large or small MIs on myocardial hydroxyproline concentration.Conclusions: Both early and delayed treatments with lisinopril increased survival. Treatment exerts no marked effects on fibrosis; early treatment has exerted beneficial influences on cardiac function whereas delayed treatment had no consistent effects. The protective effect of lisinopril is detectable only in small (< 40% of LV) MIs.

TRATAMENTO DA HIPERTENSAO ARTERIAL LEVE E MODERADA COM FOSINOPRIL. COMPARACAO DE EFEITOS ADVERSOS COM OUTROS ANTI-HIPERTENSIVOS

Purpose - To evaluate the adverse reactions of fosinopril with other antihypertensives used as monotherapy. Methods - Out-patients (n = 2,568) with diagnostic of mild to moderate hypertension, diastolic blood pressure (DBP) 95-115 mmHg, with no antihypertensive treatment for 15 days, were included to treatment initially with fosinopril (F) 10mg, once daily, for six weeks. After this period, patients with DBP >95mmHg had the dosage, once daily, increased to 20 mg, while the others were maintained with the same dosage for six more weeks. Adverse reactions of 822 patients treated as monotherapy were grouped as absent, musculoskeletal, cardiovascular, cough, gastrointestinal, neurological, genital-urinary dysfunctions and dermatological and compared with 1,568 with F. Monotherapy consist in α-methyldopa (100 patients); β-blocker (129); calcium blocker (106); diuretic (394); and another ACE inhibitors (93). Results - At the end of the period without treatment, the blood pressure (BP), 165 ± 16/105 ± 7 mmHg decreased significantly at 6(th) week to 144 ± 15/91 ± 9 mmHg (p < 0.05 vs week 0) with further lowering to 139 ± 13/86 ± 7 mmHg till the end of 12(th) week. BP response (DBP ≤90 mmHg) was obtained in 89% of the patients with F. Absence of adverse reactions were ≥70% in patients with F compared to other drugs. Conclusion - Fosinopril has demonstrated therapeutic efficacy and less adverse reactions compared to antihypertensives used previously as monotherapy.

The effect of non-antihypertensive doses of angiotensin converting enzyme inhibitor on myocardial necrosis and hypertrophy in young rats with renovascular hypertension

In renovascular hypertensive rats, low doses of angiotensin converting enzyme (ACE) inhibitors have been found to prevent myocardial hypertrophy independent of blood pressure level. This finding would suggest humoral rather than mechanical control of myocyte growth. The aim of this study was to examine the effect of nonantihypertensive doses of ACE inhibitor on myocardial hypertrophy and necrosis in hypertensive rats. Renovascular hypertension (RHT) was induced in four-week-old Wistar rats. Twenty-eight animals were treated for four weeks with three doses of ramipril (0.01, 0.1 or 1.0 mg/kg/day, which are unable to lower blood pressure. Fourteen animals were not treated (RHT group). A sham operated, age/sex-matched group was used as control (n=10). Myocardial histology was analysed in 3 μm thick sections of the ventricle stained with either haematoxylin-eosin, reticulin silver stain or Masson's trichrome. There was a significant correlation between systolic blood pressure and left ventricular to body weight ratio in both sets of animals: untreated plus controls and ramipril-treated rats. ACE inhibition prevented myocyte and perivascular necrosis and fibrosis in a dose-dependent manner. We conclude that myocardial hypertrophy in rats with renovascular hypertension is directly related to arterial pressure, and that this relationship is not affected by nonantihypertensive doses of ACE inhibitor. Myocardial necrosis/fibrosis and coronary artery damage induced by angiotensin II are prevented by ACE inhibitor in a dose-dependent manner, despite the presence of arterial hypertension.

Azul de metileno no tratamento da síndrome vasoplégica em cirurgia cardíaca. quinze anos de perguntas, respostas, dúvidas e certezas

Objective: There is strong evidence that methylene blue (MB), an inhibitor of guanylate cyclase, is an excellent therapeutic option for vasoplegic syndrome (VS) treatment in heart surgery. The aim of this article is to review the MB's therapeutic function in the vasoplegic syndrome treatment. Methods: Fifteen years of literature review. Results: 1) Heparin and ACE inhibitors are risk factors; 2) In the recommended doses it is safe (the lethal dose is 40 mg/ kg); 3) The use of MB does not cause endothelial dysfunction; 4) The MB effect appears in cases of nitric oxide (NO) up-regulation; 5) MB is not a vasoconstrictor, by blocking of the GMPc system it releases the AMPc system, facilitating the norepinephrine vasoconstrictor effect; 6) The most used dosage is 2 mg/kg as IV bolus followed by the same continuous infusion because plasmatic concentrations strongly decays in the first 40 minutes; 7) There is a possible window of opportunity for the MB's effectiveness. Conclusions: Although there are no definitive multicentric studies, the MB used to treat heart surgery VS, at the present time, is the best, safest and cheapest option, being a Brazilian contribution for the heart surgery.

Efeitos da angiotensina II no sistema cardiovascular

Angiotensin is an important peptide of renin-angiotensin-aldosterone system. This peptide has an important function on arterial blood pressure regulation and body fluid homeostasis. However, its action on abnormal conditions causes deleterious effects on the cardiovascular system. Vascular resistance, hypertension, vascular and myocytes hipertrophy, production of free radicals and pro-inflammatory substances are some of the actions of angiotensin II that can result on cardiovascular remodeling. Angiotensinconverting enzyme (ACE) inhibitors, angiotensin receptors antagonists, antiinflammatories and antioxidants are used clinically and/or experimentally to prevent or reduce the effects of angiotensin II. The purpose of this work is to review the actions and interactions of angiotensin II on the cardiovascular system, as well as the therapeutic measures employed for the control of these effects.

Avaliação cardíaca de cães com degeneração valvar mixomatosa durante o emprego de enalapril, losartana, furosemida e suas combinações

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Avaliação da função renal de cães sadios e nefropatas crônicos sob diferentes bloqueios medicamentosos do sistema renina-angiotensina-aldosterona

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

The effect of non-antihypertensive doses of angiotensin converting enzyme inhibitor on myocardial necrosis and hypertrophy in young rats with renovascular hypertension

In renovascular hypertensive rats, low doses of angiotensin converting enzyme (ACE) inhibitors have been found to prevent myocardial hypertrophy independent of blood pressure level. This finding would suggest humoral rather than mechanical control of myocyte growth. The aim of this study was to examine the effect of nonantihypertensive doses of ACE inhibitor on myocardial hypertrophy and necrosis in hypertensive rats. Renovascular hypertension (RHT) was induced in four-week-old Wistar rats. Twenty-eight animals were treated for four weeks with three doses of ramipril (0.01, 0.1 or 1. 0 mg/kg/day, which are unable to lower blood pressure. Fourteen animals were not treated (RHT group). A sham operated, age/sex-matched group was used as control (n = 10). Myocardial histology was analysed in 3 microm thick sections of the ventricle stained with either haematoxylin-eosin, reticulin silver stain or Masson's trichrome. There was a significant correlation between systolic blood pressure and left ventricular to body weight ratio in both sets of animals: untreated plus controls and ramipril-treated rats. ACE inhibition prevented myocyte and perivascular necrosis and fibrosis in a dose-dependent manner. We conclude that myocardial hypertrophy in rats with renovascular hypertension is directly related to arterial pressure, and that this relationship is not affected by nonantihypertensive doses of ACE inhibitor. Myocardial necrosis/fibrosis and coronary artery damage induced by angiotensin II are prevented by ACE inhibitor in a dose-dependent manner, despite the presence of arterial hypertension.

Diapocynin versus apocynin as pretranscriptional inhibitors of NADPH oxidase and cytokine production by peripheral blood mononuclear cells

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Variability and resistance mutations in the hepatitis C virus NS3 protease in patients not treated with protease inhibitors

The goal of treatment of chronic hepatitis C is to achieve a sustained virological response, which is defined as exhibiting undetectable hepatitis C virus (HCV) RNA levels in serum following therapy for at least six months. However, the current treatment is only effective in 50% of patients infected with HCV genotype 1, the most prevalent genotype in Brazil. Inhibitors of the serine protease non-structural protein 3 (NS3) have therefore been developed to improve the responses of HCV-infected patients. However, the emergence of drug-resistant variants has been the major obstacle to therapeutic success. The goal of this study was to evaluate the presence of resistance mutations and genetic polymorphisms in the NS3 genomic region of HCV from 37 patients infected with HCV genotype 1 had not been treated with protease inhibitors. Plasma viral RNA was used to amplify and sequence the HCV NS3 gene. The results indicate that the catalytic triad is conserved. A large number of substitutions were observed in codons 153, 40 and 91; the resistant variants T54A, T54S, V55A, R155K and A156T were also detected. This study shows that resistance mutations and genetic polymorphisms are present in the NS3 region of HCV in patients who have not been treated with protease inhibitors, data that are important in determining the efficiency of this new class of drugs in Brazil.

COX-2 Inhibitors for Cancer Treatment in Dogs

Cancer is one of the main causes of death in canines and felines, and this fact is probably related to the increase in the longevity of these species. The longer the animals live, the higher the exposure to carcinogenic agents will be. With the high incidence of cancer in companion animals, new studies are currently being performed with the aim of finding therapeutic options which make the complete inhibition of the development of neoplasms in animals possible in the future. The correlation of cyclooxygenase-2 (COX-2) whith the development of cancer opens the way for the use of new therapeutic approaches. This relationship has been suggested based on various studies which established an association between the chronic use of nonsteroidal anti-inflammatory drugs (NSAID) and a decrease in the incidence of colon carcinoma. As cancer progresses, COX-2 participates in the arachidonic acid metabolism by synthesizing prostaglandins which can mediate various mechanisms related to cancer development such as: increase in angiogenesis, inhibition of apoptosis, suppression of the immune response, acquisition of greater invasion capacity and metastasis. Accordingly, overexpression of this enzyme in tumors has been associated with the most aggressive, poor-prognosis cancer types, especially carcinomas. Therefore, treatments which use COX-2 inhibitors such as coxibs, whether administered as single agents or in combination with conventional antineoplastic chemotherapy, are an alternative for extending the survival of our cancer patients.

The Potential of p38 MAPK Inhibitors to Modulate Periodontal Infections

Periodontal disease initiation and progression occurs as a consequence of the host immune inflammatory response to oral pathogens. The innate and acquired immune systems are critical for the proper immune response. LPS, an outer membrane constituent of periodontal pathogenic bacteria, stimulates the production of inflammatory cytokines IL-1 beta TNF alpha IL-6 and RANKL either directly or indirectly. In LPS-stimulated cells, the induction of cytokine expression requires activation of several signaling pathways including the p38 MAPK pathway. This review will discuss the significance of the p38 MAPK pathway in periodontal disease progression and the potential therapeutic consequences of pharmacological antagonism of this pathway in the treatment of periodontal diseases.

Subfornical organ mediates pressor effect of angiotensin: Influence of nitric oxide synthase inhibitors, AT(1) and AT(2) angiotensin antagonist's receptors

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Crystallization and preliminary X-ray diffraction analysis of an acidic phospholipase A(2) complexed with p-bromophenacyl bromide and alpha-tocopherol inhibitors at 1.9-and 1.45-A resolution

An acidic phospholipase A(2) (PLA(2)) isolated from Bothrops jararacussu snake venom was crystallized with two inhibitors: alpha-tocopherol (vitamin E) and p-bromophenacyl bromide (BPB). The crystals diffracted at 1.45- and 1.85-Angstrom resolution, respectively, for the complexes with alpha-tocopherol and p-bromophenacyl bromide. The crystals are not isomorphous with those of the native protein, suggesting the inhibitors binding was successful and changes in the quaternary structure may have occurred. (C) 2004 Elsevier B.V. All rights reserved.