INTRODUÇÃO: A síndrome de prune belly (PBS) é caracterizada por uma tríade com flacidez da parede abdominal, criptorquidia bilateral e malformações do trato urinário que compreende bexiga de capacidade aumentada, com complacência elevada, hipossensibilidade, hipocontratilidade, com divertículo ou fístula uracal e resíduo pós-miccional elevado. Alguns autores recomendam tratamento clínico, porém outros propõe correção cirúrgica, com reconstrução da via urinária incluindo ureteroplastia e cistoplastia redutoras, orquidopexia e abdominoplastia. Mesmo após a cirurgia, alguns doentes necessitam de cateterismo limpo intermitente. A inervação vesical determina seu funcionamento, mediado por neuroreceptores na junção neuromuscular. Os adrenoreceptores a1 estão relacionados à contratilidade detrusora e o b3 ao seu relaxamento, e certas condições como obstrução infravesical levam à hiperexpressão de receptores a1. O objetivo da presente pesquisa é verificar se no detrusor de doentes com PBS há alteração na densidade de terminações nervosas, hiper ou hipoexpressão de receptores adrenérgicos a1a, a1b, a1d e b3 e proporção anormal dos tecidos muscular e conectivo. MÉTODO Trata-se de estudo retrospectivo de caso-controle que envolveu 14 espécimes de detrusor de doentes com PBS operados entre 1985 a 2005 no Hospital das Clínicas da FMUSP. Dois grupos foram constituídos como controle: 13 fragmentos de bexiga de doentes submetidos à prostatectomia radical no Departamento de Urologia da Universidade de Mainz, com urodinâmica pré-operatória normal (GC1), e cinco fragmentos de bexiga de crianças submetidas à necrópsia no SVOC-USP, sem anomalias neurológicas e de trato urinário. A coloração de van Gieson foi realizada para análise da proporção músculo/tecido conectivo, e a reação imunohistoquímica para os anticorpos policlonais anti-proteína S100 e antiadrenoreceptores a1a, a1b, a1d e b3. A coloração castanho foi considerada evidência da expressão do adrenoreceptor na célula. Cinco a dez imagens digitais foram tomadas por meio de câmara digital e microscopia óptica. Estas foram analisadas pelo programa Adobe Photoshop CS2Ò. A quantidade relativa de receptores foi calculada e a análise estatística realizada pelos testes Kruskal-Wallis e Mann-Whitney. RESULTADOS A média de idade foi de 1,28 ± 1,14 ano no grupo caso (PBS), e de 64 ± 5,22 anos e 1,41 ± 1,11 ano, nos grupos GC1 e GC2, respectivamente. A mediana da relação músculo/tecido conectivo foi de 1,08 para o grupo PBS, 1,59 para o GC1 e para o GC2 de 1,28 (p=0,173). A mediana da proporção S100/tecido muscular foi de 0,21 para o grupo caso (PBS), de 0,20 para o GC1 e para o grupo GC2 de 0,01 (p=0,003). A mediana da relação a1a/tecido muscular foi de 0,06 para o grupo PBS, de 0,16 para o GC1 e para o grupo GC2 de 0,14 (p=0,026). Para a1b, as medianas foram 0,06 no grupo PBS, 0,006 no GC1 e 0,007 no GC2 (p=0,781). No a1d, as medianas foram 0,04 (PBS), 0,04 (GC1) e 0,05 (GC2) (p=0,618). Com relação ao b3, as medianas foram 0,07 no grupo PBS, 0,14 no GC1 e 0,10 no GC2 (p=0,378). CONCLUSÕES Comparando-se fragmentos de detrusor de doentes com PBS e bexigas normais não se observou alteração na densidade de terminações nervosas. Observou-se hipoexpressão do adrenoreceptor a1a, e não houve alteração dos adrenoreceptores a1b, a1d e b3. Também não se observou alteração entre a proporção de tecido muscular e conectivo no detrusor destes doentes. Investigações adicionais, com diferentes métodos e incluindo outros receptores, são necessárias antes de se aplicar esses conhecimentos na prática clínica. / INTRODUCTION: Prune belly syndrome (PBS) is charactherized by a triad of abdominal wall flaccidity, bilateral criptorchidism and urinary tract malformation, that includes a large-capacity bladder, with high detrusor compliance, low sensibility and contractility, associated to urachal diverticulum or fistula and elevated post void residual volumes. Some autors recommend clinical treatment, but others propose surgery correction, with urinary tract reconstruction, including reductive ureteroplasty and cystoplasty, orchidopexy and abdominoplasty. Even after surgery, some patients need intermittent catheterism. The detrusor innervation determines its function, mediated by neuroceptors at the neuromuscular junction. The a1 adrenoceptors are related to detrusor contractility and b3 to relaxation, and some conditions, like infravesical obstruction, lead to a1 adrenoceptor up-regulation. The objective of this work is to verify whether, in the detrusor from patients with PBS, there is altered nerve density, up or down-regulation of a1a, a1b, a1d and b3 adrenergic receptors and if there is an abnormal proportion between muscle and connective tissue. MATERIALS AND METHODS A retrospective case-control study was performed involving 14 detrusor specimens from patients with PBS, who underwent surgical treatment between 1985 an 2005 at University of São Paulo, Medical School Hospital. Two groups were taken as control: 13 bladder fragments from patients who underwent radical prostatectomy at Department of Urology of Mainz University, with normal urodynamic study prior to the surgery (GC1) and 5 bladder fragments from children submitted to autopsy at SVOC-USP, with no neurological or urinary tract malformation (GC2). Staining was performed using the van Gieson dye to analyse the proportion between muscle and connective tissue, and immunohistochemical reaction was employed, with polyclonal antibodies against S100 protein, as well as a1a, a1b, a1d and b3 adrenoceptors. Brown colour was considered as evidence of adrenoceptor cell expression. Five to ten digital images were captured on an optic microscope with a digital camera. These images were analysed with Adobe Photoshop CS2Ò software. The relative quantity of receptors was calculated and the statistic analysis was done with the Kruskal-Wallis and Mann-Whitney tests. RESULTS Mean age was 1.28 ± 1.14 year in PBS patients, and 64 ± 5.22 yrs. and 1.41 ± 1.11 yrs. in GC1 and GC2, respectively. The median proportion between muscle and connective tissue was 1.08 in PBS, 1.59 in GC1 and in GC2 of 1.28 (p=0.173). The median proportion of S100/muscle area was 0.21 in PBS, 0.20 in GC1 and in GC2 of 0.01 (p=0.003). The median relative quantity of receptors of a1a was 0.06 in PBS, 0.16 in GC1 and 0.14 in GC2 (p=0.026). In a1b, the median values were 0.06 in PBS group, 0.006 in GC1 and 0.007 in GC2 (p=0.781). In a1d, the median values were 0.04 (PBS), 0.04 (GC1) and 0.05 (GC2) (p=0.618). Regarding b3, the median values were 0.07 in PBS, 0.14 in GC1 and 0.10 in GC2 (p=0.378). CONCLUSION Comparing detrusor fragments from patients with PBS and normal bladders, there was no alteration in the density of nerve endings. We observed downregulation of a1a adrenoceptors, but no alteration in the a1b, a1d and b3 receptors. Furthermore, there was no alteration of the proportion between muscle and connective tissue areas. Further investigations, with different methods and including other receptors, are necessary to transfer this knowledge to clinical use.

A falência de ultrafiltração (UFF) é uma causa importante de interrupção da diálise peritoneal (DP) enquanto terapia renal substitutiva. Além da inflamação crônica e aguda causadas à membrana peritoneal (MP) pelos produtos de degradação da glicose, produtos avançados da glicosilação, pH ácido das soluções e infecções, -bloqueadores (BB) também foram implicados na gênese da UFF. A vasoconstrição arteriolar esplâncnica é considerada a causa provável da UFF por BB. O nebivolol (NV), um bloqueador 1-adrenérgico altamente seletivo que, diferente de outros BB, possui efeito vasodilatador por aumento de óxido nítrico (NO) por ativar a via L-arginina-NO, foi testado em pacientes idosos com ICC e levou à redução na mortalidade. O objetivo desse estudo é analisar os efeitos do NV sobre a ultrafiltração (UF), MP e características do efluente em um modelo animal de DP, através do estudo de fenômenos envolvidos na degeneração da MP e UFF, como transição epitélio mesenquimal (EMT) e fibrose, além de parâmetros humorais e celulares de inflamação. 21 camundongos C57BL/6 fêmeas, não urêmicos, com 12 a 14 semanas, foram submetidos à colocação de cateter peritoneal. Após uma semana, foram divididos em 3 grupos de 7 animais: grupo controle (observação 30 dias), grupo SDP (2 mL/ dia de solução glicosada de diálise peritoneal a 4,25% através do cateter, por 30 dias) e grupo NV (além da infusão, receberam 8 mg/kg/dia de NV por gavagem, por 30 dias). Após 30 dias, comparou-se espessura submesotelial, volume de UF, velocidades de transporte de pequenos solutos, marcação submesotelial de pan-citoqueratina, para quantificar EMT, contagem de vasos, linfangiogênese diafragmática e concentração de IL-6 e IL-10 no efluente. A espessura da MP foi de 23,14 m no grupo controle, no grupo SDP foi de 102,4 m e no grupo NV, 29,04 m, com p<0,05. O volume de UF foi 1,94mL para o grupo controle, para o grupo SDP, 1,56 mL e, para o grupo NV, 2,05 mL, também com p<0,05. Houve menor EMT, menor angiogênese e tendência a transporte mais lento de solutos no grupo tratado, assim como menor concentração de IL-6 e proporções de populações de linfócitos semelhantes às do grupo controle. Concluímos que a droga impediu o desenvolvimento de UFF, através do bloqueio de fenômenos como EMT, espessamento da MP e neoangiogênese, além de preservar características de imunidade celular e humoral locais, merecendo ser estudada em pacientes submetidos à DP / Ultrafiltration failure (UFF) is a major cause of peritoneal dialysis (PD) discontinuation. Besides peritoneal membrane (PM) acute and chronic inflammation caused by glucose degradation products, advanced glycation end-products, acidic pH of the solutions and peritoneal infections, also -blockers (BBs) have been implicated in UFF genesis. Splanchnic arteriolar vasoconstriction has been considered the probable cause of UFF induced by BBs. Nebivolol (NV), a highly selective 1-adrenergic blocker, unlike other BBs, has a vasodilatory effect caused by its ability to increase nitric oxide (NO) through L-arginine-NO pathway activation. NV has been tested in elderly patients with congestive heart failure and led to mortality reduction. The aim of this work is to analyze the effects of NV over ultrafiltration (UF), PM and effluent characteristics in an animal model of PD. For that end, phenomena known to be involved in PM degeneration and UFF, such as epithelial-to-mesenchymal transition (EMT), fibrosis, as well as cellular and humoral parameters of inflammation have been studied. 21 C57BL/ 6 female non uremic mice, ageing 12 to 14 weeks, underwent peritoneal catheter placement. One week later, they were divided into 3 groups of 7 animals: control group (observation for 30 day), PDF group (2 mL/ day of 4.25% dextrose peritoneal dialysis fluid injected through the catheter for 30 days) and NV group (besides the PDF infusion, this group received 8 mg/ kg/ day of NV by gavage, for 30 days). After 30 days, submesotelial thickness, UF volume, small solute transport speed, submesotelial pan-cytokeratin staining (EMT quantification), vessel count, diaphragmatic lymphangiogenesis and IL-6 and IL-10 concentrations in the effluent were compared. PM thickness was 23.14 m in the control group, 102.4 m in the PDF group and 29.04 m in the NV group, p <0.05. UF volume was 1.94 mL in the control group, 1.56 mL in the SDP group, and in the NV group, 2.05 mL, p <0.05. There was less EMT, less angiogenesis and a tendency to a slower solute transport in the treated group. Lower levels of IL-6 and similar lymphocyte populations proportions to the control group were also found. We conclude that the drug can prevent UFF development, through blockade of phenomena such as EMT, PM thickening and neoangiogenesis, while characteristics of local cellular and humoral immunity were preserved. These results warrant a clinical study of the drug in PD patients

The sympathetic nervous system plays a key role in the regulation of cardiovascular and ventilatory responses during exercise. The regulation of the heart and peripheral circulation by the autonomic nervous system is accomplished by control centers that receive input from mechanical and chemical receptors through the body. Therefore, the changes in sympathetic and parasympathetic activity allow for rapid responses. <p><p>Exercise is associated with increases of ventilation, heart rate and blood pressure. Ventilation increases adaptedly to increased oxygen uptake (VO2) and carbon dioxide output (VCO2) and eventually to limit metabolic acidosis occurring above the ventilatory threshold. Cardiac output increases to meet the contracting muscles’ requirement for flow. The increase in cardiac output occurs through increases in both heart rate and stroke volume and is regulated by feed-forward mechanisms: central command and exercise pressor reflex. <p><p>Skeletal muscle contraction elicits a reflex increase in sympathetic outflow which causes vasoconstriction contributing to the exercise induced rise in blood pressure. This reflex is triggered by stimulation of metabo- and chemoreceptors. Although the precise stimulus is not known, adrenergic receptor signaling is involved in the cardiovascular and respiratory alterations in response to exercise. <p><p>This thesis has been devoted to a better understanding of the functional aspects of sympathetic nervous system activation during dynamic and resistive exercise, with use of β blocker and β2 stimulant interventions The hypotheses were: 1) that β blocker interventions would decrease aerobic exercise capacity by a limitation of maximal cardiac output, but more so the ventilatory responses to exercise because of a decreased chemosensitivity, thereby decreasing dyspnea, and 2) β2 stimulant interventions would slightly increase aerobic exercise capacity by an increase in maximal cardiac output, but also the ventilatory responses because of an increased chemosensitivity, with possible decrease of the ventilatory reserve at exercise and increased dyspnea. Both interventions could affect maximal muscle strength through central effects.<p><p>Ventilatory responses to hyperoxic hypercapnia (central chemoreflex) and to isocapnic hypoxia (peripheral chemoreflex) were confronted to measurements of ventilatory equivalents for oxygen (O2) and carbon dioxide (CO2) during standard cardiopulmonary exercise test (CPET). Resting 5 measurements of muscle sympathetic nervous activity (MSNA) were obtained in different conditions with and without pharmacological interventions. Muscle metaboreflex and muscle stength measurements were also considered. Drugs with β blocker or β2 stimulant properties were administered in range of doses used in clinical practice for the teatment of cardiovascular or rerspiratory conditions. The results show that β blockade with bisoprolol slightly reduced maximal exercise capacity as assessed by a maximal oxygen uptake (VO2max) or maximal workload (Wmax), with a decreased maximal heart rate, without significant effect on ventilation (VE) or MSNA responses to hypercapnia, hyperoxia or to isometric muscle contraction or ischemia. Both VE/VO2 and VE/VCO2 slopes were decreased during CPET, which was attributable to β blockade-related hemodynamic changes. On the other hand, stimulation of β2 receptors with salbutamol did not affect exercise capacity as assessed by VO2max or Wmax in spite of increased peripheral chemosensitivity with increased VE/VCO2 slopes and early lactic acidosis. MSNA burst frequency, muscle metaboreflex and maximal isokinetic muscle strength were not affected by salbutamol. <p><p>Thus, aerobic exercise capacity in healthy subjects is sensitive to sympathetic nervous system modulation by β blocker or β2 stimulant interventions with drugs at doses prescribed in clinical practice. B blocker intervention has a slight limitation of aerobic exercise capacity and a hemodynamic decrease in ventilation, while β2 stimulant intervention has no change in exercise capacity with associated increased ventilatory responses because of increased chemosensitivity, partly related to early lactic acidosis. None of the studied phamacologic interventions affected MSNA or muscle strength measurements. <p><p>We hope that these results might be useful for the understanding of the effects of revalidation to exercise of patients treated with β blocker or β2 stimulant drugs, document the limited ergogenic properties and also side effects of the intake of these substances in healthy exercising subjects.<p> / Doctorat en Sciences de la motricité / info:eu-repo/semantics/nonPublished

Pulmonary circulation is a high flow, low resistance, and low pressure system. Several pathologies, including mitral stenosis, may elevate the impedance of this blood circuit and lead to a pulmonary arterial hypertension. Such syndrome is usually related to a high morbity and patient s death may occur because of the ischemic failure of right ventricle. The use of systemic vasodilating drugs to treat this syndrome is limited by the simultaneous systemic arterial hypotension they often produce. More selective agents to the pulmonary vasculature, such as synthetic analogs of prostacyclin, endothelin receptor inhibitors, and phosphodiesterase III inhibitors, have been choosen for medium and long-term treatment. Unfortunately, the most selective pulmonary hypotensive agent, the inhaled nitric oxide, which is used for short-term treatment, requires special and costly equipment for its administration, making it inaccessible to many hospitals. Furthermore, some degree of toxicity was associated with that substance. The lack of an ideal substance that simultaneously shows pulmonary selectivity, atoxicity, easy handling, accessibility and low cost, motivated the present study to test the effects of clonidine on pulmonary circulation. Clonidine is an alfa-2 adrenergic agonist. It promotes a systemic cardiocirculatory balance by modulating the adrenergic discharge at both central and peripheral levels. When used in clinical doses it presents no toxicity. Furthermore, it is easy to handle, accessible, and inexpensive. However, little has been reported about its pulmonary effect. Therefore, this work aimed to evaluate the effects of clonidine on the pulmonary arterial pressure, on the hemodynamics parameters concerned to the pulmonary circulatory system, as well as on the right ventricular function. At the same time, the action of clonidine on the systemic hemodynamics, cardiac rate, cardiac index and stroke index was also evaluated. This investigation took into account the degree of selectivity of this agent to the pulmonary vessels as well as the presence of a biphasic effect on the pulmonary arterial pressure. This effect has been largely reported on the vascular periferal system. The present research was performed as a prospective clinical trial developed on a group of 16 patients with pulmonary hypertension caused by mitral stenosis of rheumatic origin. Data were obtained before the anesthetic induction, but under the patient sedation. During the control phase, the variations of hemodynamic parameters under the action of a placebo were evaluated. During the test phase, the behavior of these parameters was evaluated under the clonidine effect. The time schedule for data measurements was the following: T0 (initial control); T1 (10 minutes after placebo administration); T2 (20 minutes after placebo administration); T3 (10 minutes after clonidine administration); T4 (20 minutes after clonidine administration). T2 was used as the control time to study the clonidine effects. Statistical analysis showed that during the control phase the variables remained unchanged, but under the effect of clonidine there was a significant reduction of the mean values concerned to the following parameters: pulmonary arterial mean pressure (27.1%) and systemic arterial mean pressure (20%), pulmonary vascular resistance index (34%) and systemic vascular resistance index (14.6%), right and left ventricular systolic work indexes (19.9% and 10%, respectively), right atrium pressure (11.5%), pulmonary arterial wedge pressure (21.5%), heart rate and cardiac index (15.8% and 7.9%, respectively). Besides that, a significant increase of the stroke index (10.2%) occured. The biphasic effect on the sistemic arterial pressure occured in 50% of the studied patients, whereas the same effect on the pulmonary arterial pressure was observed in 20% of the same sample. Clonidine also exerted a moderately selective action on the pulmonary circulation, demonstrated through the reduction of the relationship between mean value of the pulmonary vascular resistance index and mean value of the systemic vascular resistance index evaluated at the times T2 and T3. / A circulação pulmonar é um sistema de alto fluxo, baixa resistência e baixa pressão. Patologias diversas, dentre elas a estenose mitral, podem elevar a impedância desse circuito, desencadeando a síndrome de hipertensão arterial pulmonar. Esta cursa com elevada morbidade, podendo levar ao óbito pela falência isquêmica do ventrículo direito. A utilização de drogas vasodilatadoras periféricas no tratamento dessa síndrome ficou limitada pela simultânea hipotensão arterial sistêmica que provoca. Agentes mais seletivos sobre a vasculatura pulmonar, como os análogos sintéticos da prostaciclina, os inibidores dos receptores de endotelina e os inibidores da fosfodiesterase III, têm sido as drogas de eleição para o tratamento de médio e de longo prazo. O mais seletivo dos agentes hipotensores pulmonares, o óxido nítrico inalado, aplicado ao tratamento de curto prazo, exige equipamento especial e oneroso para a sua administração, tornando-o inacessível a muitos nosocômios. Paralelamente, possui potencial toxicidade. A inexistência de um fármaco ideal que apresente, simultaneamente, seletividade sobre a pequena circulação, atoxicidade, fácil manuseio e disponibilidade, além de ser pouco oneroso, conduziu ao estudo da clonidina sobre a árvore circulatória pulmonar. Este agente terapêutico é um agonista alfa-2 adrenérgico, com efeitos favoráveis reconhecidos sobre o equilíbrio circulatório sistêmico por modular a descarga adrenérgica em níveis central e periférico. É atóxico quando utilizado em doses clínicas. Além disso, oferece fácil manuseio, boa acessibilidade e baixo custo. Os estudos a respeito da sua ação pulmonar são escassos. Assim, a presente investigação teve como objetivo avaliar os efeitos da clonidina sobre a pressão arterial pulmonar, sobre os demais parâmetros hemodinâmicos da pequena circulação e sobre a função ventricular direita. Paralelamente, analisou as ações sobre a hemodinâmica sistêmica, a freqüência cardíaca, o índice cardíaco e o índice de ejeção. Foi também investigado o grau de seletividade pulmonar desse agente, bem como a presença de um efeito bifásico sobre a pressão arterial pulmonar, pois este efeito tem sido amplamente relatado no sistema vascular periférico. Para a execução dos objetivos propostos, um ensaio clínico prospectivo, realizado antes da indução anestésica, mas sob sedação, foi desenvolvido num grupo de 16 pacientes, todos portadores de hipertensão pulmonar resultante de estenose mitral de origem reumática. Durante a fase controle foram analisadas as variações dos parâmetros hemodinâmicos sob a ação de um placebo. Durante a fase teste foi avaliado o comportamento dos mesmos parâmetros sob a ação da clonidina. A padronização dos tempos nos quais se fez a coleta de dados foi a seguinte: T0 (controle inicial); T1 (10 min após a administração do placebo); T2 (20 min após o placebo); T3 (10 min após a administração da clonidina); T4 (20 min após a clonidina). A análise estatística dos resultados demonstrou não haver alteração das variáveis estudadas durante a fase controle. Todavia, sob o efeito da clonidina houve variações estatisticamente significantes dos mesmos parâmetros nos seus valores médios: redução da pressão arterial pulmonar média (27,1%) e da pressão arterial sistêmica média (20%), dos índices de resistência vascular pulmonar (34%) e sistêmica (14,6%), dos índices de trabalho sistólico dos ventrículos direito (19,9%) e esquerdo (10%), da pressão do átrio direito (11,5%), da pressão de oclusão da artéria pulmonar (21,5%), da freqüência cardíaca (15,8%) e do índice cardíaco (7,9%), ao lado de uma elevação significante do índice de ejeção (10,2%). O efeito bifásico sobre a pressão arterial sistêmica ficou evidente em 50% dos pacientes estudados, enquanto que o mesmo efeito sobre a pressão arterial pulmonar ocorreu em 20% da amostra estudada. A clonidina também exerceu uma ação moderadamente seletiva sobre a circulação pulmonar, demonstrada através da diminuição do quociente obtido entre o valor médio do índice de resistência vascular pulmonar e valor médio do índice de resistência vascular sistêmica, ambos avaliados nos tempos T2 e T3.

A intolerância ao exercício físico na insuficiência cardíaca (IC) está relacionada a alterações hemodinâmicas e neurohumorais pela complexa interação dos reflexos cardiovasculares. Os quimiorreflexos central e periférico e o ergorreflexo estão envolvidos na hiperventilação de repouso e durante o exercício, contribuindo para intolerância ao esforço. Os objetivos do estudo foram avaliar o efeito da terapêutica com beta-bloqueador (betab) na resposta dos quimiorreflexos central e periférico e do ergorreflexo por meio das alterações da resposta ventilatória durante o teste de caminhada de seis minutos (T6M); e avaliar o efeito da sua otimização também sobre as catecolaminas plasmáticas e peptídeo natriurético do tipo B (BNP). Foram estudados 15 pacientes masculinos, 49.5 ± 2.5 anos, com diagnóstico de IC há mais de 3 meses, sem histórico de tratamento com betab, com fração de ejeção (FEVE) 25.9 ± 2.5%, classe funcional I-III (NYHA). Estes pacientes poderiam estar em uso de inibidores da enzima conversora da angiotensina, bloqueadores do receptor da angiotensina II e antagonista do receptor da aldosterona. Todos os indivíduos realizaram testes: ergoespirométrico em esteira segundo o protocolo de Naughton, três T6M em esteira com controle de velocidade pelo paciente randomizados (um com sensibilização dos quimiorreceptores centrais, um com sensibilização dos quimiorreceptores periféricos e um controle em ar ambiente - AA). Também realizaram T6M com e sem oclusão circulatória regional em membro inferior. Em relação aos exames laboratoriais, foram feitas análises de catecolaminas plasmáticas em repouso e BNP. Os pacientes foram então submetidos a tratamento medicamentoso padrão da Instituição, com introdução e otimização da terapêutica com ßb e, após seis meses, foram reavaliados. Após otimização do betab, houve melhora significativa na FEVE, de 26 ± 2,5 para 33 ± 2,6 (p < 0,05); diminuição de níveis de BNP (775 ± 163 para 257 ± 75; p < 0,01) e de catecolaminas plasmáticas (598 ± 104 para 343 ± 40; p < 0,05). Foi também observada diminuição significativa na frequência cardíaca de repouso, de 95.6 ± 4.5 para 69.0 ± 1.6 (p < 0,01), e aumento do pulso de O2 de repouso (3.7 ± 0.3 para 4.4 ± 0.3; p < 0,01) pós betab. Em relação ao pico do esforço, houve diminuição significativa da frequência cardíaca, de pico 144.0 ± 4.6 para 129.5 ± 4.2 (p < 0,05), aumento do pulso de O2 (11.9 ± 1.1 para 15.5 ± 0.8; p < 0,01), diminuição do VE/VCO2 slope 29.4(25.8-36.2) para 24.6 (22.5-27.5); p=0,03) e aumento do tempo de exercício (12.3 ± 1.3 para 16.1 ± 1.2; p=0,01), sem, entretanto, aumento do consumo de oxigênio. Houve diferença significativa em relação à distância percorrida no T6M entre os dois momentos (pré e pós) em todas as análises, tanto controle (AA) quanto para a sensibilização dos quimiorreceptores centrais e periféricos, além de diminuição da resposta ventilatória nas sensibilizações dos quimiorreflexos quando comparados com o controle. A otimização da terapêutica medicamentosa na IC, especialmente com betab, promove melhora hemodinâmica, metabólica e neurohormonal. O presente estudo, que examinou os efeitos da terapêutica com betab na resposta dos quimiorreflexos e ergorreflexo em pacientes com IC, documentou que o betab diminui a resposta dos quimiorreflexos durante o exercício em hipóxia e hipercapnia sem, entretanto, alterar a resposta dos ergorreflexos. Essa modulação reflexa pode ser responsável pelo aumento da tolerância ao esforço sem o aumento do consumo de oxigênio / In heart failure (HF), exercise intolerance is related to hemodynamic and neurohumoral alterations by the complex interaction of cardiovascular reflexes. The central and peripheral chemoreflex and the ergoreflex are involved in hyperventilation at rest and during exercise, contributing to exercise intolerance. The aims of the study were to assess the effect of beta-blocker (betab) therapy on the central and peripheral chemoreflexes and ergoreflex responses through ventilatory changes during the six-minute walk test (6MWT), and to assess the effect of betab optimized therapy on plasma catecholamines and B-type natriuretic peptide (BNP). We studied 15 male patients, 49.5 ± 2.5 years, diagnosed with HF for more than three months, never-treated with ßb, ejection fraction (LVEF) 25.9 ± 2.5%, functional class I-III (NYHA). These patients could be in use of angiotensin-converting enzyme inhibitors, angiotensin receptor blockers and aldosterone antagonists. All subjects underwent the following tests: cardiopulmonary exercise treadmill test according to the Naughton protocol, three randomized treadmill 6MWT with speed controlled by the patient (one with sensitization of central chemoreceptors, one with an awareness of peripheral chemoreceptors and another control in ambiental air - AA). Also all subjects underwent 6MWT with and without regional circulatory occlusion on the lower limb. Regarding laboratory tests, plasma catecholamines concentration at rest and BNP were also analyzed. Patients were then submitted to the institution standard drug therapy, with introduction and optimization of betab and were reassessed six months later. After optimization, there was a significant improvement in LVEF from 26 ± 2.5 to 33 ± 2.6 (p < 0.05); and a decrease in BNP levels (775 ± 163 to 257 ± 75, p < 0.01) and plasma catecholamines (598 ± 104 to 343 ± 40, p < 0.05). There was also a significant decrease in resting heart rate from 95.6 ± 4.5 to 69.0 ± 1.6 (p < 0.01) but O2 pulse at rest increased post optimization (3.7 ± 0.3 to 4.4 ± 0.3, p < 0.01). Regarding the peak exercise, there was a significant decrease in peak heart rate 144.0 ± 4.6 to 129.5 ± 4.2 (p < 0,05) and VE/VCO2 slope 29.4(25.8-36.2) to 24.6(22.5-27.5), p=0.03); and an increase in O2 pulse (11.9 ± 1.1 to 15.5 ± 0.8, p < 0.01), and exercise time (12.3 ± 1.3 to 16.1 ± 1.2, p=0.01), without, however, increasing oxygen consumption. There was significant difference in walked distance during the 6MWT between the two time points (before and after) in all analyzes, both control (AA) and for the sensitization of central and peripheral chemoreceptors. Also, there was a decreased ventilatory response in sensitization of chemoreflexes when compared with the control. The optimization of drug therapy in HF, especially with ßb, promotes hemodynamic, metabolic and neurohormonal improvements. This study, which examined the effect of therapy with betab on the response of the chemoreflexes and ergoreflex in HF patients, documented that ßb decreases the response of chemoreflexes during exercise in hypoxia and hypercapnia without, however, altering the ergoreflex response. This reflex modulation may be responsible for the increased exercise tolerance without increasing oxygen consumption

Cannabinoid (CB) receptors have been found in most vertebrates that have been studied. The location of various CB receptors in the body and brain are known, but their physiological functions are not fully understood. The effects CBs have on the cardiovascular system have been of growing interest in recent years. Increasing reports from emergency departments and law enforcement agencies detail acute cardiovascular and psychological effects from synthetic CB intoxication, such as JWH-018. This major health concern is substantiated by governmental agencies like the CDC and NIDA. This pilot study investigates the acute toxic effects of the synthetic CB, JWH-018, on the cardiovascular and neuroendocrine systems in Ictalurus punctatus (channel catfish). Research in organisms besides the traditional mammal models can provide new insights into CB function and physiology. Ictalurus punctatus lend multiple benefits as a model organism that permits researchers to investigate in vivo effects of both cardiovascular and neuroendocrine systems without much influence from traditional sampling methods, and further more provide ample size and tissue to perform specific cardiovascular experiments. Multiple methods were used to assess cardiovascular function and sympathetic nervous system activation. Two different doses, low (500 µg/kg) and high 1,500 µg/kg, of JWH-018 were evaluated in the study. Delivery of JWH-018, via dorsal aorta cannulation, was administered to channel catfish in order to measure cardiovascular functions and sample blood. Plasma levels of the hypothalamus-pituitary-adrenal/interrenal (HPA/I) biomarkers; ACTH, cortisol, epinephrine, and norepinephrine, were measured using ELISAs. Myocardial and neural tissue was collected after the exposures for rt-PCR analysis on β2 adrenergic and glucocorticoid receptor density change. Acute exposure of JWH-018 in undisturbed channel catfish yielded several findings: (1) High dose of JWH-018 was responsible for cardio depressor effects in catfish with a tendency to produce tachycardia, (2) rt-PCR results showed a 2.7 fold increase of glucocorticoid receptor mRNA density in catfish cardiomyocytes when exposed to each dose of JWH-018, (3) Catfish plasma ACTH levels were increased with high doses of JWH-018, while plasma cortisol was increased by low doses. Channel catfish is an excellent animal model to examine the effects of synthetic cannabinoids and cardiovascular function. Acute exposures to high levels of JWH-018 appear to produce cardiovascular dysfunction providing evidence that substantiates emergency department reports, in addition yields novel information about the interaction of CBs exposure and the increase of glucocorticoid receptors levels on cardiomyocytes. The channel catfish is a new animal model that can aid in further investigations of CB exposure and multiple physiological functions for health and toxicology studies. With relatively easy adjustments from this pilot study, the effects on CBs can be monitored on Ictalurus punctatus with confident results concerning human health.

Indiana University-Purdue University Indianapolis (IUPUI) / Background: Previous studies show that prazosin, an α1-adrenergic receptor antagonist, decreases alcohol drinking in animal models of alcohol use and dependence and in alcohol-dependent men. These studies extended previous findings by using a paradigm that allows for separate assessment of prazosin on motivation to seek versus consume ethanol or sucrose in selectively bred rats given acute or chronic prazosin treatment. Methods: Alcohol-preferring P rats were trained to complete an operant response that resulted in access to either 2% (Exp. 1) or 1% (Exp.2) sucrose or 10% ethanol. In Experiment 1, a 4-week consummatory testing phase consisted of rats bar-pressing to “pay” a specified amount up front to gain access to unlimited ethanol (or sucrose) for a 20-minute period. A 4-week appetitive testing phase examined how much the rats would bar-press for ethanol in an extinction session when no reinforcer could be obtained. In Experiment 2, during testing, the response requirement was dropped to a 1 and daily session cycles of drug (3 weeks/ 14 sessions from Tues to Fri) or vehicle (2 weeks/ 9 sessions from Tues to Fri) treatment were alternated per drug dose for a total of 3 drug doses (3 cycles) per rat. After each drug cycle, a single non-reinforced extinction session was conducted with no drug ‘on board’ and no reinforcer access. On test days, rats were given IP injections of either vehicle or one of three doses of prazosin (Exp 1: 0.5, 1.0, 1.5 mg/kg; Exp 2: 0.25, 0.5, 1.0 mg/kg; balanced design; -30 min). Results: In Experiment 1, prazosin significantly decreased ethanol-seeking at all doses tested. The highest dose decreased ethanol intake and increased the latency to first lever-press and first lick. Sucrose-seeking and intake were decreased by the same doses of prazosin. In Experiment 2, prazosin significantly decreased reinforcer-seeking at the lowest and highest doses while ethanol intake was not decreased by prazosin. Conversely, sucrose-seeking was decreased at the highest dose of prazosin tested while sucrose consumption was decreased by all doses. Latency to lever-press for sucrose was increased by the lowest dose of prazosin compared to vehicle. Conclusions: These findings extend previous research and indicate that prazosin decreases motivation to seek ethanol and sucrose. The specificity of prazosin on different behaviors and over different reinforcers suggests that these findings are not due to prazosin-induced motor-impairment or malaise. These data suggest that prazosin may work by decreasing the reinforcing properties of reinforcers in general.

[pt] A noradrenalina desempenha um papel central em diversos transtornos relacionados ao medo, como o transtorno de ansiedade generalizada (TAG). Estudos farmacológicos em humanos e animais mostraram que os comportamentos relacionados ao medo podem ser regulados pela aplicação sistêmica de drogas noradrenérgicas. No entanto, as diferenças individuais na ansiedade-traço são frequentemente negligenciadas ao estudar os efeitos não apenas de drogas noradrenérgicas, mas de outros compostos. No presente estudo, examinamos os efeitos da ioimbina, um antagonista do receptor alfa2-adrenérgico, em duas linhagens de ratos criados para respostas de alto e baixo congelamento à pistas contextuais previamente associadas a choques nos pés (ratos Carioca de Alto e Baixo Congelamento - CAC e CBC, respectivamente). Descobrimos que a administração sistêmica de ioimbina no segundo dia de condicionamento do medo contextual (sessão de teste) diminuiu significativamente as respostas de congelamento de fêmeas CAC, mas não de machos. No entanto, o tratamento com ioimbina induziu um aumento significativo no comportamento de congelamento de ratos CBC machos e fêmeas. Resultados semelhantes foram observados quando os grupos foram novamente expostos à mesma câmara de condicionamento 6 dias depois. Nossos resultados indicam que, embora a ioimbina leve a efeitos ansiolíticos em ratos CAC, ela tem um efeito ansiogênico nos ratos CBC. Entretanto, esse efeito foi mais evidente nas fêmeas do que nos machos. Nossas descobertas apontam para o papel da noradrenalina na regulação e mediação das respostas de medo em diferentes traços de ansiedade. Além disso, nossos resultados também ressaltam a relevância do uso de ambos os sexos em estudos comportamentais e farmacológicos usando modelos animais de transtornos de ansiedade. / [en] Norepinephrine plays a central role in several fear-related disorders, such as generalized anxiety disorder (GAD). Pharmacological studies in humans and animals have shown that fear-related behaviors can be regulated by the systemic application of noradrenergic drugs. However, individual differences in trait anxiety are often overlooked when studying the effects of not only noradrenergic drugs, but other compounds. In the present study we examined the effects of yohimbine, an alpha2-adrenergic receptor antagonist, in two lines of rats bred for high and low freezing responses to contextual cues previously associated with footshocks (Carioca high- and low-conditioned freezing rats - CHF and CLF, respectively). We found that systemic administration of yohimbine on the second day of contextual fear conditioning (test session) significantly decreased the freezing responses of CHF females, but not CHF males. Yet, yohimbine treatment induced a significant increase in freezing behavior of both male and female CLF rats. Similar results were observed when groups were re-exposed to the same conditioning chamber 6 days later. Our findings indicate that while yohimbine leads to anxiolytic effects on CHF rats, it has an anxiogenic effect on CLF ones. However, such effect was more evident in females than in males. Our findings point to the role of norepinephrine in regulating and mediating fear responses in different anxiety traits. Furthermore, our findings also underscore the relevance of using both sexes in behavioral and pharmacological studies using animal models of anxiety disorders.

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Despite a high proportion of the population experiencing traumatic events within their lifetime, the number of individuals who go on to develop posttraumatic stress disorder (PTSD) is comparatively small; herein highlighting the importance of individual differences in imparting risk and resilience towards the development and maintenance of PTSD. Existing literature illustrates that biological and ecological factors are important in predicting PTSD development, with pathological vulnerabilities excepting their effects at pre- peri- and post trauma stages. Whilst cognitive and emotion based models of PTSD account for the role of a minority of known pre-trauma risk factors, individual differences in peri- and post trauma processes are held as critical to the development of PTSD. The broad range of risk factors implicated in the empirical literature, and necessity of traumatic exposure to PTSD, implicates the utility of a diathesis-stress conceptualisation of PTSD development. The current thesis employed an analogue VR-trauma paradigm to investigate the respective importance of vulnerability factors at each stage, in the prediction of analogue PTSD symptoms (memory problems, startle responses, re-exposure fear habituation), whilst measuring affective and electrophysiological concomitance. Findings supported the importance of peri-traumatic responses in the prediction of PTSD, where present, showing increased predictive capacities over pre- and post-trauma factors. Biological and ecological factors also illustrated important predictive associations, with genetic SNPs implicated in reflex startle and cardiac responses towards intrusive memories. Moreover, peri-traumatic HR decelerations and accelerations mediated the association between pre-trauma factors and cued recall inaccuracy and intrusion severity respectively. Results support existing cognitive and emotional models in their emphasis on peri-traumatic processes but suggest the added utility of a diathesis stress conceptualisation of the development of PTSD, in highlighting the importance of pre-trauma biological and ecological risk and resilience factors.