Dinámica contráctil inducida por p-clorofenol alcanforado en anillos aórticos de ratas Wistar / Dinâmica contrátil induzida por cânfora-clorofenol em anéis aórticos de ratos Wistar / Camphorated p-chlorophenol-induced contractile dynamics in aortic rings of Wistar rats

Introducción: El p-clorofenol alcanforado es un derivado clorofenólico de uso común como medicación intraconducto en Endodoncia. Son escasos los reportes científicos sobre sus efectos en la musculatura lisa vascular arterial y la regulación del flujo sanguíneo local. Objetivo: Determinar el efecto del p-clorofenol alcanforado sobre la dinámica contráctil del músculo liso vascular arterial en el tiempo. Método: Se realizó una investigación experimental preclínica utilizando 14 anillos de aorta obtenidos de ratas Wistar. Los anillos se colocaron en baño de órganos y se preactivaron con noradrenalina, registrándose luego la tensión desarrollada por el músculo liso vascular tras la adición de p-clorofenol alcanforado durante diferentes intervalos de tiempo. Resultados: El 51,4 porciento de la musculatura lisa vascular se relajó por la acción del p-clorofenol alcanforado. El mayor descenso del tono vascular se produjo entre el tercer y quinto minuto de añadido el medicamento. Las pruebas de Wilcoxon de los rangos con signos evidenciaron diferencias significativas entre la tensión base inicial y la registrada en los diferentes intervalos de tiempo estudiados. Conclusiones: el p-clorofenol alcanforado, induce in vitro, relajación del músculo liso arterial a través de un acoplamiento excitación-contracción de tipo farmacomecánico, la cual se incrementa en función del tiempo(AU).

Introduction: Camphorated p-chlorophenol is a chlorophenolic derivative commonly used as an intra-oral medication in endodontics. Scientific reports on its effects in arterial vascular smooth muscle and local blood flow regulation are scarce. Objective: To determine the effect of camphorated p-chlorophenol on the contractile dynamics of arterial vascular smooth muscle. Method: An experimental and preclinical research was conducted with the use of 14 aortic rings of Wistar rats. The rings were placed in an organ bath and preactivated with noradrenaline, and the tension developed by the vascular smooth muscle at different time intervals was recorded after induction of camphorated p-chlorophenol. Results: Most of the vascular smooth muscle (51.4 percent) relaxed with the use of camphorated p-chlorophenol. The greatest decrease in vascular tone occurred between the third and fifth minute after use the drug. Wilcoxon rank tests showed significant differences between tension observed at baseline and those recorded at the different time intervals studied. Conclusions: Camphorated p-chlorophenol, induces in vitro, relax the arterial smooth muscle through a pharmacomechanical excitation-contraction link, which increases according to the time(AU).

Introdução: O cânfora-clorofenol é um derivado clorofenólico comumente utilizado como medicamento intracanal em Endodontia. Relatórios científicos sobre seus efeitos no músculo liso vascular arterial e na regulação do fluxo sanguíneo local são escassos. Objetivo: Determinar o efeito da cânfora-clorofenol na dinâmica contrátil do músculo liso vascular arterial ao longo do tempo. Método: Foi realizada investigação experimental pré-clínica com 14 anéis aórticos obtidos de ratos Wistar. Os anéis foram colocados em banho de órgãos e pré-ativados com norepinefrina, em seguida, a tensão desenvolvida pela musculatura lisa vascular foi registrada após a adição de cânfora-clorofenol em diferentes intervalos de tempo. Resultados: 51,4 porcento dos músculos lisos vasculares estavam relaxados pela ação do cânfora-clorofenol. A maior diminuição do tônus vascular ocorreu entre o terceiro e o quinto minuto após a adição do medicamento. Os testes de Wilcoxon das faixas com sinais mostraram diferenças significativas entre a tensão base inicial e a registrada nos diferentes intervalos de tempo estudados. Conclusões: O cânfora-clorofenol induz, in vitro, relaxamento da musculatura lisa arterial por meio de um acoplamento excitação-contração do tipo farmacomecânico, que aumenta em função do tempo(AU).

Effects of NO/cGMP inhibitors in a rat model of anaphylactoid shock

Anaphylactic shock can be defined as an acute syndrome, and it is the most severe clinical manifestation of allergic diseases. Anaphylactoid reactions are similar to anaphylactic events but differ in the pathophysiological mechanism. Nitric oxide (NO) inhibitors during anaphylaxis suggest that NO might decrease the signs and symptoms of anaphylaxis but exacerbate associated vasodilation. Therefore, blocking the effects of NO on vascular smooth muscle by inhibiting the guanylate cyclase (GC) would be a reasonable strategy. This study aimed to investigate the effects of NO/cGMP pathway inhibitors methylene blue (MB), Nω-nitro-L-arginine methyl ester hydrochloride (L-NAME), and indigo carmine (IC) in shock induced by compound 48/80 (C48/80) in rats. The effect was assessed by invasive blood pressure measurement. Shock was initiated by C48/80 intravenous bolus injection 5 min before (prophylactic) or after (treatment) the administration of the inhibitors MB (3 mg/kg), L-NAME (1 mg/kg), and IC (3 mg/kg). Of the groups that received drugs as prophylaxis for shock, only the IC group did not present the final systolic blood pressure (SBP) better than the C48/80 group. Regarding shock treatment with the drugs tested, all groups had the final SBP similar to the C48/80group. Altogether, our results suggested that inhibition of GC and NO synthase in NO production pathway was not sufficient to revert hypotension or significantly improve survival.

Effects of in vitro amitriptyline, fluoxetine, tranylcypromine and venlafaxine on saphenous vein grafts

Abstract Objective: In this study, we aimed to examine the effects of amitriptyline, fluoxetine, tranylcypromine and venlafaxine on saphenous vein grafts in coronary artery bypass graft surgeries. Methods: 59 patients (40 males and 19 females; mean age 65.1 years, distribution: 45-84 years) who had coronary artery bypass graft surgery between February 2014 and May 2016 were included in the study. After the saphenous vein grafts with intact and denuded endothelium were precontracted with 3×10-6M phenylephrine, amitriptyline, fluoxetine and tranylcypromine were cumulatively added to isolated organ baths in the range of 10-11-3x10-5M, while venlafaxine was added in the range of 10-9-3×10-5M. Then, the antidepressant-induced relaxation responses were recorded isometrically. Results: While the relaxation response of amitriptyline at -6.42 (Log M) was 74.6%, the response at -6.32 (Log M) was 75.5%. While the relaxation response at -6.46 (Log M) of fluoxetine was 68.02%, the response at -6.02 (Log M) was 72.12%. While the relaxation response of tranylcypromine at -7.53 (Log M) was 61.13%, the response at -7.23 (Log M) was 65.53%. While the relaxation response of venlafaxine at -6.21 (Log M) was 29.98%, the response at -5.90 (Log M) was 32.96%. Conclusion: The maximum relaxation at minimum and maximum therapeutic concentrations was obtained with amitriptyline, fluoxetine and tranylcypromine, and the minimum relaxation was obtained with venlafaxine. The relaxation responses were independent of the endothelium.

Airways and vascular smooth muscles relaxant activities of Gaultheria trichophylla

The aim of this experimental work was to explore the potential pharmacological activities of Gaultheria trichophylla Royle in hyperactive respiratory and vascular conditions. Gaultheria trichophylla was extracted with solvents, phytochemical detection tests were performed, and rabbit trachea and aorta strips were used to evaluate its effects on airways and vascular smooth muscles. Qualitative phytochemical tests showed the presence of flavonoids, alkaloids, anthraquinones, saponins, terpenoids, and condensed tannins. The methanol extract caused inhibition [EC[50] values of 3.12 mg/mL] of carbachol [1 micro M] and partial relaxation of K[+][80 mM] caused contractions in tracheal strips. The chloroform extract was comparatively more potent against carbachol than K[+] induced contraction with EC[50] values of 0.64 and 2.26 mg/mL, respectively. However, the n-hexane extract showed more potency against K[+] than cabachol induced contractions, as in case with verapamil, with EC[5]0 values of 0.61 and 6.58 mg/mL, respectively. In isolated prepared trachea, the extracts displaced the carbachol concentration response curves and maximum response was suppressed. In rabbit aorta preparations, methanol and n-hexane extracts partially relaxed phenylephrine [1 micro M] and K[+] induced vasoconstrictions. However, the chloroform extract inhibited phenylephrine induced contractions and exhibited a vasoconstrictor effect at lower concentrations and a relaxant effect at higher concentrations against K[+] precontractions. The data indicates that, in addition to others, the extracts of G .trichophylla possess verapamil like Ca[++] channel blocking components which explain the possible role of this plant in respiratory and vascular conditions

A spleen tyrosine kinase inhibitor attenuates the proliferation and migration of vascular smooth muscle cells

BACKGROUND: Pathologic vascular smooth muscle cell (VSMC) proliferation and migration after vascular injury promotes the development of occlusive vascular disease. Therefore, an effective chemical agent to suppress aberrant proliferation and migration of VSMCs can be a potential therapeutic modality for occlusive vascular disease such as atherosclerosis and restenosis. To find an anti-proliferative chemical agent for VSMCs, we screened an in-house small molecule library, and the selected small molecule was further validated for its anti-proliferative effect on VSMCs using multiple approaches, such as cell proliferation assays, wound healing assays, transwell migration assays, and ex vivo aortic ring assay. RESULTS: Among 43 initially screened small molecule inhibitors of kinases that have no known anti-proliferative effect on VSMCs, a spleen tyrosine kinase (Syk) inhibitor (BAY61-3606) showed significant anti-proliferative effect on VSMCs. Further experiments indicated that BAY61 attenuated the VSMC proliferation in both concentration- and time-dependent manner, and it also significantly suppressed the migration of VSMCs as assessed by both wound healing assays and transwell assays. Additionally, BAY61 suppressed the sprouting of VSMCs from endothelium-removed aortic rings. CONCLUSION: The present study identified a Syk kinase inhibitor as a potent VSMC proliferation and migration inhibitor and warrants further studies to elucidate its underlying molecular mechanisms, such as its primary target, and to validate its in vivo efficacy as a therapeutic agent for restenosis and atherosclerosis.

Evaluation of the effects of intra-arterial sugammadex and dexmedetomidine: an experimental study / Avaliação dos efeitos de sugamadex e dexmedetomidina intra-arterial: estudo experimental

Abstract Background: Intra-arterial injection of medications may cause acute and severe ischemia and result in morbidity and mortality. There is no information in the literature evaluating the arterial endothelial effects of sugammadex and dexmedetomidine. The hypothesis of our study is that sugammadex and dexmedetomidine will cause histological changes in arterial endothelial structure when administered intra-arterially. Methods: Rabbits were randomly divided into 4 groups. Group Control (n = 7); no intervention performed. Group Catheter (n = 7); a cannula inserted in the central artery of the ear, no medication was administered. Group Sugammadex (n = 7); rabbits were given 4 mg/kg sugammadex into the central artery of the ear, and Group Dexmedetomidine (n = 7); rabbits were given 1 µg/kg dexmedetomidine into the central artery of the ear. After 72 h, the ears were amputated and histologically investigated. Results: There was no significant difference found between the control and catheter groups in histological scores. The endothelial damage, elastic membrane and elastic fiber damage, smooth muscle hypertrophy and connective tissue increase scores in the dexmedetomidine and sugammadex groups were significantly higher than both the control and the catheter groups (p < 0.05). There was no significant difference found between the dexmedetomidine and sugammadex groups in histological scores. Conclusion: Administration of sugammadex and dexmedetomidine to rabbits by intra-arterial routes caused histological arterial damage. To understand the histological changes caused by sugammadex and dexmedetomidine more clearly, more experimental research is needed.

Resumo Justificativa: A injeção intra-arterial de medicamentos pode causar isquemia aguda e grave e resultar em morbidade e mortalidade. Não há informações na literatura que avaliem os efeitos endoteliais arteriais de sugamadex e dexmedetomidina. A hipótese de nosso estudo foi que dexmedetomidina e sugamadex causariam alterações histológicas na estrutura endotelial arterial quando administrados por via intra-arterial. Método: Os coelhos foram randomicamente divididos em quatro grupos: grupo controle (n = 7), sem intervenção; grupo cateter (n = 7), uma cânula foi inserida na artéria central da orelha e medicamentos não foram administrados; grupo sugamadex (n = 7), receberam 4 mg/kg de sugamadex na artéria central da orelha; grupo dexmedetomidina (n = 7), receberam 1 µg/kg de dexmedetomidina na artéria central da orelha. Após 72 horas, as orelhas foram amputadas e histologicamente examinadas. Resultados: Não houve diferença significativa entre os grupos controle e cateter referente aos escores histológicos. Os escores do dano causado ao endotélio e à membrana e fibra elásticas, da hipertrofia do músculo liso e do aumento do tecido conjuntivo foram significativamente maiores nos grupos dexmedetomidina e sugamadex do que nos grupos controle e cateter (p < 0,05). Não houve diferença significativa entre os grupos dexmedetomidina e sugamadex nos escores histológicos. Conclusão: A administração de sugamadex e dexmedetomidina a coelhos por via intra-arterial causou danos arteriais histológicos. Para entender as alterações histológicas causadas por sugamadex e dexmedetomidina com mais clareza, estudos experimentais adicionais são necessários.

Jabuticaba-Induced Endothelium-Independent Vasodilating Effect on Isolated Arteries / Efeito Vasodilatador Independente do Endotélio Induzido pela Jabuticaba (M. cauliflora) em Artérias Isoladas

Abstract Background: Despite the important biological effects of jabuticaba, its actions on the cardiovascular system have not been clarified. Objectives: To determine the effects of jabuticaba hydroalcoholic extract (JHE) on vascular smooth muscle (VSM) of isolated arteries. Methods: Endothelium-denuded aortic rings of rats were mounted in isolated organ bath to record isometric tension. The relaxant effect of JHE and the influence of K+ channels and Ca2+ intra- and extracellular sources on JHE-stimulated response were assessed. Results: Arteries pre-contracted with phenylephrine showed concentration-dependent relaxation (0.380 to 1.92 mg/mL). Treatment with K+ channel blockers (tetraethyl-ammonium, glibenclamide, 4-aminopyridine) hindered relaxation due to JHE. In addition, phenylephrine-stimulated contraction was hindered by previous treatment with JHE. Inhibition of sarcoplasmic reticulum Ca2+ ATPase did not change relaxation due to JHE. In addition, JHE inhibited the contraction caused by Ca2+ influx stimulated by phenylephrine and KCl (75 mM). Conclusion: JHE induces endothelium-independent vasodilation. Activation of K+ channels and inhibition of Ca2+ influx through the membrane are involved in the JHE relaxant effect.

Resumo Fundamentos: Embora a jabuticaba apresente importantes efeitos biológicos, suas ações sobre o sistema cardiovascular ainda não foram esclarecidas. Objetivos: Determinar os efeitos do extrato de jabuticaba (EHJ) sobre o músculo liso vascular (MLV) em artérias isoladas. Métodos: Aortas (sem endotélio) de ratos foram montadas em banho de órgãos isolados para registro de tensão isométrica. Foram verificados o efeito relaxante, a influência dos canais de K+ e das fontes de Ca2+ intra- e extracelular sob a resposta estimulada pelo EHJ. Resultados: Artérias pré-contraídas com fenilefrina apresentaram relaxamento concentração-dependente (0,380 a 1,92 mg/mL). O tratamento com bloqueadores de canais de K+ (tetraetilamônio, glibenclamida, 4-aminopiridina) prejudicaram o relaxamento pelo EHJ. A contração estimulada com fenilefrina também foi prejudicada pelo tratamento prévio com EHJ. A inibição da Ca2+ATPase do reticulo sarcoplasmático não alterou o relaxamento pelo EHJ. Além disso, o EHJ inibiu a contração causada pelo influxo de Ca2+ estimulado por fenilefrina e KCl (75 mM). Conclusão: O EHJ induz vasodilatação independente do endotélio. Ativação dos canais de K+ e inibição do influxo de Ca2+ através da membrana estão envolvidas no efeito relaxante do EHJ.

The Labdane Ent-3-Acetoxy-Labda-8(17), 13-Dien-15-Oic Decreases Blood Pressure In Hypertensive Rats / O Labdano Ácido Ent-3-Acetóxi-Labda-8(17), 13-Dieno-15-Óico Reduz Pressão Arterial Em Ratos Hipertensos

Abstract Background: Labdane-type diterpenes induce lower blood pressure via relaxation of vascular smooth muscle; however, there are no studies describing the effects of labdanes in hypertensive rats. Objective: The present study was designed to investigate the cardiovascular actions of the labdane-type diterpene ent-3-acetoxy-labda-8(17), 13-dien-15-oic acid (labda-15-oic acid) in two-kidney 1 clip (2K-1C) renal hypertension. Methods: Vascular reactivity experiments were performed in aortic rings isolated from 2K-1C and normotensive (2K) male Wistar rats. Nitrate/nitrite (NOx) measurement was performed in aortas by colorimetric assay. Blood pressure measurements were performed in conscious rats. Results: Labda-15-oic acid (0.1-300 µmol/l) and forskolin (0.1 nmol/l - 1 µmol/l) relaxed endothelium-intact and endothelium-denuded aortas from both 2K-1C and 2K rats. Labda-15-oic acid was more effective at inducing relaxation in endothelium-intact aortas from 2K pre-contracted with phenylephrine when compared to the endothelium-denuded ones. Forskolin was more potent than labda-15-oic acid at inducing vascular relaxation in arteries from both 2K and 2K-1C rats. Labda-15-oic acid-induced increase in NOx levels was lower in arteries from 2K-1C rats when compared to 2K rats. Intravenous administration of labda-15-oic acid (0.3-3 mg/kg) or forskolin (0.1-1 mg/kg) induced hypotension in conscious 2K-1C and 2K rats. Conclusion: The present findings show that labda-15-oic acid induces vascular relaxation and hypotension in hypertensive rats.

Resumo Fundamento: Diterpenos do tipo labdano induzem uma queda da pressão arterial por meio do relaxamento do músculo liso vascular; todavia, não há estudos que descrevam os efeitos de labdanos em ratos hipertensos. Objetivo: O presente estudo foi desenvolvido para investigar as ações cardiovasculares do labdano ácido ent-3-acetóxi-labda-8(17),13-dieno-15-óico (labda-15-óico) na hipertensão renal dois rins-1 clipe (2R-1C). Métodos: Foram feitos experimentos de reatividade vascular em anéis aórticos isolados de ratos machos 2R-1C e normotensos (2R). A medição de Nitrato/Nitrito (NOx) foi feita nas aortas por meio de ensaio colorimétrico. As medidas de pressão arterial foram feitas em ratos conscientes. Resultados: O ácido labda-15-óico (0,1 - 300 µmol/l) e a forscolina (0,1 nmol/l - 1 µmol/l) relaxaram as aortas com endotélio intacto e as aortas sem endotélio dos ratos 2R-1C e 2R. O labda-15-óico mostrou-se mais eficaz na indução do relaxamento em aortas com endotélio intacto de 2R pré-contraídas com fenilefrina em comparação àquelas sem endotélio. A forscolina mostrou-se mais potente do que o ácido labda-15-óico na indução do relaxamento vascular nas artérias tanto de ratos 2R-1C quanto de ratos 2R. O aumento dos níveis de NOx induzido pelo ácido labda-15-óico foi menor nas artérias de ratos 2R-1C em comparação a ratos 2R. A administração intravenosa de ácido labda-15-óico (0,3-3 mg/kg) ou forscolina (0,1-1 mg/kg) induziu hipertensão em ratos 2R-1C e 2R conscientes. Conclusão: Os presentes resultados mostram que o labda-15-óico induz relaxamento vascular e hipotensão em ratos hipertensos.

Effects of One Resistance Exercise Session on Vascular Smooth Muscle of Hypertensive Rats / Efeitos de uma Sessão de Exercício Resistido sobre o Músculo Liso Vascular de Ratos Hipertensos

AbstractBackground:Hypertension is a public health problem and increases the incidence of cardiovascular diseases.Objective:To evaluate the effects of a resistance exercise session on the contractile and relaxing mechanisms of vascular smooth muscle in mesenteric arteries of NG-nitro L-arginine methyl ester (L-NAME)-induced hypertensive rats.Methods:Wistar rats were divided into three groups: control (C), hypertensive (H), and exercised hypertensive (EH). Hypertension was induced by administration of 20 mg/kg of L-NAME for 7 days prior to experimental protocols. The resistance exercise protocol consisted of 10 sets of 10 repetitions and intensity of 40% of one repetition maximum. The reactivity of vascular smooth muscle was evaluated by concentration‑response curves to phenylephrine (PHEN), potassium chloride (KCl) and sodium nitroprusside (SNP).Results:Rats treated with L-NAME showed an increase (p < 0.001) in systolic blood pressure (SBP), diastolic blood pressure (DBP) and mean arterial pressure (MAP) compared to the initial period of induction. No difference in PHEN sensitivity was observed between groups H and EH. Acute resistance exercise reduced (p < 0.001) the contractile response induced by KCl at concentrations of 40 and 60 mM in group EH. Greater (p < 0.01) smooth muscle sensitivity to NPS was observed in group EH as compared to group H.Conclusion:One resistance exercise session reduces the contractile response induced by KCl in addition to increasing the sensitivity of smooth muscle to NO in mesenteric arteries of hypertensive rats.

ResumoFundamento:A hipertensão é um problema de saúde pública e faz aumentar a incidência das doenças cardiovasculares.Objetivo:Avaliar os efeitos de uma sessão de exercício resistido sobre os mecanismos contráteis e relaxantes do músculo liso vascular em artéria mesentérica de ratos hipertensos induzidos por L-NAME.Métodos:Ratos Wistar foram divididos em três grupos: Controle (C), Hipertenso (H) e Hipertenso Exercitado (HE). A hipertensão foi induzida pela administração de 20 mg/kg de NG-nitro L-arginina metil éster (L-NAME) durante sete dias antes dos protocolos experimentais. O protocolo de exercício resistido consistiu em dez séries de dez repetições e intensidade de 40% de uma repetição máxima. A reatividade do músculo liso vascular foi avaliada através de curvas concentração-resposta para a fenilefrina (FEN), cloreto de potássio (KCl) e nitroprussiato de sódio (NPS).Resultados:Os ratos tratados com L-NAME apresentaram aumento (p < 0,001) da Pressão Arterial Sistólica (PAS), da Pressão Arterial Diastólica (PAD) e da Pressão Arterial Média (PAM) quando comparados ao período inicial da indução. Não foi observada diferença na sensibilidade da FEN entre os grupos H e HE. O exercício resistido agudo reduziu (p < 0,001) a resposta contrátil induzida pelo KCl nas concentrações de 40 e 60 mM do grupo HE quando comparado ao grupo H. Foi observado maior (p < 0,01) sensibilidade do músculo liso ao NPS no grupo HE quando comparado ao grupo H.Conclusão:Uma sessão de exercício resistido reduz as respostas contráteis induzidas pelo KCl, além de aumentar a sensibilidade do músculo liso ao NO em artéria mesentérica de ratos hipertensos.

Chikungunya: un reto para los servicios de salud de la República Dominicana / Chikungunya: a challenge for the Dominican Republic's health services

Desde diciembre de 2013, la Región de las Américas se enfrenta por primera vez a una epidemia de chikungunya. Los casos iniciales se registraron en el Caribe francés y, debido al comercio y la movilización de personas, esta epidemia no tardó en llegar a la República Dominicana, cuya población es de 10 millones de habitantes y comparte con Haití la isla La Española. En este artículo se difunde información extraída de diversos artículos y documentos oficiales sobre el virus, la infección y la epidemia de chikungunya, que han sido de gran ayuda para orientar la respuesta en la República Dominicana y pueden ser útiles para mejorar tanto el conocimiento como las actuaciones frente a la epidemia de los trabajadores del sector salud de la Región. Se destaca la importancia que revisten las investigaciones realizadas en países y territorios afectados del océano Índico, como la isla de Reunión, durante la epidemia declarada entre 2005 y 2007, cuando se registró una tasa de ataque mayor de 30%, se identificaron los grupos de riesgo, las formas graves y atípicas de la infección, la transmisión vertical del virus, las formas crónicas, que pueden provocar dolores recurrentes durante tres años, y las defunciones directa o indirectamente relacionadas con el virus chikungunya. Por su alta tasa de ataque, el virus chikungunya se convierte en un reto sin precedentes para los ministerios de salud, que exige una adecuada organización de los servicios de salud, la priorización de la atención a los grupos de riesgo y a los pacientes con formas graves de la enfermedad, así como una adecuada comunicación social y respuesta intersectorial.

The Region of the Americas has been affected since December 2013 by a chikungunya epidemic for the first time. Although the first cases were recorded in the French Caribbean, the epidemic quickly spread to the Dominican Republic due to trade and people movements. The Dominican Republic, which shares the island of Hispaniola with Haiti, has a population of 10 million. This article contains information from a range of different publications and official documents about the chikungunya virus infection and epidemic. These papers were extremely helpful for guiding the response to the epidemic in the Dominican Republic and may also be useful for enhancing knowledge of the virus and responses among health workers elsewhere in the region. Particular attention is drawn to the important research undertaken in countries and territories affected by the epidemic in the Indian Ocean area. This is the case, for example, of the island of La Réunion, where the epidemic had an attack rate of more than 30% between 2005 and 2007. Researchers were able to identify risk groups, severe and atypical forms of the infection, cases of vertical transmission, chronic disease causing recurrent pain over three years, and directly- or indirectly-related deaths from the virus. Given its high attack rate, the chikungunya virus has emerged as an exceptional challenge for health ministries and calls for appropriate organized responses from the health services, prioritization of care for risk groups and patients exhibiting severe forms of the disease, and effective social communication and intersectoral actions.

Vascular O-GlcNAcylation augments reactivity to constrictor stimuli by prolonging phosphorylated levels of the myosin light chain

O-GlcNAcylation is a modification that alters the function of numerous proteins. We hypothesized that augmented O-GlcNAcylation levels enhance myosin light chain kinase (MLCK) and reduce myosin light chain phosphatase (MLCP) activity, leading to increased vascular contractile responsiveness. The vascular responses were measured by isometric force displacement. Thoracic aorta and vascular smooth muscle cells (VSMCs) from rats were incubated with vehicle or with PugNAc, which increases O-GlcNAcylation. In addition, we determined whether proteins that play an important role in the regulation of MLCK and MLCP activity are directly affected by O-GlcNAcylation. PugNAc enhanced phenylephrine (PE) responses in rat aortas (maximal effect, 14.2±2 vs 7.9±1 mN for vehicle, n=7). Treatment with an MLCP inhibitor (calyculin A) augmented vascular responses to PE (13.4±2 mN) and abolished the differences in PE-response between the groups. The effect of PugNAc was not observed when vessels were preincubated with ML-9, an MLCK inhibitor (7.3±2 vs 7.5±2 mN for vehicle, n=5). Furthermore, our data showed that differences in the PE-induced contractile response between the groups were abolished by the activator of AMP-activated protein kinase (AICAR; 6.1±2 vs 7.4±2 mN for vehicle, n=5). PugNAc increased phosphorylation of myosin phosphatase target subunit 1 (MYPT-1) and protein kinase C-potentiated inhibitor protein of 17 kDa (CPI-17), which are involved in RhoA/Rho-kinase-mediated inhibition of myosin phosphatase activity. PugNAc incubation produced a time-dependent increase in vascular phosphorylation of myosin light chain and decreased phosphorylation levels of AMP-activated protein kinase, which decreased the affinity of MLCK for Ca2+/calmodulin. Our data suggest that proteins that play an important role in the regulation of MLCK and MLCP activity are directly affected by O-GlcNAcylation, favoring vascular contraction.

Endothelium-dependent effect of sesame seed feeding on vascular reactivity of streptozotocin-diabetic rats: underlying mechanisms

Cardiovascular disorders continue to constitute major causes of morbidity and mortality in diabetic patients. In this study, the effect of chronic administration of sesame [Sesamum indicum L] seed feeding was studied on aortic reactivity of streptozotocin [STZ]-diabetic rats. Male diabetic rats received sesame seed-mixed food at weight ratios of 3% and 6% for 7 weeks, one week after diabetes induction. Contractile responses to KCl and phenylephrine [PE] and relaxation response to acetylcholine [ACh] and sodium nitroprusside [SNP] were obtained from aortic rings. Maximum contractile response of endothelium-intact rings to PE was significantly lower in sesame-treated diabetic rats [at a ratio of 6%] relative to untreated diabetics and endothelium removal abolished this difference. Endothelium-dependent relaxation to ACh was also significantly higher in sesame-treated diabetic rats [at a ratio of 6%] as compared to diabetic rats and pretreatment of rings with nitric oxide synthase inhibitor, N[G]-nitro-l-arginine methyl ester [L-NAME] significantly attenuated the observed response. Two-month diabetes also resulted in an elevation of malondialdehyde [MDA] and decreased superoxide dismutase [SOD] activity and sesame treatment significantly reversed the increased MDA content and restored activity of SOD. We thus conclude that chronic treatment of diabetic rats with sesame seed could in a dose- manner prevent some abnormal changes in vascular reactivity through nitric oxide and via attenuation of oxidative stress in aortic tissue and endothelium integrity is necessary for this beneficial effect

C-Jun NH2-Terminal Kinase Contributes to Dexmedetomidine-Induced Contraction in Isolated Rat Aortic Smooth Muscle

PURPOSE: Dexmedetomidine, a full agonist of alpha2B-adrenoceptors, is used for analgesia and sedation in the intensive care units. Dexmedetomidine produces an initial transient hypertension due to the activation of post-junctional alpha2B-adrenoceptors on vascular smooth muscle cells (SMCs). The aims of this in vitro study were to identify mitogen-activated protein kinase (MAPK) isoforms that are primarily involved in full, alpha2B-adrenoceptor agonist, dexmedetomidine-induced contraction of isolated rat aortic SMCs. MATERIALS AND METHODS: Rat thoracic aortic rings without endothelium were isolated and suspended for isometric tension recording. Cumulative dexmedetomidine (10(-9) to 10(-6) M) dose-response curves were generated in the presence or absence of extracellular signal-regulated kinase (ERK) inhibitor PD 98059, p38 MAPK inhibitor SB 203580, c-Jun NH2-terminal kinase (JNK) inhibitor SP 600125, L-type calcium channel blocker (verapamil and nifedipine), and alpha2-adrenoceptor inhibitor atipamezole. Dexmedetomidine-induced phosphorylation of ERK, JNK, and p38 MAPK in rat aortic SMCs was detected using Western blotting. RESULTS: SP 600125 (10(-6) to 10(-5) M) attenuated dexmedetomidine-evoked contraction in a concentration-dependent manner, whereas PD 98059 had no effect on dexmedetomidine-induced contraction. SB 203580 (10(-5) M) attenuated dexmedetomidine-induced contraction. Dexmedetomidine-evoked contractions were both abolished by atipamezole and attenuated by verapamil and nifedipine. Dexmedetomidine induced phosphorylation of JNK and p38 MAPK in rat aortic SMCs, but did not induce phosphorylation of ERK. CONCLUSION: Dexmedetomidine-induced contraction involves a JNK- and p38 MAPK-mediated pathway downstream of alpha2-adrenoceptor stimulation in rat aortic SMCs. In addition, dexmedetomidine-induced contractions are primarily dependent on calcium influx via L-type calcium channels.

Cardiovascular activity of the n-butanol fraction of the methanol extract of Loranthus ferrugineus Roxb

We investigated the vascular responses and the blood pressure reducing effects of different fractions obtained from the methanol extract of Loranthus ferrugineus Roxb. (F. Loranthaceae). By means of solvent-solvent extraction, L. ferrugineus methanol extract (LFME) was successively fractionated with chloroform, ethyl acetate and n-butanol. The ability of these LFME fractions to relax vascular smooth muscle against phenylephrine (PE)- and KCl-induced contractions in isolated rat aortic rings was determined. In another set of experiments, LFME fractions were tested for blood pressure lowering activity in anesthetized adult male Sprague-Dawley rats (250-300 g, 14-18 weeks). The n-butanol fraction of LFME (NBF-LFME) produced a significant concentration-dependent inhibition of PE- and KCl-induced aortic ring contractions compared to other fractions. Moreover, NBF-LFME had a significantly higher relaxant effect against PE- than against high K+-induced contractions. In anesthetized Sprague-Dawley rats, NBF-LFME significantly lowered blood pressure in a dose-dependent manner and with a relatively longer duration of action compared to the other fractions. HPLC, UV and IR spectra suggested the presence of terpenoid constituents in both LFME and NBF-LFME. Accordingly, we conclude that NBF-LFME is the most potent fraction producing a concentration-dependent relaxation in vascular smooth muscle in vitro and a dose-dependent blood pressure lowering activity in vivo. The cardiovascular effects of NBF-LFME are most likely attributable to its terpenoid content.

Cordyceps sinensis extract suppresses hypoxia-induced proliferation of rat pulmonary artery smooth muscle cells

To investigate the effects of a Chinese herb Cordyceps sinensis [C. sinensis] extract on hypoxia-induced proliferation and the underlying mechanisms involved. This prospective study was carried out at the Central Laboratory of Yichang Central People's Hospital, Yichang, China from March 2008 to April 2010. The C. sinensis was extracted from the Chinese herb C. sinensis using aqueous alcohol extraction techniques. Forty healthy adult male Sprague Dawley rats were used in the study. The proliferation of pulmonary artery smooth muscle cells [PASMCs] was measured using 3-[4,5-dimethylthiazol-2-Yl]-2,5-diphenyltetrazolium bromide [MTT] assay, and cell viability was determined by trypan blue exclusion. Cell cycles were analyzed using FACSort flow cytometric analysis. The expression of proliferating cell nuclear antigen [PCNA], c-jun, and c-fos in rat PASMCs was determined by immunohistochemistry. We found an increased proliferation of PASMCs and increased expression of transcription factors, c-jun and c-fos in PASMCs cultured under hypoxic conditions. The C. sinensis extract significantly inhibited hypoxia-induced cell proliferation in a dose-dependent manner. In addition, C. sinensis extract also significantly inhibited the expression of PCNA, c-jun, and c-fos in these PASMCs. Our results indicated that C sinensis extract inhibits hypoxia-induced proliferation of rat PASMCs, probably by suppressing the expression of PCNA, c-fos, c-jun, and decreasing the percentage of cells in synthesis phase, second gap phase, and mitotic phase in cell cycle [S+G[2]/M] phase. Our results therefore, provided novel evidence that C. sinensis extract may be used as a therapeutic reagent in the treatment of hypoxic pulmonary hypertension

New nitric oxide donors based on ruthenium complexes

Nitric oxide (NO) donors produce NO-related activity when applied to biological systems. Among its diverse functions, NO has been implicated in vascular smooth muscle relaxation. Despite the great importance of NO in biological systems, its pharmacological and physiological studies have been limited due to its high reactivity and short half-life. In this review we will focus on our recent investigations of nitrosyl ruthenium complexes as NO-delivery agents and their effects on vascular smooth muscle cell relaxation. The high affinity of ruthenium for NO is a marked feature of its chemistry. The main signaling pathway responsible for the vascular relaxation induced by NO involves the activation of soluble guanylyl-cyclase, with subsequent accumulation of cGMP and activation of cGMP-dependent protein kinase. This in turn can activate several proteins such as K+ channels as well as induce vasodilatation by a decrease in cytosolic Ca2+. Oxidative stress and associated oxidative damage are mediators of vascular damage in several cardiovascular diseases, including hypertension. The increased production of the superoxide anion (O2-) by the vascular wall has been observed in different animal models of hypertension. Vascular relaxation to the endogenous NO-related response or to NO released from NO deliverers is impaired in vessels from renal hypertensive (2K-1C) rats. A growing amount of evidence supports the possibility that increased NO inactivation by excess O2- may account for the decreased NO bioavailability and vascular dysfunction in hypertension.

Angiotensin II-induced aortic ring constriction is mediated by phosphatidylinositol 3-kinase/L-type calcium channel signaling pathway

Angiotensin II (AngII) is a crucial hormone that affects vasoconstriction and exerts hypertrophic effects on vascular smooth muscle cells. Here, we showed that phosphatidylinositol 3-kinase-dependent calcium mobilization plays pivotal roles in AngII-induced vascular constriction. Stimulation of rat aortic vascular smooth muscle cell (RASMC)-embedded collagen gel with AngII rapidly induced contraction. AngII-induced collagen gel contraction was blocked by pretreatment with a phosphatidylinositol 3-kinase (PI3K) inhibitor (LY294002) whereas ERK inhibitor (PD98059) was not effective. AngII-induced collagen gel contraction was significantly blocked by extracellular calcium depletion by EGTA or by nifedipine which is an L-type calcium channel blocker. In addition, AngII-induced calcium mobilization was also blocked by nifedipine and EGTA, whereas intracellular calcium store-depletion by thapsigargin was not effective. Finally, pretreatment of rat aortic ring with LY294002 and nifedipine significantly reduced AngII-induced constriction. Given these results, we suggest that PI3K-dependent activation of L-type calcium channels might be involved in AngII-induced vascular constriction.

The pathological observation of acute intoxication by Alangium Chinese in mice / 法医学杂志

OBJECTIVE@#To investigate the pathological change of mice organ intoxicated by Alangium Chinese and its poisoning mechanism.@*METHODS@#Mice were intoxicated by gavage with extract of Alangium Chinese. Then the histopathologic examination was made for evaluating the pathological changes in the organs of the poisoned mice by HE staining.@*RESULTS@#The main pathological changes included alveolar hemorrhage, pulmonary interstitial hemorrhage, sinus hepaticus expansion and congestion, hepatocyte edema, subarachnoid hemorrhage, congestion and hemorrhage of other organs.@*CONCLUSION@#The main target organs or tissue of Alangium Chinese are the lungs, liver and vascular smooth muscle. There is correlation between the toxic effect and the dosage.