The relationship between serum ischemia-modified albumin levels and uterine artery doppler parameters in patients with primary dysmenorrhea

Abstract Objective Primary dysmenorrhea occurs due to abnormal levels of prostanoids, uterine contractions, and uterine blood flow. However, the reasons for pain in primary dysmenorrhea have not yet been clarified. We examined the blood flow alterations in patients with primary dysmenorrhea and determined the relationship between ischemia-modified albumin (IMA) levels, as an ischemia indicator, and primary dysmenorrhea. Methods In the present study, 37 patients who had primary dysmenorrhea and were in their luteal and menstrual phase of their menstrual cycles were included. Thirty individuals who had similar demographic characteristics, who were between 18 and 30 years old and did not have gynecologic disease were included as control individuals. Their uterine artery Doppler indices and serum IMA levels were measured. Results Menstrual phase plasma IMA levels were significantly higher than luteal phase IMA levels, both in the patient and in the control groups (p < 0.001). Although the menstrual phase IMA levels of patients were significantly higher than those of controls, luteal phase IMA levels were not significantly different between the two groups. Menstrual uterine artery pulsatility index (PI) and resistance index (RI) of primary dysmenorrhea patients were significantly different when compared with luteal uterine artery PI and RI levels. There was a positive correlation between menstrual phase IMA and uterine artery PI and RI in the primary dysmenorrhea. Conclusion Ischemia plays an important role in the etiology of the pain, which is frequently observed in patients with primary dysmenorrhea. Ischemia-modified albumin levels are considered as an efficient marker to determine the severity of pain and to indicate ischemia in primary dysmenorrhea.

Influences on the Functional Behavior of Great Arteries during Orthostasis / Gravidade Influencia o Comportamento Funcional das Grandes Artérias Durante a Ortostase

Abstract Background: Arterial compliance reduction has been associated with aging and hypertension in supine position. However, the dynamic effects of orthostatism on aortic distensibility has not been defined. Objective: We sought to determine the orthostatic influence and the interference of age, blood pressure (BP) and heart rate (HR) on the great arteries during gravitational stress. Methods: Ninety-three healthy volunteers (age 42 ± 16 years). Carotid-femoral pulse wave velocity (PWV) assumed as aortic stiffness was assessed in supine position (basal phase), during tilt test (TT) (orthostatic phase) and after return to supine position (recovery phase). Simultaneously with PWV acquisition, measures of BP and HR rate were recorded. Results: PWV during TT increased significantly compared to the basal and recovery phases (11.7 ± 2.5 m/s vs. 10.1 ± 2.3 m/s and 9.5 ± 2.0 m/s). Systolic BP (r = 0.55, r = 0.46 and r = 0.39) and age (r = 0.59, r = 0.63 and r = 0.39) correlated with PWV in all phases. The significance level for all tests was established as α = 0.05. Conclusion: We conclude that there is a permanent increase in PWV during orthostatic position that was returned to basal level at the recovery phase. This dynamic pattern of PWV response, during postural changes, can be explained by an increase in hydrostatic pressure at the level of abdominal aorta which with smaller radius and an increased elastic modulus, propagates the pulse in a faster way. Considering that it could increase central pulse reflection during the orthostatic position, we speculate that this mechanism may play a role in the overall adaptation of humans to gravitational stress.

Resumo Fundamento: A redução da complacência arterial tem sido associada ao envelhecimento e à hipertensão na postura supina. Entretanto, os efeitos dinâmicos do ortostatismo na distensibilidade aórtica não foram definidos. Objetivo: Determinar a influência ortostática e a interferência da idade, pressão arterial (PA) e frequência cardíaca (FC) sobre as grandes artérias durante o estresse gravitacional. Métodos: Noventa e três voluntários saudáveis (idade de 42 ± 16 anos). A velocidade da onda de pulso carotídeo-femoral (VOP), assumida como rigidez aórtica, foi avaliada na posição supina (fase basal) durante o teste de inclinação (TT) (fase ortostática) e após o retorno à posição supina (fase de recuperação). Simultaneamente à aquisição da PWV, registrou-se as medidas de PA e FC. Resultados: A VOP durante o TT aumentou significativamente em comparação com as fases basal e de recuperação (11,7 ± 2,5 m/s vs. 10,1 ± 2,3 m/se 9,5 ± 2,0 m/s). PA sistólica (r = 0,55, r = 0,46 e r = 0,39) e idade (r = 0,59, r = 0,63 e r = 0,39) correlacionaram-se com a VOP em todas as fases. O nível de significância para todos os testes foi estabelecido como = 0,05. Conclusão: Observou-se um aumento permanente da VOP durante a postura ortostática, que retornou ao nível basal na fase de recuperação. Esse padrão dinâmico de resposta da VOP, durante as alterações posturais, pode ser explicado pelo aumento da pressão hidrostática no nível da aorta abdominal que, com raio menor e aumento do módulo de elasticidade, propaga o pulso de maneira mais rápida. Considerando-se que poderia aumentar a reflexão do pulso central durante a posição ortostática, podemos especular que esse mecanismo pode desempenhar um papel na adaptação global do humano ao estresse gravitacional.

Abnormal origin of posterior circumflex humeral artery and subscapular artery: case report and review of the literature / Origem anômala das artérias circunflexa posterior do úmero e subescapular: relato de caso e revisão de literatura

The subscapular, anterior circumflex, and posterior circumflex arteries arise from the third part of the axillary artery. During dissection of the right upper limb of the cadaver of a 70-year-old male, a common trunk was observed arising from the third part of the axillary artery which, after traveling for 0.5 cm, bifurcated into subscapular and posterior circumflex humeral arteries. The common trunk was crossed anteriorly by the radial nerve. The medial nerve was formed by medial and lateral roots on the medial side of the third part of the axillary artery, remaining medial to the brachial artery up to the cubital fossa and then following its usual course thereafter. Awareness of the vascular variations observed in the present case is important when conducting surgical procedures in the axilla, for radiologists interpreting angiographs, and for anatomy-pathologists studying rare findings

As artérias subescapular, circunflexa anterior e circunflexa posterior se originam da terceira parte da artéria axilar. Durante a dissecção de membro superior direito de um cadáver humano com 70 anos de idade, do sexo masculino, um tronco comum foi observado originando-se da terceira parte da artéria axilar, após um percurso de 0,5 cm, bifurcando-se em artéria subescapular e artéria circunflexa posterior do húmero. O tronco comum era cruzado anteriormente pelo nervo radial. O nervo medial era formado por raízes medial e lateral, no lado medial da terceira parte da artéria axilar, permanecendo em posição medial à artéria braquial até a fossa cubital e seguindo seu curso usual a partir de então. Conhecimento das variações vasculares observadas neste caso é importante ao executar procedimentos cirúrgicos na axila, para radiologistas que interpretam radiografias, e também para anatomo-patologistas que estudam achados raros

Role of NO in arterial vascular function of intertidal fish (Girella laevifrons) and marine fish (Isacia conceptionis) / Papel do NO na função vascular arterial de peixes entremarés (Girella laevifrons) e peixes marinhos (Isacia conceptionis)

Abstract Previous studies performed in intertidal fish (Girella laevifrons),as well as marine fish (Isacia conceptionis), showed that acetylcholine (ACh) produced contractions mediated by cyclooxygenases that were dependent on the area and potency of contraction in several arterial vessels. Given that the role of nitric oxide is poorly understood in fish, the objective of our study was to evaluate the role of nitric oxide in branchial afferent (ABA), branchial efferent (ABE), dorsal (DA) and mesenteric (MA) arterial vessels from both Girella laevifrons and Isacia conceptionis. We studied afferent and efferent branchial, dorsal and mesenteric arteries that were dissected from 6 juvenile specimens. Isometric tension studies were done using dose response curves (DRC) for Ach (10–13 to 10–3 M) and blockade with L-NAME (10–5 M), and DRC for sodium nitroprusside (SNP, a donor of NO). L-NAME produced an attenuation of the contractile response in the dorsal, afferent and efferent branchial arteries and a potentiation of the contraction in the MA. SNP caused 70% dilation in the mesenteric artery and 40% in the dorsal artery. Our results suggest that Ach promotes precarious dilatation in MA mediated by NO; data that is supported by the use of sodium nitroprusside. In contrast, in the vessels DA, ABA and EBA our results support that the pathway Ach-NO-relaxation is absent in both species.

Resumo Estudos anteriores, realizados no peixe intertidal (Girellalaevifrons) no peixe marinho (Isacia conceptionis), mostram que a acetilcolina (Ach) provoca contrações mediadas por ciclooxigenases que eram dependentes da área e potencia da contração em vários vasos arteriais. Tendo em conta que o papel do óxido nítrico é mal compreendido em peixes, o objetivo do nosso estudo foi avaliar o papel do óxido nítrico em vasos arteriais de ambos os peixes Girella laevifrons e Isacia conceptionis. Nós estudamos os vasos aferente, branquial (ABA), eferente branquial (ABE), dorsal (DA) e mesentérica (MA), que foram dissecadas de seis espécimes juvenis. Estudos de tensão isométrica foram realizados utilizando as curvas de dose-resposta (DRC) para Ach (10–13 a 10–3M) e bloqueio com L-NAME (10–5 M), e na DRC para o nitroprussiato de sódio (SNP, doador do NO). L- NAME produziu uma atenuação da resposta contrátil nas artérias dorsais, aferentes e eferentes branquial e uma potenciação da contração no MA. SNP causaram 70% da dilatação da artéria mesentérica e 40% na artéria dorsal. Nossos resultados sugerem que Ach promove dilatação precária em MA mediada por NO; dados que é suportada pela utlilização de nitroprussiato de sódio. Em contraste, nos vasos de DA, ABA e EBA nossos resultados suportam que a via de Ach-NO-relaxamento está ausente em ambas as espécies.

Acetylcholine produces contraction mediated by cyclooxigenase pathway in arterial vessels in the marine fish (Isacia conceptionis) / Função vascular nas artérias do peixe marinos Isacia conceptionis

Preliminary studies showed that dorsal artery contraction mediated by acetylcholine (ACh) is blocked with indomethacin in intertidal fish (G. laevifrons). Our objective was to characterize the cholinergic pathway in several artery vessels of the I. conceptionis. Afferent and efferent branchial, dorsal and mesenteric arteries were dissected of 6 juvenile specimens, isometric tension studies were done using doses response curves (DRC) for Ach (10–13 to 10–3 M), and cholinergic pathways were obtained by blocking with atropine or indomethacin. CRC to ACh showed a pattern of high sensitivity only in efferente branchial artery and low sensibility in all vessels. Furthermore, these contractions were blocked in the presence of atropine and indomethacin in all vessels. Our results corroborate previous results observed in intertidal species that contraction induced by acetylcholine is mediated by receptors that activate a cyclooxygenase contraction pathway.

Estudos preliminares mostraram que a contração da artéria dorsal mediada por acetilcolina (ACh) é bloqueada com indometacina em peixes marinhos (G. laevifrons). Nosso objetivo foi caracterizar a via colinérgica em várias artérias de I. conceptionis. Artérias aferentes e eferentes branquiais, dorsais e mesentéricas foram dissecadas de 6 espécimes juvenis. Os estudos de tensão isométrica foram feitos utilizando-se a curva dose - resposta (CDR) para Ach (10–13 a 10–3M), e identificaram-se as vias colinérgicas, bloqueando com atropina e indometacina. CRC para ACh mostrou um padrão de alta sensibilidade na artéria eferentes branquiais e baixa sensibilidade em todos os vasos sanguineos. Essas contrações foram bloqueadas na presença de atropina e indometacina em todas as artérias avaliadas. Nossos resultados confirmam que a contração induzida por acetilcolina é mediada por receptores muscarínicos que ativam ciclo-oxigenase.

The impact of paracentesis flow rate in patients with liver cirrhosis on the development of paracentesis induced circulatory dysfunction

BACKGROUND/AIMS: Ascites is a dreadful complication of liver cirrhosis associated with short survival. Large volume paracentesis (LVP) is used to treat tense or refractory ascites. Paracentesis induced circulatory dysfunction (PICD) develops if no plasma expanders are given with ominous complications. To study the effect of ascites flow rate on PICD development. METHODS: Sixty patients with cirrhosis and tense ascites underwent LVP of 8 L were randomized into 3 equal groups of different flow rate extraction; group I (80 mL/minute), group II (180 mL/minute) and group III (270 mL/minute). Plasma renin activity (PRA) was measured baseline and on day six. PICD was defined as increase in PRA >50% of the pretreatment value. RESULTS: In group I through 3; the mean age was (52.5±9.4 vs. 56.4±8.5 vs. 55.8±7.1 years; P>0.05), mean arterial pressure (81.4±5.6 vs. 81.5±7 vs. 79.5±7.2 mmHg; P>0.05), MELD (17.6±4.1 vs. 15.8±4.1 vs. 14.7±4.5). Baseline PRA was comparable (1,366.0±1244.9 vs. 1,151.3±1,444.8 vs. 951.9±1,088 pg/mL; P>0.05). There was no statistically significant (P>0.05) flow mediated changes (Delta) of creatinine (0.23±0.27 vs. 0.38±0.33 vs. 0.26±0.18 mg/dL), MELD (1.25±5.72 vs. 1.70±2.18 vs. 1.45±2.21) or PRA (450.93±614.10 vs. 394.61±954.64 vs. 629.51±1,116.46 pg/mL). PICD was detected in a similar frequency in the three groups (P>0.05). On univariate logistic analysis only female sex was a fairly significant PICD predictor (Wald 3.85, odds ratio 3.14; P=0.05). CONCLUSIONS: The ascites flow rate does not correlate with PICD development.

Vascular function in arteries of intertidal fish Girella laevifrons (Kyphosidae) / Função vascular nas artérias do peixe marinho Girella laevifrons (Kyphosidae)

Preliminary studies showed that dorsal artery contraction mediated by acetylcholine (ACh) is blocked with indomethacin in intertidal fish (Girella laevifrons). Our objective was to characterise the cholinergic pathway in several artery vessels of the G. laevifrons. Afferent and efferent branchial, dorsal and mesenteric arteries were dissected of 6 juvenile specimens, isometric tension studies were done using dose response curves (DRC) for Ach (10–13 to 10–3 M), and cholinergic pathways were obtained by blocking with atropine or indomethacin. CRC to ACh showed a pattern of high and low sensitivity. Furthermore, these contractions were blocked in the presence of atropine and indomethacin in all vessels. Our results suggest that contraction observed with acetylcholine is mediated by receptors that activate a cyclooxygenase contraction pathway.

Estudos preliminares mostraram que a contração da artéria dorsal mediada por acetilcolina (ACh) é bloqueada com indometacina em peixes marinhos Girella laevifrons. Nosso objetivo foi caracterizar a via colinérgica em várias artérias de G. laevifrons. Artérias aferentes e eferentes branquiais, dorsais e mesentéricas foram dissecadas de 6 espécimes juvenis. Os estudos de tensão isométrica foram feitos utilizando-se a curva dose - resposta (CDR) para Ach (10–13 a 10–3M), e identificaram-se as vias colinérgicas, bloqueando com atropina e indometacina. CRC para ACh mostrou um padrão de alta e baixa sensibilidade. Essas contrações foram bloqueadas na presença de atropina e indometacina em todas as artérias avaliadas. Nossos resultados sugerem que a contração observada com acetilcolina é mediada por receptores muscarínicos que ativam uma ciclo-oxigenase.

An Integrative Model of the Cardiovascular System Coupling Heart Cellular Mechanics with Arterial Network Hemodynamics

The current study proposes a model of the cardiovascular system that couples heart cell mechanics with arterial hemodynamics to examine the physiological role of arterial blood pressure (BP) in left ventricular hypertrophy (LVH). We developed a comprehensive multiphysics and multiscale cardiovascular model of the cardiovascular system that simulates physiological events, from membrane excitation and the contraction of a cardiac cell to heart mechanics and arterial blood hemodynamics. Using this model, we delineated the relationship between arterial BP or pulse wave velocity and LVH. Computed results were compared with existing clinical and experimental observations. To investigate the relationship between arterial hemodynamics and LVH, we performed a parametric study based on arterial wall stiffness, which was obtained in the model. Peak cellular stress of the left ventricle and systolic blood pressure (SBP) in the brachial and central arteries also increased; however, further increases were limited for higher arterial stiffness values. Interestingly, when we doubled the value of arterial stiffness from the baseline value, the percentage increase of SBP in the central artery was about 6.7% whereas that of the brachial artery was about 3.4%. It is suggested that SBP in the central artery is more critical for predicting LVH as compared with other blood pressure measurements.

Relação entre elasticidade arterial e outros marcadores de risco cardiovascular em indivíduos com HIV/aids em terapia antirretroviral / Relationship between arterial elasticity and other markers of cardiovascular risk in individuals with HIV/AIDS on antiretroviral therapy

Introdução: Existe crescente interesse em identificar marcadores de risco para eventos cardiovasculares em pacientes com HIV/aids. Atualmente observa-se alteração do perfil epidemiológico desses pacientes, com diminuição da mortalidade por infecção e comorbidades e aumento por eventos cardiovasculares. A elasticidade arterial, principalmente dos pequenos vasos, tem sido investigada como alteração precoce de evento cardiovascular. Objetivo: Avaliar a relação entre elasticidade arterial e outros indicadores de risco cardiovascular como fatores demográficos e socioeconômicos, hábitos de vida, estado nutricional e marcadores inflamatórios. Métodos: Foram selecionados aleatoriamente 132 indivíduos voluntários em tratamento regular com antirretrovirais em ambulatório especializado em HIV/aids, com idade entre 19 e 59 de ambos os sexos. A elasticidade arterial dos grandes vasos (LAEI) e pequenos vasos (SAEI) foi investigada pelo equipamento HDI/ PulseWaveTM CR-2000 Cardio Vascular Profiling System®. Foram determinados colesterol total e frações, triglicérides, proteína C-reativa, fibrinogênio, medidas antropométricas e de avaliação de composição corporal, fumo, consumo de bebidas alcoólicas, uso de drogas, prática de atividade física, além de avaliação de fatores demográficos e socioeconômicos e imunológicos (carga viral, T-CD4, T-CD8). Para investigar a associação entre LAEI e SAEI e outros fatores de risco cardiovascular utilizou-se análise de regressão linear múltipla

Drag reduction by polyethylene glycol in the tail arterial bed of normotensive and hypertensive rats

This study was designed to evaluate the effect of drag reducer polymers (DRP) on arteries from normotensive (Wistar) and spontaneously hypertensive rats (SHR). Polyethylene glycol (PEG 4000 at 5000 ppm) was perfused in the tail arterial bed with (E+) and without endothelium (E-) from male, adult Wistar (N = 14) and SHR (N = 13) animals under basal conditions (constant flow at 2.5 mL/min). In these preparations, flow-pressure curves (1.5 to 10 mL/min) were constructed before and 1 h after PEG 4000 perfusion. Afterwards, the tail arterial bed was fixed and the internal diameters of the arteries were then measured by microscopy and drag reduction was assessed based on the values of wall shear stress (WSS) by computational simulation. In Wistar and SHR groups, perfusion of PEG 4000 significantly reduced pulsatile pressure (Wistar/E+: 17.5 ± 2.8; SHR/E+: 16.3 ± 2.7 percent), WSS (Wistar/E+: 36; SHR/E+: 40 percent) and the flow-pressure response. The E- reduced the effects of PEG 4000 on arteries from both groups, suggesting that endothelial damage decreased the effect of PEG 4000 as a DRP. Moreover, the effects of PEG 4000 were more pronounced in the tail arterial bed from SHR compared to Wistar rats. In conclusion, these data demonstrated for the first time that PEG 4000 was more effective in reducing the pressure-flow response as well as WSS in the tail arterial bed of hypertensive than of normotensive rats and these effects were amplified by, but not dependent on, endothelial integrity. Thus, these results show an additional mechanism of action of this polymer besides its mechanical effect through the release and/or bioavailability of endothelial factors.

Effects of estrogen deprivation and physical exerciseson the arterial wall: a literature review

Over the past few decades, there has been a surge of interest in the study of the effect of estrogen on the femaleorganism and the benefits of physical activities on different species of animals. The literature review provides areview of the existing literature on the morphological and/or physiological effects of the estrogen deprivationand/or the role of physical exercises on the arteries of different species of animals and humans. This reviewincludes last decade publications found in the PubMed database. One of the most relevant findings concerningestrogen deprivation was the arterial complacency reduction due to the reduction of elastin, whereas physicalexercises have been widely indicated for the treatment of several cardiovascular disorders and for the hardening of central arteries.

Spectral Doppler ultrasound in the major arteries of normal conscious immature micropigs

Spectral waveform analysis of blood flow velocity in the major arteries of six healthy, conscious immature micropigs was determined using Doppler ultrasonography. Doppler spectral tracings were recorded from the external iliac artery, femoral artery, and renal arcuate artery. Tracings were also taken from three parts of the common carotid artery and two parts of the abdominal aorta. Spectral Doppler parameters included peak systolic velocity, early diastolic velocity, peak systolic velocity-to-end diastolic velocity ratio, resistive index, and pulsatility index. In addition, the diameter of major arteries and indirect blood pressure were measured. These results from spectral Doppler analysis in major arteries may be useful as reference ranges in the future studies of vascular hemodynamics in immature micropigs.

Intra-arterial blood pressure response in hypertensive subjects during low- and high-intensity resistance exercise

OBJECTIVE: The aim of this study was to describe blood pressure responses during resistance exercise in hypertensive subjects and to determine whether an exercise protocol alters these responses. INTRODUCTION: Resistance exercise has been recommended as a complement for aerobic exercise for hypertensive patients. However, blood pressure changes during this kind of exercise have been poorly investigated in hypertensives, despite multiple studies of normotensives demonstrating significant increases in blood pressure. METHODS: Ten hypertensive and ten normotensive subjects performed, in random order, two different exercise protocols, composed by three sets of the knee extension exercise conducted to exhaustion: 40 percent of the 1-repetition maximum (1RM) with a 45-s rest between sets, and 80 percent of 1RM with a 90-s rest between sets. Radial intra-arterial blood pressure was measured before and throughout each protocol. RESULTS: Compared with normotensives, hypertensives displayed greater increases in systolic BP during exercise at 80 percent (+80±3 vs. +62±2 mmHg, P<0.05) and at 40 percent of 1RM (+75±3 vs. +67±3 mmHg, P<0.05). In both exercise protocols, systolic blood pressure returned to baseline during the rest periods between sets in the normotensives; however, in the hypertensives, BP remained slightly elevated at 40 percent of 1RM. During rest periods, diastolic blood pressure returned to baseline in hypertensives and dropped below baseline in normotensives. CONCLUSION: Resistance exercise increased systolic blood pressure considerably more in hypertensives than in normotensives, and this increase was greater when lower-intensity exercise was performed to the point of exhaustion.

Differences in functional and structural properties of segments of the rat tail artery

The investigation of resistance vessels is generally costly and difficult to execute. The present study investigated the diameters and the vascular reactivity of different segments of the rat tail artery (base, middle, and tail end) of 30 male Wister rats (EPM strain) to characterize a conductance or resistance vessel, using a low-cost simple technique. The diameters (mean ± SEM) of the base and middle segments were 471 ± 4.97 and 540 ± 8.39 µm, respectively, the tail end was 253 ± 2.58 µm. To test reactivity, the whole tail arteries or segments were perfused under constant flow and the reactivity to phenylephrine (PHE; 0.01-300 µg) was evaluated before and after removal of the endothelium or drug administration. The maximal response (Emax) and sensitivity (pED50) to PHE of the whole tail and the base segment increased after endothelium removal or treatment with 100 µM L-NAME, which suggests modulation by nitric oxide. Indomethacin (10 µM) and tetraethylammonium (5 mM) did not change the Emax or pED50 of these segments. PHE and L-NAME increased the pED50 of the middle and the tail end only and indomethacin did not change pED50 or Emax. Tetraethylammonium increased the sensitivity only at the tail end, which suggests a blockade of vasodilator release. Results indicate that the proximal segment of the tail artery possesses a diameter compatible with a conductance vessel, while the tail end has the diameter of a resistance vessel. In addition, the vascular reactivity to PHE in the proximal segment is nitric oxide-dependent, while the tail end is dependent on endothelium-derived hyperpolarizing factor.

El endotelio mantiene elevada la capacidad de conducción arterial y reduce la poscarga dinámica ventricular de una manera frecuencia-dependiente / Endothelium maintains capacity of arterial conduction high and reduces ventricular dynamic afterload in a frecuency dependent way

Introducción: Las propiedades geométricas y la viscosidad (V) y elasticidad (E) arteriales son determinantes de la función de conducción (FC) y amortiguamiento arterial (FA), así como del trabajo elástico (WE) y viscoso (WV) desarrollado por el ventrículo durante la eyección (poscarga dinámica externa). Se desconoce el rol endotelial en el control de la V, FC, FA, WE y WV, y resta por establecerse si el endotelio controla la poscarga dinámica de manera frecuencia-dependiente. Objetivo: Caracterizar el rol endotelial en la regulación de la V, FC, FA, WE y WV, y analizar el control endotelial de la poscarga dinámica ante aumentos de frecuencia de estimulación. Material y método: Arterias braquiocefálicas ovinas (n=9) se estudiaron en un simulador circulatorio en condiciones hemodinámicas símil fisiológicas. Se midió flujo, presión y diámetro arterial a 60, 80 y 100 latidos/minuto. Para cada frecuencia se calculó E, V, FC, FA, WE y Wv, antes y luego de remover el endotelio. La adecuada eliminación endotelial se comprobó mediante estudios histológicos. Resultados: La presencia de endotelio permitió mantener reducidos E, V, WE y WV, y elevada la FC (p<0,05). La reducción de los determinantes de la poscarga fue mayor a elevados niveles de frecuencia de estimulación (p<0,05). Conclusiones: El endotelio regula la viscoelasticidad arterial, reduciendo la poscarga dinámica, a la vez que permite mantener elevada la FC y no modifica la capacidad de la arteria de autoprotegerse. La mayor reducción de la poscarga a mayor frecuencia (mayor consumo de oxígeno), supone un beneficio adicional sobre la función ventricular.

Introduction: The geometrical properties, the viscosity (V) and elasticity (E) of the arteries determine the arterial conduit (CF) and buffer (BF) functions, as well as the elastic (WE) and viscous (WV) work developed by the ventricle during the ejection (external dynamic afterload). It remains to be established the role of the endothelium in controlling V, CF, BF, WE and WV, and if the endothelium’s regulation of the dynamic afterload depends on the frequency. Objetive: To characterize the endothelial role in the regulation of V, CF, BF, WE and WV, and to analyze the endothelial control of the dynamic afterload during the increase in the frequency of stimulation. Methods: Ovine brachiocephalic arteries (n=9) were studied in a circulation mock during physiological haemodynamic conditions. Arterial flow, pressure and diameter were measured at 60, 80 and 100 cycles/minute. At each frequency E, V, CF, BF, WE y Wv, were calculated before and after the endothelium removal. Hystological studies verified the adequacy of the endotelial removal. Results: The endothelium allowed keeping E, V, WE and WV in low levels, and a high CF (p<0,05). The reduction in the afterload determinants was higher at higher levels of frequency (p<0,05). Conclusions: The endothelium regulates the arterial viscoelasticity, with a reduction in the dynamic afterload; at the time it allows keeping the CF at high levels, and does not change the arterial auto-protection. The higher reduction in the afterload at high frequencies (increased oxigen demand), represents an additional beneficial effect in the ventricle function.

Irrigação da bolsa cloacal em Gallus gallus domesticus (matrizes de corte Hubbard) / Irrigation of the cloacal bursa in Gallus gallus domesticus (breeding stoch of Hubbard lineage)

Estudou-se em 30 galinhas da linhagem Hubbard, com idade variando de 10 a 12 semanas, a origem, o número e a ordenação dos vasos arteriais da Bolsa Cloacal mediante injeção do sistema vascular com solução aquosa a 50 por cento de Neoprene Látex 450 e posterior dissecação. Os resultados mostraram a participação das artérias pudenternas esquerda e direita em todos os casos, às quais associavam-se as artérias mesentérica caudal (33,33 por cento), caudal mediana (3,33 por cento) e ilíaca interna esquerda (3,33 por cento). O número total de ramos, independentemente da sua origem, variou de 2 a 9 com maior freqüência de 4 ramos. A distribuição dos vasos se fez de maneira própria para cada peça.

The Cloacal Bursa's arteries of 30 females Hubbard were injected with 50 percent Neoprene Latex 450 solution, and submited to dissection. The ages of the birds was to 10 to 12 weeks. The vessel's origin, number and sequence were studied The results showed the participation of the left and right internal pudendal artery in all cases, witch the association of the cranial mesenteric artery (333,33 percent), to median caudal artery (3,33 percent), and to left internal iliac artery (3,33 percent). The total branches number, without considering its origin, varied in 2 to 9, being 4 branches the major frequency. The vessels distribuition was the same in each bird.

Arterial distensibility as a possible compensatory mechanism in chronic aortic regurgitation

OBJECTIVE: To evaluate elastic properties of conduit arteries in asymptomatic patients who have severe chronic aortic regurgitation. METHODS: Twelve healthy volunteers aged 30Ý1 years (control group) and 14 asymptomatic patients with severe aortic regurgitation aged 29Ý2 years and left ventricular ejection fraction of 0.61Ý0.02 (radioisotope ventriculography) were studied. High-resolution ultrasonography was performed to measure the systolic and diastolic diameters of the common carotid artery. Simultaneous measurement of blood pressure enabled the calculation of arterial compliance and distensibility. RESULTS: No differences were observed between patients with aortic regurgitation and the control group concerning age, sex, body surface, and mean blood pressure. Pulse pressure was significantly higher in the aortic regurgitation group compared with that in the control group (78Ý3 versus 48Ý1mmHg, P<0.01). Arterial compliance and distensibility were significantly greater in the aortic regurgitation group compared with that in the control group (11.0Ý0.8 versus 8.1Ý0.7 10-10 N-1 m4, P=0.01 e and 39.3Ý2.6 versus 31.1Ý2.0 10-6 N-1 m², P=0.02, respectively). CONCLUSION: Patients with chronic aortic regurgitation have increased arterial distensibility. Greater vascular compliance, to lessen the impact of systolic volume ejected into conduit arteries, represents a compensatory mechanism in left ventricular and arterial system coupling