The potential role of lower limb blood pooling in reducing venous return to the heart during orthostasis and elevated venous pressure is investigated. This study compares lower limb capacitance, microvascular filtration, and peripheral resistance between a group of highly trained endurance athletes and a group of their sedentary peers. Seven endurance trained males were selected between the ages of 23-33 [(29.1 4.1 yr), mean SD]. The subjects weekly cycling mileage ranged from 80 to 150 miles per week with an average of 125 8.5 miles/week. Nine healthy, age-matched sedentary subjects (25.8 4.8 yr.) were selected for the control group, based upon their reporting they had not participated in repeated lower-body or cardiovascular exercise in the months prior to their study. Results show that both subject groups had similar calf venous capacitances, rates of capillary fluid filtration, and local flow shunting (vascular resistance change) in response to venous thigh occlusion and 70 head-up tilt (HUT). The only significant difference found between groups was the cyclist groups smaller rise in heart rate in response to HUT. The findings of this study suggest that cyclists are not predisposed to orthostatic intolerance due to any changes in lower limb function.

Despite over a century of inquiry, the mechanisms that achieve the close matching of oxygen supply to demand during exercise remain elusive. It has been proposed that in addition to its role as the primary oxygen carrier, the red blood cell (RBC) functions as a roving oxygen sensor, linking the oxygen demand at the muscle with oxygen delivery via the circulation (Ellsworth et al. 1995). It is hypothesised that the RBC would release adenosine triphosphate (ATP) in proportion to the number of unoccupied binding sites on the haemoglobin molecule as it traverses regions of high oxygen demand such as the microcirculation of active skeletal muscle. ATP would then stimulate the release of vasodilatory substances from the endothelium which would diffuse to neighbouring vascular smooth muscle resulting in vasodilation and an increase in blood flow in accordance with the oxygen demand set by the muscle. The first step in establishing a role for this mechanism during exercise in humans is to determine whether ATP increases in the venous blood draining an active muscle bed. Based on the handful of published studies, there is an increase in ATP concentration in the femoral vein during knee extensor exercise. However the response has not been studied in other vascular beds in humans. As such, the main aim of this thesis was to measure the ATP response to dynamic handgrip exercise. Secondary aims were to determine whether the response was modified by hypoxia, and to provide information about the timing of the changes in ATP concentration during a bout of handgrip exercise. These questions were addressed in Studies 3 and 4. Because blood flow is central to this hypothesis, a substantial portion of this thesis was also associated with the measurement of forearm blood flow (FBF) using venous occlusion strain gauge plethysmography (VOSGP), and this was conducted in Studies 1 and 2. VOSGP is based on the assumption that with venous outflow prevented, any increase in limb volume is proportional to the rate of arterial inflow. The rate of arterial inflow is determined as the slope of the change in limb volume over time. The slope must be calculated over the initial linear portion of this relationship, when arterial inflow is unaffected by the inevitable rise in venous pressure associated with venous occlusion. VOSGP was initially used to measure blood flow at rest and in response to pharmacological interventions which produced only modest increases in arterial inflow (Joyner et al. 2001). However, measurement of the high rates of arterial inflow that occur with exercise may challenge the limits of this technique. Tschakovsky et al. (1995) reported a marked reduction in arterial inflow over the first four cardiac cycles during venous occlusion following static handgrip exercise that elevated blood flow to 22-24 mL/min/100mL. Only during the first cardiac cycle was arterial inflow unaffected by cuff inflation. As such, the window for measuring high rates of arterial inflow may be very brief. Therefore Study 1 aimed to determine whether blood flow could be measured using VOSGP across the range of arterial inflows that occur with dynamic handgrip exercise. Participants (n = 7) completed four, five-minute bouts of dynamic handgrip exercise at 15, 30, 45, and 60% of maximum voluntary contraction (MVC). FBF was measured using VOSGP at rest, and following five minutes of dynamic handgrip exercise. The slope of the change in limb volume was measured over the first one, two, three, and four consecutive cardiac cycles following the onset of occlusion. FBF was 2.5 ± 0.5 at rest, and 16.5 ± 4.9, 24.9 ± 9.4, 44.1 ± 22.0, and 57.8 ± 14.9 mL/min/100mL following five minutes of exercise at 15, 30, 45, and 60% MVC, respectively. At rest, arterial inflow decreased across the four cardiac cycles (P = 0.017 for the main effect), however post-hoc pairwise comparisons revealed no significant differences between any of the cardiac cycles. In contrast, the inclusion of two, three, or four cardiac cycles at 30 and 60% MVC, and three or four cardiac cycles at 15 and 45% MVC resulted in reductions in calculated arterial inflow compared with using the first cardiac cycle alone (P > 0.05). The inclusion of just two cardiac cycles resulted in a 9-26% reduction in calculated arterial inflow depending on the workload. This reduction was even more pronounced when three (19-40%) or four (26-50%) cardiac cycles were included. In conclusion, resting FBF can be calculated over at least four cardiac cycles during venous occlusion at rest. However, exercising FBF should be calculated from the first cardiac cycle only following dynamic handgrip exercise across the range of intensities used in this study. This extends the findings of Tschakovsky et al. (1995) who demonstrated this effect following handgrip exercise at a single intensity. Study 2 was designed to establish the FBF response to dynamic handgrip exercise, whether the workloads produced different blood flow responses, and to establish the within- and between-day reproducibility of FBF measured using VOSGP. In Part A (within-day reproducibility), participants (n = 7) completed three trials of dynamic handgrip exercise at four intensities (15, 30, 45, and 60% MVC), with each exercise trial separated by 10 minutes of rest. In Part B (between-day reproducibility) participants (n = 7) completed three trials of dynamic handgrip exercise at 15, 30, and 45% MVC on three separate days within a two week period. FBF was measured at rest, and each minute of exercise during brief (5-7 second) pauses in contractions. FBF response. FBF increased from rest at all workloads (P > 0.05), and then plateaued between Minutes 1 to 5 at the 15 and 30% MVC workloads and between Minutes 2 and 5 at the 45% workload (P > 0.05 for each minute compared to Minute 5). Too few participants completed the 60% workload to permit any statistical analysis. FBF reached values of 13.0 ± 2.0, 26.8 ± 8.4, 44.8 ± 14.9, and 52.9 ± 5.1 mL/min/100mL in the final minute of exercise at the 15, 30, 45, and 60% MVC workloads. FBF was different between the 15, 30, and 45% workloads by Minute 3 (P > 0.05). Reproducibility. The within-day test-retest reliability of exercising FBF was poor to moderate (ICC = 0.375-0.624) with individual coefficients of variation (CVs) ranging from 6-25%, 9-23%, and 9-31% for the 15, 30, and 45% MVC workloads, respectively. The between-day test-retest reliability for resting FBF was moderate (ICC = 0.644, P > 0.05; individual CVs between 1 and 31%). Between-day test-retest reliability for exercising FBF was poor to moderate (ICC = 0.381-0.614), with individual CVs ranging from 14-24%, 8-23%, and 6-18% for the 15, 30, and 45% workloads, respectively. It was concluded from this study that VOSGP provides adequately reproducible measurements to detect changes in FBF of the magnitude seen between workloads in this study. However, the variability in the measurement precludes its use when smaller differences are of interest. Based on the previous findings reporting an increase in ATP concentration during dynamic knee extensor exercise in the leg (Gonzalez-Alonso et al. 2002; Yegutkin et al. 2007), Study 3 was designed to determine whether ATP concentration increased in the venous effluent during dynamic handgrip exercise in the forearm. Since the deoxygenation of haemoglobin is a primary stimulus for ATP release from red blood cells, a further aim was to determine whether this response was augmented by systemic hypoxia. Participants (n = 6) completed four, five-minute bouts of dynamic handgrip exercise at 30, 45, 65, and 85% MVC under normoxia (inspired oxygen fraction = 0.21) and hypoxia (inspired oxygen fraction = 0.12). Blood samples for the determination of ATP concentration were drawn at rest and 180 seconds after the onset of exercise at each workload from a catheter inserted into a forearm vein. Venous plasma ATP concentration at rest was 0.28 ± 0.11 μM/L and remained unchanged during exercise at workloads up to 85% MVC (P > 0.05). Systemic hypoxia, sufficient to reduce arterial oxygen saturation to 83 ± 2%, also failed to alter the plasma ATP concentration (P = 0.148). The lack of a change in ATP concentration was unexpected but there are several possible explanations. It is possible, although unlikely, that ATP was not released in the forearm microcirculation. The previous demonstration that ATP increased in response to static handgrip exercise (Forrester and Lind 1969) would suggest that this was probably not the case. When considered in the context of the findings from Study 4, the most plausible explanation is that a less than optimal blood sampling site may have hindered the measurement of a change in ATP. The blood flow response at the onset of dynamic exercise in the forearm is at least biphasic; Phase 1 describes the immediate, large increase in blood flow within 2 seconds of the onset of exercise and is believed to be governed by mechanical factors whereas Phase 2 has a latency of ~20 seconds and describes a further, slower increase until blood flow reaches steady state (Saunders et al. 2005b). The temporal characteristics of Phase 2, along with the fact that blood flow during this phase is closely related to the metabolic rate of the muscle, suggest regulation by metabolic factors. Currently there is scant evidence detailing the time course of vasodilator release, although it is important to demonstrate that the release of a vasodilatory substance precedes the blood flow response it is proposed to influence (Delp 1999). ATP is released from red blood cells in proportion to the offloading of oxygen and a reduction in the oxygen content of venous blood draining a muscle bed occurs within 10 seconds of the onset of exercise. Thus the release of ATP should follow soon thereafter. As such, Study 4 was designed to determine whether ATP increased in the venous effluent of the forearm following 30 and 180 seconds of dynamic handgrip exercise at 45% MVC; and whether this increase corresponded with a decrease in venous oxygen content. Participants (n = 10) completed two bouts of dynamic handgrip exercise at 45% MVC; the first was one minute in duration, and the second was four minutes in duration. Venous blood samples for the determination of ATP and venous oxygen content were drawn at rest and during exercise from a catheter inserted in a retrograde manner into the median cubital vein. Arterialised samples for the estimation of arterial blood gases and ATP concentration were obtained from the non-exercising hand. ATP concentration in arterialised blood from the non-exercising arm was 0.79 ± 0.30 μM/L at rest and remained unchanged at both time points during exercise (P > 0.05). ATP concentration in the venous blood of the exercising arm increased from 0.60 ± 0.17 μM/L at rest to 1.04 ± 0.33 μM/L 30 seconds after the onset of exercise (P > 0.05), and remained at this higher level after 180 seconds (0.92 ± 0.26 μM/L, P > 0.05 versus rest). This corresponded with a decrease in venous oxygen content from 103 ± 23 mL/L at rest to 68 ± 16 mL/L 30 seconds after the onset of exercise (P > 0.05) and 76 ± 15 mL/L (P > 0.05 versus rest) 180 seconds into exercise. Furthermore, at 180 seconds of exercise, ATP concentration was moderately and inversely related to venous oxygen content (r = -0.651, p > 0.05). In conclusion, this study provides the first evidence that ATP concentration is increased in the blood draining the exercising forearm muscles in response to dynamic handgrip exercise. The finding that ATP concentration was increased just 30 seconds after the onset of exercise is also novel, and particularly interesting in the context of the recently reported dynamic response characteristics of the forearm blood flow response. In conclusion, the work contained within this thesis provides several important findings. The first study has provided evidence that measuring high rates of arterial inflow using VOSGP is possible, but that the window for making these measurements is small, probably as brief as a single cardiac cycle. The second study demonstrated that while the reproducibility of forearm blood flow measurements using VOSGP is poor, it is adequate to detect the large changes that occurred between workloads. However, VOSGP cannot be used to detect more modest differences. Common to both Study 3 and 4 was the measurement of ATP at rest, and 180 seconds after the onset of dynamic handgrip exercise at 45% MVC. The primary difference was the position of the catheter which was inserted in an antegrade manner in Study 3, and in a retrograde manner in Study 4. Since ATP was unchanged in Study 3 but increased under similar conditions in Study 4, it is likely that ATP was also released during exercise in Study 3, but that a less than optimal blood sampling site precluded its measurement. This illustrates the necessity to sample blood from as close as possible to the probable site of ATP release, the muscle microcirculation. The most important and novel findings from this body of work come from Study 4. This is the first study to demonstrate an increase in ATP concentration in the forearm in response to dynamic handgrip exercise. However, the most novel finding was that ATP concentration was elevated just 30 seconds after the onset of exercise. Such an early increase has not previously been reported during dynamic exercise in any vascular bed. This is an important finding since establishing the time course for the release of vasodilatory substances is critical to our understanding of the mechanisms that regulate blood flow during exercise.

O envelhecimento populacional é um fenômeno mundial, assim como o predomínio de mortes por doenças cardiovasculares. Estudos demonstram que o envelhecimento acarreta aumento da rigidez vascular e perturbações na reatividade macrovascular. O presente estudo comparou a microcirculação deste processo com adultos jovens através da pletismografia de oclusão venosa (POV) e da videocapilaroscopia do leito periungueal (VC). Para isto, desenvolveu-se um estudo transversal com dois grupos: idade entre 18 e 30 anos (n=16) e outro grupo com idade igual ou superior a 60 anos (n=21), além da subdivisão deste grupo em três subgrupos: idosas saudáveis (n=8), idosas em tratamento de hipertensão arterial (IDHAS,n=6) e idosas em tratamento de dislipidemia (IDDIS,n=6). Foram realizadas avaliações clínica, antropométrica, bioquímica e microcirculatória. Como resultados, a VC mostrou aumento dos diâmetros capilares aferente, apical e eferente e redução da relação velocidade máxima/ velocidade basal de deslocamento de hemácias para grupo de idosas e todos os subgrupos. A POV revelou diminuição da vasodilatação endotélio-dependente em todos os grupos estudados e a vasodilatação endotélio-independente alterou-se apenas em IDHAS e IDDIS. Como conclusões houve, no envelhecimento, alterações estruturais e funcionais da microcirculação assim como redução da vasodilatação endotélio-dependente. A vasodilatação endotélio-independente manteve-se inalterada, indicando que a célula muscular lisa da parede vascular permanece preservada, porém sofre alterações nos grupos IDHAS e IDDIS. / Population aging is a worldwide phenomenon, as well as the prevalence of deaths from cardiovascular diseases. Studies show that aging brings increased vascular stiffness and altered vascular reactivity. The present study compared the microcirculation of elderly people to young adults by venous occlusion plethysmography (POV) and nailfold videocapillaroscopy (NVC). For this, we developed a cross-sectional study with two groups: those aged between 18 and 30 years (n = 16) and another group aged over 60 years (n = 21), and the subdivision of this group into three subgroups: healthy elderly (n = 8), elderly women being treated for hypertension (IDHAS, n = 6) and older in the treatment of dyslipidemia (IDDIS, n = 6). Clinical, anthropometric, biochemical and microcirculatory parameters were evaluated. As results, NVC showed an increase of afferent, apical and efferent capillary diameters and a lower ratio maximum red blood cell velocity/ baseline red blood cell velocity for the older group and all subgroups. POV showed decreased endothelium-dependent vasodilation in all groups and the endothelium-independent vasodilation was altered only in IDHAS and IDDIS. In conclusion, in the aging, there were structural and functional changes of microcirculation as well as reduced endothelium-dependent vasodilation. The endothelium-independent vasodilation remained unchanged, indicating that smooth muscle cells of the vascular wall remains preserved, but show changes in the groups IDHAS and IDDIS.

O envelhecimento populacional é um fenômeno mundial, assim como o predomínio de mortes por doenças cardiovasculares. Estudos demonstram que o envelhecimento acarreta aumento da rigidez vascular e perturbações na reatividade macrovascular. O presente estudo comparou a microcirculação deste processo com adultos jovens através da pletismografia de oclusão venosa (POV) e da videocapilaroscopia do leito periungueal (VC). Para isto, desenvolveu-se um estudo transversal com dois grupos: idade entre 18 e 30 anos (n=16) e outro grupo com idade igual ou superior a 60 anos (n=21), além da subdivisão deste grupo em três subgrupos: idosas saudáveis (n=8), idosas em tratamento de hipertensão arterial (IDHAS,n=6) e idosas em tratamento de dislipidemia (IDDIS,n=6). Foram realizadas avaliações clínica, antropométrica, bioquímica e microcirculatória. Como resultados, a VC mostrou aumento dos diâmetros capilares aferente, apical e eferente e redução da relação velocidade máxima/ velocidade basal de deslocamento de hemácias para grupo de idosas e todos os subgrupos. A POV revelou diminuição da vasodilatação endotélio-dependente em todos os grupos estudados e a vasodilatação endotélio-independente alterou-se apenas em IDHAS e IDDIS. Como conclusões houve, no envelhecimento, alterações estruturais e funcionais da microcirculação assim como redução da vasodilatação endotélio-dependente. A vasodilatação endotélio-independente manteve-se inalterada, indicando que a célula muscular lisa da parede vascular permanece preservada, porém sofre alterações nos grupos IDHAS e IDDIS. / Population aging is a worldwide phenomenon, as well as the prevalence of deaths from cardiovascular diseases. Studies show that aging brings increased vascular stiffness and altered vascular reactivity. The present study compared the microcirculation of elderly people to young adults by venous occlusion plethysmography (POV) and nailfold videocapillaroscopy (NVC). For this, we developed a cross-sectional study with two groups: those aged between 18 and 30 years (n = 16) and another group aged over 60 years (n = 21), and the subdivision of this group into three subgroups: healthy elderly (n = 8), elderly women being treated for hypertension (IDHAS, n = 6) and older in the treatment of dyslipidemia (IDDIS, n = 6). Clinical, anthropometric, biochemical and microcirculatory parameters were evaluated. As results, NVC showed an increase of afferent, apical and efferent capillary diameters and a lower ratio maximum red blood cell velocity/ baseline red blood cell velocity for the older group and all subgroups. POV showed decreased endothelium-dependent vasodilation in all groups and the endothelium-independent vasodilation was altered only in IDHAS and IDDIS. In conclusion, in the aging, there were structural and functional changes of microcirculation as well as reduced endothelium-dependent vasodilation. The endothelium-independent vasodilation remained unchanged, indicating that smooth muscle cells of the vascular wall remains preserved, but show changes in the groups IDHAS and IDDIS.

The purpose of the present investigation was to: 1) Determine the relationship between cardiac output (estimated using the acetylene rebreathing methodology) and oxygen consumption in a homogeneous group of men who are paraplegic. 2) Investigate whether lower limb elevation increases stroke volume and decreases heart rate at rest and during submaximal arm exercise. 3) Investigate whether the application of constant circumferential pneumatic pressure applied to dependent lower limbs increases stroke volume and decreases heart rate at rest and during submaximal arm exercise.

Fundação Carlos Chagas Filho de Amparo a Pesquisa do Estado do Rio de Janeiro / O Chá Verde, derivado das folhas da planta Camellia sinensis, rico em flavonóides, cuja maior concentração é de Epigalocatequina gallato (EGCG), possui efeito termogênico, além de promover a oxidação da gordura corporal, tendo potencial interesse para o tratamento da obesidade, que atinge prevalência alarmante em diversos países no mundo. O objetivo deste estudo foi a avaliação de parâmetros bioquímicos e investigação da função endotelial em mulheres com Índice de Massa Corporal (IMC) entre 30kg/m2 e 40kg/m2, na faixa de 30 e 50 anos, antes e após 03 meses de consumo de chá verde (600mL/dia, equivalente a 114,42mg de EGCG). Todas as 60 pacientes voluntárias foram submetidas à análise das medidas antropométricas (Peso, Altura, Índice de Massa Corporal, Circunferência de Cintura, Circunferência de Quadril, Relação Cintura-Quadril, Pressão Arterial, à análise da bioquímica de rotina (Glicemia e Insulina de jejum, Triglicerídeos, Colesterol Total, HDL-Colesterol, LDL-Colesterol, Teste Oral de Tolerância à Glicose, Hemograma Completo, Proteína C-Reativa), à análise da bioquímica específica para estresse oxidativo e inflamação (Interleucinas 1 e 6, Fator de Necrose Tumoral Alfa, LDL-Oxidado, VCAM Vascular Cell Adhesion Molecule, ICAM Intercellular Adhesion Molecule, e E-Selectina) e à Pletismografia de Oclusão Venosa (variação de fluxo médio máximo durante a Hiperemia Reativa/Fluxo Basal 1 (VQ Hiper) e fluxo após administração de 0,4mg de Nitroglicerina Sublingual/Fluxo Basal 2 (VQ Nitro)). Após os 3 meses (3M) de tratamento houve redução no peso corporal (86,35[83,00-94,25] vs 3M = 86,00[81,50-92,00] Kg, P < 0,05); no IMC (34,02[32,05-35,62] vs 3M = 33,13[32,28-35,05] kg/m2, P < 0,05); na circunferência de cintura (99[93-107] vs 3M = 98[91-105]cm, P < 0,001); na circunferência de quadril (115[110-119] vs 3M = 114[110-117] cm, P < 0,001); na relação cintura-quadril (0,89[0,84-0,93] vs 3M = 0,88[0,83-0,93], P < 0,001); e, na pressão arterial diastólica (75[73-82] vs 3M = 69[67-72] mmHg, P < 0,001); e, melhora significativa no fluxo sanguíneo da VQ Hiper (4,57[3,54-5,01] vs 3M = 5,83[4,46-6,56], P < 0,001); e da VQ Nitro (1,26[1,13-1,38] vs 3M = 1,41[1,25-1,50], P < 0,001). Com o uso do chá verde, 600mL/dia, contendo 114,42mg de EGCG, durante 3 meses observamos a redução de 3% no IMC e a redução da circunferência de cintura e de circunferência de quadril em 1cm; a não modificação do padrão bioquímico, incluindo os marcadores de inflamação e de estresse oxidativo; e, o aumento das vasodilatações endotélio-dependente e endotélio-independente, visualizadas por Pletismografia de Oclusão Venosa Não-Invasiva. / Green tea, derived from the leaves of the plant Camellia sinensis, rich in flavonoids, whose greatest concentration is Epigallocatechin gallato (EGCG), has termogenic effect, and promote fat oxidation, with potential interest for the treatment of obesity, which is reaching alarming prevalence in many countries worldwide. The aim of this study was to evaluate biochemical parameters and endothelial function in women with Body Mass Index (BMI) between 30kg/m2 and 40kg/m2, 30 and 50 years old, before and after 03 months of consumption of green tea (600mL/day, equivalent to 114.42mg of EGCG). All the 60 voluntary patients were submitted to the analyses of anthropometric measures (weight, height, body mass index, waist circumference, hip circumference, waist-hip ratio, blood pressure), to the biochemicalanalysis of routine (fasting glucose and insulin, triglycerides, total cholesterol, HDL-cholesterol, LDL-cholesterol, oral glucose tolerance, hemogram, C-Reactive protein), to the biochemical analysis of specific oxidative stress and inflammation (interleukins 1 and 6, tumor necrosis factor alpha, oxidized LDL, VCAM - Vascular Cell Adhesion Molecule, ICAM - Intercellular Adhesion Molecule and E-selectin) and to venous occlusion plethysmography (variation of maximum average flux during Reactive Hyperemia/Basal 1 Flow (VQ Hiper) and flow after administration of 0,4mg Sublingual Nitroglycerin/Basl 2 Flow (VQ Nitro)).After 03 months (3M) of treatment there was a reduction in body weight (86.35[83.00-94.25] vs 3M = 86.00[81.50-92.00] Kg, P < 0.05); in BMI (34.02[32.05-35.62] vs 3M = 33.13[32.28-35.05] kg/m2, P < 0.05); in waist circumference (99[93-107] vs 3M = 98[91-105]cm, P < 0.001); in hip circumference (115[110-119] vs 3M = 114[110-117] cm, P < 0.001); in waist-hip ration (0.89[0.84-0.93] vs 3M = 0.88[0.83-0.93], P < 0.001); and in diastolic blood pressure (75[73-82] vs 3M = 69[67-72] mmHg, P < 0.001); and, a significant improvement in blood flow of VQ Hiper (4.57[3.54-5.01] vs 3M = 5.83[4.46-6.56], P < 0.001); and in blood flow of VQ Nitro (1.26[1.13-1.38] vs 3M = 1.41[1.25-1.50], P < 0.001). With the use of green tea, 600mL/day, containing 114.42mg of EGCG for 3 months we saw a reduction of 3% in BMI and in the waist and hip circumferences of 1cm. There were no modification of standard biochemical parameters, including markers of inflammation and oxidative stress. There was increased endothelium-dependent and endothelium-independent vasodilation, viewed by noninvasive venous occlusion plethysmography.

Fundação Carlos Chagas Filho de Amparo a Pesquisa do Estado do Rio de Janeiro / O Chá Verde, derivado das folhas da planta Camellia sinensis, rico em flavonóides, cuja maior concentração é de Epigalocatequina gallato (EGCG), possui efeito termogênico, além de promover a oxidação da gordura corporal, tendo potencial interesse para o tratamento da obesidade, que atinge prevalência alarmante em diversos países no mundo. O objetivo deste estudo foi a avaliação de parâmetros bioquímicos e investigação da função endotelial em mulheres com Índice de Massa Corporal (IMC) entre 30kg/m2 e 40kg/m2, na faixa de 30 e 50 anos, antes e após 03 meses de consumo de chá verde (600mL/dia, equivalente a 114,42mg de EGCG). Todas as 60 pacientes voluntárias foram submetidas à análise das medidas antropométricas (Peso, Altura, Índice de Massa Corporal, Circunferência de Cintura, Circunferência de Quadril, Relação Cintura-Quadril, Pressão Arterial, à análise da bioquímica de rotina (Glicemia e Insulina de jejum, Triglicerídeos, Colesterol Total, HDL-Colesterol, LDL-Colesterol, Teste Oral de Tolerância à Glicose, Hemograma Completo, Proteína C-Reativa), à análise da bioquímica específica para estresse oxidativo e inflamação (Interleucinas 1 e 6, Fator de Necrose Tumoral Alfa, LDL-Oxidado, VCAM Vascular Cell Adhesion Molecule, ICAM Intercellular Adhesion Molecule, e E-Selectina) e à Pletismografia de Oclusão Venosa (variação de fluxo médio máximo durante a Hiperemia Reativa/Fluxo Basal 1 (VQ Hiper) e fluxo após administração de 0,4mg de Nitroglicerina Sublingual/Fluxo Basal 2 (VQ Nitro)). Após os 3 meses (3M) de tratamento houve redução no peso corporal (86,35[83,00-94,25] vs 3M = 86,00[81,50-92,00] Kg, P < 0,05); no IMC (34,02[32,05-35,62] vs 3M = 33,13[32,28-35,05] kg/m2, P < 0,05); na circunferência de cintura (99[93-107] vs 3M = 98[91-105]cm, P < 0,001); na circunferência de quadril (115[110-119] vs 3M = 114[110-117] cm, P < 0,001); na relação cintura-quadril (0,89[0,84-0,93] vs 3M = 0,88[0,83-0,93], P < 0,001); e, na pressão arterial diastólica (75[73-82] vs 3M = 69[67-72] mmHg, P < 0,001); e, melhora significativa no fluxo sanguíneo da VQ Hiper (4,57[3,54-5,01] vs 3M = 5,83[4,46-6,56], P < 0,001); e da VQ Nitro (1,26[1,13-1,38] vs 3M = 1,41[1,25-1,50], P < 0,001). Com o uso do chá verde, 600mL/dia, contendo 114,42mg de EGCG, durante 3 meses observamos a redução de 3% no IMC e a redução da circunferência de cintura e de circunferência de quadril em 1cm; a não modificação do padrão bioquímico, incluindo os marcadores de inflamação e de estresse oxidativo; e, o aumento das vasodilatações endotélio-dependente e endotélio-independente, visualizadas por Pletismografia de Oclusão Venosa Não-Invasiva. / Green tea, derived from the leaves of the plant Camellia sinensis, rich in flavonoids, whose greatest concentration is Epigallocatechin gallato (EGCG), has termogenic effect, and promote fat oxidation, with potential interest for the treatment of obesity, which is reaching alarming prevalence in many countries worldwide. The aim of this study was to evaluate biochemical parameters and endothelial function in women with Body Mass Index (BMI) between 30kg/m2 and 40kg/m2, 30 and 50 years old, before and after 03 months of consumption of green tea (600mL/day, equivalent to 114.42mg of EGCG). All the 60 voluntary patients were submitted to the analyses of anthropometric measures (weight, height, body mass index, waist circumference, hip circumference, waist-hip ratio, blood pressure), to the biochemicalanalysis of routine (fasting glucose and insulin, triglycerides, total cholesterol, HDL-cholesterol, LDL-cholesterol, oral glucose tolerance, hemogram, C-Reactive protein), to the biochemical analysis of specific oxidative stress and inflammation (interleukins 1 and 6, tumor necrosis factor alpha, oxidized LDL, VCAM - Vascular Cell Adhesion Molecule, ICAM - Intercellular Adhesion Molecule and E-selectin) and to venous occlusion plethysmography (variation of maximum average flux during Reactive Hyperemia/Basal 1 Flow (VQ Hiper) and flow after administration of 0,4mg Sublingual Nitroglycerin/Basl 2 Flow (VQ Nitro)).After 03 months (3M) of treatment there was a reduction in body weight (86.35[83.00-94.25] vs 3M = 86.00[81.50-92.00] Kg, P < 0.05); in BMI (34.02[32.05-35.62] vs 3M = 33.13[32.28-35.05] kg/m2, P < 0.05); in waist circumference (99[93-107] vs 3M = 98[91-105]cm, P < 0.001); in hip circumference (115[110-119] vs 3M = 114[110-117] cm, P < 0.001); in waist-hip ration (0.89[0.84-0.93] vs 3M = 0.88[0.83-0.93], P < 0.001); and in diastolic blood pressure (75[73-82] vs 3M = 69[67-72] mmHg, P < 0.001); and, a significant improvement in blood flow of VQ Hiper (4.57[3.54-5.01] vs 3M = 5.83[4.46-6.56], P < 0.001); and in blood flow of VQ Nitro (1.26[1.13-1.38] vs 3M = 1.41[1.25-1.50], P < 0.001). With the use of green tea, 600mL/day, containing 114.42mg of EGCG for 3 months we saw a reduction of 3% in BMI and in the waist and hip circumferences of 1cm. There were no modification of standard biochemical parameters, including markers of inflammation and oxidative stress. There was increased endothelium-dependent and endothelium-independent vasodilation, viewed by noninvasive venous occlusion plethysmography.

O sistema cardiovascular está estrutural e funcionalmente disposto de modo “circular”. Situações de obstrução do fluxo sanguíneo determinam o aparecimento de mecanismos que visam suplantar tais interrupções e manter a circularidade íntegra. À nível molecular, o principal elemento envolvido nestes mecanismos é o Vascular Endothelial Growth Factor (VEGF). A expressão do VEGF quando há oclusão arterial está bem documentada, faltando elementos com relação à oclusão venosa. Neste estudo objetivamos verificar se a oclusão à nível arterial determina uma expressão do VEGF diferente daquela que ocorre se a oclusão acontecer à nível venoso. Para isso randomizamos dois grupos de ratos de experimentação. Em um grupo realizamos a oclusão da aorta infra-renal e em outro a oclusão da veia cava infra-renal. Posteriormente medimos a expressão do VEGF através da contagem do número de células marcadas imunoistoquimicamente no omento destes ratos. O resultado demonstrou que a expressão do VEGF, quando analisada pelo método proposto foi igual no grupo da oclusão venosa e no grupo da oclusão arterial. / The cardiovascular system is structurally and functionally circular. Situations in which there is obstruction to blood flow trigger mechanisms to bypass these blockages and maintenance the integrity of the circularity. At the molecular level the main factor involved is the Vascular Endothelial Growth Factor (VEGF). The VEGF expression associated with arterial occlusion is well documented but is lacking evidence when venous occlusion occurs. This study aimed to verify if the expression of VEGF when an occlusion occurs at venous level is the same or different from that caused at the arterial level. Two groups of rats were randomized by infra-renal aortic occlusion or inferior vena cava occlusion. VEGF was measured by counting the immunohistochemistry method marked cells at the omentum level. It was demonstrated that the VEGF expression is the same in the venous group obstruction as the arterial obstruction group.

O sistema cardiovascular está estrutural e funcionalmente disposto de modo “circular”. Situações de obstrução do fluxo sanguíneo determinam o aparecimento de mecanismos que visam suplantar tais interrupções e manter a circularidade íntegra. À nível molecular, o principal elemento envolvido nestes mecanismos é o Vascular Endothelial Growth Factor (VEGF). A expressão do VEGF quando há oclusão arterial está bem documentada, faltando elementos com relação à oclusão venosa. Neste estudo objetivamos verificar se a oclusão à nível arterial determina uma expressão do VEGF diferente daquela que ocorre se a oclusão acontecer à nível venoso. Para isso randomizamos dois grupos de ratos de experimentação. Em um grupo realizamos a oclusão da aorta infra-renal e em outro a oclusão da veia cava infra-renal. Posteriormente medimos a expressão do VEGF através da contagem do número de células marcadas imunoistoquimicamente no omento destes ratos. O resultado demonstrou que a expressão do VEGF, quando analisada pelo método proposto foi igual no grupo da oclusão venosa e no grupo da oclusão arterial. / The cardiovascular system is structurally and functionally circular. Situations in which there is obstruction to blood flow trigger mechanisms to bypass these blockages and maintenance the integrity of the circularity. At the molecular level the main factor involved is the Vascular Endothelial Growth Factor (VEGF). The VEGF expression associated with arterial occlusion is well documented but is lacking evidence when venous occlusion occurs. This study aimed to verify if the expression of VEGF when an occlusion occurs at venous level is the same or different from that caused at the arterial level. Two groups of rats were randomized by infra-renal aortic occlusion or inferior vena cava occlusion. VEGF was measured by counting the immunohistochemistry method marked cells at the omentum level. It was demonstrated that the VEGF expression is the same in the venous group obstruction as the arterial obstruction group.

O sistema cardiovascular está estrutural e funcionalmente disposto de modo “circular”. Situações de obstrução do fluxo sanguíneo determinam o aparecimento de mecanismos que visam suplantar tais interrupções e manter a circularidade íntegra. À nível molecular, o principal elemento envolvido nestes mecanismos é o Vascular Endothelial Growth Factor (VEGF). A expressão do VEGF quando há oclusão arterial está bem documentada, faltando elementos com relação à oclusão venosa. Neste estudo objetivamos verificar se a oclusão à nível arterial determina uma expressão do VEGF diferente daquela que ocorre se a oclusão acontecer à nível venoso. Para isso randomizamos dois grupos de ratos de experimentação. Em um grupo realizamos a oclusão da aorta infra-renal e em outro a oclusão da veia cava infra-renal. Posteriormente medimos a expressão do VEGF através da contagem do número de células marcadas imunoistoquimicamente no omento destes ratos. O resultado demonstrou que a expressão do VEGF, quando analisada pelo método proposto foi igual no grupo da oclusão venosa e no grupo da oclusão arterial. / The cardiovascular system is structurally and functionally circular. Situations in which there is obstruction to blood flow trigger mechanisms to bypass these blockages and maintenance the integrity of the circularity. At the molecular level the main factor involved is the Vascular Endothelial Growth Factor (VEGF). The VEGF expression associated with arterial occlusion is well documented but is lacking evidence when venous occlusion occurs. This study aimed to verify if the expression of VEGF when an occlusion occurs at venous level is the same or different from that caused at the arterial level. Two groups of rats were randomized by infra-renal aortic occlusion or inferior vena cava occlusion. VEGF was measured by counting the immunohistochemistry method marked cells at the omentum level. It was demonstrated that the VEGF expression is the same in the venous group obstruction as the arterial obstruction group.