ABSTRACT
Background: Resistance exercise effects on cardiovascular parameters are not consistent. Objectives: The effects of resistance exercise on changes in blood glucose, blood pressure and vascular reactivity were evaluated in diabetic rats. Methods: Wistar rats were divided into three groups: control group (n = 8); sedentary diabetic (n = 8); and trained diabetic (n = 8). Resistance exercise was carried out in a squat device for rats and consisted of three sets of ten repetitions with an intensity of 50%, three times per week, for eight weeks. Changes in vascular reactivity were evaluated in superior mesenteric artery rings. Results: A significant reduction in the maximum response of acetylcholine-induced relaxation was observed in the sedentary diabetic group (78.1 ± 2%) and an increase in the trained diabetic group (95 ± 3%) without changing potency. In the presence of NG-nitro-L-arginine methyl ester, the acetylcholine-induced relaxation was significantly reduced in the control and trained diabetic groups, but not in the sedentary diabetic group. Furthermore, a significant increase (p < 0.05) in mean arterial blood pressure was observed in the sedentary diabetic group (104.9 ± 5 to 126.7 ± 5 mmHg) as compared to that in the control group. However, the trained diabetic group showed a significant decrease (p < 0.05) in the mean arterial blood pressure levels (126.7 ± 5 to 105.1 ± 4 mmHg) as compared to the sedentary diabetic group. Conclusions: Resistance exercise could restore endothelial function and prevent an increase in arterial blood pressure in type 1 diabetic rats. .
Fundamento: Os efeitos do exercício resistido sobre os parâmetros cardiovasculares não são consistentes. Objetivos: Foram avaliados os efeitos do exercício resistido sobre as alterações na glicemia, reatividade vascular e pressão arterial de ratos diabéticos. Métodos: Ratos Wistar foram divididos em três grupos: grupo controle (n = 8), diabético sedentário (n = 8) e diabético treinado (n = 8). O exercício resistido foi realizado no aparelho de agachamento para ratos e consistiu em três séries de dez repetições com uma intensidade de 50%, três vezes por semana, durante 8 semanas. As alterações na reatividade vascular foram avaliadas em anéis de artéria mesentérica superior. Resultados: Foi observada uma redução significativa da resposta máxima dos relaxamentos induzidos por acetilcolina no grupo diabético sedentário (78,1% ± 2) e um aumento do grupo diabético treinado (95 ± 3%), sem alterar a potência. Na presença de NG-nitro-L-arginina metil éster, os relaxamentos induzidos por acetilcolina foram significativamente reduzidos nos grupos controle e diabético treinado, mas não no grupo diabético sedentário. Além disso, foi observado um aumento significativo (p < 0,05) da pressão arterial média no grupo diabético sedentário de 104,9 ± 5 para 126,7 ± 5 mmHg, quando comparado ao grupo controle. Por outro lado, o grupo diabético treinado apresentou redução significativa (p < 0,05) nos níveis da pressão arterial média de 126,7 ± 5 mmHg para 105,1 ± 4 mmHg, quando comparado ao diabético sedentário. Conclusões: O exercício resistido foi capaz de restaurar a funcionalidade endotelial e impedir o aumento da pressão arterial em ratos com ...
Subject(s)
Animals , Male , Blood Pressure/physiology , Diabetes Mellitus, Experimental/physiopathology , Diabetes Mellitus, Type 1/physiopathology , Endothelium, Vascular/physiopathology , Physical Conditioning, Animal/physiology , Resistance Training/methods , Acetylcholine/pharmacology , Blood Glucose/drug effects , Blood Glucose/physiology , Blood Pressure/drug effects , Cholinergic Agonists/pharmacology , Enzyme Inhibitors/pharmacology , Models, Animal , Mesenteric Artery, Superior/physiopathology , NG-Nitroarginine Methyl Ester/pharmacology , Rats, WistarABSTRACT
Vascular hyporeactivity is an important factor in irreversible shock, and post-shock mesenteric lymph (PSML) blockade improves vascular reactivity after hemorrhagic shock. This study explored the possible involvement of myosin light chain kinase (MLCK) in PSML-mediated vascular hyporeactivity and calcium desensitization. Rats were divided into sham (n=12), shock (n=18), and shock+drainage (n=18) groups. A hemorrhagic shock model (40±2 mmHg, 3 h) was established in the shock and shock+drainage groups. PSML drainage was performed from 1 to 3 h from start of hypotension in shock+drainage rats. Levels of phospho-MLCK (p-MLCK) were determined in superior mesenteric artery (SMA) tissue, and the vascular reactivity to norepinephrine (NE) and sensitivity to Ca2+ were observed in SMA rings in an isolated organ perfusion system. p-MLCK was significantly decreased in the shock group compared with the sham group, but increased in the shock+drainage group compared with the shock group. Substance P (1 nM), an agonist of MLCK, significantly elevated the decreased contractile response of SMA rings to both NE and Ca2+ at various concentrations. Maximum contractility (Emax) in the shock group increased with NE (from 0.179±0.038 to 0.440±0.177 g/mg, P<0.05) and Ca2+ (from 0.515±0.043 to 0.646±0.096 g/mg, P<0.05). ML-7 (0.1 nM), an inhibitor of MLCK, reduced the increased vascular response to NE and Ca2+ at various concentrations in the shock+drainage group (from 0.744±0.187 to 0.570±0.143 g/mg in Emax for NE and from 0.729±0.037 to 0.645±0.056 g/mg in Emax for Ca2+, P<0.05). We conclude that MLCK is an important contributor to PSML drainage, enhancing vascular reactivity and calcium sensitivity in rats with hemorrhagic shock.
Subject(s)
Animals , Male , Calcium/metabolism , Lymph/physiology , Mesenteric Artery, Superior/physiopathology , Muscle, Smooth, Vascular/physiopathology , Myosin-Light-Chain Kinase/physiology , Shock, Hemorrhagic/physiopathology , Muscle Contraction , Mesenteric Artery, Superior/metabolism , Muscle, Smooth, Vascular/metabolism , Myosin Light Chains/metabolism , Myosin-Light-Chain Kinase/analysis , Random Allocation , Rats, Wistar , Shock, Hemorrhagic/enzymologyABSTRACT
PURPOSE: To investigate the role of protein kinase G (PKG) in blocking post-shock mesenteric lymph (PSML) return ameliorating the calcium sensitivity in hemorrhagic shock rats. METHODS: Male Wistar rats were randomly divided into sham, shock, shock+ligation (shock plus mesenteric lymph duct ligation (MLDL)), shock+drainage (shock plus PSML drainage) groups. After shock (hypotension 40mmHg) for three hours or corresponding times, the superior mesenteric artery (SMA) was taken out for detecting the PKG and phospho PKG (p-PKG) contents, and the vascular rings of SMA were prepared for assaying the calcium sensitivity using an isolated organ perfusion system. RESULTS: The PKG and p-PKG contents of SMA in shock group were significantly increased than that of sham group, and MLDL or PSML drainage reducing the levels of PKG and p-PKG. Meanwhile, the vascular calcium sensitivity in shock group was significantly lower than that of sham group, MLDL or PSML drainage enhanced the calcium sensitivity. After incubating with PKG regulators in shock+ligation and shock+drainage groups, the PKG agonist 8Br-cGMP reduced the contractility of vascular rings to gradient calcium ions and Emax and the PKG inhibitor agonist KT5823 elevated the calcium sensitivity significantly. CONCLUSION: Protein kinase G plays an important role in post-shock mesenteric lymph blockage improving vascular calcium sensitivity.
Subject(s)
Animals , Male , Rats , Calcium/metabolism , Cyclic GMP-Dependent Protein Kinases/physiology , Mesenteric Artery, Superior/metabolism , Shock, Hemorrhagic/metabolism , Blotting, Western , Calcium/analysis , Cyclic GMP-Dependent Protein Kinases/analysis , Enzyme-Linked Immunosorbent Assay , Muscle Contraction , Mesenteric Artery, Superior/physiopathology , Random Allocation , Rats, Wistar , Shock, Hemorrhagic/physiopathologyABSTRACT
OBJECTIVES: Intestinal neovascularization and abnormal abdominal arterial flow rates have been reported in Crohn's disease. The aim of this study was to evaluate Doppler sonography as a method for assessing Crohn's disease activity based on changes in splanchnic hemodynamics. METHODS: Forty-eight patients with Crohn's disease, 22 healthy volunteers and 12 patients with irritable bowel syndrome were evaluated by Doppler ultrasound for flow parameters of the aorta and superior mesenteric artery. This evaluation included the cross-sectional area, maximum flow volume, peak systolic velocity, end diastolic velocity, resistance and the pulsatility index. Disease activity was classified according to the Crohn's disease activity index. RESULTS: Most measurements in the aorta and superior mesenteric artery were significantly different between Crohn's disease patients and both control groups. Only the aortic maximum flow volume (CC = 0.37, p = 0.009) and aortic peak systolic velocity (CC = 0.30, p = 0.035) showed a significant positive correlation with the Crohn's disease activity index. The determination of cut-off points for the aortic maximum flow volume and peak systolic velocity measurements increased the sensitivity (80 and 75% for flow volume and velocity, respectively), specificity (57 and 75%), accuracy (67 and 75%) and positive (57 and 68%) and negative (80 and 81%) predictive values. These cut-off values permitted the correct classification of most of the patients with Crohn's disease with respect to disease activity. None of the superior mesenteric artery measurements were able to discriminate patients in relation to disease activity. CONCLUSION: The aortic maximum flow volume and peak systolic velocity levels estimated by Doppler sonography reflected disease activity in Crohn's disease. Doppler sonography of the aorta is therefore a novel noninvasive adjunct method that may be ...
Subject(s)
Adolescent , Adult , Aged , Female , Humans , Male , Middle Aged , Young Adult , Crohn Disease , Splanchnic Circulation/physiology , Ultrasonography, Doppler, Color/methods , Aorta/physiopathology , Aorta , Blood Flow Velocity/physiology , Crohn Disease/physiopathology , Epidemiologic Methods , Hemodynamics , Irritable Bowel Syndrome/physiopathology , Irritable Bowel Syndrome , Mesenteric Artery, Superior/physiopathology , Mesenteric Artery, Superior , Predictive Value of Tests , Pulsatile FlowABSTRACT
PURPOSE: To evaluate hemodynamic and systemic changes during and after splanchnic ischemia and reperfusion (I/R). METHODS: Rats were divided into two groups: a) control: animals submitted to surgery, but not to I/R, treated with saline (5 ml/kg/h) for 150 min; b) group I/R: animals continuously infused with saline, and submitted to occlusion of the celiac trunk, superior mesenteric artery (SMA), and inferior mesenteric artery for 30 min, followed by a 120-min reperfusion. Mean arterial blood pressure (MABP), venous pressure, aortic and SMA blood flow, heart rate, esophageal temperature and hematocrit were evaluated. RESULTS: During reperfusion in I/R groups, there was a progressive decrease in MABP, aortic blood flow, SMA blood flow, heart rate and esophageal temperature; vein pressure and hematocrit remained unchanged during the experiment. CONCLUSION: The model of ischemia used causes systemic changes, which are evidenced by hypotension, decrease in mesenteric blood flow, heart rate and esophageal temperature.
OBJETIVO: Avaliar as alterações hemodinâmicas e sistêmicas decorrentes de isquemia e reperfusão (I/R) esplâncnica em ratos. MÉTODOS: Vinte ratos foram divididos em dois grupos: grupo controle: os animais foram submetidos à cirurgia, mas não a I/R e foram tratados com solução fisiológica (5 ml/kg/h) por 150 minutos; grupo I/R: os animais foram submetidos à administração contínua de solução fisiológica e à oclusão do tronco celíaco, artéria mesentérica superior e artéria mesentérica inferior por 30 minutos, seguidos por 120 minutos de reperfusão. Avaliou-se a pressão arterial média, pressão venosa, fluxo sangüíneo na aorta e na artéria mesentérica superior, freqüência cardíaca, temperatura esofágica e hematócrito. RESULTADOS: Durante a reperfusão, no grupo I/R, houve uma diminuição progressiva da pressão arterial média, fluxo sangüíneo na aorta e artéria mesentérica superior, freqüência cardíaca e temperatura esofágica; pressão venosa e hematócrito não sofreram alteração. CONCLUSÃO: O modelo de isquemia provocado por oclusão da artéria mesentérica superior, artéria mesentérica inferior e tronco celíaco por 30 minutos seguidos por 120 minutos de reperfusão provoca alterações sistêmicas evidenciadas por hipotensão, diminuição do fluxo sangüíneo mesentérico, da freqüência cardíaca e da temperatura esofágica.
Subject(s)
Animals , Male , Rats , Blood Pressure/physiology , Intestines/blood supply , Ischemia/physiopathology , Mesenteric Arteries/physiopathology , Reperfusion Injury/physiopathology , Splanchnic Circulation/physiology , Aorta/physiopathology , Disease Models, Animal , Hematocrit , Heart Rate/physiology , Mesenteric Artery, Inferior/physiopathology , Mesenteric Artery, Superior/physiopathology , Rats, WistarABSTRACT
La isquemia mesentérica es una insuficiencia circulatoria inadecuada para los requerimientos de la pared intestinal. Su presentación suele ser de extrema gravedad con historia de dolor abdominal crónico y/o infarto intestinal, con alta mortalidad y diagnóstico tardío. En el presente trabajo se realiza una revisión con los avances en el diagnóstico y manejo de esta condición, de acuerdo al compromiso vascular y los territorios afectados, con énfasis en su reconocimiento precoz y tratamiento agresivo, principalmente quirúrgico en los casos proximales al colon y médico en este último.
Subject(s)
Humans , Colon/blood supply , Intestines/blood supply , Ischemia/physiopathology , Mesentery/blood supply , Angioplasty , Mesenteric Artery, Superior/physiopathology , Abdominal Pain/etiology , Acute Disease , Chronic Disease , Ischemia/diagnosis , Ischemia/therapy , Venous ThrombosisABSTRACT
PURPOSE: Ischemia and reperfusion of the small intestine disrupts gut barrier, causes bacterial translocation and activates inflammatory responses. An experimental study was planned to evaluate if 99mTc labelled Escherichia coli translocates to mesenteric lymph nodes, liver, spleen, lung and serum of rats submitted to mesenteric ischemia/reperfusion. Additionally, it was observed if the time of reperfusion influences the level of translocation. METHODS: Forty male Wistar rats underwent 45 minutes of gut ischemia by occlusion of the superior mesenteric artery. The translocation of labelled bacteria to different organs and portal serum was determined in rats reperfused for 30 minutes, 24 hours, sham(S) and controls(C), using radioactivity count and colony forming units/g (CFU). RESULTS: All the organs from rats observed for 24 hours after reperfusion had higher levels of radioactivity and positive cultures (CFU) than did the organs of rats reperfused for 30 minutes, C and S, except in the spleen (p<0,01). CONCLUSION: The results of this study indicated that intestinal ischemia/reperfusion led to bacterial translocation, mostly after 24 hours of reperfusion.
Subject(s)
Animals , Male , Rats , Bacterial Translocation , Escherichia coli , Intestines , Ischemia , Reperfusion , Technetium , Mesenteric Artery, Superior/physiopathology , Rats, WistarABSTRACT
Spontaneous dissection of the superior mesenteric artery is an unusual cause of mesenteric ischemia. Diagnosis can be based on findings of the helicoidal computed tomography or selective angiography of the superior mesenteric artery. We report two male patients, aged 47 and 50 years, who were admitted for abdominal pain. Isolated superior mesenteric artery dissection was confirmed by angiography. Both patients were treated with anticoagulation, conservative measures and recovered uneventfully
Subject(s)
Humans , Male , Middle Aged , Ischemia , Mesenteric Artery, Superior/physiopathology , Aortography , Angiography , TomographyABSTRACT
OBJETIVO: A avaliaçäo do fluxo sanguíneo mesentérico utilizando-se a Dopplervelocimetria transcutânea de artéria mesentérica superior (AMS) é método näo invasivo que permite avaliar fatores envolvidos na perfusäo sanguínea intestinal. Este estudo teve como objetivo determinar as variáveis Dopplervelocimétricas da AMS em recém-nascidos normais a termo, relacionando-as aos fatores ligados a gestaçäo e crescimento fetal. MÉTODOS: A amostra continha 58 mäes e 59 recém-nascidos a termo (1 gestaçäo gemelar), cujos partos ocorreram no Hospital Israelita Albert Einstein. Utilizou-se equipamento Toshiba SSH 140 com sistema duplex-Doppler colorido de alta resoluçäo, avaliando-se a AMS na sua origem, determinando-se calibre, velocidade sistólica, velocidade diastólica, velocidade média e índices de resistência e pulsatilidade. RESULTADOS: Verificou-se que a média do calibre da artéria mesentérica superior foi 1.94 mm, a média da velocidade sistólica. 86.47 cm/s, a média da velocidade diastólica 17.66 cm/s e a média da velocidade média, 36.93 cm/s. Os valores médios dos índices de resistência e pulsatilidade foram respectivamente 0.79 e 1.91. O calibre da AMS correlacionou-se positivamente com o peso de nascimento e negativamente com o perímetro cefálico ; velocidades e índices guardam relaçäo com os dados antropométricos do recém-nascido, com o número de horas de vida, com o número de minutos em jejum e com o peso da mäe no fim da gestaçäo. CONCLUSÃO: As variáveis Doppleervelocimetricas estäo relacionadas a variáveis maternas e dos recém-nascidos, discutem-se fatores possivelmente implicados na associaçäo. Sexo do recém-nascido e peso da mäe no inicio da gestaçäo näo alteraram nossos resultados.
Subject(s)
Humans , Male , Female , Pregnancy , Infant, Newborn , Mesenteric Artery, Superior/physiopathology , Ultrasonography, Doppler , Blood Flow VelocityABSTRACT
Hoy en día la isquemia mesentérica aguda es una emergencia vascular intraabdominal tratable cuya etiología depende de cuatro causas muy específicas: Oclusión embólica de la arteria mesentérica superior, oclusión trombótica de la vena mesentérica superior e isquemia mesentérica no oclusiva. Para mejorar la supervivencia de estos pacientes se requiere un total índice de sospecha, maniobras tempranas y agresivas de resucitación, y del empleo de procedimientos diagnósticos selectivos (arteriografía mesentérica) que determinen específicamente la etiología. Esto permitirá poder ofrecer revascularizaciones quirúrgicas directas, optimización del funcionamiento cardiaco y corrección de estados de hipercoagulabilidad; todo ello encaminado a maximizar la cantidad de intestino funcionante que pueda ser salvado. Todas estas estrategias son las piedras angulares para el manejo exitoso de esta catástrofe vascular
Subject(s)
Humans , Mesenteric Artery, Superior/physiopathology , Ischemia/diagnosis , Ischemia/therapy , Mesenteric Vascular Occlusion/physiopathology , Mesenteric Vascular Occlusion/therapy , Superior Vena Cava Syndrome/diagnosis , Superior Vena Cava Syndrome/etiologyABSTRACT
Se presenta un caso clínico de una mujer de 17 años de edad, con un mixoma en atrium izquierdo, que ocasionó embolización a las arterias cerebral, mesentérica superior e iliaca externa izquierda. Fue resuelto quirúrgicamente. La paciente tuvo evolución satisfactoria