Systemic evaluation on ischemia and reperfusion injury of splanchnic organs in rats.

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.

Systemic evaluation on ischemia and reperfusion injury of splanchnic organs in rats / Alterações sistêmicas na isquemia e reperfusão de órgãos esplâncnicos em ratos

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.

Inferior mesenteric artery back pressure and collateral circulation to the distal colon.

The contribution of the hypogastric and superior mesenteric arteries to inferior mesenteric artery collateral (back) pressure (r-IMA) was measured in eight patients who were free from arterial disease and were operated on for small sigmoid carcinoma. Peak and mean r-IMAs were measured after clamping both common iliac arteries and the middle colic artery together with the marginal artery of Drummond. Measurements were repeated after the injection of 50 mg papaverine into the inferior mesenteric artery. For comparison the r-IMA was normalized against the radial artery pressure to create the r-IMA:radial artery pressure ratio. At peak systolic pressure the r-IMA:radial artery pressure was approximately 0.6. This fell with crossclamping of the middle colic artery and marginal artery of Drummond; a slightly greater fall was observed when the common iliac arteries were clamped. The findings were similar when mean pressures were compared. The changes in pressure ratio observed after collateral clamping were slightly amplified by injection of papaverine. These data suggest that the hypogastric arteries make at least as great or a slightly greater contribution to r-IMA than do the middle colic artery plus marginal artery of Drummond. The data also indicate the presence of other substantial collaterals. These findings stress the importance of the hypogastric collateral supplying the sigmoid colon when the inferior mesenteric artery is acutely occluded as it is during aneurysm resection.