RESUMO
INTRODUCTION: We study the effect on Intralipid on pulmonary circulation. METHODS: A 10% infusion of Intralipid was administered at a dose of 0.5/kg in 14 isolated rabbit lungs in which constant blood flow infusion was carried out principally in zone 3. The liquid filtration rate (LFR) and the mean pressure of the pulmonary artery were measured. RESULTS: A constant increase of mean pressure of the pulmonary artery was observed following the infusion (from 12.32 +/- 3.66 cm of H2O to 39.92 +/- 07.68 cmH2O (p < 0.01) which was associated to a significant increase in the rate of liquid filtration (from 0.018 +/- 0.01 g/min to 0.198 +/- 0.04 g/min; p < 0.01). CONCLUSIONS: The administration of Intralipid produces a statistically significant increase of mean pressure of the pulmonary artery and the rate of liquid filtration. This is probably caused by vasoconstriction due to metabolic changes produced by Intralipid on pulmonary circulation.
Assuntos
Pressão Sanguínea/efeitos dos fármacos , Espaço Extracelular/efeitos dos fármacos , Emulsões Gordurosas Intravenosas/farmacologia , Artéria Pulmonar/efeitos dos fármacos , Animais , Pressão Sanguínea/fisiologia , Permeabilidade Capilar/efeitos dos fármacos , Permeabilidade Capilar/fisiologia , Espaço Extracelular/fisiologia , Artéria Pulmonar/fisiologia , CoelhosRESUMO
The contribution of cyclo-oxygenase and 5-lipoxygenase metabolites on hemodynamics and oedema formation was investigated in 21 isolated rabbit lungs after a 10 min Oleic Acid (OA) infusion, by recording the changes on Fluid Filtration Rate (FFR) and Pulmonary Artery Pressure (PAP). Lungs (n = 7) were pre-treated with indomethacin (cyclo-oxygenase inhibitor) 50 min prior to OA or with Diethylcarbamazine (5-lipoxygenase inhibitor) (n = 7) or not pre-treated at all (control group, n = 7). The FFR in the indomethacin group was significantly greater than in the control and Diethylcarbamazine (DEC) groups 12 min after OA (7.6 +/- 2.3 mg.min-1 vs. 2.3 +/- 0.8 mg.min-1 and 0.96 +/- 0.8 mg.min-1 respectively) (P < 0.01). The FFR in the control lungs 20 min after OA was significantly greater than the corresponding DEC value (4.2 +/- 0.5 mg.min-1 vs. 1.6 +/- 1.0 mg.min-1) (P < 0.01). Mean Pulmonary Artery Pressure (MPAP) increased both in control and indomethacin groups (16.0 +/- 2.0 Torr to 24.3 +/- 3.7 Torr after 20 min OA and 14.4 +/- 2.5 Torr to 24.6 +/- 3.6 Torr at 10 min after OA, respectively), but MPAP value in DEC group did not significantly change 30 min after OA (14.7 +/- 1.5 Torr to 16.0 +/- 2.3 Torr) (P > 0.05). So we conclude that the selective inhibition of the 5-lipoxygenase metabolites (leukotriene-5hete) may play a protective role in OA induced oedema, whereas the selective inhibition of the cyclo-oxygenase pathway may have a deleterious effect on the hemodynamics and endothelial permeability in our experimental condition.
Assuntos
Indometacina/farmacologia , Inibidores de Lipoxigenase , Edema Pulmonar/induzido quimicamente , Animais , Pressão Sanguínea/efeitos dos fármacos , Permeabilidade Capilar/efeitos dos fármacos , Inibidores de Ciclo-Oxigenase/farmacologia , Bombas de Infusão , Ácidos Oleicos , Pré-Medicação , Artéria Pulmonar/fisiologia , CoelhosRESUMO
The contribution of cyclo-oxygenase and 5-lipoxygenase metabolites on hemodynamics and oedema formation was investigated in 21 isolated rabbit lungs after a 10 min Oleic Acid (OA) infusion, by recording the changes on Fluid Filtration Rate (FFR) and Pulmonary Artery Pressure (PAP). Lungs (n = 7) were pre-treated with indomethacin (cyclo-oxygenase inhibitor) 50 min prior to OA or with Diethylcarbamazine (5-lipoxygenase inhibitor) (n = 7) or not pre-treated at all (control group, n = 7). The FFR in the indomethacin group was significantly greater than in the control and Diethylcarbamazine (DEC) groups 12 min after OA (7.6 +/- 2.3 mg.min-1 vs. 2.3 +/- 0.8 mg.min-1 and 0.96 +/- 0.8 mg.min-1 respectively) (P < 0.01). The FFR in the control lungs 20 min after OA was significantly greater than the corresponding DEC value (4.2 +/- 0.5 mg.min-1 vs. 1.6 +/- 1.0 mg.min-1) (P < 0.01). Mean Pulmonary Artery Pressure (MPAP) increased both in control and indomethacin groups (16.0 +/- 2.0 Torr to 24.3 +/- 3.7 Torr after 20 min OA and 14.4 +/- 2.5 Torr to 24.6 +/- 3.6 Torr at 10 min after OA, respectively), but MPAP value in DEC group did not significantly change 30 min after OA (14.7 +/- 1.5 Torr to 16.0 +/- 2.3 Torr) (P > 0.05). So we conclude that the selective inhibition of the 5-lipoxygenase metabolites (leukotriene-5hete) may play a protective role in OA induced oedema, whereas the selective inhibition of the cyclo-oxygenase pathway may have a deleterious effect on the hemodynamics and endothelial permeability in our experimental condition.
RESUMO
The contribution of cyclo-oxygenase and 5-lipoxygenase metabolites on hemodynamics and oedema formation was investigated in 21 isolated rabbit lungs after a 10 min Oleic Acid (OA) infusion, by recording the changes on Fluid Filtration Rate (FFR) and Pulmonary Artery Pressure (PAP). Lungs (n = 7) were pre-treated with indomethacin (cyclo-oxygenase inhibitor) 50 min prior to OA or with Diethylcarbamazine (5-lipoxygenase inhibitor) (n = 7) or not pre-treated at all (control group, n = 7). The FFR in the indomethacin group was significantly greater than in the control and Diethylcarbamazine (DEC) groups 12 min after OA (7.6 +/- 2.3 mg.min-1 vs. 2.3 +/- 0.8 mg.min-1 and 0.96 +/- 0.8 mg.min-1 respectively) (P < 0.01). The FFR in the control lungs 20 min after OA was significantly greater than the corresponding DEC value (4.2 +/- 0.5 mg.min-1 vs. 1.6 +/- 1.0 mg.min-1) (P < 0.01). Mean Pulmonary Artery Pressure (MPAP) increased both in control and indomethacin groups (16.0 +/- 2.0 Torr to 24.3 +/- 3.7 Torr after 20 min OA and 14.4 +/- 2.5 Torr to 24.6 +/- 3.6 Torr at 10 min after OA, respectively), but MPAP value in DEC group did not significantly change 30 min after OA (14.7 +/- 1.5 Torr to 16.0 +/- 2.3 Torr) (P > 0.05). So we conclude that the selective inhibition of the 5-lipoxygenase metabolites (leukotriene-5hete) may play a protective role in OA induced oedema, whereas the selective inhibition of the cyclo-oxygenase pathway may have a deleterious effect on the hemodynamics and endothelial permeability in our experimental condition.
RESUMO
We studied the effect of varying ventilatory frequency (VF) using intermittent positive pressure ventilation (IPPV) on fluid filtration rate (FFR) in 16 isolated rabbit lung preparations perfused at constant blood flow and airway pressure (AWP). Mean pulmonary artery pressure (MPAP), AWP, pulmonary vascular resistance (PVR), pH, PaO2, PaCO2 and colloid osmotic pressure (COP) were measured. Ventilation was performed by a piston pump ventilator. VF was ahanged every 10 min. by the following schedule 25-40-55-70-40-25 breaths per min. A group of 6 rabbits was ventilated under normal hemodynamic conditions and another group of 10 rabbit was ventilated after the prodution of hydrostatic pulmonary edema. Blood gas exhange was satisfactory in both groups of rabbits. There was not statistically significant correlation between VF and FFR in the two experimental situations (p>0.05). In conclusion, VF variation using IPPV (keeping AWP constant) did not alter liquid transfer between the microvasculature and lung interstitial space under normal hemodynamic conditions nor in hydrostatic lung edema in insolated perfused rabbits lung