Olson N C, Brown T T
Am J Vet Res. 1986 Oct;47(10):2187-92.
Effects of dexamethasone on pulmonary hemodynamics, pulmonary mechanics, and gas exchange were determined in anesthetized (pentobarbital sodium) and paralyzed (pancuronium bromide) calves (9.4 +/- 0.4 weeks old) during 5 hours of endotoxemia. Escherichia coli endotoxin (055-B5) was infused IV at 20 micrograms/kg the 1st hour, followed by a continuous infusion at 10 micrograms/kg/hour for the following 4 hours. Dexamethasone (5 mg/kg) was given IV 18 hours and 1 hour before endotoxin administration, and was also administered IV (1 mg/kg/hr) during endotoxemia. Endotoxin induced large increases in pulmonary artery pressure, pulmonary vascular resistance, alveolar-arterial O2 gradient, alveolar dead-space ventilation, postmortem gravimetric lung weight of bloodless lung, albumin and total protein concentrations in bronchoalveolar lavage fluid, and the number of neutrophils recovered from bronchoalveolar lavage fluid. Endotoxin induced decreases in the cardiac index, dynamic lung compliance, and PaO2. Dexamethasone attenuated most of the cardiopulmonary responses induced by endotoxin, especially during the first 3 hours of endotoxemia. Dexamethasone blocked endotoxin-induced increases in bronchoalveolar lavage albumin, total protein, and neutrophil content. Therefore, glucocorticoids modify endotoxin-induced pulmonary injury in calves, possibly by limiting mobilization of endogenous arachidonic acid.
在5小时的内毒素血症期间，测定了地塞米松对麻醉（戊巴比妥钠）和麻痹（泮库溴铵）的犊牛（9.4±0.4周龄）肺血流动力学、肺力学和气体交换的影响。第1小时静脉输注大肠杆菌内毒素（055 - B5），剂量为20微克/千克，随后在接下来的4小时内以10微克/千克/小时的速度持续输注。在内毒素给药前18小时和1小时静脉给予地塞米松（5毫克/千克），在内毒素血症期间也静脉给药（1毫克/千克/小时）。内毒素导致肺动脉压、肺血管阻力、肺泡 - 动脉血氧梯度、肺泡死腔通气、无血肺的死后重量、支气管肺泡灌洗液中的白蛋白和总蛋白浓度以及从支气管肺泡灌洗液中回收的中性粒细胞数量大幅增加。内毒素导致心脏指数、动态肺顺应性和动脉血氧分压降低。地塞米松减弱了内毒素诱导的大多数心肺反应，尤其是在内毒素血症的前3小时。地塞米松阻止了内毒素诱导的支气管肺泡灌洗白蛋白、总蛋白和中性粒细胞含量的增加。因此，糖皮质激素可能通过限制内源性花生四烯酸的动员来减轻犊牛内毒素诱导的肺损伤。
