Martínez-Caro Leticia, Lorente José A, Marín-Corral Judith, Sánchez-Rodríguez Carolina, Sánchez-Ferrer Alberto, Nin Nicolás, Ferruelo Antonio, de Paula Marta, Fernández-Segoviano Pilar, Barreiro Esther, Esteban Andrés
Centro de Investigación en Red de Enfermedades Respiratorias (CibeRes), Hospital Universitario de Getafe, Universidad Europea de Madrid, Carretera de Toledo, km 12.500, Getafe, 28905 Madrid, Spain.
Intensive Care Med. 2009 Jun;35(6):1110-9. doi: 10.1007/s00134-009-1469-5. Epub 2009 Apr 10.
To demonstrate that increased formation of reactive oxygen (ROS) and nitrogen species (RNS) is involved in VILI-induced vascular dysfunction.
Male Sprague-Dawley anesthetized rats were ventilated for 60 min using low V(T) ventilation [V(T) 9 ml/kg, positive end-expiratory pressure (PEEP) 5 cmH(2)O, n = 18], and high V(T) ventilation (V(T) 35 ml/kg, zero PEEP, n = 18). Arterial pressure and respiratory system mechanics were monitored. Blood samples for the determination of arterial blood gases and lactate concentration were drawn. Vascular rings from the thoracic aortae were mounted in organ baths for isometric tension recording. We studied endothelium-dependent relaxation in norepinephrine-precontracted rings (acetylcholine, 10 nM-10 microM) and contraction induced by norepinephrine (1 nM-10 microM) in resting vessels. Vascular rings were preincubated for 30 min with Zn-Mn-SOD (100 u/ml) or tempol (10(-4) M) (extracellular and intracellular superoxide scavengers, respectively) or MnTMPyP (10(-5) M) (a superoxide and peroxynitrite scavenger). The presence of superoxide and nitrotyrosine in aortic rings was evaluated by immunofluorescence.
High V(T) ventilation induced hypotension, systemic acidosis, hypoxemia and hyperlactatemia, as well as impairment in acetylcholine and norepinephrine-induced responses in vitro. Responses to acetylcholine were improved by tempol (P = 0.004) and completely corrected (P < 0.001) by MnTMPyP. Responses to norepinephrine were also improved by treatment with tempol (P < 0.001) and MnTMPyP (P < 0.001). However, Zn-Mn-SOD did not improve acetylcholine- or norepinephrine-induced responses. Immunostaining for both superoxide and nitrotyrosine was increased in aortic rings from the high V(T) group.
Our data support a role for intracellular ROS and peroxynitrite in the high V(T) ventilation-induced vascular dysfunction.
证明活性氧（ROS）和活性氮（RNS）生成增加参与了机械通气所致肺损伤（VILI）引起的血管功能障碍。
对雄性Sprague-Dawley麻醉大鼠分别采用低潮气量通气[潮气量（V(T)）9 ml/kg，呼气末正压（PEEP）5 cmH₂O，n = 18]和高潮气量通气（V(T) 35 ml/kg，零PEEP，n = 18）进行60分钟通气。监测动脉血压和呼吸系统力学。采集血样测定动脉血气和乳酸浓度。取胸主动脉血管环置于器官浴槽中进行等长张力记录。我们研究了去甲肾上腺素预收缩血管环中的内皮依赖性舒张（乙酰胆碱，10 nM - 10 μM）以及静息血管中去甲肾上腺素诱导的收缩（1 nM - 10 μM）。血管环分别用Zn - Mn - SOD（100 u/ml）或tempol（10⁻⁴ M）（分别为细胞外和细胞内超氧化物清除剂）或MnTMPyP（10⁻⁵ M）（超氧化物和过氧亚硝酸盐清除剂）预孵育30分钟。通过免疫荧光评估主动脉环中超氧化物和硝基酪氨酸的存在情况。
高潮气量通气导致低血压、全身性酸中毒、低氧血症和高乳酸血症，以及体外乙酰胆碱和去甲肾上腺素诱导反应受损。tempol可改善对乙酰胆碱的反应（P = 0.004），MnTMPyP可使其完全恢复正常（P < 0.001）。tempol（P < 0.001）和MnTMPyP（P < 0.001）处理也可改善对去甲肾上腺素的反应。然而，Zn - Mn - SOD并未改善乙酰胆碱或去甲肾上腺素诱导的反应。高潮气量组主动脉环中超氧化物和硝基酪氨酸的免疫染色均增加。
我们的数据支持细胞内ROS和过氧亚硝酸盐在高潮气量通气诱导的血管功能障碍中起作用。
