The Role of c-AMP and Ca ion on Awake Sheep Lung Injury

(1)绵羊肺损伤是由低压缺氧引起的缺氧性肺血管收缩所致。这被抑制的行政dibutyryl c-AMP。无论是暴露前20分钟给药，还是暴露后20分钟给药，都有明显的效果。对于体循环血压，db c-AMP没有引起任何显著变化。已知db c-AMP对内毒素诱导的肺损伤的抑制作用也显着。在另一系列实验中，我们的小组成员测试了扑尔敏（一种HI受体拮抗剂）、db c-AMP和钙通道拮抗剂维拉帕米和硝苯地平对聚凝胺诱导的肺损伤的预处理抑制潜力。结果表明，只有维拉帕米和db c-AMP能显著减弱聚凝胺的通透性改变，说明聚凝胺引起的通透性改变可受细胞内Ca ~（2+）和/或c-AMP水平的调节。(2)细胞通透性的影响 ...更多信息 用离体大鼠肺灌流法观察了c-AMP的二丁酰衍生物对肺血管反应性的影响。在用同种血液灌注的肺中，肺动脉输注db c-AMP（30 μ g/min）抑制缺氧诱导的血管收缩和由于推注血管紧张素II引起的血管收缩。氨茶碱对cAMP磷酸二酯酶的抑制作用与db c-AMP在减少缺氧引起的血管收缩中具有协同作用。在肺灌注细胞和蛋白质的盐溶液中，db cAMP抑制初始和长期的血管收缩后，弹丸注射2微克白三烯C4。因此认为db c-AMP非特异性地抑制肺血管反应性。(3)将兔耳垂浸入冷液中，通过开放动静脉动脉瓣来补偿毛细血管血流。这种现象是从激光多普勒组织流量计获得的记录的图案变化中注意到的。(4)在某些情况下，这些动物实验正在人类高海拔反应中进行测试，治疗正在进行测试。少

(1) Sheep lung injury was produced by hypobaric hypoxia which caused hypoxic pulmonary vasoconstriction. This was inhibited by administration of dibutyryl c-AMP. The effect was proved either in the case of the administration 20min before hypobaric exposure or 20 min after the exposure. For the systemic blood pressure, db c-AMP did not cause any significant change. The inhibitory effect of db c-AMP for endotoxin-induced lung injury was also known tobe remarkable. In another series of experiments our group members tested the pretreatment-inhibition potential of chlorpheniramine ( an HI receptor antagonist), db c-AMP, and the Ca channel antagonists verapamil and nifedipine on polybrene-induced lung injury. It was thus found that only verapamil and db c-AMP significantly attenuated the permeability effects of polybrene.It was interpreted that the permeability alteration induced by polybrene could be modulated by intracellular calcium and/or c- AMP levels.(2) The effects of the cell-permeab … More le dibutyryl derivative of c- AMP on the vascular reactivity of isolated perfused rat lungs were examined. In lungs perfused with homologous blood, pulmonary arterial infusion of db c-AMP (30 micro g/min) inhibited hypoxia- induced vasoconstriction and vasoconstriction due to bolus injection of angiotensin II. Cyclic AMP phosphodiesterase inhibition by aminophylline acted synergistically with db c-AMP in the reduction of hypoxia-induced vasoconstriction. In lungs perfused with cell and protein-free salt solution, db cAMP inhibited both initial and prolonged vasoconstriction following bolus injection of 2 micro g leukotriene C4. It is therefor considered that db c-AMP inhibited pulmonary vascular reactivity nonspecifically.(3) Using rabbit earlobes immersed in cold liquid, capillary blood flow was compensated by opening of arterio-venous anastomoses. This phenomenon was noticed from the pattern change of the record obtained by a laser-Doppler tissue flow meter.(4) These animal experiments were in some cases being tested in human high altitude responses and the treatment is being tested. Less