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

(1)绵羊肺损伤是由低氧缺氧引起的肺血管缺氧收缩引起的。这被二丁基c-AMP抑制。在低压暴露前20分钟或暴露后20分钟给药的情况下，证明了这种效果。对于全身血压，db - c-AMP没有引起任何明显的变化。db - c-AMP对内毒素诱导的肺损伤也有显著的抑制作用。在另一系列实验中，我们的小组成员测试了氯苯那敏（一种HI受体拮抗剂）、db - c-AMP和Ca通道拮抗剂维拉帕米和硝苯地平对聚苯乙烯诱导的肺损伤的预处理抑制潜力。结果发现，只有维拉帕米和db - c-AMP能显著减弱聚苯乙烯的通透性。结果表明，聚苯乙烯诱导的通透性改变可能受细胞内钙和/或c- AMP水平的调节。(2)研究了c- AMP细胞透性衍生物对离体灌注大鼠肺血管反应性的影响。在同源血灌注肺中，肺动脉灌注db - c-AMP（30微g/min）可抑制缺氧诱导的血管收缩和大剂量注射血管紧张素II引起的血管收缩。氨茶碱对环AMP磷酸二酯酶的抑制作用与db - c-AMP协同作用，减少缺氧引起的血管收缩。在肺灌注无细胞和无蛋白盐溶液后，db cAMP抑制2微g白三烯C4后的初始和延长的血管收缩。因此，我们认为db - c-AMP非特异性地抑制肺血管反应性。(3)兔耳垂浸泡在冷液中，通过打开动静脉吻合口来补偿毛细血管血流。这种现象是由激光多普勒组织流量计记录的模式变化引起的。(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，并且正在测试治疗方法。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