高原缺氧对脓毒败血症时TXA_2，PGI_2及L－ENK含量的影响及其与肺损伤

EHects of altitude hypoxia on TXA_2,PGI_2 and L-ENK contents andtheir correlations with lung injury induced by septicemia

目的：作者探讨高原（海拔３０８０ｍ）缺氧对脓毒败血症性肺损伤的影响．方法：采用盲肠结扎穿孔方法复制脓毒败血症模型，采用￣１２５Ⅱ放免测定方法测定家兔静脉血中血栓素Ａ＿２（ＴＸＡ＿２），前列腺环素（ＰＧＩ＿２）和动脉壁内亮氨酸脑啡肽（Ｌ－ＥＮＫ）的含量及小鼠死亡率的变化．结果：高原缺氧使动物２４ｈ累积死亡率（９７．１％）显著增加；ＴＸＢ＿２含量是对照组的４倍，６－ｋｅｔｏ－ＰＧＦ＿（１α）含量也有增加；花生四烯酸代谢的改变可以被消炎痛所阻断；肠、肾及肺动脉壁内Ｌ－ＥＮＫ含量明显降低（Ｐ＜０．０１）；支气管肺泡灌洗液中白蛋白含量明显增加（Ｐ＜０．０１）．结论：结果表明环氧酶代谢产物不是肺通透性的主要介质，ＴＸＡ＿２和Ｌ－ＥＮＫ的变化可能是脓毒败血症时肺动脉压增高、肺血管阻力增加的机制之一．

Objective: The aim is to explore the effects of altitude(3080 m above sea level) hypoxia on septicpulmonary injury. Methods :A model of septicemia induced by cecal ligation and puncture,thromboxane A_2(TXA_2),prostacyclin (PGI_2 ) of the venous plasma and leucine-enkephalins (L-ENK)in the arterial wallswere measured by using radioimmunoassay in 31 rabbits,and mouse mortality was observed.Results : 24-haccumulative mortality of mouse(97.1%)was greater than that of control(35%); TXB_2 was as 4 timesmuch as the concentration of control group and 6-keto-PGF_(1α) was elevated too. These changes of arachidonicmetabolism could be blocked by indomethasin. The content of L-ENK in arterial walls of pulmonary,mesen-teric and renal arteries decreased significantly compared with control group(P<0.01).The albumin contentof the bronchoalveolar lavage fluid increased significantly compared with control group(P<0.01 ).Conclu-sion: The results demonstrate that the metabolites of cyclooxygenase are not the major mediators to increasepulmonary permeability in the experiment.The content alteration of TXA_2 and L-ENK may be one of themechanisms,by which the pulmonary artery pressure and pulmonary vascular resistance increased during sepsis.