Cytochrome P450 regulation by hyperoxia and nitric oxide

描述(由申请人提供)： 吸入一氧化氮(INO)和补充氧气在临床上用于 与呼吸衰竭相关的肺部疾病的治疗 婴儿。在早产儿和足月儿中，氧气和/或一氧化氮 治疗可能会导致肺损伤。此应用程序的长期目标是 为防治肺部疾病制定合理的策略 婴儿暴露在高氧和INO环境中的病理学。此应用程序 包括4个具体目标：(1)通过以下方式描述具体机制 哪种高氧和INO单独或联合作用，调节肝脏和 肺细胞色素P450酶表达与急性肺损伤的关系 受伤。新生大鼠将暴露在高氧环境中(超过95% 氧)，INO，高氧和INO的混合物，或在室内空气中保持 选定的时间点，最多7天。消息级别[(Northern 逆转录聚合酶链式反应(RT-PCR)杂交 原位杂交)、载脂蛋白含量(Western blotting和 免疫组织化学)和酶活性(荧光法) 肝脏和肝脏中的亚型，即细胞色素P1A1/LA2和细胞色素P2EI将被测定 阿龙。(2)检验内源性NO参与 高氧对细胞色素P450酶的下调及其机制(S) 高氧所致的肺损伤。缺乏NOS2或NOS3基因的小鼠将是 用来专门测试内源性NO对 高氧性肺损伤。(3)确定芳基的可能作用 烃类受体(AHR)在新生儿不同易感性中的作用 暴露于高氧或高氧+INO的啮齿动物。将使用AHR空小鼠 目的：探讨AHR在急性肺损伤中的作用。(4)测试 一种假说是暴露在空气中导致新生儿CYP酶印记 高氧，[NO，或高氧+INO]导致肺发育异常。 成年大鼠。研究结果将提供有关急性呼吸道感染的关键信息。 INO和高氧对细胞色素P450表达的影响 新生儿肺成熟异常时这些酶的印迹 在成人生活中度过。这些研究还将有助于确定适当的 支持性治疗将由此产生的不良反应降至最低 临床上重要的治疗方法。

DESCRIPTION (provided by applicant): Inhaled nitric oxide (INO) and supplemental oxygen are used clinically in the treatment of pulmonary diseases associated with respiratory failure in infants. In preterm and term human infants, oxygen and/or nitric oxide therapy may contribute to lung injury. The long-term goal of this application is to develop rational strategies for the prevention/treatment of lung pathologies in infants exposed to hyperoxia and INO. This application comprises 4 Specific Aims: (1) To characterize the specific mechanisms by which hyperoxia and INO, alone or in combination, modulate hepatic and pulmonary cytochrome P450 (CYP) enzyme expression, in relation to acute lung injury. Newborn rats will be exposed to hyperoxia (geater than 95 percent oxygen), INO, a mixture of hyperoxia and INO, or maintained in room air for selected time points for up to 7 days. Message levels [(Northern hybridization, reverse transcriptase polymerase chain reaction (RT-PCR), in situ hybridization), apoprotein contents (Western blotting and immunohistochemistry), and enzyme activities (fluorimetry) of specific CYP isoforms, i.e. CY`PlAl/lA2 and CYP2EI will be determined in the liver and lung. (2) To test the hypothesis that endogenous NO contributes to the downregulation of specific CYP enzymes by hyperoxia, and to the mechanism(s) of lung injury by hyperoxia. Mice lacking the gene for NOS2 or NOS3 will be used to specifically test the hypothesis that endogenous NO contributes to hyperoxic lung injury. (3) To determine the possible role of the aryl hydrocarbon receptor (AHR) in the differential susceptibilities of newborn rodents exposed to hyperoxia or hyperoxia + INO. AHR null mice will be used to determine the possible role of the AHR in acute lung injury. (4) To test the hypothesis that neonatal imprinting of CYP enzymes caused by exposure to hyperoxia, [NO, or hyperoxia + INO contributes to abnormal lung maturation in adult rats. The results will provide critical information about the acute effects of INO and hyperoxia on CYP expression, and the contribution of neonatal imprinting of these enzymes in abnormal lung maturation occurring through adult life. The studies will also help identify appropriate supportive therapies to minimize any adverse effects arising out of this clinically important therapy.