Shellito J E, Kolls J K, Summer W R
Section of Pulmonary and Critical Care Medicine, Louisiana State University Medical Center, New Orleans 70112, USA.
Am J Respir Cell Mol Biol. 1995 Jul;13(1):45-53. doi: 10.1165/ajrcmb.13.1.7541222.
We investigated the effect of intratracheal (i.t.) lipopolysaccharide (LPS) on alveolar macrophage release of nitric oxide. Mice received i.t. LPS at doses ranging from 1 to 100 micrograms/100 g body weight and were killed at serial intervals for bronchoalveolar lavage. Control mice received i.t. phosphate-buffered saline. We found that after i.t. LPS, there was an early (1 to 3 days) influx of neutrophils followed by a later (5 to 7 days) influx of macrophages into the lungs. Alveolar macrophages lavaged from mice given i.t. LPS did not spontaneously release nitric oxide (measured as nitrite), but the capacity of these cells to release nitric oxide in vitro in response to interferon-gamma (IFN-gamma) or LPS was markedly upregulated. Alveolar macrophages lavaged from mice given i.t. LPS but not i.t. phosphate-buffered saline also expressed mRNA for inducible nitric oxide synthase as measured by semiquantitative reverse-transcription polymerase chain reaction. To investigate possible mechanisms for cellular priming for increased nitric oxide release after i.t. LPS, mice were depleted of CD4+ lymphocytes with an anti-CD4 antibody. Alveolar macrophages from CD4-depleted mice given i.t. LPS released significantly less nitric oxide in vitro in comparison to macrophages from nondepleted mice. Additional mice were treated with neutralizing doses of anti-tumor necrosis factor or anti-IFN-gamma antibody before i.t. LPS. Pretreatment with each cytokine antibody decreased but did not eliminate macrophage priming for nitric oxide release after i.t. LPS. We conclude that intratracheal LPS induces mRNA for nitric oxide synthase in alveolar macrophages, priming the cells for increased release of nitric oxide in vitro.(ABSTRACT TRUNCATED AT 250 WORDS)
我们研究了气管内注射脂多糖（LPS）对肺泡巨噬细胞释放一氧化氮的影响。小鼠接受剂量范围为1至100微克/100克体重的气管内注射LPS，并在连续的时间间隔处死以进行支气管肺泡灌洗。对照小鼠接受气管内注射磷酸盐缓冲盐水。我们发现，气管内注射LPS后，早期（1至3天）有中性粒细胞流入，随后晚期（5至7天）有巨噬细胞流入肺部。从接受气管内注射LPS的小鼠中灌洗得到的肺泡巨噬细胞不会自发释放一氧化氮（以亚硝酸盐测量），但这些细胞在体外对干扰素-γ（IFN-γ）或LPS作出反应时释放一氧化氮的能力明显上调。通过半定量逆转录聚合酶链反应测量，从接受气管内注射LPS而非磷酸盐缓冲盐水的小鼠中灌洗得到的肺泡巨噬细胞也表达诱导型一氧化氮合酶的mRNA。为了研究气管内注射LPS后细胞引发一氧化氮释放增加的可能机制，用抗CD4抗体使小鼠的CD4+淋巴细胞耗竭。与未耗竭小鼠的巨噬细胞相比，接受气管内注射LPS的CD4耗竭小鼠的肺泡巨噬细胞在体外释放的一氧化氮明显减少。另外的小鼠在气管内注射LPS之前用中和剂量的抗肿瘤坏死因子或抗IFN-γ抗体进行处理。每种细胞因子抗体预处理后，气管内注射LPS后巨噬细胞引发的一氧化氮释放减少，但并未消除。我们得出结论，气管内注射LPS诱导肺泡巨噬细胞中一氧化氮合酶的mRNA表达，使细胞在体外引发一氧化氮释放增加。（摘要截短至250字）
