Jesch N K, Dörger M, Enders G, Rieder G, Vogelmeier C, Messmer K, Krombach F
Institute for Surgical Research, University of Munich, Germany.
Environ Health Perspect. 1997 Sep;105 Suppl 5(Suppl 5):1297-300. doi: 10.1289/ehp.97105s51297.
Nitric oxide (NO) is suggested to play a role in mediating pulmonary injury. However, interspecies differences appear to exist in the ability of alveolar macrophages (AM) to express the inducible nitric oxide synthase (iNOS) and to generate NO. The purpose of this study was to compare iNOS expression and NO production by rat, hamster, monkey, and human AM using the identical experimental conditions in vitro. As AM donors, CD rats, Syrian golden hamsters, cynomolgus monkeys, and nonsmoking, healthy human volunteers were used. The AM were obtained by bronchoalveolar lavage and stimulated in vitro with various concentrations and combinations of lipopolysaccharide (LPS) and interferon-gamma (IFN-gamma). The oxidation product of NO, nitrite, was measured in the AM supernatant by the Griess reaction. The expression of iNOS in AM was detected using immunocytochemistry and immunoblotting. The expression of iNOS mRNA was assessed by reverse transcriptase-polymerase chain reaction (RT-PCR). Rat AM, stimulated with either LPS or IFN-gamma, produced nitrite in a time- and dose-dependent manner. Combination of LPS and IFN-gamma resulted in a significantly enhanced nitrite formation. However, none of the treatments was able to induce hamster, monkey, or human AM to release measurable amounts of nitrite. Whereas expression of iNOS protein was only detected in stimulated rat AM, expression of iNOS mRNA was found in unstimulated and stimulated rat AM, slightly in stimulated hamster AM, but not in monkey and human AM. In conclusion, our findings point to distinct regulatory mechanisms of the NO pathway in AM from these four different species.
一氧化氮（NO）被认为在介导肺损伤中起作用。然而，肺泡巨噬细胞（AM）表达诱导型一氧化氮合酶（iNOS）并产生NO的能力似乎存在种间差异。本研究的目的是在体外相同实验条件下比较大鼠、仓鼠、猴子和人类AM的iNOS表达和NO产生情况。作为AM供体，使用了CD大鼠、叙利亚金黄仓鼠、食蟹猴和不吸烟的健康人类志愿者。通过支气管肺泡灌洗获得AM，并在体外用不同浓度和组合的脂多糖（LPS）和干扰素-γ（IFN-γ）进行刺激。通过格里斯反应测量AM上清液中NO的氧化产物亚硝酸盐。使用免疫细胞化学和免疫印迹检测AM中iNOS的表达。通过逆转录聚合酶链反应（RT-PCR）评估iNOS mRNA的表达。用LPS或IFN-γ刺激的大鼠AM以时间和剂量依赖性方式产生亚硝酸盐。LPS和IFN-γ的组合导致亚硝酸盐形成显著增强。然而，这些处理均未能诱导仓鼠、猴子或人类AM释放可测量量的亚硝酸盐。虽然仅在受刺激的大鼠AM中检测到iNOS蛋白的表达，但在未受刺激和受刺激的大鼠AM中均发现了iNOS mRNA的表达，在受刺激的仓鼠AM中略有表达，但在猴子和人类AM中未发现。总之，我们的研究结果表明这四种不同物种的AM中NO途径存在不同的调节机制。
