Rüstow B, Haupt R, Stevens P A, Kunze D
Institute of Pathological and Clinical Biochemistry, Charité Hospital, Humboldt University, Berlin, Germany.
Am J Physiol. 1993 Aug;265(2 Pt 1):L133-9. doi: 10.1152/ajplung.1993.265.2.L133.
Lung surfactant is exposed to strongly oxidizing conditions. We examined the hypothesis that in lung, lipophilic antioxidants are secreted together with surfactant to counteract the peroxidation of surfactant constituents. Lung lavage and the subfractions of the alveolar surfactant contain the lipophilic antioxidants vitamin E, vitamin A, and plasmalogens. The specific radioactivity of vitamin E isolated from serum, lung homogenate, lamellar bodies, and lung lavage increased linearly up to 3 h after intraperitoneal application of [3H]tocopherol. [3H]tocopherol was secreted in situ together with [14C]palmitic acid-labeled phospholipid in response to isoproterenol. Type II cells cultured in presence of [3H]tocopherol or of [3H]cholecalciferol and [14C]palmitic acid responded to isoproterenol by a time-dependent increase in secretion of [3H]tocopherol and of 14C-labeled phospholipids but not of [3H]cholecalciferol. The isoproterenol-stimulated secretion of [3H]tocopherol and of 14C-labeled phospholipids by type II cells is inhibited by surfactant protein A. We conclude that the alveolar surfactant contains lipophilic antioxidants as integral constituents. [3H]tocopherol seems to be secreted together with surfactant.
肺表面活性物质会暴露于强氧化环境中。我们检验了这样一种假说：在肺中，亲脂性抗氧化剂与表面活性物质一同分泌，以对抗表面活性物质成分的过氧化作用。肺灌洗物以及肺泡表面活性物质的亚组分含有亲脂性抗氧化剂维生素E、维生素A和缩醛磷脂。腹腔注射[3H]生育酚后，从血清、肺匀浆、板层小体和肺灌洗物中分离出的维生素E的比放射性在3小时内呈线性增加。[3H]生育酚与[14C]棕榈酸标记的磷脂一起原位分泌，以响应异丙肾上腺素。在[3H]生育酚或[3H]胆钙化醇和[14C]棕榈酸存在的情况下培养的II型细胞，对异丙肾上腺素的反应是[3H]生育酚和14C标记的磷脂分泌呈时间依赖性增加，但[3H]胆钙化醇的分泌没有增加。表面活性蛋白A抑制了异丙肾上腺素刺激的II型细胞分泌[3H]生育酚和14C标记的磷脂。我们得出结论，肺泡表面活性物质含有亲脂性抗氧化剂作为其组成成分。[3H]生育酚似乎与表面活性物质一起分泌。
