The effect of exposure to hypoxia on superoxide formation by alveolar macrophages is indirect.

Aims: To elucidate the role of alveolar macrophages (AM) in the pathogenesis of hypoxic pulmonary hypertension (HPH), we tested the effects of sustained hypoxia on AM polarization and on the formation of superoxide by AM in vivo and in vitro.

Main Methods: Rat AM were obtained by bronchoalveolar lavage. 4-day exposure to hypoxia (10% O2) was carried out in vivo (rats in isobaric hypoxic chamber, controls kept in air) or in vitro (control AM in 21% O2 and 5% CO2).

Decreased collagen VI in the tunica media of pulmonary vessels during exposure to hypoxia: a novel step in pulmonary arterial remodeling.

The development of hypoxic pulmonary hypertension is characterized by the structural remodeling of pulmonary arteries. However, the relationship between changes of arterial cells and the extracellular matrix remains unclear. We focused on the evaluation of the non-fibrillar collagen changes in tunica media induced by a four-day exposure to hypoxia and the correlation of these changes with the pulmonary arterial wall structure modifications.

Depletion of alveolar macrophages attenuates hypoxic pulmonary hypertension but not hypoxia-induced increase in serum concentration of MCP-1.

Exposure to hypoxia, leading to hypoxic pulmonary hypertension (HPH), is associated with activation of alveolar macrophages (AM). However, it remains unclear how AM participate in this process. There are studies which imply that the AM product monocyte chemoattractant protein-1 (MCP-1) plays an important role.

Oxidative Stress in the Developing Rat Brain due to Production of Reactive Oxygen and Nitrogen Species.

Oxidative stress after birth led us to localize reactive oxygen and nitrogen species (RONS) production in the developing rat brain. Brains were assessed a day prenatally and on postnatal days 1, 2, 4, 8, 14, 30, and 60. Oxidation of dihydroethidium detected superoxide; 6-carboxy-2',7'-dichlorodihydrofluorescein diacetate revealed hydrogen peroxide; immunohistochemical proof of nitrotyrosine and carboxyethyllysine detected peroxynitrite formation and lipid peroxidation, respectively.

Comparison of the effects of tert-butyl hydroperoxide and peroxynitrite on the oxidative damage to isolated beef heart mitochondria.

Isolated beef heart mitochondria have been exposed to tert-butyl hydroperoxide (tBHP) and peroxynitrite (PeN) in order to model the effects of reactive oxygen and nitrogen species on mitochondria in vivo. The formation of malondialdehyde (MDA), protein carbonyls, lipofuscin-like pigments (LFP), and nitrotyrosine was studied during incubations with various concentrations of oxidants for up to 24 h. The oxidants differed in their ability to oxidize particular substrates.