摘要 : We Studied the in vivo persistence of hypoxia-inducible factor-l alpha (HIF-l alpha), main transducer of hypoxia, the differential response in organs exposed to the same degree of hypoxemia and the relationship with apoptosis. We ... 展开 We Studied the in vivo persistence of hypoxia-inducible factor-l alpha (HIF-l alpha), main transducer of hypoxia, the differential response in organs exposed to the same degree of hypoxemia and the relationship with apoptosis. We measured HIF-l alpha (immunohistochemistry peroxidase and Western blot) and apoptosis (TUNEL) in heart, liver, kidney, gastrocnemius, and brain of rats exposed to chronic normobaric hypoxia (10% O-2) or normoxia (21% O-2) for 2 weeks. Despite same arterial O-2 pressure and increased hemoglobin concentration (219 +/- 5 vs. 124 +/- 4 g/L), the organs responded differently. While marked in brain, muscle, and kidney cortex, HIF-1 alpha Was undetectable in heart and liver. In kidney medulla, HIF-l alpha was high in both normoxia and hypoxia. By contrast, apoptosis was marked in heart, slight in kidney medulla, and undetectable in other organs. We conclude that the HIF-l alpha response to chronic hypoxia can be a Sustained phenomenon, but not in all organs, and that apoptosis responds differently from HIF-l alpha. (c) 2006 Elsevier Inc. All rights reserved. 收起