High-altitude hypoxia. A challenging strain targeting cellular redox homeostasis

摘要: After putting forward some evidence of hypobaric hypoxia as a particular stimulus causing systemic, tissue and cellular challenging strains, the present short review is focused on current findings relating reasoning increased generation reactive oxygen nitrogen species (RONS) when humans animals organisms are exposed to high-altitude environments. In contrast earlier concepts, hypoxia-induced decreased physiological availability seems be prompt condition loss redox homeostasis resulting in oxidative stress, which does not further augment upon reoxygenation. The apparently paradoxical free radical production regulated by very specific mechanisms, being mitochondria special sources targets RONS well critical organelles related death mediated apoptosis. Key-words: hypoxia, radicals, damage, mitochondria, apoptosis RESUMO Hipoxia de altitude. Um estimulo indutor alteracoes na homeostasia Apos considerar evidencias da hipoxia hipobarica enquanto um deleterias nivel sistemico, tecidual e celular, presente breve revisao focar-se-a sobre os principais mecanismos associados producao adicional especies reactivas oxigenio nitrogenio (ERON) em humanos animais submetidos condicoes ambientais hipoxia. Em oposicao aos conceitos pioneiros, diminuicao disponibilidade que se verifica uma condicao favoravel perda celular resultando num incremento do stress oxidativo, o qual nao agravado apos periodos reoxigenacao. Esta aparente paradoxal geracao radicais livres regulada por celulares especificos, sendo mitocondrias fontes simultaneamente alvos das ERON, bem como organelos criticos morte mediada apoptose. Palavras-chave: hipoxia, livres, lesao oxidativa, mitocondrias, apoptose 4. revista (164pp):miolo 30/12/08 14:08 Page 459