title: Intracellular diffusion of oxygen and hypoxic sensing: role of mitochondrial respiration.
abstract: In vivo, diffusional O(2) gradients from the capillary blood to the intracellular space determine O(2) availability at the O(2) sensing molecules in the cell. With a novel technique for imaging intracellular O(2) levels using green fluorescent protein (GFP), we examined the possibility that diffusional O(2) concentration gradients might be involved in the cellular hypoxic sensing in cultured Hep3B cells. In the present study, we failed to demonstrate significant gradients of intracellular O(2) when mitochondrial respiration was maximally elevated by an uncoupler of oxidative phosphorylation. Thus, we conclude that intracellular O(2) gradients may be negligible at normal mitochondrial O(2) demand in these cells.
authors.affiliation: Department of Physiology, Yamagata University School of Medicine, Yamagata, Japan. eiji@med.id.yamagata-u.ac.jp
authors.forename: Eiji
authors.initials: E
authors.lastname: Takahashi
authors.forename: Michihiko
authors.initials: M
authors.lastname: Sato
mesh_terms: D045744:Cell Line, Tumor; D019069:Cell Respiration; D004058:Diffusion; D006801:Humans; D000860:Hypoxia / Q000378:metabolism*; D042541:Intracellular Space / Q000378:metabolism*; D008928:Mitochondria / Q000378:metabolism*; D010100:Oxygen / Q000378:metabolism*; D013050:Spectrometry, Fluorescence
chemical_list: D010100:Oxygen