Alteration of adenosine triphosphate and other nucleotides after sublethal oxidant injury to rat type II alveolar epithelial cells.
The alveolar epithelial cells of the lower respiratory tract are continuously exposed to injurious agents, including oxygen radicals. The type II alveolar epithelial cell is critically important to the normal function of the lung, because it is responsible for synthesis of surfactant and other essential duties. The present investigation measured the level of intracellular nucleotides and adenosine over time after exposure of type II cells to sublethal concentrations of physiologically relevant oxidants, hydrogen peroxide and hypochlorous acid (HOCl). Initially, it was determined that 250 microM HOCl or 250 microM hydrogen peroxide could each cause sublethal injury to the type II cells after exposure of up to 1 and 2 hours, respectively. After exposure to 250 microM hydrogen peroxide, the intracellular levels of adenosine, adenosine diphosphate, and adenosine triphosphate all initially increased in the first 1 to 15 minutes, but subsequently decreased significantly, ultimately reaching close to 40% below control levels. The level of adenosine monophosphate remained significantly elevated throughout the exposure until returning to control levels after 2 hours. Similar results occurred after the type II cells were exposed to 250 microM HOCl. This study demonstrates that adenosine triphosphate and other cellular nucleotides and nucleosides were decreased in type II cells before lethal injury and subsequent cell death.
Abernathy
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Department of Medicine, Ohio State University, Columbus.
Pacht
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D000255:Adenosine Triphosphate / Q000378:metabolism*; D000818:Animals; D002470:Cell Survival / Q000187:drug effects; D004848:Epithelium / Q000187:drug effects / Q000378:metabolism; D006861:Hydrogen Peroxide / Q000008:administration & dosage / Q000494:pharmacology; D006997:Hypochlorous Acid / Q000008:administration & dosage / Q000494:pharmacology; D008297:Male; D009711:Nucleotides / Q000378:metabolism*; D016877:Oxidants / Q000494:pharmacology; D011650:Pulmonary Alveoli / Q000187:drug effects / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley
D009711:Nucleotides; D016877:Oxidants; D006997:Hypochlorous Acid; D000255:Adenosine Triphosphate; D006861:Hydrogen Peroxide