title: Methane biogenesis during sodium azide-induced chemical hypoxia in rats.
abstract: Previous studies demonstrated methane generation in aerobic cells. Our aims were to investigate the methanogenic features of sodium azide (NaN(3))-induced chemical hypoxia in the whole animal and to study the effects of l-α-glycerylphosphorylcholine (GPC) on endogenous methane production and inflammatory events as indicators of a NaN(3)-elicited mitochondrial dysfunction. Group 1 of Sprague-Dawley rats served as the sham-operated control; in group 2, the animals were treated with NaN(3) (14 mg·kg(-1)·day(-1) sc) for 8 days. In group 3, the chronic NaN(3) administration was supplemented with daily oral GPC treatment. Group 4 served as an oral antibiotic-treated control (rifaximin, 10 mg·kg(-1)·day(-1)) targeting the intestinal bacterial flora, while group 5 received this antibiotic in parallel with NaN(3) treatment. The whole body methane production of the rats was measured by means of a newly developed method based on photoacoustic spectroscopy, the microcirculation of the liver was observed by intravital videomicroscopy, and structural changes were assessed via in vivo fluorescent confocal laser-scanning microscopy. NaN(3) administration induced a significant inflammatory reaction and methane generation independently of the methanogenic flora. After 8 days, the hepatic microcirculation was disturbed and the ATP content was decreased, without major structural damage. Methane generation, the hepatic microcirculatory changes, and the increased tissue myeloperoxidase and xanthine oxidoreductase activities were reduced by GPC treatment. In conclusion, the results suggest that methane production in mammals is connected with hypoxic events associated with a mitochondrial dysfunction. GPC is protective against the inflammatory consequences of a hypoxic reaction that might involve cellular or mitochondrial methane generation.
authors.affiliation: Institute of Surgical Research, Faculty of Medicine, University of Szeged, Szeged, Hungary.
authors.forename: Eszter
authors.initials: E
authors.lastname: Tuboly
authors.forename: Andrea
authors.initials: A
authors.lastname: Szabó
authors.forename: Dénes
authors.initials: D
authors.lastname: Garab
authors.forename: Gábor
authors.initials: G
authors.lastname: Bartha
authors.forename: Ágnes
authors.initials: Á
authors.lastname: Janovszky
authors.forename: Gábor
authors.initials: G
authors.lastname: Erős
authors.forename: Anna
authors.initials: A
authors.lastname: Szabó
authors.forename: Árpád
authors.initials: Á
authors.lastname: Mohácsi
authors.forename: Gábor
authors.initials: G
authors.lastname: Szabó
authors.forename: József
authors.initials: J
authors.lastname: Kaszaki
authors.forename: Miklós
authors.initials: M
authors.lastname: Ghyczy
authors.forename: Mihály
authors.initials: M
authors.lastname: Boros
mesh_terms: D000255:Adenosine Triphosphate / Q000032:analysis; D000818:Animals; D015687:Cell Hypoxia; D004791:Enzyme Inhibitors / Q000009:adverse effects*; D005765:Gastrointestinal Agents / Q000494:pharmacology; D041981:Gastrointestinal Tract / Q000187:drug effects / Q000378:metabolism / Q000382:microbiology; D005997:Glycerylphosphorylcholine / Q000494:pharmacology; D007249:Inflammation / Q000139:chemically induced / Q000378:metabolism; D008102:Liver Circulation / Q000187:drug effects; D008297:Male; D008697:Methane / Q000096:biosynthesis*; D008833:Microcirculation / Q000187:drug effects; D018613:Microscopy, Confocal / Q000379:methods; D018715:Microscopy, Video / Q000379:methods; D009195:Peroxidase / Q000032:analysis; D061088:Photoacoustic Techniques / Q000379:methods; D051381:Rats; D017207:Rats, Sprague-Dawley; D012294:Rifamycins / Q000494:pharmacology; D000078262:Rifaximin; D019810:Sodium Azide / Q000009:adverse effects*; D014968:Xanthine Dehydrogenase / Q000032:analysis
chemical_list: D004791:Enzyme Inhibitors; D005765:Gastrointestinal Agents; D012294:Rifamycins; D005997:Glycerylphosphorylcholine; D000255:Adenosine Triphosphate; D019810:Sodium Azide; D009195:Peroxidase; D014968:Xanthine Dehydrogenase; D000078262:Rifaximin; D008697:Methane