title: Direct effect of carbon monoxide on hexobarbital metabolism in the isolated perfused liver in the absence of hemoglobin.
abstract: The interaction of carbon monoxide (CO) with cytochrome P-450 associated with hexobarbital metabolism was observed in hemoglobin-free perfused rat liver by using a scanning reflectance spectrophotometer. The evidence obtained showed that CO bound to the substrate complexed cytochrome P-450 and, at a CO/O2 ratio of over 0.1 in the perfusate, inhibited the hexobarbital metabolism estimated from the hexobarbital uptake, and oxygen consumption. Although the oxygen supply to the liver cell was one of the major limiting factors during CO hypoxia, CO binding to cytochrome P-450 significantly enhanced the suppression of hexobarbital oxidation caused by hypoxic hypoxia.
mesh_terms: D000818:Animals; D002248:Carbon Monoxide / Q000494:pharmacology*; D002851:Chromatography, High Pressure Liquid; D003577:Cytochrome P-450 Enzyme System / Q000378:metabolism*; D005470:Fluorometry; D006591:Hexobarbital / Q000378:metabolism*; D000860:Hypoxia / Q000378:metabolism; D008099:Liver / Q000187:drug effects* / Q000378:metabolism; D008297:Male; D009243:NAD / Q000378:metabolism; D010101:Oxygen Consumption; D051381:Rats; D011919:Rats, Inbred Strains; D013053:Spectrophotometry
chemical_list: D009243:NAD; D002248:Carbon Monoxide; D003577:Cytochrome P-450 Enzyme System; D006591:Hexobarbital