[A selective decrease in cytochrome P450 in the liver microsomes of male rats following phenobarbital and 3-methylcholanthrene induction and acute tetrachloromethane poisoning].
The liver microsomal content of cyt. P450 and b5 and activities of selected mixed-function oxidases were compared following phenobarbital (PB)- and 3-methylcholantrene (MC) induction and acute intoxication with carbontetrachloride (CT). PB increased the content of P450 and the activities of both NADPH-cytochrome c reductase and benzphetamin demethylase. MC increased only the content of cytochrome b5. CT after 4 hours damaged selectively the liver monoxidase components: 1. the activity of NADPH-cytochrome c reductase and the content of b5 were not changed in the three groups; 2. the content of P450 was decreased differently: more sensitive to the destructive effect of CT was the PB-inducible P450. Most resistant was the MC-inducible P450; 3. MC decreased the benzphetamin demethylation in control- and PB-microsomes in lower degree than the content of P450. The relative high rates of the benzphetamin demethylase after CT by PB-microsomes was explained by increased activity of NADPH-cytochrome c reductase in this group. The selective damaging effect of CT on P450 was interpreted by complex of local factors: metabolizing of CT to CCL3, lipid peroxidation, phospholipid microenvironment, pO2, antioxidants concentration, activity of heme degrading enzymes.
Angelov
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EP
D000208:Acute Disease; D000818:Animals; D002252:Carbon Tetrachloride Poisoning / Q000201:enzymology*; D003577:Cytochrome P-450 Enzyme System / Q000032:analysis / Q000096:biosynthesis / Q000187:drug effects*; D015786:Cytochromes b5 / Q000032:analysis / Q000096:biosynthesis / Q000187:drug effects; D004790:Enzyme Induction / Q000187:drug effects; D008297:Male; D008748:Methylcholanthrene / Q000494:pharmacology*; D008862:Microsomes, Liver / Q000737:chemistry / Q000187:drug effects* / Q000201:enzymology; D010634:Phenobarbital / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar
D008748:Methylcholanthrene; D015786:Cytochromes b5; D003577:Cytochrome P-450 Enzyme System; D010634:Phenobarbital
Selektivno namalenie na tsitokhrom P450 v chernodrobni mikrozomi ot mŭzhki plŭkhove sled induktsiia s fenobarbital i 3-metilkholamtren i ostra intoksikatsiia s tetrakhlormetan.