Lowering effect of carbon tetrachloride on microsomal cytochrome P-450 of rat liver.
The lowering effect of carbon tetrachloride (CCl4) on the amount of hepatic microsomal cytochrome P-450 of male rats was studied in vitro. It was found that CCl4 added directly into the media containing microsomal supensions decreased the amount of cytochrome P-450 detectable by difference spectra at zero time of incubation. The incubation of the media with CCl4 at 37 degrees in an open system or in a closed system did not decrease the content of cytochrome P-450. As cytochrome P-420 was not detected in the addition of CCl4 lower than 10 mul, it was postulated that the decrease in the content of cytochrome P-450 was not due to its conversion to cytochrome P-420. The activity of NADPH-cytochrome c reductase was not affected by CCl4. The results indicate that the decrease of the amount of detectable cytochrome P-450 by CCl4 is due to the destruction of cytochrome P-450 and the binding of cytochrome P-450 with CCl4in a lower concentration of CCl4 and in addition it is due to the conversion of cytochrome P-420 from cytochrome P-450 in a higher concentration of CCl4.
D000818:Animals; D002251:Carbon Tetrachloride / Q000494:pharmacology*; D003470:Culture Media; D003577:Cytochrome P-450 Enzyme System / Q000378:metabolism*; D008297:Male; D008862:Microsomes, Liver / Q000187:drug effects / Q000201:enzymology* / Q000648:ultrastructure; D009251:NADPH-Ferrihemoprotein Reductase / Q000378:metabolism; D051381:Rats; D013250:Steroid Hydroxylases / Q000378:metabolism; D013739:Testosterone
D003470:Culture Media; D013739:Testosterone; D003577:Cytochrome P-450 Enzyme System; D002251:Carbon Tetrachloride; D013250:Steroid Hydroxylases; D009251:NADPH-Ferrihemoprotein Reductase