Cytochrome P-450-dependent metabolism of xenobiotics. A comparative study of rat hepatic and plant microsomal metabolism.
1. A comparison was made between rat hepatic and plant microsomal cytochrome P-450 and cytochrome P-450 linked enzymic activities. 2. The results show that, compared with plant microsomes, rat hepatic microsomal protein concentrations were 165-fold higher, and rat hepatic cytochrome P-450 concentration were 32-fold higher. 3. Rat hepatic Cytochrome P-450 linked enzyme activities were 1765-fold and 25-fold greater when compared with plant microsomes using aldrin and biphenyl as substrates, respectively. 4. Rats metabolised biphenyl to 2- and 4-hydroxybiphenyl, whereas plants produced only the latter metabolite. 5. Pretreatment of rats and plant tissues with biphenyl, Aroclor 1248 and the sodium salt of phenobarbital increased significantly the microsomal protein concentrations, and enzyme activities linked to cytochrome P-450. 6. Unlike rat microsomes, those of plants were unable to metabolise halosubstituted biphenyls at measurable rates.
Borlakoglu
J T
JT
Department of Biochemistry and Physiology, University, Whiteknights, Reading, U.K.
John
P
P
D000452:Aldrin / Q000378:metabolism; D000818:Animals; D001140:Aroclors / Q000378:metabolism; D001713:Biphenyl Compounds / Q000378:metabolism; D003577:Cytochrome P-450 Enzyme System / Q000502:physiology*; D004852:Epoxy Compounds / Q000378:metabolism; D005260:Female; D005659:Fungicides, Industrial / Q000378:metabolism; D006900:Hydroxylation; D008861:Microsomes / Q000201:enzymology / Q000378:metabolism*; D008862:Microsomes, Liver / Q000201:enzymology / Q000378:metabolism*; D010634:Phenobarbital / Q000378:metabolism; D010944:Plants / Q000378:metabolism*; D051381:Rats; D013055:Spectrophotometry, Infrared; D015262:Xenobiotics / Q000378:metabolism*
D000452:Aldrin; D001140:Aroclors; D001713:Biphenyl Compounds; D003577:Cytochrome P-450 Enzyme System; D004852:Epoxy Compounds; D005659:Fungicides, Industrial; D010634:Phenobarbital; D015262:Xenobiotics; C028617:aroclor 1248; C055142:2-chlorobiphenyl; C010574:biphenyl