title: The interactions of hydrazine derivatives with rat-hepatic cytochrome P-450.
abstract: The ability of different classes of hydrazine derivatives to modify cytochrome P-450 function during turnover as judged by loss of absorbance at 416 nm, loss of CO-reactive cytochrome P-450, or destruction of haem has been studied. Addition of monosubstituted hydrazines to rat-liver microsomes caused considerable loss of CO-reactive cytochrome P-450 and haem destruction; monosubstituted hydrazides caused mainly loss of CO-reactive cytochrome P-450, most likely due to abortive complex formation. Metabolism of 1,1-disubstituted hydrazines by microsomal cytochrome P-450 resulted in loss of CO-reactive cytochrome P-450 only, with no haem destruction. The 1,2-disubstituted hydrazines and hydrazides, procarbazine and iproniazid, acted similarly to the monosubstituted hydrazines, while 1,2-dimethylhydrazine elicited no response, either in observable spectral changes or loss of CO-reactive cytochrome P-450. Synthetic diazene intermediates of phenylhydrazine and N-aminopiperidine reacted rapidly with microsomal cytochrome P-450 to form a spectral intermediate resembling the putative iron porphyrin-diazenyl complex. The decomposition of certain iron porphyrin-diazenyl derivatives apparently leads to destruction of the porphyrin prosthetic group, most likely due to haem alkylation.
mesh_terms: D000818:Animals; D001665:Binding Sites; D065607:Cytochrome P-450 Enzyme Inhibitors; D003577:Cytochrome P-450 Enzyme System / Q000378:metabolism; D006418:Heme / Q000378:metabolism; D006834:Hydrazines / Q000378:metabolism / Q000494:pharmacology*; D007094:Imides / Q000378:metabolism; D066298:In Vitro Techniques; D008862:Microsomes, Liver / Q000201:enzymology*; D009249:NADP / Q000378:metabolism; D010089:Oxidoreductases, N-Demethylating / Q000037:antagonists & inhibitors; D011166:Porphyrins / Q000378:metabolism; D011485:Protein Binding; D051381:Rats; D013329:Structure-Activity Relationship
chemical_list: D065607:Cytochrome P-450 Enzyme Inhibitors; D006834:Hydrazines; D007094:Imides; D011166:Porphyrins; D006418:Heme; D009249:NADP; D003577:Cytochrome P-450 Enzyme System; C019781:benzphetamine N-demethylase; D010089:Oxidoreductases, N-Demethylating