Microsomal metabolism of the Z and E isomers of N-nitroso-N-methyl-N-n-pentylamine.
N-Nitrosomethyl-N-n-pentylamine was separated into its E and Z isomers by HPLC. When the metabolism was examined using microsomes isolated from uninduced Fischer 344 rats, it was found that, at a constant final concentration of 0.5 mM, the yield of formaldehyde produced increased as the proportion of the Z isomer rose. The yield of valeraldehyde, on the other hand, decreased with an increasing proportion of the Z isomer. Kinetic constants were determined for the metabolism of the two isomers. During the metabolism of the Z isomer, the Vmax was 2.2-fold higher for the formation of formaldehyde than that for the E. The Vmax for valeraldehyde was 2.0-fold lower during the metabolism of the Z isomer. The results indicate that the relative position of the nitroso group can have a profound effect on the metabolism of each side of this type of molecule.
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NCI-Frederick Cancer Research Facility, BRI-Basic Research Program, MD 21701.
Farrelly
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D000447:Aldehydes / Q000378:metabolism; D000818:Animals; D002851:Chromatography, High Pressure Liquid; D004938:Esophageal Neoplasms / Q000139:chemically induced; D005557:Formaldehyde / Q000378:metabolism; D007536:Isomerism; D008297:Male; D008862:Microsomes, Liver / Q000378:metabolism*; D009602:Nitrosamines / Q000032:analysis / Q000493:pharmacokinetics* / Q000633:toxicity; D051381:Rats; D011916:Rats, Inbred F344
D000447:Aldehydes; D009602:Nitrosamines; C025033:N-amyl-N-methylnitrosamine; D005557:Formaldehyde; C046012:pentanal