Metabolism of <i>N‘</i>-Nitrosonornicotine Enantiomers by Cultured Rat Esophagus and in Vivo in Rats
作者:Edward J. McIntee、Stephen S. Hecht
DOI:10.1021/tx990171l
日期:2000.3.1
predominantly to products of 2'-hydroxylation, 4-oxo-4-(3-pyridyl)butanoic acid (keto acid) and 4-hydroxy-1-(3-pyridyl)-1-butanone (keto alcohol). In contrast, the major metabolite of (R)-NNN under these conditions was 4-hydroxy-4-(3-pyridyl)butanoic acid (hydroxy acid), a product of NNN 5'-hydroxylation. The 2'-hydroxylation:5'-hydroxylation metabolite ratio ranged from 6.22 to 8.06 at various time intervals
使用烟草产品的人会暴露于相当数量的N'-亚硝基松香碱(NNN),这是一种在大鼠中已经确立的食道致癌物。人们认为,NNN在吸烟者和鼻烟壶中引起食道和口腔癌起重要作用。NNN的致癌性取决于其代谢活化。但是,迄今为止,几乎所有有关NNN代谢的研究都使用了外消旋物质。在这项研究中,我们检查了在培养的大鼠食管和大鼠体内的[5-(3)H]-(S)-NNN和[5-(3)H]-(R)-NNN的代谢。培养的大鼠食道主要通过2'-羟基化,4-氧代-4-(3-吡啶基)丁酸(酮酸)和4-羟基-1-(3-吡啶基)的产物代谢(S)-NNN(1 microM) )-1-丁酮(酮醇)。相反,在这些条件下,(R)-NNN的主要代谢物是4-羟基-4-(3-吡啶基)丁酸(羟基酸),是NNN 5'-羟基化的产物。与(S)-NNN孵育时,不同时间间隔的2'-羟基化:5'-羟基化代谢物比率在6.22至8.06之间,而在(R)-NNN的实验中,相应比率为1