Figure 2.3. Metabolic pathways of benzo[a]pyrene (B[a]P) and 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK).

Figure 2.3Metabolic pathways of benzo[a]pyrene (B[a]P) and 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK)

Note: Metabolic pathways of B[a]P and NNK were modified from Cooper et al. 1983 and Hecht 1996, 1998. Some human enzymes involved in the various reactions are indicated (Gelboin 1980; Pelkonen and Nebert 1982; Cooper et al. 1983; Ketterer et al. 1992; Smith et al. 1992; Yamazaki et al. 1992; Yun et al. 1992; Tiano et al. 1993; Conney et al. 1994; Friedberg et al. 1996; Baird and Ralston 1997; Staretz et al. 1997; Sundberg et al. 1997; Kim et al. 1998; Penning et al. 1999). ADP = adenosine diphosphate; DHD = 4 dihydrodiol dehydrogenase; EH = 4 epoxide hydrolase; GST = 4 glutathione S-transferase; NNAL = 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol; NO2 = nitrogen dioxide; P-450 = 4 cytochrome P-450; UGT = 4 UDP(uridine 5′-diphosphate)-glucuronosyl transferase; 1-OH, 3-OH: 4 1-hydroxy B[a]P, 3-hydroxy B[a]P; National Institutes of Health shift (where the shift [a biochemical process] was first identified) = intramolecular hydrogen migration, which can be observed in enzymatic and chemical hydroxylations of aromatic rings.

Source: Hecht 1999. Adapted with permission.

From: 2, Toxicology of Secondhand Smoke

Cover of The Health Consequences of Involuntary Exposure to Tobacco Smoke
The Health Consequences of Involuntary Exposure to Tobacco Smoke: A Report of the Surgeon General.
Office on Smoking and Health (US).

NCBI Bookshelf. A service of the National Library of Medicine, National Institutes of Health.