Cytochrome metabolic regulation

Guengerich, F. P. (1999). Cytochrome P-450 3A4 regulation and role in drug metabolism. Annu. Rev. Pharmacol. Toxicol, 39, 1-17. 

The parasitic nematode, Ascaris suum, undergoes a number of well-characterized metabolic transitions during its development (Table 14.1), but little is known about the regulation of these events (Barrett, 1976 Komuniecki and Komuniecki, 1995). Adults reside in the porcine small intestine and fertilization takes place under low oxygen tensions. The unembryonated egg that leaves the host is metabolically quiescent, has no detectable cytochrome oxidase activity or ubiquinone and appears to be transcriptionally inactive (Cleavinger et al., 1989 Takamiya et al., 1993). Embryonation requires oxygen and after about 48-72 h is accompanied by... 

No information is available as to whether metabolism of -hexane in children differs from that of adults. No studies were located comparing metabolism in young and adult animals. The toxicity of -hexane results from biotransformations yielding the active metabolite, 2,5-hexanedione. The initial step is an oxidation to 2-hexanol catalyzed by a cytochrome P-450 enzyme. Some P-450 enzymes are develop-mentally regulated (Leeder and Keams 1997). As the above discussion indicates, it is not completely clear which P-450 enzymes are involved in -hexane metabolism. 

Guzelian, PS. and Bissell, D.M. (1974). Metabolic factors in the regulation for cytochrome P-450. Studies in rat hepatocyte monolayer culture. FedProc. 33 1246. 

Wang, H. and Negishi, M. (2003) Transcriptional regulation of cytochrome p450 2B genes by nuclear receptors. Current Drug Metabolism, 4, 515-525. 

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