Some Biotransformation Enzymes Responsible for Polycyclic Aromatic Hydrocarbon Metabolism in Rat Nasal Turbinates: Effects on Enzyme Activities of in Vitro Modifiers and Intraperitoneal and Inhalation Exposure of Rats to Inducing Agents

摘要: Abstract Respiratory tract biotransformation of many xenobiotics found in inhaled environmental pollutants is generally considered essential for the mutagenic, carcinogenic, and/or toxic response lung tissue to these xenobiotics. Typical contain known carcinogens adsorbed onto particles which can deposit nasal pharyngeal region respiratory tract. The purpose this study was characterize metabolic capacity rat tissue. Both oxidative and nonoxidative enzyme activities were investigated included aryl hydrocarbon hydroxylase (AHH), epoxide hydrolase (EH), uridine 5′-diphosphate-glucuronyltransferase (UDPGT), glutathione transferase. Specific AHH, EH, UDPGT, transferase 0.023, 6.4, 20.4, 24.8 nmol product per mg protein min, respectively. Benzo( a )pyrene metabolized by AHH dihydrodiols, quinones, phenols quantities about 10 times greater than those reported microsomes. Small, but detectable, benzo( tetrols also measured reaction flasks incubated with )pyrene. Attempts increase microsomal UDPGT pretreating rats various inducing agents both i.p. injection (phenobarbital, 3-methylcholanthrene, Aroclor 1254, 2,3,7,8-tetrachlorodibenzo- p -dioxine) inhalation exposure (BaP) resulted monooxygenases only being induced (2-fold) after pretreatment -dioxine. Phenobarbital increased EH 50%. These data suggest that may multiple forms cytochrome P-450 UDPGT. results from support notion be important determining fate