GENDER DEPENDENT EFFECTS OF CIGARETTE-SMOKE ON HEPATIC AND PULMONARY XENOBIOTIC-METABOLIZING ENZYMES IN RATS

The adult male and female rats were exposed to cigarette smoke (CS) 5 times a day, with 1 h intervals, for 3 days in a chamber where smoke a nd fresh air lead alternatively and were killed 16 h after the last tr eatments and hepatic and pulmonary monooxygenase (MO) activities (anil ine-4-hydroxylase, AH; aminopyrine-N-demethylase, AMND; 7-ethoxyresoru fin-O-deethylase, EROD; p-nitroanisole-O-demethylase, p-NAOD), lipid p eroxidation (LP) and reduced glutathione (GSH) levels and glutathione- S-transferases (GSTs) activities toward several substrates (1-chloro-2 ,4-dinitrobenzene, CDNB; 1,2-dichloro-4-nitrobenzene, DCNB; ethacrynic acid, EAA; 1,2-epoxy-3-(p-nitrophenoxy)-propane, ENPP) were determine d. CS significantly increased hepatic AMND, EROD and p-NAOD activities whereas it unaltered AH activity in both genders as compared with con trols. In the lung, EROD and p-NAOD activities were also significantly increased by CS in both genders. Pulmonary AH activity, however, sign ificantly increased in males but remained unchanged in females. Pulmon ary AMND activity significantly increased in females but remained unal tered in males. A significant decrease was noted in the LP level of ma les, while that of females was unaltered by CS in the liver. Pulmonary GSH and LP, and hepatic GSH levels were significantly increased by CS in both genders. In males, GST activities toward CDNB and DCNB did no t alter, whereas GST activities toward EAA and ENPP significantly incr eased and decreased, respectively, in the liver. In females, CS signif icantly increased hepatic GST activity toward DCNB but it was ineffect ive on the other hepatic GST activities. All pulmonary GST activities of males were significantly depressed by CS. In females, however, CS s ignificantly increased pulmonary GST activities toward CDNB and DCNB b ut was ineffective on GST activities toward EAA and ENPP. These result s suggest that gender related differences exist in the modulations of hepatic GST, and pulmonary MO and GST activities but not in those of h epatic MO activities, by CS in rats. (C) 1998 Elsevier Science B.V.