TY - JOUR
T1 - Neonatal exposure to toluene
T2 - Effects on the development of liver microsomal cytochrome P-450 and serum hormone levels in the rat
AU - Hansson, Tiiu
AU - Petterson, Britt Mari
AU - Eneroth, Peter
AU - Gustafsson, Jan Åke
N1 - Funding Information:
This study was supported by a grant from the Swedish Work Environment Health Fund.
Copyright:
Copyright 2014 Elsevier B.V., All rights reserved.
PY - 1985/10
Y1 - 1985/10
N2 - Lactating Sprague-Dawley rats and their pups were exposed on postnatal days 1-7, 6 h/day, to 80,500 and 1000 ppm toluene, respectively, by inhalation. Exposure to 80 ppm toluene decreased the liver microsomal AHH activity and the rate of 7α- and 6β-hydroxylation of androstenedione in 8-day-old-pups. On the other hand, neonatal exposure to 500 or 1000 ppm toluene resulted in a significant increase in AHH and 7-ethoxyresorufin O-deethylase activities and in the formation of 16-oxygenated metabolites of androstenedione in 8-day-old animals. Exposure to toluene increased the cytochrome P-450 content at all 3 dose levels in male but not in female pups. Twenty-one days after neonatal exposure no such effects were seen in young animals of either sex. In 56-day-old male rats, however, neonatal exposure to 80 ppm toluene resulted in a decreased rat of 6β-hydroxylation of androstenedione and a reduced AHH activity. No such effects were seen in female rats of the same age. Neonatal exposure to toluene affected the body and liver weights in 8-day-old pups of both sexes but had no effect on these parameters in 21-day-old animals of either sex. Exposure to 80 ppm toluene during the neonatal period gave a significantly increased body weight of 56-day-old male but not of female rats of the same age although this treatment increased liver weight in both sexes at this age. Serum testosterone levels were decreased in 21-day-old male rats following neonatal exposure to 80 or 500 ppm toluene and in 56-day-old male rats exposed neonatally to 1000 ppm toluene. In conclusion, exposure to toluene during the first week of life caused significant changes in various liver microsomal cytochrome P-450 dependent enzyme activities in 8-day-old pups, whereas the long-term effects on liver metabolism of the adult animal were small.
AB - Lactating Sprague-Dawley rats and their pups were exposed on postnatal days 1-7, 6 h/day, to 80,500 and 1000 ppm toluene, respectively, by inhalation. Exposure to 80 ppm toluene decreased the liver microsomal AHH activity and the rate of 7α- and 6β-hydroxylation of androstenedione in 8-day-old-pups. On the other hand, neonatal exposure to 500 or 1000 ppm toluene resulted in a significant increase in AHH and 7-ethoxyresorufin O-deethylase activities and in the formation of 16-oxygenated metabolites of androstenedione in 8-day-old animals. Exposure to toluene increased the cytochrome P-450 content at all 3 dose levels in male but not in female pups. Twenty-one days after neonatal exposure no such effects were seen in young animals of either sex. In 56-day-old male rats, however, neonatal exposure to 80 ppm toluene resulted in a decreased rat of 6β-hydroxylation of androstenedione and a reduced AHH activity. No such effects were seen in female rats of the same age. Neonatal exposure to toluene affected the body and liver weights in 8-day-old pups of both sexes but had no effect on these parameters in 21-day-old animals of either sex. Exposure to 80 ppm toluene during the neonatal period gave a significantly increased body weight of 56-day-old male but not of female rats of the same age although this treatment increased liver weight in both sexes at this age. Serum testosterone levels were decreased in 21-day-old male rats following neonatal exposure to 80 or 500 ppm toluene and in 56-day-old male rats exposed neonatally to 1000 ppm toluene. In conclusion, exposure to toluene during the first week of life caused significant changes in various liver microsomal cytochrome P-450 dependent enzyme activities in 8-day-old pups, whereas the long-term effects on liver metabolism of the adult animal were small.
KW - Cytochrome P-450
KW - Enzyme development
KW - Induction
KW - Neonatal rat
KW - Toluene
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U2 - 10.1016/0300-483X(85)90111-8
DO - 10.1016/0300-483X(85)90111-8
M3 - Article
C2 - 4060169
AN - SCOPUS:0022405680
VL - 37
SP - 39
EP - 50
JO - Toxicology
JF - Toxicology
SN - 0300-483X
IS - 1-2
ER -