The rat liver foci bioassay: II. Investigations on the dose-dependent induction of ATPase-deficient foci by vinyl chloride at very low doses.
In order to study the dose-dependence of the genotoxic effect of vinyl chloride (VC) hepatocellular ATPase-deficient foci were evaluated after subchronic exposure of newborn rats. Wistar rats were exposed from day 1 after birth over 10 weeks to 10, 40, 70, 150, 500 and 2000 p.p.m. VC (8 h/day; 5 days/week). One week after cessation of exposure hepatic ATPase-deficient foci were quantitated. For a subsequent investigation lower dose range groups of female and male Wistar and Sprague-Dawley rats were exposed (8 h/day; 5 days/week) to 2.5, 5, 10, 20, 40 and 80 p.p.m. VC. Exposure started at day 3 of life and lasted for 3 weeks. After cessation of exposure the animals were maintained for 10 weeks without further treatment until ATPase-deficient foci were quantitated. Both sets of experiments revealed a straight linear relationship between the dose of VC and the % foci area induced. Within the dose range investigated, no obvious threshold for the induction of pre-neoplastic foci by VC was observed.
Laib
R J
RJ
Pellio
T
T
Wünschel
U M
UM
Zimmermann
N
N
Bolt
H M
HM
D000251:Adenosine Triphosphatases / Q000172:deficiency*; D000818:Animals; D001681:Biological Assay / Q000379:methods*; D004305:Dose-Response Relationship, Drug; D005260:Female; D008099:Liver / Q000201:enzymology; D008114:Liver Neoplasms, Experimental / Q000139:chemically induced*; D008297:Male; D011230:Precancerous Conditions / Q000139:chemically induced*; D051381:Rats; D011919:Rats, Inbred Strains; D012737:Sex Factors; D013045:Species Specificity; D014752:Vinyl Chloride / Q000633:toxicity*; D014753:Vinyl Compounds / Q000633:toxicity*
D014753:Vinyl Compounds; D000251:Adenosine Triphosphatases; D014752:Vinyl Chloride