0000000000726233
AUTHOR
H.m. Bolt
Exhalation of ethylene oxide by rats on exposure to ethylene.
Abstract When rats are exposed to ethylene in a closed desiccator jar chamber, the rate of metabolic elimination of the compound is influenced by pretreatment with Aroclor 1254 (metabolism increased) and diethyldithiocarbamate (metabolism inhibited). Biotransformation of ethylene leads to ethylene oxide as reactive intermediate. This is exhaled and can be quantitated in the gas phase of the system.
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 wee…
The rat liver foci bioassay: I. Age-dependence of induction by vinyl chloride of ATPase-deficient foci
The age-dependence of the induction of pre-neoplastic enzyme-altered hepatic foci was investigated. Rats were exposed (8 h/day, 7 days/week) to 2000 p.p.m. vinyl chloride (VC) either 'transplacentally' (exposure of pregnant females), or immediately after birth for different time intervals (5, 11, 17, 47, 83 days) or from an age of 7 or 21 days onwards. The animals were then kept without further treatment; livers were evaluated for ATPase-deficient foci at the age of 4 months. 'Transplacental' exposure and exposure from day 1 through 5 caused no increase over controls in ATPase-deficient foci, probably due to the lack of hepatocellular proliferation and the low rate of VC metabolism at this …