Role of metallothionein induction and altered zinc status in maternally mediated developmental toxicity: Comparison of the effects of urethane and styrene in rats
The authors hypothesize that maternal metallothionein (MT) induction by toxic dosages of chemicals may contribute to or cause developmental toxicity by a chain of events leading to a transient but developmentally adverse decrease in Zn availability to the embryo. The hypothesis was tested by evaluating hepatic MT induction, maternal and embryonic Zn status, and developmental toxicity after exposure to urethane, a developmental toxicant, or styrene, which is not a developmental toxicant. Pregnant Sprague-Dawley rats were given 0 or 1 g/kg urethane ip, or 0 or 300 mg/kg styrene in corn oil po, on Gestation Day 11 (sperm positive = Gestation Day 0). These were maternally toxic dosages. As both treatments decreased food consumption, separate pair-fed control groups were also evaluated for effects on MT and Zn status and development. In addition, Gestation Day 11 rat embryos were exposed to urethane in vitro in order to determine whether urethane has the potential to be directly embryotoxic. Urethane treatment induced hepatic MT 14-fold over control; styrene treatment induced MT 2.5-fold. The MT induction by styrene could be attributed to decreased food intake, as a similar level of induction was observed in a pair-fed untreated control group. However, the level of MT induction by urethane was much greater than that produced by decreased food intake alone. (Copyright (c) 1991 Academic Press, Inc.)
- Research Organization:
- Environmental Protection Agency, Research Triangle Park, NC (United States). Health Effects Research Lab.
- OSTI ID:
- 5818006
- Report Number(s):
- PB-92-124635/XAB
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ALKYLATED AROMATICS
ANIMALS
AROMATICS
BIOSYNTHESIS
BODY
CARBAMATES
CARBONIC ACID DERIVATIVES
CARBOXYLIC ACID SALTS
COMPARATIVE EVALUATIONS
DIGESTIVE SYSTEM
ELEMENTS
ENZYME INDUCTION
EVALUATION
GENE REGULATION
GLANDS
HYDROCARBONS
LIVER
MAMMALS
MEMBRANE TRANSPORT
METALLOPROTEINS
METALLOTHIONEIN
METALS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANS
PROTEINS
RATS
RODENTS
STYRENE
SYNTHESIS
TOXICITY
URETHANE
VERTEBRATES
ZINC