Teratogenic effects and distribution of cadmium (Cd2+) administered via osmotic minipumps to gravid CF-1 mice.

Studies to identify the mechanisms underlying the teratogenic effects of cadmium (Cd2+) have been complicated by the inherent difficulties of chronically and subchronically administering specific doses of Cd2+ to gravid animals under strictly controlled conditions. The objective of the present study was to develop a relatively simple animal model for examining the teratogenic effects of subchronic Cd2+ exposure. Cd2+ was administered to gravid CF-1 mice by subcutaneously implanted Alzet osmotic minipumps, which released fixed amounts of Cd2+ over a 14-day period between days 5 and 18 of gestation. The results showed that Cd2+ administered in this manner produced fetal anomalies and that the patterns of Cd2+ distribution and the specific developmental defects were similar to those that have been reported for other routes of Cd2+ administration. These findings indicate that osmotic minipumps may serve as useful tools in long-term studies of Cd2+ teratogenicity. They would appear to be especially useful in teratogenic evaluations where minimizing maternal stress and administering precise doses of Cd2+ are important.