PLACENTAL TRANSFER OF CHROMIC CHLORIDE AND ITS TERATOGENIC POTENTIAL IN EMBRYONIC MICE

Abstract

Nulliparous female mice were injected subcutaneously with CrCl₃ 9 times every other day from the 0 day to the 16th day of gestation and the placental transfer of Cr and its effects on fetal growth were examined (Experiment I). In addition, pregnant mice were given a single intraperitoneal injection of CrCl₃ on the 7th, 8th or 9th day of gestation to examine teratogenic potentials of Cr (Experiment II-1). Furthermore, in order to examine a possible dose-response relationship, pregnant mice were injected with 4 dose levels on the 8th day of gestation (Experiment II-2). In these experiments the mothers were killed on the 18th day of gestation and their uteri were examined for implantation and resorption sites; each fetus was weighed and examined for both external and skeletal anomalies. Concentration of Cr in fetal tissues was negligible and trace. A significant decrease of weight gain was observed among fetuses in Exp. I. In case of group injected on the 8th day (Exp. II-1), external malformations were obseved at the highest rate. In Exp. II-2, together with a significant decrease of weight gain, notable increase in the incidence of both external and skeletal anomalies occurred also and among them the incidences of exencephalies (including acephalies) and rib fusions were the most frequent. The positive dose-response relationship between amounts of CrCl₃ injected to pregnant mice and the incidences of both external and skeletal anomalies was demonstrated. It is concluded that trivalent chromium has apparent teratogenic effects and inhibits growth in mice.