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Pregnant rats were injected subcutaneously on day 10 of pregnancy with 0.0, 0.25, 0.50, 1.0 or 3.0 mg cadmium/kg and sacrificed at term (day 21). There were no fetal or maternal deaths following the cadmium exposure with the exception of the e.0 mg/kg level where a 54% fetal mortality rate was observed. At doses of 1.0 mg/kg or less, non-specific parameters of fetal toxicity including body weight, crown-rump length, and liver weight were not significantly different from control values. The same was true of term placental weight as well as maternal weight gain over the 48-h treatment period. Following gel-filtration of hepatic cytosols from control fetuses, over 70% of the endogenous cytosolic zinc was associated with a peak previously described as metallothionein. It was found that cadmium exposure at sub-lethal doses caused a depression in both total cytosolic zinc and metallothionein-bound zinc levels in the fetus, whereas both these parameters increased in the maternal liver. In vitro cadmium saturation prior to gel filtration revealed that the cadmium-binding capacity of the metallothionein peak was significantly reduced at all dosage levels in the fetus but increased in maternal liver. These findings suggest that maternal administration of cadmium can depress fetal metallothionein levels and cytosolic zinc levels at doses which do not produce overt fetal toxicity. This reduction in fetal metallothionein is in sharp contrast with the well established finding of induction of metallothionein seen in the adult following exposure to cadmium.

We describe the electrothermal atomic absorption spectrophotometry of cadmium in rabbit semen collected before and after seven days of subcutaneous administration of 0.5 mg of cadmium per kilogram body weight per day. The analytical technique involves combining an aliquot of an acid-digested semen sample with an equal volume of an (NH4)2HOP4 solution (50 g/L), to allow an increase in charring temperature, which results in more nearly complete destruction of matrix. Cadmium values as determined by this method correlated well with those determined by the method of standard additions. The dosing regimen resulted in a statistically significant (p < 0.01) increase in cadmium concentrations in semen (and whole blood) sampled just after the last day of cadmium administration.

Seven American alligators, Alligator mississippiensis, were each administered a single, intracardiac injection of cadmium chloride, at a dose of 1.0 mg Cd/kg body wt. At sacrifice, the highest concentration of Cd was found in the liver, bound to a cytosolic protein with characteristics similar to mammalian metallothionein (MT). Gel filtration (Sephadex G-75) of the cytosol revealed a peak containing Cd and to a lesser extent, zinc (Zn), having the same relative elution volume (Ve/Vo) as rat hepatic Cd, Zn-MT. Anion-exchange chromatography (DEAE-Sephacel) of material having a Ve/Vo of 1.7-1.9 revealed a major Cd-peak corresponding to rat Cd, Zn-MT(I) and a minor peak corresponding to Cd, Zn-MT(II). Neither peak contained significant amounts of Zn. Heat treatment of alligator hepatic cytosol, followed by selective acetone precipitation, yielded material having a molar Cd:Zn ratio of 9.15:1 compared to 0.67:1 in material purified from Cd-pretreated rat liver. Spectral analysis of the material purified from both sources showed an absorbance peak between 250 and 260 nm and no absorbance peak at 280 nm, characteristic of mammalian MT.