EFFECTS OF FEEDING URANIUM NITRATE HEXAHYDRATE IN THE DIETS OF BREEDING WHITE RATS

¹ Division of Pharmacology and Toxicology, Department of Radiation Biology, School of Medicine and Dentistry, University of Rochester, Rochester 7, New York

1) Two groups of 50 pairs of rats each were maintained for 7 months on a control diet and on a diet containing 2 per cent of uranium nitrate hexahydrate, respectively.

2) The growth rate of both male and female rats receiving the 2 per cent uranium nitrate hexahydrate diet was notably depressed. An increased growth occurred, however, when the experimental rats were placed on the control diet 7 months after the start of the experiment.

3) Uranium feeding sharply reduced the number of female rats having litters. In addition, the experimental rats had fewer young per litter. When the experimental rats were replaced on the stock diet the females having litters were more productive than the control rats. Females which failed to have litters on the experimental diet did not have litters later on the stock diet.

4) Rats fed 2 per cent uranium nitrate hexahydrate exhibited a slightly greater mortality during the 12-month period.

5) Uranium nitrate hexahydrate feeding produces an irregularity of oestrus cycle. Only 19 of 44 experimental female rats had regular oestrus cycles and regular matings.

6) Uranium, except in traces, does not cross the placental barrier.