THE GROWTH AND REPRODUCTION OF RATS FED DIETS CONTAINING LEAD ACETATE AND ARSENIC TRIOXIDE AND THE LEAD AND ARSENIC CONTENT OF NEWBORN AND SUCKLING RATS

¹ Division of Pharmacology, Food and Drug Administration, United States Department of Agriculture, Washington, D. C.

1. The maternal transfer of both lead and arsenic to the fetus has been demonstrated for the rat.

2. The average lead content of newborn from dams on a diet containing 64 mgm. of lead per kilogram was eight times that of the controls, while the lead content of newborn from dams on a diet containing 512 mgm. of lead per kilogram was forty times that of the controls.

3. The lead content per gram of dry weight for the two levels fed was almost identically the same for the newborn and for the animals at 15 days of age.

4. The arsenic content of the first litter of animals at both levels of arsenic fed was less than that of any succeeding litter.

5. The arsenic content per gram of dry weight was much higher for newborn than for animals at 15 days of age.