Cadmium-109 metabolism in mice. II. Organ retention in mice fed a nutritionally deficient diet during successive rounds of gestation and lactation.

Organ retention of 109Cd was studied in multiparous and virgin female mice provided trace amounts of 109Cd in drinking water and stable Cd as well as certain nutrient minerals, vitamins, and fat all apportioned in solid diet in amounts appropriate for the itai-itai experience. Breeder females maximally experienced 4 nonconsecutive rounds of gestation/lactation in a total of 5 such 42-d periods. On a round-by-round basis, breeder organ 109Cd content and concentration values were compared with those from their time-matched virgin controls. By the end of round 5, most organ 109Cd content values in breeders were still increasing. Relative to control values at that point, the following increases were observed: whole body (minus gastrointestinal tract), 4.7-fold; mammary tissue, 12.5-fold; liver, 4.7-fold; and kidney, 4.8-fold. Analogous increases in 109Cd concentration values were mammary tissue, 9.8-fold; liver, 2.8-fold; and kidney, 2.9-fold. Through the five rounds, a temporal shift in fractional Cd distribution was noted for breeder tissues where transfer occurred from those of the mammaries and remaining carcass to kidneys. Although by the end of the period 109Cd content in the liver still exceeded that in the kidneys, 109Cd concentration was 4.7-fold greater in renal tissues--an increase not matched by other breeder females consuming nutrient-replete rather than nutrient-deficient (itai-itai) diet. For virgin female mice over the same period, a shift of similar magnitude was observed from remaining carcass to kidneys. Not unlike the breeders, hepatic 109Cd content again exceeded that in renal tissues, while 109Cd concentration was 4.5-fold greater in the kidneys. With respect to renal 109Cd increases, the greater portion of these shifts had occurred by the end of round 3 for both breeder and virgin mice. Comparison of both content and concentration measures for a single, time-matched, virgin male group with those from a virgin female one at the end of round 3 showed only those for mammary tissues to be distinguishable, and by either measure were about fourfold higher in the female group.