Influence of some factors on cadmium pharmacokinetics and toxicity

Cadmium metabolism in the young and in conditions of dietary contamination with ash from coal gasification were investigated. The experiments were performed in adult rats which received ash in the diet (5%) and/or cadmium in drinking water (100 ppm) over a period of five weeks and in sucklings whose mothers were given the same treatment throughout pregnancy and lactation. In pharmacokinetic studies, (115m)Cd was administered orally or intraperitoneally to determine the intestinal absorption, retention, and distribution. Cadmium toxicity (LD(50)) was determined in different age groups of animals treated with ash for five weeks before a single oral or intraperitoneal administration of cadmium chloride. After intraperitoneal administration, (115m)Cd body retention decreased with age and was independent of the dietary treatment. Sucklings had a higher retention in the blood, carcass, and gut than adults. After oral administration, sucklings had a much higher body retention than adults regardless of the dietary treatment of their mothers. Cadmium toxicity was also independent of the dietary treatment. Most striking was a very high oral toxicity of cadmium in sucklings. It is concluded that the young might be at a special risk at the same level of environmental cadmium exposure because of the high oral cadmium toxicity at this age which is most probably due to a high cadmium retention in the gut. It is also concluded that the mixture of elements contained in ash is not likely to influence cadmium metabolism and toxicity in conditions of dietary exposure.