Lactose facilitates the intestinal absorption of lead in weanling rats

The milk sugar lactose is known to facilitate calcium absorption and has been shown to enhance the uptake of essential trace metals from the intestines as well. Its physiological role as the major carbohydrate source for suckling mammals is thus complemented by its ability to facilitate the absorption of necessary minerals. The studies reported here show that the intestinal absorption of lead and its uptake into blood, liver, kidney, and bone are also increased by lactose in young weanling rats. These data extend the known range of lactose facilitation of mineral absorption to a nonessential, toxic element, confirming the nonspecificity of its action on the gut. In addition, they suggest an explanation for some of the conflicting evidence regarding the prophylactic efficacy of milk in lead poisoning.