Effects of supplemental nutrition on lead-induced depression of growth and food consumption in weanling rats.

The objective of this study was to determine whether growth-depressant effects of lead (Pb) could be prevented by preventing the accompanying depression of caloric intake from ad libitum food consumption by caloric supplementation. The animal used was the female weanling rat. Three experiments were performed in which progressively increasing levels of caloric supplementation were provided in order to attain a level of nutrition which would totally prevent growth depression from Pb exposure. Nutritional supplementation of Pb-exposed animals almost completely eliminated the Pb-induced depression of weight gains. We conclude that the deficit in growth due to Pb can be adequately explained on the basis of a primary effect on appetite, rather than being secondary to depression of proliferative responses of cells to growth factors, e.g., insulin-like growth factor I.