Albumin Promotes the Absorption of Pb in the Intestine: A Possible Pathway Linking to the High Absorption of Pb in Adolescence

High blood lead (Pb) levels have long been a significant environmental issue affecting the health and development of adolescents. However, the main reasons behind this phenomenon, especially the absorption and transportation processes of Pb in the intestine, have not been elucidated, which is the major barrier to reducing blood Pb levels in the human body, especially in adolescents. In this study, we explored the intestinal absorption process of Pb in rats of different ages at environmentally relevant concentrations. The results indicated that albumin serves as a crucial mediating role in the process of gradually decreasing Pb levels with age (aging). Next, experiments with induced senescence and the addition of albumin confirmed that binding to albumin facilitates the absorption and transportation of Pb. Furthermore, a low-protein diet can reduce Pb levels by approximately 50%, possibly due to a decrease in the synthesis of albumin resulting from reduced raw materials. Collectively, these findings reveal the potential reasons for high Pb levels in adolescents, elucidate the influence of albumin on Pb absorption and transportation, and provide an alternative pathway for regulating intestinal Pb absorption in adolescents at ambient concentrations.