Effects of acute oral lead exposure on the levels of essential elements of mice: a metallomics and dose-dependent study

Lead (Pb) has been reported to disturb the metabolism of essential elements, such as calcium (Ca), magnesium (Mg), iron (Fe) and zinc (Zn) in vivo. This study focused on the relationship between various dose of Pb and the essential elements. 50 healthy male C57BL/6 mice underwent oral administration of 0.2 mL lead acetate trihydrate solution (0, 20, 100, 500, and 1000 mg Pb/day/kg body weight) for 3 days. The concentrations of Pb and four essential elements (Ca, Zn, Fe and Mg) in the blood, kidney, liver, bone and brain were quantified with inductively coupled plasma mass spectrometry. Various doses of Pb led to significant increases in the contents of Ca, Fe and Zn in the liver, and decreased contents of Mg and Fe in the blood in a dose-dependent pattern. The Pb dose of 20 mg/kg reduced the concentration of bone Ca, which did not continue to show an obvious decline with continued increases in the oral Pb dose. Pb also caused alterations in the Mg distribution pattern, and decreased the correlation of Mg, Ca and Zn in the brain, both findings were dose-dependent. In addition to the changes in metallomics, the related oxidative stress was exacerbated, but no significant changes were detected in hepatic and renal histopathological lesions after a short period of Pb exposure. This study contributes to a thorough analysis of the Pb-poisoning mechanism, and indicates that the concentrations of essential elements could be used as sensitive toxicological indicators of Pb exposure.