Objective To study whether maternal pre-pregnant low-level lead exposure could affect skeletal calcium metabolism in newborn mice.
Methods A group of six female Kunming mice were exposed to lead acetate in drinking water (10.0 mol/L, pure lead) for four weeks before pregnancy. Another six female Kunming mice were set as controls. At the postnatal day 21 and 60, three newborn mice from each group were neutralized to detect the levels of lead, calcium, and parathyroid hormone (PTH) in samples of femur, blood, and serum by graphite furnace atomic absorption spectrometry, flame atomic absorption spectrometry, and radioimmunoassay, respectively.
Results On postnatal day 21, compared with the control offspring, the levels of blood calcium and femur calcium were significantly lower(1.75±0.24) mmol/L and (10.17±1.03) mmol/g, respectively, P<0.05, the le vels of blood lead, femur lead, and serum PTH were significantly elevated in the lead-treated newborn mice(0.31±0.03) μmol/L, (57.24±4.65) nmol/g, and (3.40±0.74) μg/L respectively, P<0.05. On postnatal day 60, compared with the postnatal day 21 results, the levels of blood calcium in the preconceptional-lead-exposed newborn mice were increased to (2.11±0.17) mmol/L, and there were no significant differences when compared with the control offspring (P > 0.05); the levels of femur calcium and PTH were in creased to (13.65±2.11) mmol/g and (5.91±0.85) μg/L, respectively, and there were significant differences compared with the corresponding indicators of the controls (P<0.05); the levels of femur lead were decreased to (45.04±7.62) nmol/g, and significantly higher than those of control offspring (P<0.05); the levels of blood lead (0.29±0.02)μmol/L were significantly higher than those of the control offspring (P<0.05) though little change was found versus the postnatal day 21 results.
Conclusion Maternal preconceptional low-level lead exposure could affect skeletal calcium metabolism in newborn mice.
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