Objective     To study the effect of lead on the calcium absorption and bone development in weanling rats.      Methods     Totally 80 weanling Wistar rats were equally divided into normal control (given with pure water and standard feed

including 1.15% calcium)

lead group (given 1.0 g/L lead acetate water and standard feed)

lead+low calcium group (1.0 g/L lead acetate water and feed including 0.69% calcium)

and lead+high calcium group (1.0 g/L lead acetate water and feed including 1.72 % calcium). The development of rats was observed. Serum contents of osteocalcin and parathormone，and bone levels of lead and calcium in the femur were determined. The femur was examined with histological method. Another 5 Wist

ar rats received gastric irrigation of 10% lead acetate for 5 d

5 more rats served as control

and then their absorption of calcium was detected with

45

CaCl

2

.      Results     Lead and low calcium inhibited the development of rat remarkably

with the content of osteocalcin

the length and diameter of the femur decreased. High calcium antagonized these effects of lead. The absorption of calcium in rats was repressed by lead.      Conclusion     Bone depression by lead may be due to that lead inhibits the absorption of calcium in rats

and the supplement of calcium is helpful to minimize the repression.