摘要：Lead kinetics was examined for 32 or 48 weeks after discontinuance of 32-week lead administration to rats. The animals received solid feed containing 1 and 5% of lead as lead acetate. Changes in lead concentration in organ tissues during the experiment period were analyzed by means of kinetic study. Lead was taken into the body relatively rapidly after the start of administration and its concentration reached a near-steady state with 32-week administration. Steady-state distribution ratios (1 in the blood) of the lead concentration in vivo were estimated to be 1.5 in the lung, 2 in the cerebrum, 4 in the liver, 13 in the spleen, 40 in the kidney, 400 in the teeth, 540 in the skull and 600 in the femur. Lead retention in the hard tissues was very high. The pattern of lead elimination after discontinuance of the administration varied among three groups of tissues. The elimination was slow in the hard tissues. Lead concentration was relatively high but elimination was quick in the kidney, spleen and liver. The concentration was low and the elimination was slow in the lung, brain and blood. Restroration to the levels of the control group was not observed in the 48-week observation period in any of the three groups.
