Different effects on hemesynthesis in male and female rabbits treated with lead acetate

The feasibility of an animal model was investigated to study the mechanisms underlying the difference in response to inorganic lead exposure between males and females, as shown in the different increase of zincprotoporphyrin (ZPP) in blood concentrations. Groups of rabbits of both sexes received s.c. injections of 0.25 (L) or 0.50 (H) mg lead acetate/kb b.w. or a control solution three times a week during 14 weeks. A steep increase of blood lead (PbB) was found in the first 4 weeks of exposure; in subsequent weeks PbB leveled off. In the L-group PbB increased to 775--1387 microgram/l rbc and in the H-group to 892--1522 microgram/l rbc. In female rabbits ZPP increased earlier than in males; the relative increase of ZPP was stronger in female rabbits, particularly in the H-group. No effect on Hb, Ht and body weight was observed. The response to lead in female and male rabbits is very similar to that observed in humans.