RESUMO
<p><b>OBJECTIVE</b>To observe the effect of chronic lead contaminant on protein expression of protein kinase (PKC) and calmodulin (CaM) in hippocampus of baby-rats.</p><p><b>METHODS</b>The Wistar pregnant rats were randomly divided into 3 groups fed with distilled water and lead-contained water (0.2% and 1.0% lead acetate) respectively. The lead exposure period ranged from the 0 day of pregnancy to the offspring weaned. Then the baby-rats were fed with lead water the same as their mothers. Pups were killed at postnatal day 8 and 50 respectively. Atomic absorption spectrometry was used to determine lead content of rats' brain. Western-blotting was used to observe protein expression of PKC and CaM in hippocampus of baby-rats.</p><p><b>RESULTS</b>The brain lead content of test groups was much higher than that of the control group in the same growth period (P < 0.01). The content of brain lead in rats of postnatal day 50 was significantly higher than that of rats of postnatal day 8 (P < 0.01). Compared with control group, PKC and CaM protein expressions of chronic lead exposure baby-rats in the hippocampus were down trend (P < 0.05).</p><p><b>CONCLUSION</b>The decrease of PKC and CaM protein expression level in hippocampus might be one of the molecular mechanisms of lead induced impairment of learning and memory.</p>