Effects of moderate lead poisoning on the hippocampus tissue of rabbits in juvenile stage / 中华预防医学杂志

ABSTRACT

<p><b>OBJECTIVE</b>To understand the effects of moderate lead poisoning on the hippocampus tissue of rabbits in juvenile stage.</p><p><b>METHODS</b>Sixteen 45-day-old male New Zealand rabbits were randomly divided into blank group and lead-exposed group,8 for each group. Rabbits in the lead-exposed group were treated with 5 mg x kg(-1) x d(-1) lead acetate in their forage for 6 weeks to establish a moderate lead poisoning animal model. The blood lead levels and the lead contents in the hippocampus were determined by atomic absorption spectrometer and inductively coupled plasma-mass spectrometry respectively. Histopathology and ultra-microstructure in the hippocampus tissue were observed by light microscope and electron microscope. The NR1, NR2A and NR2B protein expressions in the CA1 hippocampal region were analyzed through immunohistochemical method.</p><p><b>RESULTS</b>Compared with those of blank group, the blood lead levels of lead-exposed group were significant increased, (428.63 +/- 9.46) vs (66.38+/-3.93) microg/L (t = 100.08, P<0.01); and lead contents of hippocampus was significantly increased, (44.57+/-2.03) vs (21.20+/-1.53) ng/g, (t = 26.05, P<0.01); the hippocampus wet weight were significant decreased, (0.735 +/-0.012) vs (0.808+/-0.010), (t =12.97, P<0.01); the coefficient of hippocampus wet weight, was (0.458 +/-0.004) vs (0.476+/-0.005), (t =7.87, P<0.01). The significant declines in both the positive rate of NR1 and NR2A in the CA1 hippocampal region for NR1 (37.44 +/- 2.05)% vs (41.81+/-2.50)% (t = 3.82, P<0.01) and for NR2A 21.97+/-1.08 vs 25.48+/-1.30 (t =5.89, P<0.01) were also observed. With light microscope and electron microscope, the histopathology and ultra-microstructure of neuron and glial cell in the hippocampus tissue were changed.</p><p><b>CONCLUSION</b>The impairment of hippocampus of rabbits in juvenile stage with chronic moderate lead poisoning were observed, and the histopathology and N-methyl-D-aspartate receptor protein expressions in the hippocampus tissue were changed.</p>