铅对大鼠海马生长抑素神经元及其基因表达的影响

Effects of lead on somatostatin positive neuron and its mRNA expression in rat's hippocampus

研究铅对大鼠海马不同亚区生长抑素 (SS)神经元及其基因表达的影响 ,Wistar大鼠采用饮水加2 0 0 0 μg ml醋酸铅 (PbAc)方法染毒 3个月后 ,用原子吸收分光光度法测定血液和海马铅的含量 ,并通过免疫组化和原位杂交技术检测海马SS和SSmRNA阳性神经元蛋白和基因表达。结果显示 ,染铅组大鼠血液和海马铅含量分别为 (1 30 0 5± 1 4 2 1 )mg L和 (1 0 1 1 62± 59 54)ng L ,较对照组的 (5 54± 0 76)mg L和 (1 81 98±47 2 7)ng L明显增高 ,差异有显著性 (P <0 0 5) ;染铅组大鼠海马CA1 区SS和SSmRNA阳性神经元数目分别为 (2 3 2 7± 4 58)和 (37 60± 9 69) ,较对照组的 (40 38± 7 61 )和 (53 48± 1 0 2 2 )明显减少 ,差异有非常显著性(P <0 0 1 ) ;染铅组大鼠海马CA3 区SS和SSmRNA阳性神经元数目为 (1 2 1 6± 3 40 )和 (1 6 1 8± 6 1 9) ,较对照组的 (1 7 68± 5 86)和 (2 5 93± 7 47)明显减少 ,差异有显著性 (P <0 0 5)。提示染铅后大鼠海马各区SS阳性神经元的蛋白。

In order to study the changes of hippocampal SS and SSmRNA positive neurons, Wistar rats were exposed to lead by drinking 2000μg/ml lead acetate solution for three months, the blood and hippocampal lead concentration were measured with atomic absorption spectometry, and the number of hippocampal SS and SSmRNA positive neurons were observed with immunohistochemistry ,and in situ hybridization respectively. The results showed that the blood and hippocampal lead content in lead exposed rats were obviously higher than those of the control rats (130 05±14 21)mg/L and (1011 62±59 54)ng/L respectively v.s (5 54±0 76)mg/L and (181 98±47 27)ng/L respectively ( P <0 05 ). The number of SS and SSmRNA positive neurons in CA 1 area of lead exposed rats were significantly smaller than those of the control rats (23 27±4 58 and 37 60±9 69 respectively v.s 40 38±7 61 and 53 48±10 22 respectively, P <0 01). The numbers of SS and SSmRNA positive neurons in CA 3 area of lead exposed rats were smaller than that of the controls rats (12 16±3 40 and 16 18±6 19 respectively v.s 17 68±5 86 and 25 93±7 47 respectively, P <0 05). The study suggested that the hippocampal SS and SSmRNA positive neurons of lead exposed rat have a lower expression of SS and SSmRNA.