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

In order to study the changes of hippocampal SS and SSmRNA positive neurons, Wistar rats were exposed to lead by drinking 2000 micrograms/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 CA1 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 CA3 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.