摘要
目的:探讨慢性氟中毒大鼠胸髓神经细胞的凋亡及其发生机制。方法:60只Wistar大鼠饲养1周后随机分为2组,每组30只,实验组饮氟化水(氟化钠200mg/L),对照组饮蒸馏水,每组分别于4周、8周、12周时用不锈钢代谢笼收集24h尿液并取血测定血、尿氟含量;实验组在分组后和处死前行脊柱CT检查;12周时将两组大鼠全部处死,取胸段脊髓约5mm长,连续横切片,片厚5μm,行苏木素-伊红(HE)染色、脱氧核糖核苷酸末端转移酶介导的缺口末端标记法(TUNEL)对凋亡细胞进行标记、免疫组化检测半胱氨酸蛋白酶-3(Caspase-3)的表达。结果:饲养12周后对照组大鼠门齿呈瓷白色半透明,实验组大鼠门齿全部出现斑釉;各时间点实验组大鼠血、尿氟含量与对照组大鼠比较明显升高,差异有显著性(P<0.01);实验组大鼠12周时胸椎CT未见椎管狭窄,无脊髓受压;实验组大鼠12周时胸髓HE染色显示神经细胞空泡变性和固缩改变;,TUNEL染色可见神经细胞凋亡明显,阳性细胞数为3.17±0.23个/10个高倍视野,对照组偶见阳性细胞,阳性细胞数为0.14±0.02个/10个高倍视野,两组比较有显著性差异(P<0.01);对照组偶有Caspase-3表达,其阳性细胞数为0.13±0.01个/10个高倍视野,实验组Caspase-3阳性细胞数为2.67±0.37个/10个高倍视野,两组有显著性差异(P<0.01)。结论:慢性氟中毒大鼠的胸髓神经细胞凋亡明显,Caspase-3的参与和过度表达可能是慢性氟中毒时胸髓神经细胞发生凋亡的原因之一。
Objective：To study the expression of neurocyte apoptosis of thoracic spinal cord in rats with chronic fluorosis and discuss the related mechanism.Method：60 Wistar rats were divided randomly into two groups after a week feeding,30 rats in study group fed by high dose of NaF water （NaF 200mg/L）,others in control group fed by pure water.The serum and urine fluoride were detected at the fourth,eighth and twelfth week.At both the beginning and the twelfth week of the study,all thoracic spine were examed by CT scan. The rats of both groups were sacrisficed at the twelfth week.Store long thoracic spinal cord were harvested from the sacrisficed rats.Cytologic changes of neurocytes in thoracic spinal cord after chronic fluorosis were analysed by HE staining,apoptosis was marked by a terminal deoxyribo-nucleotide transferase-mediated UTP- biotin nick end labeling （TUNEL） and expression of Caspase-3 was determined by immunohistochemistry through 5μm thick slices.Result：Dental fluorosis was found in all rats in study group but never detected in control group,the serum and urine fluoride of study group were significant higher than that of control group at each time of the test （P〈0.01）,CT scan at the twelfth week did not show spinal canal stenosis and compression of spinal cord.Apoptosis of neurocytes was detected significantly in gray matter of thoracic spinal cord in study group compared with those in control group by TUNEL test （3.17±0.23 positive cell/10hp VS 0.14±0.02 posfive cell/10hp,P〈0.01）.Caspase-3 staining results also showed overexpression in the rats of study group （2.67±0.37 positive cell/10hp VS 0.13±0.01 postive cell/10hp,P〈0.01）.HE staining presented vacuolar degeneration and pyknosis of neurocytes at the twelfth week.Conclusion：There is a tendency to develop the apoptosis of neurocytes of thoracic spinal cord in rats with chronic fluorosis.Caspase-3 probably plays an important role in the mechanism of the apoptosis induced by excessive fluorine.
出处
《中国脊柱脊髓杂志》
CAS
CSCD
2008年第7期542-545,I0003,共5页
Chinese Journal of Spine and Spinal Cord
关键词
氟中毒
胸髓
神经细胞
凋亡
大鼠
Fluorosis
Spinal cord
Neurocyte
Apoptosis
Rat
