组织型谷氨酰胺转移酶抑制剂对凝血酶脑组织毒性的影响

The effect of tissue transglutaminase inhibitor on the toxicity of thrombin to brain

目的通过动物在体实验了解组织型谷氨酰胺转移酶(tissue transglutaminase,tTG)抑制剂(monodansyl-cadaverine,MDC)对凝血酶(thrombin,Tm)脑组织毒性的影响。方法第1组动物用4种剂量的Tm(0、5、10、15U溶于5μl生理盐水)通过立体定向仪注射入大鼠纹状体,第2组动物在各剂量Tm中同时加入MDC(5mM)加以干预作为相应对照,动物存活24h后取注射部位石蜡包埋切片,做常规HE染色和凋亡特异性TUNEL染色及照相。观察两种染色的切片细胞变化并对各组TUNEL特异染色的凋亡细胞进行计数,以了解在大鼠体内MDC抑制tTG对Tm诱导凋亡作用的影响。结果Tm处理脑组织的胞体发生肿胀,细胞核发生浓缩固缩现象,核仁消失,核膜完整性破坏,且浓度越高异常形态的细胞越多。而在对照的Tm+MDC处理组织切片的异常细胞减少。TUNEL凋亡细胞特异性染色计数,5、10和15UTm凋亡细胞数分别为(13.78±3.31)、(25.56±4.16)和(35.00±5.96)个;而同时加入MDC3种不同浓度的凋亡细胞数分别为(8.56±2.51)、(16.89±2.03)和(28.33±5.83)个。结论MDC可通过抑制tTG减少Tm引起的细胞凋亡。

Objective To observe the effect of MDC （inhibitor of tissue transglutaminase） to the thrombin toxicity on brain. Methods Four concentrations （0μ, 5μ, 10μ and 15μ） of Tm with/without MDC（5mM） were injured into striatum corpora of adult rats. Injection site paraffin was imbeded after 24 h. Sections were stained using HE and TUNEL. Compared with different changes of cells and countering the apoptosis cells marked by TUNEL between the two treatments, the effect of MDC on the apoptosis induced was explored. Results Cell damage could be observed on HE stained sections under a light microscope. Cell swelling, pycnosis of nucleus, disappearance of plasmosome and nuclear membrane disintegrity could be found. With the increasing concentration of Tm, more cells shared with abnormal structures appeared. However, fewer damage cells could be found in the control group, which was treated with Tm and MDC together. TUNEL special marked apoptosis cells are 13.78±3.31 （5U）, 25.56±4.16 （10U）, 35.00±5.96 （15U）; but decreased to 8.56±2.51, 16.89±2.03 and 28.33±5.83 if co-treat cell use Tm with MDC. Conclusions MDC can decrease thrombin induced neuron apoptosis by the inhibition of tTG.