摘要
大鼠sc氯丙烯100和150 mg/kg,研究其对在体神经纤维MT,NF和胞浆内Ca^(2+),Mg^(2+)含量的影响.氯丙烯可引起MT,NF变性和数量减少,胞浆内Ca^(2+)含量升高.Ca^(2+)含量升高能抑制MT聚合和促进其解聚,分解NF蛋白,致使MT和NF减少,抑制或阻断轴浆转运.
In this article,the morphologic changes of the microtubule(MT)and ncurofilamcnt(NF)were observed,and the number of MT and NF per unit area was cal-culated in rats; the concentrations of Ca2+,Mg2+,Cl-in rat scrum and ischiofcmoral nerve were determined.Presuming that all of the Cl-is in membranous external phase and according to the concentration ratios of Ca3+,Mg2+,Cl-in membranous external(E)and those in serum(S),such as,the water of membranous external and concentrations of Ca2+,Mg2+ in nerve cytoplasm werecalculated.After allyl chloride exposure,the MT and NF showed coarse unclear margins,depolymerization in morphology and became lessened in number; Ca2+ concentrations in the serum,nerve fibre and nerve cytoplasm were elevated significantly and with a remarkable dose-effect relationship; Mg2+ concentrations were increased in the serum and nerve fibre but decreased in the nerve cytoplasm which also showed dose-effect relationship.In this experiment,the relationship that the decrease of MT and NF paralleled the increase of Ca2+conccntration in nerve cytoplasm was found,which indicated that Ca2+ may exert regulative effect on the MT and NF.Ca2+ regulates MT mainly through calmodulin(CaM).when Ca2+ concentration is elevated Ca2+ may combine with CaM resulting in the activation of CaM.Activated CaM may activate the cAMP dependent pro-tein kinase causing the phosphorylation of MAP2 followed by the inhibition of MT synthesization or promotion of its depolymerization leading to the decrease or disappearance of MT.Ca2+excrts regulation on NF by Ca2+ dependent protease.The increase of Ca2+ concentration may activate protease causing the decomposition of NF protein and resulting in the decrease or disapperancc of NF.The decrease or disappearance of MT and NF may block the axoplasmic transport.In this experiment,the increase of Ca2+ concentration in nerve cytoplasm was related positively to the increase of K+ concentration in nerve fibre(r=0.92-0.94)or was related to the Na+ metabolic disorder which disturbed the Na+/Ca2+
出处
《中国药理学与毒理学杂志》
CAS
CSCD
北大核心
1989年第4期293-297,共5页
Chinese Journal of Pharmacology and Toxicology
关键词
氯丙烯
微管
神经微丝
钙
镁
allyl chloride
microtu-bulc
neurofilamcnt
Ca2+
Mg2+
