K^+和pH4.0乙酸对根面牙本质胶原蛋白降解影响的实验研究

Experimental study of effects of K^+ and pH 4.0 acetic acid on the degradation of human root dentin collagen

目的 :观察K+ 、乙酸 (HAc)、胰蛋白酶对根面牙本质胶原蛋白降解的影响。方法 :制备根面牙本质粉 ,置于 0 .1mol/L乙酸和 0 .15moL/L氯化钾 (KCl)液中 ,对乙酸、KCl和HEPES缓冲液作对照 ,加入5 0 μg/mL 胰蛋白酶 ,37℃孵育 ,分别于 1、7、14、2 1、2 8d离心后 ,取上清液作羟脯氨酸分析和Ca2 + 测定。结果 :0 .15mol/LKCl组K+ 和pH 4 .0乙酸能明显增加根面牙本质胶原蛋白的降解量 ,同时加入两者降解更为明显。HAc-KCl组与HAc组之间 ,在孵育处理 7d后 ,胶原蛋白降解量有显著性差异 (P <0 .0 5 ) ;Ca2 + 释放量在 2 8d内均无显著性差异 (P >0 .0 5 )。HAc组和HAc -KCl组与HEPES组和HEPES -KCl组相比 ,在所测 2 8d内胶原蛋白降解量和Ca2 + 释放量均有极显著性差异 (P <0 .0 1)。HEPES组与HEPES -KCl组Ca2 + 释放量无显著性差异 (P >0 .0 5 ) ,孵育 7d后 ,胶原蛋白降解量有显著性差异 (P <0 .0 5 )。结论 :K+ 、pH 4 .

AIM:To observe the effects of K + and pH 4.0 acetic acid and trysin on the degradation of human root dentin collagen.METHODS:Experiments were done with powdered human root dentin. Root powder was subjected into the following solutions:0.1 mol /L acetic acid,pH 4.0;0.1 mol/L acetic acid +0.15 mol/L KCl;0.1 mol/L HEPES, pH 7.0;or to 0.1 mol/L HEPES+0.15 mol/L KCl,pH 7.0.All solutilons were treated with trysin and incubated at 37℃ for 28 d.Extracts of root dentin solutions were analysed for hydroxyproling and Ca 2+.RESULTS:There was significant difference of denaturation of the root dentin collagen between HAc-KCl and HAc groups after seven days incubation (P<0.05),but there was no significant difference of Ca 2+ release within twenty-eight days incubation (P>0.05). The denaturation of collagen and release of Ca 2+ of HAc-KCl and HAc groups all had very significant difference within twenty-eight days incubation when compared to HEPES and HEPES-KCl groups (P<0.01). There was no significant difference of Ca 2+ release between HEPES and HEPES-KCl groups (P>0.05), but the denaturation of collagen had significant difference between the two groyps after seven days incubation (P<0.05). CONCLSUION:The K + and acetic acid have synergetic effect on the solubility of root dentin collagen.