Calmodulin blocker inhibits Ca++-ATPase activity in secretory ameloblast of rat incisor.
Calmodulin blocker inhibits Ca++-ATPase activity in secretory ameloblast of rat incisor.
复制标题
钙调蛋白阻滞剂抑制大鼠门牙分泌性成釉细胞中 Ca -ATP 酶的活性。
DOI：
10.1007/bf01239969
复制
发表时间：
1987
影响因子：
3.6
通讯作者：
Garant,PR
中科院分区：
文献类型：
--
作者：
Sasaki,T;Garant,PR
研究了钙调素阻断剂三氟拉嗪（TEP）对正常大鼠和tfp注射大鼠下门牙牙釉质器官膜结合Ca++- atp酶、Na+-K+- atp酶（EC 3.6.1.3）及超微结构的影响。取体重约100 g的大鼠，分别经颈静脉给予0.2 ml生理盐水或溶解于0.2 ml生理盐水中的100 μg TFP，分别于TFP给药后1和2 h经心灌注甲醛-戊二醛混合物固定。下切牙制备厚度小于50 μm的珐琅质器官非脱钙切片，在碱性条件下用一步铅法对Ca++-ATPase和Na+-K+-ATPase进行超细胞化学反应。在盐水注射的对照动物中，Ca++-ATPase的酶促反应在分泌性成釉细胞的整个细胞表面的质膜上进行。中间层和乳突层细胞的质膜也有中等程度的酶促反应。Na+-K+- atp酶活性的反应沉淀仅在细胞的中间层和乳头层的细胞膜上有明显的定位。TFP最显著的影响是，除了在面向中间层的核下区基底外侧细胞表面有一个微弱的持续反应外，分泌性成釉细胞的质膜上ca2 ++- atp酶的酶促反应明显消失。而中间层和乳头层细胞即使在TFP处理后仍继续对ca++ - atp酶发生反应。同样，这些细胞中的Na+-K+- atp酶活性不受TFP的抑制。分泌性成釉细胞的超微结构检查显示，TFP没有引起明显的细胞学变化，也没有细胞毒性作用。这些结果表明，分泌性成釉细胞可能具有活跃的钙离子运输系统，该系统由内源性钙调蛋白调节。
The effects of the calmodulin blocker, trifluoperazine (TEP), on membrane-bound Ca++-ATPase, Na+-K+-ATPase (EC 3.6.1.3.) and the ultrastructure of the enamel organ were investigated in the lower incisors of normal and TFP-injected rats. The rats, of about 100 g body weight, were given either 0.2 ml physiological saline or 100 μg TFP dissolved in 0.2 ml physiological saline through a jugular vein and fixed by transcardiac perfusion with a formaldehyde-glutaraldehyde mixture at 1 and 2 h after TFP administration. Non-decalcified sections of the enamel organ less than 50 μm in thickness, prepared from dissected lower incisors, were processed for the ultracytochemical demonstration of Ca++-ATPase and Na+-K+-ATPase by the one-step lead method at alkaline pH. In control saline-injected animals the most intense enzymatic reaction of Ca++-ATPase was demonstrated along the plasma membranes of the entire cell surfaces of secretory ameloblasts. Moderate enzymatic reaction was also observed in the plasma membranes of the cells of stratum intermedium and papillary layer. Reaction precipitates of Na+-K+-ATPase activity were localized clearly along the plasma membranes of only the cells of stratum intermedium and papillary layer. The most drastic effect of TFP was a marked disappearance of enzymatic reaction of Ca++-ATPase from the plasma membranes of secretory ameloblasts, except for a weak persistent reaction in the basolateral cell surfaces of the infranuclear region facing the stratum intermedium. The cells of stratum intermedium and papillary layer, however, continued to react for Ca++-ATPase even after TFP treatment. Similarly, Na+-K+-ATPase activity in these cells was not inhibited by TFP administration. Ultrastructural examination of secretory ameloblasts revealed that administration of TFP caused no considerable cytological changes and did not act as a cytotoxic agent. These results suggest that secretory ameloblasts may have an active Ca++transport system, which is modulated by an endogenous calmodulin.