固定剂和蛋白激酶C活性对蛙骨骼肌纤维三联体超微结构的影响  

EFFECTS OF FIXATIVE AND PROTEIN KINASE C ACTIVITY ON ULTRASTRUCTURE OF TRIAD OF FROG SKELETAL MUSCLE FIBRES

作　　者：吴光明[1] 朱培闳[1] 

机构地区：[1]中国科学院上海生理研究所

出　　处：《解剖学报》1998年第1期72-77,I013,共7页Acta Anatomica Sinica

基　　金：国家自然科学基金;博士后基金

摘　　要：用透射电镜研究了不同固定方法和蛋白激酶Ｃ（ＰＫＣ）活性对蛙骨骼肌纤维三联体超微结构，特别是对接头足（以下简称为足）形态和数量的影响。结果表明，常规戊二醛固定和含苦味酸的多聚甲醛固定对三联体的超微结构无明显影响，足可以分为柱、不完整足、空心柱、桥和非典型足等５类，各类足的比例及数量也相似。肌纤维用ＰＫＣ激动剂和抑制剂作用后，三联体的横小管和肌浆网形态无改变，而各种形态足的比例有变化。但是，这些变化与已知的ＰＫＣ活性变化无关。上述结果提示，作为Ｒｙａｎｏｄｉｎｅ受体／钙释放通道蛋白分子一部分的足在形态上是一种多变的结构。如果过去观察到的ＰＫＣ激动剂引起的兴奋收缩去耦联是由肌纤维的结构变化引起的，则这一变化不在三联体或不能用透射电镜显示。The effects of fixative and protein kinase C (PKC) activity on the ultrastructure of the triad of frog skeletal muscle fibres, especially on the morphology and number of the junction feet, were investigated with transmission electron microscopy. It is shown that fixation with conventional glutaraldehyde fixative or paraformaldehyde fixative containing picric acid produced no difference in the triad ultrastructure. Using these two fixatives, the feet could be categorized morphologically into column, imperfect feet, pillar, bridge and atypical feet. In addition, there was no variance in the proportion of the various feet and the feet number. After the fibres were treated with PKC activator or/and inhibitor for between 0.5 and 24h, no change was observed in the morphology of the transverse tubule and sarcoplasmic reticulum. Although some changes in the proportion of various feet were seen, these changes are unrelated to the known change of PKC activity. It is suggested that the feet, as a part of ryanodine receptor/calcium release channel, may be labile morphologically. Moreover, if phorbol 12,13 dibutyrate (PKC activator) induced excitation contraction uncoupling seen previously results from some morphological changes of muscle fibres, these changes might not be located at the triad or could not be revealed by the method uesd in this study.

关 键 词：蛋白激酶C 三联体 骨骼肌纤维 蛙 固定剂 PDBu 

分 类 号：R329.47[医药卫生—人体解剖和组织胚胎学]