Ultrastructure of isolated sarcolemma from dog and rabbit myocardium. Comparison to intact tissue.
Ultrastructure of isolated sarcolemma from dog and rabbit myocardium. Comparison to intact tissue.
复制标题
狗和兔心肌离体肌膜的超微结构。
DOI：
10.1161/01.res.54.4.414
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发表时间：
1984
影响因子：
20.1
通讯作者：
Beydler,S
中科院分区：
文献类型：
--
作者：
Frank,JS;Philipson,KD;Beydler,S
我们比较了从狗和兔心脏中分离的心肌细胞膜的形态与完整细胞中的心肌细胞膜，使用冷冻断裂和薄切片电子显微镜。此外，我们还根据冷冻断裂形态学和唾液酸含量及Na，K-ATP酶活性的生化测定来估计分离的肌膜的侧性。分离膜中的双分子层在形态上与完整膜相似。分离的肌膜囊泡具有与完整肌膜相同的膜内颗粒密度/微米2（约2800/微米2）。分离的肌膜中的颗粒计数非常均匀，颗粒密度曲线中的峰值与完整细胞中发现的相同。在完整的心肌中，肌膜和横管膜具有相同密度的膜内颗粒。薄切片形态的孤立的肌膜显示一个完整的表面涂层，而部分的外板缺席。生物化学和形态学数据均表明，在该制剂中存在相当大比例的由内向外和右侧向外的囊泡。考虑到形态学和生物化学方法中固有的近似，我们发现值得注意的是囊泡取向估计的定性一致性。
We compared the morphology of cardiac sarcolemmal membranes isolated from dog and rabbit hearts with the sarcolemma in intact cells, using freeze-fracture and thin-section electron microscopy. In addition, we estimated the sidedness of the isolated sarcolemma based on its freeze-fracture morphology and biochemical determinations of sialic acid content and Na,K-ATPase activity. The bilayer in isolated membranes is similar, in its morphology, to intact membrane. The isolated sarcolemmal vesicles have the same density of intramembrane particles per micron2 as the intact sarcolemma (approximately 2800/micron2). The particle counts in isolated sarcolemma were very homogeneous, with the peak in particle density curve the same as found for intact cells. In the intact myocardium, both sarcolemmal and transverse tubular membranes have the same density of intramembrane particles. Thin-section morphology of the isolated sarcolemma shows an intact surface coat, whereas portions of the external lamina are absent. Both the biochemical and morphological data indicate that there is a substantial fraction of inside-out and right side-out vesicles in this preparation. Considering the approximations inherent in both morphological and biochemical approaches, we find the qualitative agreement of the estimations of vesicle orientation noteworthy.