Leknes I L
Gegenbaurs Morphol Jahrb. 1984;130(3):451-9.
The ultrastructure of the heart in 2 and 6 d old larvae of Melanogrammus aeglefinus and 1, 7, 14, and 21 d old larvae of Poecilia reticulata, is described. Additional studies were done on prenatal specimens of P. reticulata. In the atrium of M. aeglefinus the endocardium is separated from the muscle wall by a wide, electron lucent space, which probably contains cardiac jelly (Davis 1924). The myocardium is an 1 cell-thick layer in the atrium, whereas it consists of 2 to 4 cells in the ventricle. Cardiac trabeculae seem to be absent. The contractile material appears more developed at the endocardial side of the muscle wall than at the epicardial side. Thus, in the latter area the myofibrils are thin, few in number, and embedded in large amounts of free ribosomes. Often they radiate from a spot of electron dense material or an intercalated disc. Generally, intercalated discs, short nexuses and specific heart granules (Jamieson and Palade 1964) occur in ventricular as well as in atrial myocardial tissue. In P. reticulata cardiac jelly seems absent, whereas cardiac trabeculae occur regularly, particularly in the ventricle. The myofibrillar apparatus displays a nearly adult structure. However, in the ventricular wall, there occur spots and bands of intracellular, electron dense material at that sarcolemma facing the subepicardial space. Normally, myofibrils extend from this material into the cellular cytoplasm. Subsarcolemmal electron dense material was only scarcely seen in the atrial wall.(ABSTRACT TRUNCATED AT 250 WORDS)
描述了黑线鳕2日龄和6日龄幼虫以及孔雀鱼1日龄、7日龄、14日龄和21日龄幼虫心脏的超微结构。还对孔雀鱼的产前标本进行了额外研究。在黑线鳕的心房中，心内膜与肌肉壁之间被一个宽阔的、电子透明的空间隔开，该空间可能含有心胶（戴维斯，1924年）。心房中的心肌是一层细胞厚，而心室中的心肌由2至4层细胞组成。心脏小梁似乎不存在。收缩物质在肌肉壁的心内膜侧比在心外膜侧更发达。因此，在后一区域，肌原纤维细、数量少，且嵌入大量游离核糖体中。它们常常从电子致密物质点或闰盘放射状延伸。一般来说，闰盘、短连接和特定的心脏颗粒（贾米森和帕拉德，1964年）在心室和心房的心肌组织中均有出现。在孔雀鱼中，心胶似乎不存在，而心脏小梁规则出现，尤其是在心室中。肌原纤维装置呈现出近乎成体的结构。然而，在心室壁中，面向心外膜下空间的肌膜处出现细胞内电子致密物质的斑点和条带。正常情况下，肌原纤维从这种物质延伸到细胞质中。心内膜下电子致密物质在心房壁中仅很少见到。（摘要截断于250字）
