Rentería V G, Ferrans V J, Jones M
Am J Pathol. 1976 Oct;85(1):85-98.
Straited membranous structures (SMS), which consisted of sheets or ribbons of 130 to 220 A in thickness, showed variable patterns of periodic substructure, and resembled SMS described in renal and ocular tissues in various diseases, were found in extracellular locations in a) mitral valve (2 patients) and tricuspid valve (1 patient) of 2 patients with mitral valvular prolapse, b) mitral valve and femoral artery of 1 patient with Marfan's syndrome and prolapsed mitral valve, and c) myocardium (2 patients) and thickened endocardium (3 patients) of 3 patients with congenital heart disease associated with muscular obstruction to right ventricular outflow. Striated membranous structures measured up to several microns in diameter, often were highly folded and convoluted, and sometimes appeared circular in outline. Some SMS measured from 130 to 150 A in thickness and had indistinct edges and poorly defined periodicity. The majority of SMS, however, had greater thicknesses, in the range of 200 A, and a periodicity characterized by alternating light and dark bands with a spacing that varied from 100 to 160 A. The structures were associated with thickened basement membranes, elastic fibers, and membrane-bound bodies of the type thought to be involved in elastogenesis. Evidence available suggests that SMS results from an unusual pattern of arrangement of a component, possibly Type IV collagen, of basement membrane material.
横纹膜状结构（SMS）由厚度为130至220埃的薄片或带状物组成，呈现出不同的周期性亚结构模式，类似于在各种疾病的肾脏和眼部组织中所描述的SMS，在以下情况的细胞外位置被发现：a）2例二尖瓣脱垂患者的二尖瓣（2例）和三尖瓣（1例）；b）1例患有马凡综合征和二尖瓣脱垂患者的二尖瓣和股动脉；c）3例患有与右心室流出道肌肉梗阻相关的先天性心脏病患者的心肌（2例）和增厚的心内膜（3例）。横纹膜状结构直径可达数微米，常常高度折叠和卷曲，有时轮廓呈圆形。一些SMS厚度为130至150埃，边缘模糊且周期性不明确。然而，大多数SMS厚度更大，在200埃范围内，其周期性特征为明暗带交替，间距在100至160埃之间变化。这些结构与增厚的基底膜、弹性纤维以及被认为参与弹性生成的膜结合体相关。现有证据表明，SMS是由基底膜材料的一种成分（可能是IV型胶原）的异常排列模式导致的。
