THE ENTERIC SURFACE COAT ON CAT INTESTINAL MICROVILLI
THE ENTERIC SURFACE COAT ON CAT INTESTINAL MICROVILLI
复制标题
猫肠微绒毛上的肠溶表面涂层
作者：
S. Ito
猫、蝙蝠和人的肠微绒毛被一层明显的由细丝组成的膜，细丝从质膜的外部致密小叶辐射。这种表面被膜在吸收细胞上很明显，但在杯状细胞和未分化的隐窝细胞上不那么厚。在其他物种中，表面被膜不发达或不一致，但所有的肠微绒毛在微绒毛的尖端和侧面都有这种涂层的痕迹。用普通切片技术制备的组织，在用醋酸双氧铀染色后再用铅染色时，通常可以显示出这种成分。表面被膜为强过碘酸-希夫（PAS）阳性，与阿辛蓝或黑尔胶体铁染色剂反应，以检测酸性粘多糖。它也被甲苯胺蓝在低pH值下染色。反复洗涤或与各种化学试剂孵育未能去除或明显改变涂层的外观，但经历自溶的挤出细胞失去了它们的表面涂层。粘多糖被膜的稳定性、持续存在和紧密结合表明它可能是质膜的组成部分，而不是“外来被膜”。"
The enteric microvilli of the cat, bat, and man are coated with a conspicuous layer composed of fine filaments radiating from the outer dense leaflet of the plasma membrane. This surface coat is prominent on the absorptive cells but is not so thick on the goblet and undifferentiated crypt cells. In other species the surface coat is poorly developed or inconsistent, but all intestinal microvilli have traces of such a coating over the tips and sides of the microvilli. Tissues prepared by the ordinary sectioning techniques for electron microscopy usually reveal this component when stained with uranyl acetate followed by lead staining. The surface coat is intensely periodic acid-Schiff (PAS) positive and reacts with Alcian blue or Hale's colloidal iron stain for acid mucopolysaccharide. It is also stained by toluidine blue at low pH. Repeated washings or incubation with various chemical agents have failed to remove or markedly alter the appearance of the coating, but extruded cells undergoing autolysis lose their surface coats. The stability, consistent presence, and intimate association of the mucopolysaccharide coat suggest that it may be an integral part of the plasmalemma rather than an "extraneous coat."