Fernandez-Madrid F, Noonan S, Riddle J, Karvonen R, Sasaki D
J Anat. 1980 Mar;130(Pt 2):229-41.
Corium fragments incubated in vitro with colchicine or obtained from chick embryos 11 days old after in vivo injection of this alkaloid were studied with the electron microscope. The well known effect of colchicine in producing an accumulation of procollagen was demonstrated by electrophoretic separation of the collagenous products in polyacrylamide gels after incubation of corium fragments in vitro with labelled amino acids. Electron microscopical studies showed various types of cytoplasmic vacuoles containing collagenous fibrillar structures. Some of these vacuoles contained non-striated filaments, fibres with the periodicity of native collagen, and segment long spacing (SLS) crystallites, embedded in an electrondense substance. The central aspect of this communication is the finding of intracellular SLS in cytoplasmic vacuoles. These crystallites were morphologically intact, and had no additional bands at the NH2 or COOH ends, suggesting that they were formed by the aggregation of tropocollagen molecules. Since the presence of intact SLS in cytoplasmic vacuoles suggests that these are secretory, we believe that inhibition of the transcellular transport system by colchicine permitted the visualization of vacuoles containing the products of tropocollagen interconversions. We interpret these findings as an example of autophagocytosis, with intracellular processing of procollagen, occurring in chick embryo fibroblasts when the secretion of procollagen is inhibited by colchicine.
用秋水仙碱在体外孵育真皮碎片，或从体内注射该生物碱11天后的鸡胚中获取真皮碎片，并用电子显微镜进行研究。在用标记氨基酸体外孵育真皮碎片后，通过聚丙烯酰胺凝胶中胶原产物的电泳分离，证实了秋水仙碱产生前胶原积累的众所周知的作用。电子显微镜研究显示，各种类型的细胞质空泡含有胶原纤维结构。其中一些空泡含有无横纹细丝、具有天然胶原周期性的纤维以及嵌入电子致密物质中的段长间距（SLS）微晶。本通讯的核心内容是在细胞质空泡中发现细胞内SLS。这些微晶在形态上是完整的，在NH2或COOH末端没有额外的条带，表明它们是由原胶原分子聚集形成的。由于细胞质空泡中存在完整的SLS表明这些空泡是分泌性的，我们认为秋水仙碱对跨细胞运输系统的抑制使得能够观察到含有原胶原相互转化产物的空泡。我们将这些发现解释为自噬的一个例子，即当秋水仙碱抑制原胶原分泌时，鸡胚成纤维细胞中发生原胶原的细胞内加工。
