Metaplasia produced in cultures of chick ectoderm by high vitamin A
Metaplasia produced in cultures of chick ectoderm by high vitamin A
复制标题
DOI：
10.1113/jphysiol.1953.sp004860
复制
发表时间：
1953-03
期刊：
影响因子：
--
通讯作者：
H. B. Fell;E. Mellanby
中科院分区：
文献类型：
--
作者：
H. B. Fell;E. Mellanby
鸡的外胚层和高维生素A的表皮，特别是颗粒层的表皮，角蛋白的形成速度降低，角质透明质的产生增加。他们评论说，他们自己和Studer&Frey的实验都表明，但没有确定，高浓度的维生素A能够抵消皮肤表皮中角蛋白的形成。从这些实验中可以明显看出，增加维生素A的浓度，无论是全身给药还是局部应用，对皮肤表皮都有一定的影响。已知胚胎雏鸡的外胚层在组织培养中发育正常，但早熟(Miszurski，1937)，并产生大量角蛋白。我们进行了以下实验，以了解在这些培养物中添加过量的维生素A会对角质化有什么影响。结果表明，高维生素A完全抑制角化，但也产生了意想不到的效果。在高A培养液中，外胚层分化为分泌粘液的纤毛膜，与正常鼻黏膜相似，当将外植体转移到正常培养液中时，这种化生改变被逆转，产生了皮肤的自然角化上皮。第一部分(第一节)研究了过量维生素A对外胚层分化的影响；将来自每个胚胎一侧的外植体生长在添加维生素A的培养基(+A)中，而来自相反一侧的外植体生长在正常的(对照)培养基中。第二组实验(见第二节)是为了确定维生素的作用是否可逆；每只鸡的两侧外植体在+A培养基中培养7~14天，然后将一侧的外植体转移到正常培养基中，另一侧的外植体在转移到正常培养基时固定以显示组织的组织学，或在+A培养基中培养，直到正常培养基中的姐妹培养固定。
CHICK ECTODERM AND HIGH VITAMIN A epidermis, particularly of the stratum granulosum, and a decreased rate of keratin-formation with an increased production of kerato-hyalin. They remark that both their own experiments and those of Studer & Frey suggest, but do not establish, the ability of vitamin A in high concentrations to counteract keratin-formation inthe skin epidermis. It is evident from these experiments that increased concentrations of vitamin A, whether systemically given or locally applied, have a definite effect on skin epidermis. The ectoderm of the embryonic chick is known to develop normally though precociously in tissue culture (Miszurski, 1937) and to produce large quantities of keratin. The following experiments were undertaken to see what effect the addition of excess vitamin A to the medium would haveon keratinization in such cultures. The results to be described showed that cornification was com-pletely suppressed by the high vitamin A, but a quite unexpected effect was also produced. In the high A medium, the ectoderm differentiated into a mucus-secreting sometimes ciliated membrane resembling that of the normal nasal mucosa, and when the explants were transferred to normal medium, this metaplastic change was reversed, and the naturalkeratinizing epithelium of the skin was produced.Two main groups of experiments were made. In the first (described in section I) the effect of excess vitamin A on the differentiation of the ectoderm was studied; the explants derived from one side of each embryo were grown in medium to which vitamin A had been added (+ A medium) and those from the opposite side in normal (control) medium. The second group of experiments (see section II) were undertaken to find whether the effect of the vitamin was reversible; the explants from both sides of each chick were grown in+ A medium for periods ranging from 7 to 14 days; the explants from one side were then transferred to normal medium and those from the other were either fixed to show the histology of the tissue at the time of transfer to normal medium, or were cultivated in+ A medium until the sister cultures in normal medium were fixed.