- 期刊
Fine Structures of the Thyroid Gland in the Aero Central Myelin Defcient Jimpy Moues
中樞神經髓鞘不全鼠Jimpy甲狀腺之微細構造
摘要
19-25日大的神經髓鞘形成不全鼠Jimpy, 其甲狀腺以Araldite包埋後，其切片利用光學與電子顯微鏡進行形態學的研究。於光學顯微鏡觀察時，腺狀組織包含著：由單層柱狀腺囊上皮細胞及一些傍腺囊細胞環繞而成大小不一致的腺囊、分化不完全的上皮細胞集團、非常發達的終鰓囊、豐富的腺囊間與上皮內微血管、以及大量的脂肪組織。腺囊上皮細胞具有濃染的大細胞核與薄薄的細胞漿，稀疏的環繞著膠體。於腺囊壁，幾乎每一上皮細胞皆密切的被一上皮內微血管伴隨著。 於電子顯微鏡觀察時，甲狀腺腺囊上皮細胞之形態學構造的特徵為具許多微絨毛，非常發達的顆粒內質網及其擴大的小池、大而且種種型狀不一的線粒體、數群高爾基氏器以及豐富的濃密核心小泡、畸型的偽足與再吸收的膠體小滴、以及大細胞核和許多的核孔複合體等。於有些腺囊，可觀察到許多內有標準9+2規則排列的微小管之纖毛由上皮細胞的頂面突出於腺囊膠體。於腺囊壁，觀察到富線粒體細胞、透明細胞（C-細胞）與富動漿細胞。富線粒體細胞含有許多桿狀及卵圓型的線粒體，透明細胞內含兩種不同型的濃密核心分泌顆粒，而富動漿細胞其富於動漿小池內有細微膠體樣小顆粒。 腺囊上皮細胞的微細結構上的特點顯示出甲狀腺腺囊非常活躍於甲狀腺球蛋白的合成與碘化，以及甲狀腺素與三碘甲狀腺原氨酸的釋放。上皮內微血管壁的各種型狀的孔便利於取方向的細胞運輸作用，更加速了碘離子的吸收及甲狀腺素和三碘甲狀腺原氨酸的散佈。於分化未完成的上皮細胞集團，可觀察到單細皰性微小腺囊上皮細胞之細胞內微腔覆蓋著許多微絨毛而且充滿了膠體。同時觀察到正在進行有絲分裂的上皮細胞與僅由3或4上皮細胞構成的小腺囊。這些未完全分化的上皮細胞集團內的構成，是腺囊於早期發育時構造上的特徵，也代表了腺囊的新腺囊形成、腺囊形成及腺囊成長的各個發育時期。這些特徵於正常鼠應僅見於胚胎期第16日以前。 於非常發達的終鰓囊的壁，有三種不同的細胞：副腺囊細胞、透明細胞及纖毛細胞存在著。這些非常發達終鰓囊的存在，顯示出甲狀腺腺囊的發育不完全。因為在正常情況下，甲狀腺腺囊能夠壓迫而且抑制了終鰓囊的殘留。 Jimpy 鼠的神經髓鞘形成不完全，主要是由於其甲狀腺的發育不完全及Jimpy基因引起的。
關鍵字
無資料並列摘要
The thyroid glands of 19-25 days old hypomyelinated jimpy mice were embedded in Araldite for morphological studies. The fine structures of the thyroid follicular epithelial cells were characterized by numerous microvilli, well developed rough endoplasmic reticulum with dilated cisternae, large and variously shaped mitochondria , groups of Golgi complex and abundant dense-cored vesides, bizzare shaped pseudopodos and many reabsorbed colloid droplets, and a large nucleus with abundant nuclear pore complex. Occasionally, cilia protruded from the apical surface of epithelial cells into the follicular lumen. In addition , mito-chondria-rich cells, clear cells (c-cells) , ergastoplasm-rich cells, and fenestrated intraepithelial capillaries were found on the follicular wall. Among thyroid foilicles, some incompletely differentiated epithelial masses appeared, which were composed of microfollicular epithelial cells, active mitotic epithelial cells , and small follides. These components were characteristic structures of the early embryonic development and represented the active proliferating stage of folliculogenesis. There were three types of cells observed on the wall of well de-veloped ultimobranchial cysts; i.e., secondary follide cells,c-cells , and ciliated cells. The presence of cysts implicated the underdevelopment of thyroid follicles which normally compressed and inhibited the persistence of ultimobranchial cysts . The evidence presented here proves that the hypomyelination of jimpy mice may be induced by the under - development of their thyroid glands and jimpy genes.