Bertossi M, Roncali L
J Submicrosc Cytol. 1981 Jul;13(3):391-406.
A study has been made of the ultrastructural changes undergone by the capillaries of the blood vessel network during development of the pars distalis of the adenohypophysis in the chicken embryo. The adenohypophysial sinusoids attain their full set-up during the last third of embryonic life, and the main features of the differentiation process of the capillary wall concern: (1) a progressive thinning of the endothelium commencing at the 14th i.d., accompanied by a reduction of the cytoplasmic organelles of its cells from the 16th i.d.; (2) a gradual disappearance of the largely overlapping cytoplasmic projections of adjoining endothelial cells, and a progressive increment of the pores, closed by diaphragms, in their thinnest peripheral extensions; (3) a marked narrowing, from the 14th i.d. on, of the perivascular space, which attains its definitive characteristics only at hatching, when the endothelial basement lamina forms. The significance of endothelial porous vacuoles throughout maturation of the vessel wall is discussed, and some remarks on the relationships between histogenesis and vessel development in the chicken pars distalis of the adenohypophysis are advanced.
对鸡胚腺垂体远侧部发育过程中血管网络毛细血管的超微结构变化进行了研究。腺垂体血窦在胚胎期最后三分之一阶段发育完全，毛细血管壁分化过程的主要特征包括：（1）从孵化后第14天开始内皮细胞逐渐变薄，从第16天起其细胞内的细胞器减少；（2）相邻内皮细胞大量重叠的细胞质突起逐渐消失，在其最薄的周边延伸处，由隔膜封闭的孔隙逐渐增多；（3）从孵化后第14天起，血管周隙明显变窄，只有在孵化时内皮基底膜形成时才达到其最终特征。讨论了内皮多孔泡在血管壁整个成熟过程中的意义，并对鸡腺垂体远侧部组织发生与血管发育之间的关系提出了一些看法。
