Pelletier R M, Friend D S
Am J Anat. 1983 Oct;168(2):213-28. doi: 10.1002/aja.1001680208.
The development and maintenance of the Sertoli cell junctional complex were investigated in prepubertal and adult guinea pigs. To correlate the structure of the blood-testis barrier with its permeability, the polyene antibiotic filipin (a cholesterol-binding agent of low molecular weight: 570.70) was added to the fixative as a tracer visible in freeze-fracture replicas. Discontinuous zonules, intermediate junctions (i.e., adhering fasciae) and gap junctions all proved permeable to filipin in the two age groups. Only the continuous occluding zonules characteristic of the adult guinea pig's testis were impermeable to the tracer. In pubertal animals, the establishment of the blood-testis barrier coincided with the completion of the junctional strands in occluding zonules. The formation of occluding zonules was similar in the newborn and the adult. In the adult, the Sertoli cell junctional complexes contained three types of cell junctions: occluding, adhering, and gap junctions. The sequence of occluding and adhering junctions from the base to the apex of the epithelium was the reverse of that demonstrated in most epithelia. The impermeable continuous occluding zonules at the base showed parallel patterns of uninterrupted junctional strands, whereas the permeable discontinuous zonules found higher in the epithelium showed a meandering pattern of broken strands. Our observations indicate that (1) Sertoli cell junctional complexes form near the young germinal cells at the base of the seminiferous epithelium and break down near the older germinal cells toward the apex; (2) the various patterns and orientations of the junctional strands reflect, respectively, the different stages of disintegration of the occluding zonules and the conformation of the mature Sertoli cell to the irregular contours of the germinal cells; (3) there is no relationship between permeability and junctional strand orientation; and (4) the cellular contacts between Sertoli cells and germinal cells situated below the blood-testis barrier may represent the early stages of formation of junctional elements which ultimately become incorporated into the Sertoli cell junctional complex.
研究了青春期前和成年豚鼠支持细胞连接复合体的发育和维持情况。为了将血睾屏障的结构与其通透性相关联，将多烯抗生素制霉菌素（一种低分子量的胆固醇结合剂：570.70）添加到固定剂中，作为在冷冻断裂复制品中可见的示踪剂。在两个年龄组中，不连续的小带、中间连接（即粘着带）和缝隙连接均被证明对制霉菌素具有通透性。只有成年豚鼠睾丸特有的连续闭锁小带对示踪剂不具有通透性。在青春期动物中，血睾屏障的建立与闭锁小带中连接丝的完成同时发生。新生儿和成年人闭锁小带的形成相似。在成年人中，支持细胞连接复合体包含三种类型的细胞连接：闭锁连接、粘着连接和缝隙连接。从上皮基部到顶端，闭锁连接和粘着连接的顺序与大多数上皮中所示的顺序相反。基部不可渗透的连续闭锁小带显示出不间断连接丝的平行模式，而上皮中较高位置发现的可渗透的不连续小带则显示出断裂丝的蜿蜒模式。我们的观察结果表明：（1）支持细胞连接复合体在生精上皮基部的年轻生殖细胞附近形成，并在靠近顶端的较老生殖细胞附近分解；（2）连接丝的各种模式和方向分别反映了闭锁小带解体的不同阶段以及成熟支持细胞对生殖细胞不规则轮廓的构象；（3）通透性与连接丝方向之间没有关系；（4）血睾屏障下方支持细胞与生殖细胞之间的细胞接触可能代表了最终并入支持细胞连接复合体的连接元件形成的早期阶段。
