Jenik R A, Fisch J E, Goodridge A G
Department of Pharmacology, Case Western Reserve University, Cleveland, Ohio 44106.
Cell Tissue Res. 1987 Nov;250(2):315-21. doi: 10.1007/BF00219076.
The secretory tissue of the uropygial gland is of the holocrine type, containing both dividing progenitor cells and lipid-filled differentiated cells. In this study, we examined the relationship between cell division and differentiation. The location of dividing cells was determined by autoradiography of tissue sections from ducklings injected intra-abdominally with 3H-thymidine. Only cells on the basal lamina of the tubules contained labeled nuclei. Dividing cells were distributed uniformly over the length of the tubules. Over the next five days, most of the labeled cells migrated to the lumen of the tubules and disappeared. Cells containing the "lipogenic" enzymes, fatty acid synthase and malic enzyme, were localized either immunocytochemically using affinity-purified antibodies or cytochemically using a specific assay for malic enzyme activity. Fatty acid synthase and malic enzyme were undetectable in dividing basal cells but present at high levels in differentiating and differentiated cells. Thus, basal cells lying along the basal lamina of the tubules were replacing lipid-laden cells that were continually sloughed into the lumens of the tubules. The signals for differentiation and enzyme accumulation appear to be linked to one another and to cessation of cell division.
尾脂腺的分泌组织属于全浆分泌型，包含正在分裂的祖细胞和充满脂质的分化细胞。在本研究中，我们检测了细胞分裂与分化之间的关系。通过对腹腔注射³H-胸腺嘧啶核苷的雏鸭组织切片进行放射自显影，确定正在分裂的细胞的位置。只有小管基膜上的细胞含有标记的细胞核。正在分裂的细胞在小管的长度范围内均匀分布。在接下来的五天里，大多数标记细胞迁移到小管腔并消失。含有“生脂”酶（脂肪酸合酶和苹果酸酶）的细胞，要么使用亲和纯化抗体通过免疫细胞化学方法定位，要么使用苹果酸酶活性的特异性检测方法通过细胞化学方法定位。在正在分裂的基底细胞中未检测到脂肪酸合酶和苹果酸酶，但在分化和已分化的细胞中含量很高。因此，沿着小管基膜排列的基底细胞正在替代不断脱落到小管腔中的充满脂质的细胞。分化信号和酶积累似乎相互关联，并且与细胞分裂的停止有关。
