PITUITARY TUMORIGENESIS IN AGING FEMALE C57BL-6J MICE - A LIGHT AND ELECTRON-MICROSCOPIC STUDY
PITUITARY TUMORIGENESIS IN AGING FEMALE C57BL-6J MICE - A LIGHT AND ELECTRON-MICROSCOPIC STUDY
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DOI：
10.1002/ar.1091990310
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发表时间：
1981-01-01
影响因子：
--
通讯作者：
FINCH, CE
中科院分区：
文献类型：
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作者：
SCHECHTER, JE;FELICIO, LS;FINCH, CE
用光学显微镜和电镜观察了2 1/2、11、15、22、23、24和30月龄雌性C57 BL/6 J小鼠自发性垂体瘤。22个月时，> 50%的小鼠肉眼可见肿瘤。或更老，显微镜评价> 80%。在22-30个月时，活跃和肥大的乳房营养细胞是肿瘤内的主要细胞类型，通常完全填充肿瘤块的大部分。分泌颗粒的胞吐是广泛的从mammotrophs，但从其他实质细胞丰富得多。生长激素细胞和促性腺激素细胞也存在，并出现活跃，往往显着肥大。肿瘤的特征在于实质和毛细血管完整性的破坏，这导致形成仅由肿瘤细胞（通常是乳房营养细胞）内衬的大血管湖。观察到肿瘤细胞明显转移到血管湖中。在11和15个月。小鼠小肿瘤或肿瘤前病灶在显微镜评价中在一些小鼠中是明显的，尽管它们在肉眼下不可见。它们的发展程度有些不同，但它们与老年小鼠中更晚期的肿瘤具有基本相同的特征。瘤前病灶的特点是更温和的破坏实质细胞和毛细血管的完整性;细胞肥大，特别是生长激素细胞和促性腺激素细胞;和小血管湖的存在。两个半月后。小鼠肿瘤不能用肉眼或显微镜定位，垂体由界限清楚的细胞索和完整的毛细血管床组成。2个半月内偶见毛细血管和组织破坏的小病灶区。小鼠雌性C57 BL/6 J小鼠的垂体肿瘤发生过程始于中年，随后逐渐发展为大型乳腺营养型肿瘤。
Spontaneous pituitary tumors were studied by light microscopy and EM in female C57BL/6J mice at 2 1/2, 11, 15, 22, 23, 24 and 30 mo. Tumors were evident macroscopically in > 50% of mice 22 mo. or older and > 80% on microscopic evaluation. Active and hypertrophied mammotrophs were the predominant cell type within the tumors at 22-30 mo., often totally filling large portions of the tumor mass. Exocytosis of secretory granules was extensive from the mammotrophs but much less abundant from other parenchymal cells. Somatotrophs and gonadotrophs were also present and appeared active and often strikingly hypertrophied. The tumors were characterized by disruptions of parenchymal and capillary integrity which resulted in the formation of large vascular lakes lined solely by tumor cells, generally mammotrophs. Apparent metastasis of tumor cells into the vascular lakes was observed. In 11 and 15 mo. mice small tumors or pretumor foci were evident in some mice on microscopic evaluation, although they were not visible macroscopically. Their degree of development was somewhat variable but they had essentially the same features as more advanced tumors in older mice. Pretumor foci were characterized by more moderate disruptions of parenchymal cell and capillary integrity; cellular hypertrophy, particularly of somatotrophs and gonadotrophs; and the presence of small vascular lakes. In 2 1/2 mo. mice tumors could not be localized macroscopically or microscopically and the pituitary was composed of well-defined cell cords and an intact capillary bed. Small focal zones of capillary and tissue disruption were apparent occasionally in 2 1/2 mo. mice. The process of pituitary tumorigenesis in female C57BL/6J mice is initiated by midlife, with subsequent progressive development into large, mammotroph-dominated tumors.