Marin F, Cheng Z, Kovacs K
Department of Pathology, St Michael's Hospital, University of Toronto, Ontario.
Arch Pathol Lab Med. 1993 Mar;117(3):254-8.
Ubiquitin involved in nonlysosomal protein degradation was studied in 31 nontumorous pituitary glands and 133 pituitary adenomas by immunocytochemical techniques. Normal nontumorous hypophyses were immunonegative for ubiquitin. Ubiquitin immunoreactivity was present in 3% to 30% of corticotrophs containing Crooke's hyaline in 10 of 12 glucocorticoid-treated patients. Fifty-eight adenomas showed ubiquitin-immunoreactive cells. Ubiquitin immunoreactivity was found in cytokeratin immunopositive filamentous inclusions of Crooke's cell adenomas and in fibrous bodies of somatotroph adenomas. Forty-five adenomas showed a diffuse cytoplasmic immunopositivity. No correlation was revealed between ubiquitin immunoreactivity, hormone content, and bromocriptine and octreotide treatments. The results are consistent with the interpretation that ubiquitin immunoreactivity in nontumorous corticotrophs containing Crooke's hyaline and in various adenomas is secondary to glucocorticoid excess or to altered metabolic activity. Whether ubiquitin expression reflects increased ubiquitin synthesis or decreased breakdown of ubiquitinated conjugates remains to be elucidated.
采用免疫细胞化学技术，在31个非肿瘤性垂体和133个垂体腺瘤中研究了参与非溶酶体蛋白降解的泛素。正常非肿瘤性垂体对泛素呈免疫阴性。在12例接受糖皮质激素治疗的患者中，10例含有克鲁克透明变性的促肾上腺皮质激素细胞中，3%至30%有泛素免疫反应性。58例腺瘤显示有泛素免疫反应性细胞。在克鲁克细胞腺瘤的细胞角蛋白免疫阳性丝状包涵体和生长激素细胞腺瘤的纤维小体中发现了泛素免疫反应性。45例腺瘤显示弥漫性细胞质免疫阳性。泛素免疫反应性、激素含量以及溴隐亭和奥曲肽治疗之间未发现相关性。结果与以下解释一致：在含有克鲁克透明变性的非肿瘤性促肾上腺皮质激素细胞和各种腺瘤中，泛素免疫反应性是糖皮质激素过量或代谢活性改变的继发表现。泛素表达是反映泛素合成增加还是泛素化结合物降解减少，仍有待阐明。
