Kendall M E, Lawson D M
Department of Physiology, Wayne State University, School of Medicine, Detroit, Michigan 48201.
Proc Soc Exp Biol Med. 1988 Dec;189(3):291-6. doi: 10.3181/00379727-189-42809.
Depletion of pituitary prolactin (PRL) and PRL release into culture medium were simultaneously examined over a 3.5- to 4.0-hr incubation period from anterior pituitary fragments obtained from Fischer-344 or Wistar-Furth female rats treated with estrogen for 5 days, in pituitary tumors induced by 8 weeks of diethylstilbestrol (DES) treatment in Fischer-344 rats and in MtTW15 pituitary tumors transplanted subcutaneously in Wistar-Furth rats for 4 weeks. Our objective was to determine if the event known as transformation, which we define as a loss in the tissue PRL content without a corresponding and equivalent increase in the medium PRL content, occurs in rat pituitary tumors. Our results indicated that transformation did not occur in vitro in rat anterior pituitary tumors induced in Fischer-344 rats by DES treatment but was present in pituitaries from Fischer-344 rats treated for 5 days with estrogen, which served as controls. We also observed in vitro transformation in the anterior pituitary of Wistar-Furth rats treated with estrogen for 5 days (controls) and in the pituitaries of Wistar-Furth rats inoculated with the MtTW15 tumor for 4 weeks, but not in the MtTW15 tumor itself. Although transformation was present in both Fischer-344 and Wistar-Furth rats treated acutely with estrogen the timing of the transformation was delayed 1-2 hr in the Fischer-344 rats compared with Wistar-Furth females. We concluded that transformation does not precede release of prolactin in rat pituitary tumors and that in normal pituitaries the mechanisms of transformation are induced differently between the strains of rats examined.
在3.5至4.0小时的孵育期内，同时检测了从接受5天雌激素处理的Fischer-344或Wistar-Furth雌性大鼠获得的垂体前叶碎片、经8周己烯雌酚（DES）处理诱导的Fischer-344大鼠垂体肿瘤以及皮下移植Wistar-Furth大鼠4周的MtTW15垂体肿瘤中垂体催乳素（PRL）的消耗情况以及PRL释放到培养基中的情况。我们的目的是确定在大鼠垂体肿瘤中是否发生了我们定义为组织PRL含量降低而培养基中PRL含量没有相应且同等增加的转化现象。我们的结果表明，DES处理诱导的Fischer-344大鼠垂体前叶肿瘤在体外未发生转化，但在作为对照的接受5天雌激素处理的Fischer-344大鼠垂体中存在转化现象。我们还观察到，接受5天雌激素处理的Wistar-Furth大鼠（对照）的垂体前叶以及接种MtTW15肿瘤4周的Wistar-Furth大鼠的垂体在体外发生了转化，但MtTW15肿瘤本身未发生转化。尽管急性接受雌激素处理的Fischer-344和Wistar-Furth大鼠均出现了转化现象，但与Wistar-Furth雌性大鼠相比，Fischer-344大鼠的转化时间延迟了1至2小时。我们得出结论，在大鼠垂体肿瘤中，转化现象不会先于催乳素的释放发生，并且在正常垂体中，所检测的大鼠品系之间转化机制的诱导方式有所不同。
