REGULATION OF RAT PITUITARY HYPERPLASIA AND NEOPLASIA

催乳素细胞增生的发生与催乳素分泌的关系 转化为肿瘤性泌乳素分泌垂体 将使用形态学， 免疫组化和生化方法。 形态 免疫组化光、电镜观察 微观水平将用于表征各种亚型 催乳素细胞和促乳腺生长细胞（ 催乳素和生长激素）， 肿瘤性MtT/W15和MtT/F4组织。 的职能 正常、增生和 肿瘤性垂体将通过以下方法进行研究： 免疫组织化学和超微结构研究。 的作用 S100蛋白在调节催乳素分泌中的作用 研究了 初步研究结果表明，S100蛋白 它存在于垂体滤泡星状细胞中， 催乳素在体外释放，表明这些细胞可能发挥 催乳素释放的旁分泌型调节。 丰富 肿瘤性催乳素、生长激素和 乳腺增生性和滤泡星状细胞 将通过单位速度沉降制备垂体 重力和密度梯度离心。 这些富集的细胞 人群将用于研究体外催乳素释放并 分析多巴胺和雌激素受体在相对 同质细胞群。 最近的研究表明 雌激素抑制可移植的MtT/W15的生长， MtT/F4垂体瘤并同时增加生长 MtT/W15肿瘤的激素产生。 我们计划在 原位和细胞质斑点杂交分析， 生长激素和催乳素信使的定量变化 雌激素诱导的生长抑制过程中肿瘤细胞中的RNA。 雌激素和多巴胺在其调节中的作用 垂体瘤发生过程中的受体， 通过研究受体水平的变化来分析， 从增生到瘤形成的转变。 这个的目标 研究是1）更清楚地定义形态和 垂体增生和肿瘤的生化特征 组织，2）分析滤泡星状细胞和S100的作用 蛋白调节催乳素细胞增生和退化， 自主肿瘤的生长，3）分析的作用， 垂体瘤中雌激素和多巴胺及其受体 （4）发展更精细、更具体的方法 分析催乳素和生长激素的调节 在增生性和肿瘤性肿瘤中， 垂体

The development of prolactin cell hyperplasia and the transformation to neoplastic prolactin producing pituitary tumors will be investigated in rats using morphological, immunohistochemical and biochemical methods. Morphological and immunohistochemical studies at the light and electron microscopic levels will be used to characterize various subtypes of prolactin cells and mammosomatotropic cells (which produced both prolactin and growth hormone) in hyperplastic and neoplastic MtT/W15 and MtT/F4 tissues. The functions of the pituitary folliculostellate cells in normal, hyperplastic and neoplastic pituitaries will be investigated by immunohistochemical and ultrastructural studies. The role of S100 protein in regulating prolactin secretion will be investigated. Preliminary findings indicate that S100 protein which is present in pituitary folliculo-stellate cells can stimulate prolactin releases in vitro suggesting that these cells may exert a paracrine type regulation of prolactin release. Enriched populations of neoplastic prolactin, growth hormone and mammosmatotropic and folliculo-stellate cells from hyperplastic pituitaries will be prepared by velocity sedimentation at unit gravity and density gradient centrifugation. These enriched cell populations will be used to study prolactin release in vitro and to analyze dopamine and estrogen receptors in relatively homogeneous cell population. Recent studies have shown that estrogens inhibit the growth of transplantable MtT/W15 and MtT/F4 pituitary tumors and concurrently increases growth hormone production by the MtT/W15 tumor. We plan to use in situ and cytoplasmic dot blot hybridization to analyze and quantitate changes in growth hormone and prolactin messenger RNA in tumor cells during estrogen-induced growth-inhibition. The role of estrogen and dopamine in the regulation of their receptors during development of pituitary tumors will be analyzed by studying changes in receptor levels during transformation from hyperplasia to neoplasia. The goals of this study are 1) to define more clearly the morphological and biochemical features of hyperplastic and neoplastic pituitary tissues, 2) analyze the role of folliculostellate cells and of S100 protein is regulating prolactin cell hyperplasia and regression and the growth of autonomous tumors, 3) analyze the role of estrogen and dopamine and their receptors in pituitary tumor development and 4) develop more refined and specific methods to analyze the regulation of prolactin and growth hormone biosynthesis at the cellular level in hyperplastic and neoplastic pituitaries.