Molecular and cellular analysis of pituitary cel differentiation and proliferation.

本研究旨在阐明大鼠垂体生长激素细胞（GH细胞）和泌乳激素细胞（PRL细胞）的分化、增殖和发育（终末分化）。本研究的结果如下。(1)GH 18日龄时检测PRL细胞，19日龄时检测PRL细胞。本文用免疫电镜观察了哺乳动物出生后体内既产生GH又产生PRL的哺乳动物营养体（MS细胞），虽然数量很少。MS细胞被认为是GH细胞和PRL细胞的祖细胞，或介于Botti Gil细胞和PRL细胞之间的过渡细胞。（2）免疫电镜观察显示Gil细胞和PRL细胞形态不均一。GH细胞和PRL细胞根据分泌颗粒的大小和细胞形状可分为三个亚型。各亚型的相对比例随时间的变化而变化， ...更多信息 h年龄和几种激素治疗。这些变化与每种细胞类型分泌活动的变化密切相关。（3）反向溶血空斑试验显示GH细胞功能的异质性。GH细胞分为高分泌活性细胞和低分泌活性细胞两个亚群。（4）观察链脲佐菌素诱导的糖尿病大鼠垂体细胞增殖情况。糖尿病大鼠垂体DNA合成细胞的相对比例低于对照组。此外，与对照组大鼠相比，糖尿病大鼠垂体细胞对雌激素对细胞增殖的反应较低。因此，垂体细胞的增殖可能依赖于胰岛素水平。（5）研究了垂体后叶激素对GH和PRL mRNA表达的影响。Gil和PRL细胞在转录水平上的GH和PRL合成均随增龄而减少。因此，本研究阐明了大鼠从胎龄到老年期生长激素细胞和催乳素细胞的形态和功能变化。少

The present study was aimed to clarify differentiation, proliferation and development(terminal diffelentiation)of somatotroplis(GH cells)and mammotroptis(PRL cells)of the rat pituitary. The findings obtained in the present study are as follows. (1)GH cells were immunohistochemically detected at 18 days of fetal age, and PRL eells were at 19 days of fetal age. Mammosomato trophs(MS cells), which produced both GH and PRL at the same time, were immunoeIectron microscopicaIIy observed during the postnatal period, although the number of them were quite few. MS cells are considered to be the progenitor cells of both GH cells and PRL cells, or the transitional cells between botti Gil cells and PRL cells. (2)Immunoelectron microscopical study snowed morphological heterogeneity of Gil cells and PRL cells. GH cells and PRL cells were sub-divided into three subtypes, respectively on the basis of the size of secretory granules and the cell shape. The relative proportion of each subtype changed wit … More h age and by several hormonal treatments. These changes are closely correlated with changes in the secretory activities of each cell type. (3)Reverse hemolytic plaque assay snowed functional heterogeneity of GH cells. there were two subpopulations in GH cells : high secretory activity cell and low secretory activity cell. (4)The proliferation of pituitary cells were studied in streptozotocin-induced diabetes rats. The relative proportion of DNA-synthesizing pituitary cells was lower in the diabetic rats than in control rats. Also, response of pituitary cells in the diabetic rats to estrogen on the cell proliferation was low as compared with control rats. Thus, the proliferation of pituitary cells may depend on the insulin level. (5)Age-related changes in GH and PRL mRNA levels were studied. The GH and PRL syntheses at the transcription level decreased in each Gil and PRL cell with aging. Thus, the present study clarified morphological and functional changes in GH cells and PRL cells of rats from the fetal ages to senile ones. Less