颅脑损伤大鼠垂体促肾上腺皮质激素细胞免疫组织化学变化

目的: 观察颅脑损伤大鼠垂体远侧部促肾上腺皮质激素(ACTH)细胞的免疫组织化学变化。方法: 采用落体法致大鼠颅脑损伤; 伤后24 h断头处死,用免疫组织化学和图像分析方法观察颅脑损伤后大鼠ACTH细胞的变化。结果: 颅脑损伤大鼠ACTH细胞的面数密度、平均吸光度及免疫组化反应均显著强于对照组(P<0.05)。结论: 颅脑损伤大鼠ACTH细胞合成分泌促肾上腺皮质激素功能增强。     

大鼠腺垂体促肾上腺皮质激素细胞分泌方式的免疫电镜观察

实验用雄性Ｗｉｓｔａｒ大鼠，以在无菌条件下腹腔注射松节油的方法制成急性非特异性腹膜炎，取大鼠腺垂体用免疫电镜方法进行染色，发现促肾上腺皮素激素细胞内分泌颗粒向细胞表面突起，并可见细胞间隙内完整的金标记的内分泌颗粒，实验结果表明：ＡＣＴＨ细胞除传统认为的胞吐分泌外还有其他分泌方式。     

吗啡依赖及戒断后大鼠垂体远侧部促肾上腺皮质激素细胞和甲状腺刺激激素细胞组织学研究

目的:观察吗啡依赖大鼠及戒断大鼠垂体远侧部促肾上腺皮质激素(ACTH)细胞和甲状腺刺激激素(TSH)细胞的变化。方法:皮下规律注射吗啡建立大鼠吗啡依赖模型,戒断后造成戒断模型并用免疫组织化学和图像分析方法检测吗啡依赖及戒断后大鼠垂体远侧部ACTH细胞和TSH细胞的变化。结果: 吗啡依赖大鼠ACTH细胞和TSH细胞免疫反应减弱(P＜0.01),短期戒断后这些改变仍持续存在。 结论:吗啡可导致大鼠脑垂体分泌功能紊乱,且短期戒断后未能完全恢复。     

糖尿病大鼠正中隆起室管膜细胞的超微结构变化

目的:观察糖尿病大鼠不同时期正中隆起的室管膜细胞形态学变化.方法:应用扫描、透射电镜对2、4、8、11周的糖尿病大鼠及正常大鼠的正中隆起进行形态学观察.结果:对照组分泌颗粒的分布有明显区域特异性,表面光滑,且漏斗隐窝处的分泌颗粒密集,呈片状、散在分布.2周组,分泌颗粒大小、分布均匀,交界区可见多个吞噬细胞样室管膜上细胞.4周组,分泌颗粒减少且漏斗隐窝处分泌颗粒粘附在一起聚集成团状.8周组,交界区出现大量的分泌颗粒.11周组,分泌颗粒集中在正中隆起中间部,呈窄长带状分布.透射电镜下模型组分泌颗粒稀疏,体积较小,微绒毛稀疏.结论:糖尿病大鼠发病不同时期正中隆起处分泌颗粒的分布区域有明显差异,且室管膜细胞分泌功能下降.     

吗啡依赖及乌拉地尔戒断大鼠垂体远侧部 ACTH 细胞免疫组织化学研究

目的观察吗啡依赖及乌拉地尔戒断大鼠垂体远侧部促肾上腺皮质激素(ACTH)细胞的变化。为探讨乌拉地尔对吗啡依赖大鼠 ACTH 细胞分泌功能影响提供形态学依据。方法用皮下注射吗啡法建立雄性大鼠吗啡依赖模型，戒断组给吗啡依赖大鼠侧脑室注射(IVC)乌拉地尔。用免疫组织化学和图像分析方法观察吗啡依赖大鼠及乌拉地尔戒断大鼠垂体远侧部 ACTH 细胞的变化。结果吗啡依赖大鼠及乌拉地尔戒断大鼠 ACTH 细胞免疫反应减弱(P＜0．01)。侧脑室注射乌拉地尔正常大鼠 ACTH 细胞免疫反应增强(P＜0．05)。结论乌拉地尔可引起吗啡依赖大鼠垂体远侧部 ACTH 细胞分泌功能减弱，引起正常大鼠 ACTH 细胞分泌功能增强。     

糖尿病大鼠穹窿下器室管膜细胞的形态学变化

目的:观察糖尿病大鼠不同时期穹窿下器的室管膜细胞的形态学变化.方法:雄性Wistar大鼠,每只大鼠给予链脲佐菌素60 mg/kg,腹腔一次性注射,建立Ⅰ型糖尿病大鼠模型.造模成功后分别于2、4及8周,扫描电镜和透射电镜观察穹窿下器不同时期室管膜细胞的形态学变化.结果:扫描电镜观察,对照组细胞膨隆,表面光滑,有清晰的微绒毛.2周组细胞扁平、塌陷,细胞表面可见到圆形小破孔.4周组室管膜细胞表面凹凸不平,出现皱褶,细胞膜可见大小不一的多个小破孔,并可见细胞膜缺失、细胞器裸露的细胞.8周组室管膜细胞表面皱褶明显,可见大量的球形分泌颗粒.透射电镜观察显示,对照组穹窿下器室管膜细胞脑室面完整,有少量的微绒毛和乳头状微突起,模型组室管膜面可见大量分泌颗粒.结论:糖尿病可导致大鼠穹窿下器室管膜细胞破损及分泌大量的分泌颗粒.     

垂体ACTH分泌瘤分泌调节的体外研究

本文对来源于柯兴氏病病人2例单纯垂体人CTH瘤用单层细胞培养的方法,以N-POMC作为ACTH分泌的指标,详细研亢了癌细胞ACTH分泌的调节。结果丧明cRH和AVP均能兴奋N-POMC分泌,并有协同作用;皮质醇对ACTH瘸细胞N-POMC分泌不抑制反使其分泌反常增加,表明皮质醇对AcTH分泌的负反馈调节消失;β-内啡肽对ACTH瘤细胞有直接兴奋N-POMC允泌的作用,这种作用可被纳洛酮阻断;GHRH_(1-44)、SRIF、AT_Ⅱ和VIP对N-POMC分泌无明显影响。     

寒冷应激对大鼠肾上腺髓质亨廷顿蛋白相关蛋白1表达的影响

目的 探讨亨廷顿蛋白相关蛋白1(HAP1)在大鼠肾上腺髓质的超微结构定位,以及寒冷应激对大鼠肾上腺髓质HAP1表达的影响. 方法 成年雄性Wistar大鼠14只,2只用于免疫电镜研究,12只用于寒冷实验研究.寒冷实验中,将动物随机分为对照组和寒冷组,每组6只,寒冷组动物放置4℃环境下,12h后用免疫组织化学和Western blotting方法 检测大鼠肾上腺髓质HAP1表达的变化. 结果 免疫电镜结果 显示,HAP1免疫反应产物分布在肾上腺髓质细胞分泌颗粒外膜及分泌颗粒间的膜性细胞器上.寒冷组大鼠肾上腺髓质HAP1的表达明显减少,和对照组比较有显著性差异( P <0.01). 结论 HAP1可能与肾上腺髓质细胞内分泌颗粒及位于分泌颗粒内的肾上腺素/去甲肾上腺素的运输和释放有关.     

去卵巢大鼠第四脑室外侧隐窝室管膜细胞的形态学变化

目的:观察卵巢切除后雌性大鼠第四脑室外侧隐窝室管膜的形态学变化.方法:雌性大鼠随机分为正常对照组、假手术组和卵巢切除后15d组,用H-E染色和扫描电镜观察第四脑室外侧隐窝室管膜细胞的形态学变化.结果:H-E染色显示雌性大鼠第四脑室外侧隐窝腹侧部室管膜细胞数目在卵巢切除后15d组高于正常对照组和假手术组,差异有统计学意义.在卵巢切除后15d组的室管膜细胞表面可见一层淡染的絮状结构,其他两组不明显.扫描电镜观察显示,正常对照组和假手术组第四脑室外侧隐窝部位可见散在的分泌颗粒,卵巢切除后15d组在该处观察到大量分泌颗粒和淤泥样分泌物.结论:卵巢切除后大鼠第四脑室外侧隐窝室管细胞数目增多,分泌功能增强,这些改变可能与雌激素水平降低有关.     

分泌颗粒素Ⅱ和促肾上腺皮质激素在脑损伤大鼠垂体腺细胞共存(英文)

采用荧光双标记技术研究了脑损伤时大鼠垂体前叶促肾上腺皮质激素和分泌颗粒素 的定位。垂体前叶细胞呈现分泌颗粒素 染色强阳性 ,阳性物质位于胞浆中。免疫荧光双标记技术用于鉴定分泌颗粒素 和促肾上腺皮质激素共存的细胞 ,共聚焦显微镜观察显示促肾上腺皮质激素和分泌颗粒素 共存于同一细胞。结果表明 :分泌颗粒素 可在大鼠垂体前叶促肾上腺皮质激素阳性细胞表达 ,其生理作用可能是调节分泌泡的 p H值以利于促肾上腺皮质激素从其前体裂解。     

大鼠实验性胃溃疡自愈期间垂体远侧部ACTH细胞的免疫电镜研究

用成年雄性Ｗｉｓｔａｒ大鼠，分为溃疡组和对照组。用免疫电镜包埋后免疫金间接法村记ＡＣＴＨ细胞，研究胃溃疡自愈过程中垂体远侧部ＡＣＴＨ细胞的超微结构变化，结果显示，在实验性胃溃疡第４ｄ，一些ＡＣＴＨ细胞含少量很小的分泌颗粒，沿质膜分布，有较多的ＡＣＴＨ细胞胞质出现许多空泡。溃疡第６ｄ，ＡＣＴＨ细胞的高尔基复合体发达，其扁囊膨大部含中等电子密度的内容物，其内可见金颗粒标记。溃疡６－１０ｄ，较多的ＡＣＴ     

Regulation of prolactin gene expression in a DMBA-estrogen-induced transplantable rat pituitary tumor.

A new transplantable rat pituitary tumor was induced in F344 female rats with dimethylbenz(a)anthracene and estrogen (MtT/F-DMBA) and studied for 20 serial transplant generations. The tumor grew without estrogen supplements in female rats by the second transplant generation. Sensitivity to estrogens, as indicated by a prolonged latency period for tumor development, was seen at the 20th, but not the 5th transplant generation. MtT/F-DMBA tumors expressed prolactin (PRL), growth hormone (GH), and adrenocorticotropin (ACTH) mRNAs. A decrease in the percentage of cells expressing PRL mRNA, PRL protein, and in the number of secretory granules per cell occurred with serial transplantation. S-100 protein-positive folliculostellate cells were present in the hyperplastic pituitary but not in the transplantable tumors. Estrogen treatment at the 20th transplant generation prolonged the tumor latency period, increased the number of cells expressing PRL mRNA greater than 5-fold by in situ hybridization analysis (14 +/- 2% versus 77 +/- 5%), increased PRL secretion (132 +/- 40 ng/ml versus 3762 +/- 890 ng/ml), and increased the number of cytoplasmic secretory granules per cell. These results indicate that hyperplastic pituitary and true pituitary neoplasms differ in their ability to grow readily after transplantation. The presence of S-100 protein-positive folliculostellate cells, which are present in hyperplastic but not in neoplastic pituitary tissues, may serve as a morphologic marker to separate hyperplastic and neoplastic rat pituitary tissues. Transplantable tumors remained responsive to estrogen with expression of a more differentiated phenotype, including an increased number of cells expressing PRL mRNA and increased numbers of PRL secretory granules.     

免疫组化电镜示垂体LH细胞

应用免疫组化电镜显示垂体黄体生成素(LH)细胞的形态特徵、超微结构以及反应阳性颗粒的分布状况等,并按此将LH细胞分为四型。一、二型细胞内大小分泌粒均含有LH;三型细胞长(?)的150 nm及200 nm颗粒显免疫反应阳性,且部分胞膜和微绒毛顶部界膜内外附着致密细粒;四型细胞出现反应阴性颗粒,仅在rER膜囊外显有直径30～40 nm黑色细粒。LH细胞的分泌可能以外排、分子渗透和局部分泌三种方式排出LH。     

Effects of pergolide on diethylstilbestrol-induced rat pituitary hyperplasia.

Hyperplastic anterior pituitary glands were produced in female rats by treatment with 10 mg of diethylstilbestrol in Silastic tubing. This led to increased numbers of immunoreactive prolactin cells and increased serum prolactin levels. After 6 weeks of diethylstilbestrol treatment, one group of rats was treated with daily injections of pergolide for 3 weeks. Pergolide produced a significant decrease in pituitary gland weight and in serum prolactin levels but did not change the percentage of prolactin cells significantly, compared with that of control rats. Ultrastructural studies showed a significant increase in the numbers of prolactin secretory granules and numerous large intracellular bodies with associated secretory granules in pituitaries from rats treated with pergolide. In one group of rats in which the diethylstilbestrol was discontinued for 3 weeks after 6 weeks of treatment there was a significant decrease in pituitary gland weight and serum prolactin and a significant decrease in the percentage of prolactin cells, compared with values in the rats treated with diethylstilbestrol for 9 weeks. These results indicate that pergolide causes decreased release of prolactin from secretory granules in anterior pituitary prolactin cells and an increase in the numbers of PRL secretory granules per cell but does not change the percentage of prolactin-producing pituitary cells after 3 weeks of treatment.     

FINE STRUCTURAL STUDIES OF RAT ADENOHYPOPHYSIS —EFFECTS OF EXOGENOUS GROWTH HORMONE AND HYPOTHALAMIC LESIONS ON SOMATOTROPHS

The response of rat pituitary somatotrophs to transplantation of the MtT-W10 pituitary tumor and prolonged treatment with large doses of purified bovine growth hormone was examined. The effects of hypo-thalamic lesions on the somatotrophs were also studied.
Involution occurred in somatotrophs of the anterior pituitary of rats bearing a transplantable tumor. The changes in the somatotrophs were observable at 4 weeks and consisted of smaller cells and fewer secretory granules.
Administration of growth hormone produced a triphasic response; (1) increased cross-sectional area of cell, increased size and number of secretory granule, (2) return of parameters to normal levels, and (3) suppression of somatotrophs by exogenous growth hormone.
Following destruction of ventromedial nucleus (VMN), the number of secretory granules per somatotroph increased. Concomitantly, there was an enlargement of the mean diameter as well as an increase in the mean surface area of the somatotrophs. After destruction of dorsomedid nucleus (DMN), the number of secretory granules decreased rapidly and reached the lowest level. Two days after the operation, the secretory granules re-accumulated very slowly in the cytoplasm but remained below control level. Accompanying the decreased granule count, the mean diameter of the largest granule was smaller than that of the controls during all experimental periods.     

Decreased prolactin level in secretory granules and their increased exocytosis in estrogen-induced pituitary hyperplasia in rats treated with a dopamine agonist.

Treatment with bromocriptine (CB) stimulates the release of secretory granules from human prolactinomas by exocytosis in spite of a remarkable decrease in serum prolactin (PRL) levels. In an attempt to elucidate the reasons for this phenomenon, secretory granules were analyzed in estrogen-induced pituitary hyperplasia in rats which served as a model of human disease. The amount of protein contained in cell fractions rich in secretory granules was the same in CB-treated pituitaries as that in the controls, whereas PRL levels decreased to about a half the level of the controls. Morphometric analysis using point-counting and electron immunocytochemistry revealed that the PRL concentrations in secretory granules decreased to about 50% after CB-treatment. Serum PRL levels estimated by counting the exocytotic secretory granules were remarkably lower in CB-treated rats than in the controls. It was suggested that the composition of secretory granules changed or that nonhormonal constituents in the granules disintegrated more slowly after CB treatment, thus allowing exocytosed granules to be observed more frequently. Additionally CB might also suppress a bypass release of PRL by which PRL is secreted without being packaged into secretory granules.     

Heterogeneity of secretory granules of silent pituitary adenomas

Silent pituitary adenomas were compared with hormonally active tumors taking into account the size, number, and ultrastructural characteristics of secretory granules (SG). The study group (a total of 79 primary pituitary adenomas) comprised 27 silent, 21 growth hormone (GH)-producing-, 16 prolactin (PRL)-producing-, 5 GH-PRL-producing- and 10 adrenocorticotropic hormone (ACTH)-producing adenomas. The SG of silent adenomas were significantly smaller than SG in endocrine active adenomas. All hormonally inactive tumors also contained small (mean, 94 nm) specific cytoplasmic granules, designated "silent adenoma granules" (SIG). The fine structural features of the SIG included: a flocculent, granular material occupying an eccentric position in a larger vesicle limited by a double membrane. In the silent adenomas this particular granule was present in up to 90% of the adenoma cells and constituted approximately 10 to 50% of the granules in each cell. These granules were not seen in hormonally active tumors and considered therefore diagnostic of silent pituitary adenomas.     

Biological aspects of pituitary tumors induced by synthetic salmon calcitonin (TZ-CT) in Sprague-Dawley rats. Immunohistochemical and ultrastructural studies.

Rat pituitary tumors induced by synthetic salmon calcitonin (TZ-CT) were studied by the indirect peroxidase-labeled antibody method, together with ultrastructure and serum hormone measurement. Immunohistochemically, TZ-CT-induced pituitary tumors showed staining for only rLH alpha subunit, and were negative for other peptide hormones including GH, PRL, alpha MSH and ACTH, and the beta subunit of glycoprotein hormones. Electron microscopic examination showed that the majority of tumor cells possessed numerous small secretory granules, 100 to 200 nm in diameter. The serum PRL concentrations of rats with TZ-CT-induced pituitary tumors were markedly elevated, but not beyond 130 ng/ml. From our data, TZ-CT-induced pituitary tumors are considered to be endocrinologically inactive and to produce alpha subunit. Furthermore, these tumors are thought to be potentially useful models of alpha subunit-producing pituitary tumors in humans. This is the first report to document the tumorigenesis of alpha subunit-producing pituitary tumors in rats after long-term treatment with calcitonin.     

ULTRASTRUCTURE OF THE "NON-PATHOLOGIC" HUMAN PITUITARY GLAND

The ultrastructure of "non-pathologic" human pituitary gland obtained from eight cases at autopsy, who received no hormonal therapy and who revealed no significant changes in the pituitary and its target organs, was investigated in an attempt to identify human adenohypophyseal cells by comparing their secretory granules with those of experimental animals. Besides the follicular cell, Ave different granulated cell types were distinguished The Type I cell contained abundant, dense secretory granules (350–500 mμ across). The Type II cell was characterized by dense granules, which were the largest in size (500–700 mμ across) and the most irregular in shape. Granules of the Type III cell were less characteristic (200–300 m/t) across). The Type IV cell contained dense granules, which were the smallest in size (100–150 mμ across) and were characteristically arranged along the plasma membrane. The Type V cell was characterized by the presence of small, haloed granules (100–200 mμ across). The cells of these five types could presumably be the somatotroph, lactotroph, gonadotroph, thyrotroph and corticotroph, respectively.