【作者】 张芙蓉；

【导师】 孟庆海；

【作者基本信息】 青岛大学 ， 神经外科， 2006， 硕士

【摘要】 目的：通过应用与ghrelin功能相同人工合成的生长激素释放剂GHRP-6对体外培养的人垂体生长激素腺瘤细胞GH分泌影响的观察，探讨GHRP-6对GH腺瘤细胞作用的生物学特征及多种细胞内第二信使调控GH分泌的机制，并分析其可能的临床意义。材料和方法：用原代细胞培养技术，观察了10例人垂体GH腺瘤细胞和6例正常胚胎垂体细胞对GHRP-6、生长释放激素(GH-releasing hormone，GHRH)和生长抑素(somatostatin，SS)的体外分泌效应。结果：体外细胞培养中，GHRP-6对所有10例GH腺瘤细胞GH分泌表现出明显的刺激效应(P＜0.01)，但远不如正常垂体细胞敏感，但GH腺瘤细胞对持续的GHRP-6刺激反应时间延长。GHRH和SS仅对部分GH腺瘤细胞有作用，且SS不能完全阻断GHRP-6对于GH分泌的刺激效应。结论：在体外细胞培养中，正常垂体细胞大小形态一致，呈圆形或椭圆形，分散，悬浮生长，不易贴壁，而异常垂体细胞大小形态不一致，贴壁后的细胞呈椭圆形或梭形，成团状或片状生长，分裂旺盛，细胞周围有伪足，部分悬浮生长，增加了培养的难度，其帖壁时间在培养的24小时后，因此细胞培养的成功为进一步的垂体GH腺瘤的分子生物学的研究打下坚实的基础。GH腺瘤细胞对生长激素释放剂GHRP-6的GH分泌刺激效应远不如正常垂体细胞那样敏感，表现为一定的功能自主性。而腺瘤细胞对于体外GHRP-6持续刺激的异常反应，表明垂体GH腺瘤中可能存在GH释放剂受体(GHS-R)所固有的负反馈机制——“脱敏”机制的减弱，且与肿瘤发病机制有关。更多还原

【Abstract】 Objective: To observe the effects of GH releasing peptide-6 (GHRP-6) on GH secretion of human pituitary somatotrophinoma cells in vitro,and to investigate the regulatory effects of multiple intracellular "second messengers" on GH secretion by human pituitary somatotrophinomas.Materials and Methods: The response to GHRP-6, GH-releasing hormone(GHRH) and somatostatin(SS) in 6 somatotrophinomas and 3 embryo pituitaries in vitro were observed..Results:In vitro cell culture, a stimulatory response to GHRP-6 was found in both groups of somatotrophinomas, and excitative effects is not as more sensitive as normal pituitary. Howerer, the GH response time to repeated administration of GHRP-6 to somatotrophinomas was prolonged. The GH-secreting effects of GHRH or SS was only obtained in parts of somatotrophinomas. Moreover, SS only attenuation but abolished GH response to GHRP-6.Conclusion: In vitro cell culture, human pituitary cells have the same form and size, they grow dispersed and suspended, and not easy to adherence. On the contrary the abnomal human pituitary cells have different form and size, the attached cells were longer and shaped ellipse or shuttle and grown like a round or a flat under microscopy, they grow clumpy and desintegrate vigorous. The abnomal cells have parapodium and grow suspended partly, the adherence time of them is more than 24 hours, all of this increase the difficulty of cell culture. So, the success of cell culture is the compact base of studying the pituitary somatotrophinoma molecular biology. In vitro cell culture, the GH-secreting excitative effect of GHRP-6 to somatotrophinomas was not as far more sensitive as normal pituitary ,So GH-secreting pituitary adenomas manifestated autocrine characteristics. The abnormal response to repeated administration of GHRP-6 in vitro showed that the lack of desensition--negative feedback loops of GH releasing hormone receptors was associated with tumorigenesis of GH secreting adenomas.更多还原