REGULATION OF PARATHYROID FUNCTION

描述(改编自申请人的摘要)：主要 甲状旁腺机能亢进症是一种相对常见的内分泌功能障碍，伴有 发病率为每10万人口40-45例。次要的 甲状旁腺机能亢进是肾功能衰竭的一种表现。已经结束了 美国有10万名接受透析的患者。因此，失调症 甲状旁腺功能给医疗保健管理带来巨大负担 以及每年的劳动力流失。甲状旁腺的控制 激素分泌几乎是独一无二的，因为钙最终会抑制 分泌，而在大多数其他系统中，钙刺激分泌。这 研究的重点是涉及到的分子机制。 控制钙介导的甲状旁腺素分泌。GTP结合信号的作用 正常甲状旁腺分泌物中的转导蛋白和蛋白激酶C 将会被研究。将使用合成的寡核苷酸探针来选择 正常牛甲状旁腺表达文库中的DNA序列 构建于噬菌体lambda gtl0中。与该信号相对应的DNA 转导蛋白将通过双脱氧基进行亚克隆和测序 链终止法推断GTP结合蛋白的类型 在甲状旁腺细胞中表达。这将确定是否 甲状旁腺细胞含有其他细胞共有的信号转导蛋白 分泌组织，或者如果有一种独特的转导蛋白 甲状旁腺激素，可解释钙敏感性的逆转 荷尔蒙分泌。根据衍生的氨基酸序列、多肽 将合成特定序列的。这些多肽将被用于 产生针对单个信号转导的多克隆抗血清 蛋白质，以便在甲状旁腺细胞中对这些蛋白质进行定量。这个 作为百日咳毒素和百日咳毒素底物的转导蛋白 霍乱毒素和一种与磷脂酶C连锁的毒素不敏感蛋白 将被描述为。百日咳毒素和霍乱毒素对小鼠免疫功能的影响 钙、镁和锶对甲状旁腺激素分泌的抑制作用 细胞内钙离子的变化将被评估。蛋白激酶的作用 甲状旁腺分泌物中的C将通过监测酶活性来评估， 并通过使用针对三种抗体的抗肽抗血清 蛋白激酶C.Sphingoid碱基代谢的异构体 细胞外钙、镁和锶将被评估为 蛋白激酶C抑制剂的生产。这些研究利用了 甲状旁腺表达文库、DNA测序及抗肽抗体 将构成今后检查正常和异常的基础 甲状旁腺功能。

DESCRIPTION (Adapted from the Applicant's Abstract): Primary hyperparathyroidism is a relatively common endocrine dysfunction with an incidence of 40-45 cases per 100,000 population. Secondary hyperparathyroidism is a manifestation of renal failure. There are over 100,000 patients on dialysis in the United States. Thus, disorders of parathyroid function impose a significant burden on health care management and loss from the labor force each year. The control of parathyroid hormone secretion is almost unique in that calcium ultimately inhibits secretion whereas in most other systems calcium stimulates secretion. This investigation focuses on molecular mechanisms that are involved in the control of calcium-mediated PTH secretion. The role of GTP-binding signal transducing proteins and protein kinase C in normal parathyroid secretion will be studied. Synthetic oligonucleotide probes will be used to select for DNA sequences in a normal bovine parathyroid expression library constructed in phage lambda gtl0. The DNA corresponding to the signal transduction proteins will be subcloned and sequenced by the dideoxy chain-termination method to deduce the types of GTP-binding proteins expressed in the parathyroid cell. This will establish whether the parathyroid cell contains signal transduction proteins common to other secretory tissues, or if there is a unique transducing protein to the parathyroid which can account for the reverse calcium sensitivity of hormone secretion. Based upon the derived amino acid sequences, peptides of specific sequence will be synthesized. These peptides will be used to generate polyclonal antisera specific to the individual signal transduction proteins in order to quantitate these proteins in parathyroid cells. The transducing proteins which serve as substrates for pertussis toxin and cholera toxin, and a toxin-insensitive protein linked to phospholipase C will be characterized. The effect of pertussis toxin and cholera toxin on calcium, magnesium and strontium-induced suppression of PTH secretion and changes in cytosolic calcium will be evaluated. The role of protein kinase C in parathyroid secretion will be evaluated by monitoring enzyme activity, and through the use of anti-peptide antisera specific for the three isoforms of protein kinase C. Sphingoid base metabolism as a function of extracellular calcium, magnesium and strontium will be evaluated for the production of protein kinase C inhibitors. These studies utilizing the parathyroid expression library, DNA sequencing and antipeptide antibodies will form a basis for the future examination of normal and abnormal parathyroid function.