MECHANISMS OF VASOPRESSIN RESISTANCE

加压素抵抗的机制

基本信息

批准号：
3234391
负责人：
Tomas Berl
金额：
$ 4.72万
依托单位：
UNIVERSITY OF COLORADO DENVER
依托单位国家：
美国
项目类别：
财政年份：
1985
资助国家：
美国
起止时间：
1985-07-01 至 1988-06-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/3234391
关键词：
adenylate cyclase calcium metabolism cyclic AMP drug administration rate /duration drug metabolism guanine nucleotides hormone regulation /control mechanism hypercalcemia lithium neoplastic cell nephrogenic diabetes insipidus phosphodiesterase inhibitors prostaglandin E prostaglandin endoperoxide synthase prostaglandin inhibitors urination water drinking behavior

项目摘要

The objective of this proposal is to examine the biochemical mechanisms of renal resistance to vasopressin (AVP) in three settings associated with nephrogenic diabetes insipidus (NDI): hypercalcemia, pharmacologic agents (lithium and demeclocycline) and congenital NDI. The primary system in which studies will be performed is a primary culture of inner medullary collecting tubule cells that respond specifically to AVP by forming the intermediate effector of the hormone's action, cAMP in a dose dependent manner. The measurement of cAMP formation, in the presence and absence of phosphodiesterase inhibition, prostaglandin E2 production and adenylate cyclase activity will be employed. The effects of changes in extracellular calcium (Ca), agents that impair cellular Ca uptake, agents that enhance entry of Ca into cells, calmodulin inhibitors, and prostaglandin synthesis inhibitors on cAMP production will be assessed. Definition of the site of the cyclase at which any changes occur will be performed. A binding assay will examine receptor function, guanine nucleotide regulatory unit stimulation will examine the regulatory subunit and forskolin will be employed to look at the catalytic unit. The latter will be complemented by studies on cells that are deficient in the regulatory subunit, the cyc mutant of murine S49 lymphoma cells. Similar examination of the cyclase system and prostaglandin dependent mechanisms will be undertaken with lithium and demeclocycline. The culture technique will be applied to mice in order to define the defect in mice with severe congenital NDI. Studies directed to assess whether a guanine nucleotide regulatory subunit defect is operant will employ a complementation adenylate cyclase assay employing the murine S49 lymphoma cells. These studies should significantly enhance our understanding of the biochemical mechanisms that underline commonly encountered AVP resistance states characterized clinically by polyuria, polydipsia and impaired urinary concentration.

该提案的目的是检查生物化学机制三种情况下肾对加压素（AVP）的抵抗与肾性尿崩症 (NDI)：高钙血症、药物（锂和地美环素）和先天性 NDI。初级系统在将进行的研究是内髓的原代培养收集对 AVP 产生特异性反应的小管细胞，形成激素作用的中间效应器，cAMP 呈剂量依赖性方式。在存在或不存在 cAMP 的情况下测量 cAMP 形成磷酸二酯酶抑制、前列腺素 E2 产生和腺苷酸将利用环化酶活性。变化的影响细胞外钙 (Ca)、损害细胞 Ca 吸收的药物、药物增强 Ca 进入细胞、钙调蛋白抑制剂和前列腺素合成抑制剂对 cAMP 产生的影响将被评估。发生任何变化的环化酶位点的定义是执行。结合测定将检查受体功能、鸟嘌呤核苷酸调节单元刺激将检查调节亚单元毛喉素将被用来检查催化单元。后者将通过对缺乏该基因的细胞的研究来补充调节亚基，鼠S49淋巴瘤细胞的cyc突变体。相似的检查环化酶系统和前列腺素依赖性机制将使用锂和地美环素进行治疗。养殖技术将应用于小鼠，以确定患有严重疾病的小鼠的缺陷先天性 NDI。研究旨在评估鸟嘌呤核苷酸是否调节亚基缺陷是可操作的，将采用互补使用鼠 S49 淋巴瘤细胞进行腺苷酸环化酶测定。这些研究应显着增强我们对生化的理解强调常见 AVP 抵抗状态的机制临床特征为多尿、多饮和排尿障碍专注。