1,25-DIHYDROXYVITAMIN D RECEPTOR/FUNCTION IN NEW TARGETS

新靶标中的 1,25-二羟基维生素 D 受体/功能

基本信息

批准号：
3230391
负责人：
MARIAN R WALTERS
金额：
$ 11.05万
依托单位：
TULANE UNIVERSITY OF LOUISIANA
依托单位国家：
美国
项目类别：
财政年份：
1983
资助国家：
美国
起止时间：
1983-04-01 至 1994-06-30
项目状态：
已结题

项目摘要

The overall goal of this project is to elucidate the function(s) of 1,25-dihydroxyvitamin D3(1,25(OH)2D3), or the lack thereof, in new putative target tissues by addressing the hypothesis that 1,25(OH)2D3, exerts specific and important effects therein via previously described receptors. Thus, 1,25(OH)2D3 function will be rigorously evaluated by a series of physiological and biochemical criteria in the model systems rat heart and testis. The first phases of these studies are focused on testing the hypothesis that 1,25(OH)2D3 plays a role in intracellular calcium homeostasis. However, because of the fallacy in limiting such studies to any one area of possible functions, the hypothesis that 1,25(OH)2D3 affects these systems through alternate mechanisms must be tested in the future. Whether there is a correlation between vitamin D status or 1,25(OH)2D3 receptor and physiological function will be tested by evaluating the effects of vitamin D status in normocalcemic rats on the contractile properties of heart muscles and on testicular function and examining whether 1,25(OH)2D3 receptor levels in putative new target tissues correlate with physiological status of the vitamin D endocrine system. Effects of 1,25(OH)2D3 status and receptors on intracellular calcium homeostasis in heart and Sertoli cells will be evaluated by studying the hormonal effects on uptake of 45Ca into intact cultured heart myocytes and Sertoli cells. Effects of 1,25(OH)2D3 on selected mechanisms/subcellular organelles will be evaluated by determining 45Ca uptake in heart myocytes and Sertoli cells in the absence and presence of pharmacological probes. Additional studies will extend studies of the effects of 1,25(OH)2D3 status/receptors on calcium binding proteins detected by 45CA binding to proteins transblotted to nitrocellulose membranes, on proteins modulated by calmodulin by the 125-I-calmodulin gel overlay technique, and by immunocytochemical localization of calcium binding proteins that demonstrate vitamin D regulation. These interrelated studies of 1,25(OH)2D3 function and receptors in putative new targets will add much to our understanding of the vitamin D endocrine system and will provide a basis for future assessments of 1,25(OH)2D3 function in both normal and diseased individuals.

该项目的总体目标是阐明功能 1,25-二羟基维生素D3（1,25（oh）2d3），或缺乏的1,25-二羟基维生素通过解决以下假设： 1,25（OH）2d3，通过其中发挥特定而重要的效果先前描述的受体。因此，1,25（OH）2d3功能将通过一系列生理和模型系统大鼠心脏和睾丸的生化标准。这些研究的第一阶段的重点是测试假设1,25（OH）2d3在细胞内钙中起作用稳态。但是，由于限制了这种谬论对任何可能功能的任何一个领域的研究，这是 1,25（OH）2d3必须通过替代机制影响这些系统将来要测试。是否之间存在相关性维生素D状态或1,25（OH）2d3受体和生理功能将通过评估维生素D状态在心脏肌肉收缩特性的正常大鼠以及睾丸功能并检查1,25（OH）2d3是否推定的新靶组织中的受体水平与维生素D内分泌系统的生理状态。效果 1,25（OH）2d3状态和受体在细胞内钙上心脏和Sertoli细胞中的稳态将通过研究荷尔蒙对45CA摄取完整的影响培养的心肌细胞和Sertoli细胞。 1,25（OH）2d3的效果在选定的机制/亚细胞器中将通过确定心脏肌细胞和Sertoli细胞的45CA摄取药理学探针的不存在和存在。其他研究将扩展对1,25（OH）2d3状态/受体的影响的研究在45CA与蛋白质结合检测的钙结合蛋白上传输到硝酸纤维素膜，在调制的蛋白质上通过125-i-钙调蛋白凝胶覆盖技术的钙调蛋白，并通过钙结合蛋白的免疫细胞化学定位证明维生素D调节。这些相互关联的研究假定的新目标中的1,25（OH）2d3功能和受体将增加我们对维生素D内分泌系统和将为将来评估1,25（OH）2d3功能提供基础在正常和患病的人中。