DEVELOPMENT OF RENAL PHOSPHATE REGULATION

肾磷酸盐调节的发展

• 批准号: 3234432
• 负责人: AVIAD HARAMATI
• 金额: $ 14.2万
• 依托单位: GEORGETOWN UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1986
• 资助国家: 美国
• 起止时间: 1986-01-01 至 1988-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3234432
• 关键词: calcitonin; dietary constituent; diphosphonate; histogenesis; homeostasis; hormone regulation /control mechanism; kidney metabolism; parathyroid hormones; phosphates; phosphorus metabolism; renal tubular transport; weanling animal

The need for young, immature animals to maintain positive phosphate balance for growth is well recognized. However, the adaptations that occur in the kidney to facilitate this process have not been clarified. The objective is to evaluate the intrarenal regulation of phosphate reabsorption during development. Micropuncture techniques will be used to examine the nephron sites of phosphate reabsorption and their response to dietary and hormonal factors regulating phosphate homeostasis. Comparisons will be made between immature, weaned rats (3-4 weeks) and adult rats (6 months). The hypothesis to be tested is that the developing animal displays avid phosphate reabsorption due to greater participation of deep nephrons and enhanced reabsorption in distal nephron segments. Furthermore, relative hyporesponsiveness to phosphaturic stimuli also contributes to the renal retention of phosphate. Specific protocols are designed to evaluate the following parameters: a) the nephron sites of phosphate reabsorption, b) the transport capacities of superficial and deep nephron proximal tubules, c) the response of these sites to phosphaturic stimuli (high phosphate diet, PTH, calcitonin), and d) the possible restoration of responsiveness to hhosphaturic hormones (with acute phosphate infusions, diphosphonate treatment). These studies will provide important information regarding the intrarenal mechanisms involved in the adaptations for growth.

需要年轻，不成熟的动物，以保持积极的磷酸盐平衡 增长是公认的。 然而，发生在 肾脏促进这一过程尚未阐明。 客观 是为了评估磷酸盐重吸收的肾内调节， 发展 显微穿刺技术将用于检查肾单位 磷酸盐重吸收位点及其对饮食和激素的反应 调节磷酸盐稳态的因子。 将在以下方面进行比较： 未成熟、断奶大鼠（3 - 4周）和成年大鼠（6个月）。 的 有待检验的假设是，发育中的动物表现出对 磷酸盐重吸收，由于深肾单位的更多参与， 增强远端肾单位段的重吸收。 此外，相对 对磷酸盐尿刺激的低反应性也有助于肾功能损害。 保持磷酸盐。 设计了特定的方案来评估 以下参数：a）磷酸盐重吸收的肾单位位点，B） 浅表和深层肾单位近端小管的转运能力， c）这些部位对磷酸尿刺激（高磷酸盐）的反应 饮食，PTH，降钙素），和d）可能恢复的反应性 磷酸尿激素（急性磷酸盐输注，二磷酸盐 治疗）。 这些研究将提供有关 参与生长适应的肾内机制。