FLUID SECRETION BY GLOMERULAR RENAL TUBULES

肾小球肾小管的液体分泌

• 批准号: 3152237
• 负责人: Klaus W Beyenbach
• 金额: $ 7.18万
• 依托单位: CORNELL UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1983
• 资助国家: 美国
• 起止时间: 1983-06-01 至 1986-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3152237
• 关键词: biological fluid transport; chlorine; glomerular filtration; magnesium; renal glomerulus; renal tubular transport; saltwater environment; secretion; sodium; sulfur compounds

From the 42,000 vertebrate species only 30 produce urine without glomerular filtration. In these aglomerular species fluid secretion is recognized as a tubular transport mechanism. Fluid secretion in glomerular renal tubules, however, is thought to be negligible. Preliminary studies conducted at the Mt. Desert Island Biological Laboratory question this popular notion. Proximal tubules from the glomerular winter flounder Pseudopleuronectes americanus, isolated by microdissectiona nd bathed in Ringer's solution generate their own tubular fluid without perfusion of the lumen. Rates of fluid secretion average 27.1 pl/min per mm tubule length and depend on the presence of NaCl in the peritubular bathing medium. Primary secreted fluid (298.9 mOsm/kg H2O) is slightly hyperosmotic to the bathing medium (290.5 mOsm/Kg H2O) presumably through the secretory transport of Mg and S. The principal ions in secreted fluid are in mmoles/liter, Na (152.4), Cl (155.4), Mg (25.3), and S (9.9) as measured by electron probe (WDS) analysis. Fluid secretion is often observed to be associated with radial constrictions of the tubule and the movement of cilia in the tubule lumen. This grant application proposes the detailed study of fluid secretion: its driving forces and its mechanisms. Experiments will then focus on the mechanism of secretory Mg and S transport. All studies will be conducted on isolated proximal tubules. The results are expected to have broad implications for our understanding of 1) transepithelial volume flow in renal proximal tubules, 2) proximal tubule secretory transport of monovalent and divalent ions, 3) hypo-osmotic regulation of marine teleosts, and possibly 4) the evolution of vertebrate kidney functions. Does fluid secretion as observed in glomerular proximal tubules of the flounder represent an intermediary stage in the development of aglomerular renal functions? Or is fluid secretion a basic function of glomerular proximal tubules which in higher vertebrates has not been detected because of high fluid absorption rates?

在42，000种脊椎动物中，只有30种产生尿液而不产生肾小球。 过滤 在这些无肾小球物种中，液体分泌被认为是 管状输送机构。 肾小球肾脏液体分泌 然而，小管被认为是可忽略的。 初步研究 在Mt。荒岛生物实验室对此提出质疑 流行的概念。 肾小球冬拟鲽的近端小管 通过显微解剖分离出美洲拟鲽， 林格氏液产生自己的肾小管液，而不灌注 流明 液体分泌速率平均为27.1 pl/min/mm小管长度 并依赖于管周浴介质中NaCl的存在。 初级分泌液（298.9 mOsm/kg H2O）相对于 浸浴介质（290.5 mOsm/Kg H2O）可能通过分泌 Mg和S的迁移。 分泌液中的主要离子是 mmol/L，Na（152.4），Cl（155.4），Mg（25.3）和S（9.9），通过 电子探针（WDS）分析。 经常观察到液体分泌 与肾小管的径向收缩和 纤毛在小管腔。 本补助金申请提出了详细的 液体分泌的研究：其驱动力和机制。 实验将集中在分泌镁和硫的机制 运输 所有研究都将在离体近端小管上进行。 预计这些结果将对我们的理解产生广泛的影响 1）肾近端小管中的跨上皮体积流量，2）近端 一价和二价离子的小管分泌运输，3）低渗 海洋硬骨鱼的调节，以及可能的4）脊椎动物的进化 肾功能 肾小球近端是否有液体分泌 比目鱼的小管是发育的中间阶段 肾小球肾功能不全 还是说液体分泌是 肾小球近端小管，这在高等脊椎动物中还没有 是因为液体吸收率高吗

项目成果

Peptide nature of two mosquito natriuretic factors.

两种蚊子利尿钠因子的肽性质。

• DOI: 10.1152/ajpregu.1986.250.3.r328
• 发表时间: 1986
• 期刊: The American journal of physiology
• 作者: Petzel,DH;Hagedorn,HH;Beyenbach,KW
• 通讯作者: Beyenbach,KW

Mechanism of fluid secretion in isolated shark renal proximal tubules.

离体鲨鱼肾近曲小管液体分泌机制。

• DOI: 10.1152/ajprenal.1985.249.6.f884
• 发表时间: 1985
• 期刊: The American journal of physiology
• 作者: Sawyer,DB;Beyenbach,KW
• 通讯作者: Beyenbach,KW

Renal proximal tubule of flounder II. Transepithelial Mg secretion.

牙鲆的肾近端小管 II.

• DOI: 10.1152/ajpregu.1986.250.4.r616
• 发表时间: 1986
• 期刊: The American journal of physiology
• 作者: Cliff,WH;Sawyer,DB;Beyenbach,KW
• 通讯作者: Beyenbach,KW

Dibutyryl-cAMP increases basolateral sodium conductance of mosquito Malpighian tubules.

二丁酰-cAMP 增加蚊子马氏小管的基底外侧钠电导。

• DOI: 10.1152/ajpregu.1985.248.3.r339
• 发表时间: 1985
• 期刊: The American journal of physiology
• 作者: Sawyer,DB;Beyenbach,KW
• 通讯作者: Beyenbach,KW

Comparative physiology of the renal proximal tubule.

肾近曲小管的比较生理学。

• DOI: 10.1159/000173056
• 发表时间: 1985
• 期刊: Renal physiology
• 作者: Beyenbach,KW