Characterization of the macula densa stimulus for renin secretion.
Characterization of the macula densa stimulus for renin secretion.
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肾素分泌的致密黄斑刺激的表征。
DOI：
10.1152/ajprenal.1990.259.1.f186
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发表时间：
1990
期刊：
影响因子：
--
通讯作者：
Briggs,JP
中科院分区：
文献类型：
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作者：
Lorenz,JN;Weihprecht,H;Schnermann,J;Skott,O;Briggs,JP
这些研究利用离体灌注兔肾小球器（JGA）研究在没有血管内压力和肾神经活动的混杂影响的情况下，致密斑的肾素分泌信号。在第一个实验系列中，JGAs交替灌注高和低NaCl溶液，以确定可逆性的肾素响应NaCl浓度的变化。与高NaCl对照组相比，低NaCl溶液灌注导致肾素分泌速率（RSR）增加5倍[2.1-10.0 nano-Goldblatt hog单位（nGU）/min]，并且这种反应在很大程度上是可逆的。当溶液以相反的顺序呈现时，观察到高NaCl的类似抑制。在第二个系列中，JGAs灌注高，中，低NaCl溶液，以确定敏感范围的肾素响应NaCl浓度的变化。完整的肾素反应（3.2-16.6 nGU/min），类似的幅度在系列1中看到的，发现发生在80和24 mM之间的Na+和61和7 mM的Cl-。在第三个系列中，灌注液的NaCl浓度和流速被独立地改变，以分离流速、NaCl输送和NaCl浓度对RSR的影响。尽管灌注液流速的降低略微增加了RSR（3.4-8.1 nGU/min），但NaCl浓度的可比降低导致RSR（26.3 nGU/min）更高。我们的结论是，在该制剂中，1）RSR对致密斑NaCl浓度的增加和减少的反应相同，并且这些变化是快速的且在很大程度上是可逆的，2）完全的肾素反应发生在正常发生在致密斑的浓度范围内，即，低于80 mM Na+和61 mM Cl-，以及3）RSR对NaCl浓度变化的响应比对NaCl输送或液体流速的响应更大。
These studies utilize the isolated perfused rabbit juxtaglomerular apparatus (JGA) to study the macula densa signal for renin secretion in the absence of the confounding influences of intravascular pressure and renal nerve activity. In the first experimental series, JGAs were perfused alternately with high- and low-NaCl solutions to determine the reversibility of the renin response to changes in NaCl concentration. Compared with high-NaCl controls, perfusion with a low-NaCl solution resulted in a fivefold increase in renin secretion rate (RSR) [2.1-10.0 nano-Goldblatt hog units (nGU)/min], and this response was largely reversible. When the solutions were presented in the reverse order, a similar inhibition by high NaCl was observed. In the second series, JGAs were perfused with high-, medium-, and low-NaCl solutions to determine the sensitive range of the renin response to NaCl concentration changes. The full renin response (3.2-16.6 nGU/min), similar in magnitude to that seen in series 1, was found to occur between 80 and 24 mM for Na+ and 61 and 7 mM for Cl-. In the third series, the NaCl concentration and flow rate of the perfusate were altered independently to separate the effects of flow rate, NaCl delivery, and NaCl concentration on RSR. Although a decrease in perfusate flow rate slightly increased RSR (3.4-8.1 nGU/min), a comparable decrease in NaCl concentration resulted in a much higher RSR (26.3 nGU/min). We conclude that in this preparation 1) RSR responds equally to both increases and decreases in macula densa NaCl concentration, and these changes are rapid and largely reversible, 2) the full renin response occurs within the concentration range normally occurring at the macula densa, i.e., below 80 mM Na+ and 61 mM Cl-, and 3) RSR responds with a larger change to alterations in NaCl concentration than in NaCl delivery or fluid flow rate.