药理剂量血管加压素对大鼠肾脏钠重吸收的影响。

Effect of pharmacologic doses of vasopressin on sodium reabsorption in the rat kidney.

作者信息

Knight T F, Weinman E J

出版信息

J Lab Clin Med. 1977 May;89(5):987-91.

Abstract

Administration of pharmacologic doses of vasopressin (50 mU./min./kg.) to the rat resulted in significant increases in both the urinary excretion of sodium (0.02 +/- 0.02 to 6.24 +/- 0.76 micronEq/min.) and the urine flow rate (4.5 +/- 0.5 to 30.5 +/- 6.0 micronl/min). Simultaneous free-flow micropuncture studies demonstrated a decrease in end-proximal TF/Pinulin ratios from 2.82 +/- 0.15 to 1.90 +/- 0.90 (p less than 0.01), indicating decreased water reabsorption in this portion of the nephron. To reduce the influence of the pressor effect of these doses of vasopressin on the kidney, the aorta was constricted proximal to the renal arteries and this resulted in a decrease in urinary sodium excretion to 2.87 +/- 0.57 micronEq/min. and in urine flow rates to 16.6 +/- 3.6 micronl/min. compared with animals given vasopressin alone. End-proximal TF/Pinulin ratio was 2.01 +/- 0.15, a value not significantly different than that in animals given vasopressin alone, suggesting a continued proximal inhibitory effect of vasopressin. It is concluded that pharmacologic doses of vasopressin inhibit sodium reabsorption in the proximal convoluted tubule as well as in distal portions of the nephron. The magnitude of sodium excretion observed is a function both of vasopressin inhibition of sodium reabsorption and the pressor effect of vasopressin.

摘要

给大鼠注射药理剂量的血管加压素（50 毫单位/分钟/千克），导致钠的尿排泄量（从 0.02±0.02 增加到 6.24±0.76 微当量/分钟）和尿流率（从 4.5±0.5 增加到 30.5±6.0 微升/分钟）均显著增加。同时进行的自由流微量穿刺研究表明，近端小管末端 TF/P 菊粉比值从 2.82±0.15 降至 1.90±0.90（p＜0.01），表明该肾单位部分的水重吸收减少。为降低这些剂量的血管加压素对肾脏的升压作用的影响，在肾动脉近端结扎主动脉，这导致尿钠排泄量降至 2.87±0.57 微当量/分钟，尿流率降至 16.6±3.6 微升/分钟，与单独给予血管加压素的动物相比。近端小管末端 TF/P 菊粉比值为 2.01±0.15，该值与单独给予血管加压素的动物相比无显著差异，提示血管加压素对近端小管仍有抑制作用。结论是，药理剂量的血管加压素抑制近端曲管以及肾单位远端部分的钠重吸收。观察到的钠排泄量大小是血管加压素对钠重吸收的抑制作用和血管加压素的升压作用两者的函数。