Greven J, Heidenreich O
Naunyn Schmiedebergs Arch Pharmacol. 1975;287(2):117-28. doi: 10.1007/BF00510444.
To explain the mechanism of the isoprenaline induced antidiuresis the effect of this substance on fluid and electrolyte reabsorption in various nephron segments of the rat kidney has been studied using micropuncture techniques. Isoprenaline (1.5x10-9mol/kg-min i.v.) decreased GFR of superficial nephrons and increased fractional proximal fluid, sodium and potassium reabsorption. However, the fractions of filtered fluid and electrolytes, which had been reabsorbed up to early distal tubule were unchanged after isoprenaline. This indicated that the increased fractional proximal reabsorption has been completely compensated by decreased reabsorption from Henle's loops. In the distal convoluted tubules an increase in the fractional fluid and sodium reabsorption could be established using a recollection technique. Given directly into the distal tubular lumen isoprenaline stimulated the isotonic fluid reabsorption, which was measured by the Gertz split oil droplet method. From these results it is concluded that the decrease in superficial GFR and the increased distal tubular fluid and sodium reabsorption lead to the decrease in urine volume and in urinary electrolyte excretion after isoprenaline.
为了解释异丙肾上腺素诱导抗利尿作用的机制，已采用微穿刺技术研究了该物质对大鼠肾脏各肾单位节段液体和电解质重吸收的影响。异丙肾上腺素（静脉注射1.5×10⁻⁹摩尔/千克·分钟）降低了浅表肾单位的肾小球滤过率（GFR），并增加了近端液体、钠和钾的重吸收分数。然而，在异丙肾上腺素作用后，直至远端小管早期已重吸收的滤过液体和电解质的分数没有变化。这表明近端重吸收分数的增加已被亨利袢重吸收的减少完全补偿。在远端曲管中，采用重吸收技术可确定液体和钠的重吸收分数增加。直接注入远端小管腔的异丙肾上腺素刺激了等渗液体重吸收，这是通过格茨分裂油滴法测量的。从这些结果可以得出结论，浅表GFR的降低以及远端小管液体和钠重吸收的增加导致异丙肾上腺素作用后尿量和尿电解质排泄减少。
