Ray C, Carney S L, Gillies A H
Clin Sci (Lond). 1985 Sep;69(3):293-8. doi: 10.1042/cs0690293.
The precise role of prostaglandins in modulating urine concentration and dilution is unclear. Evidence in vitro has recently cast doubt on the accepted theory that renal prostaglandins inhibit the hydro-osmotic effect of vasopressin. Urine clearance studies were performed on indomethacin treated (prostaglandin deficient) and control anaesthetized water diuretic rats both before and during the addition of vasopressin in maximal (10 m-units) and supramaximal (100 m-units) concentrations. Before the addition of vasopressin, indomethacin treatment inhibited the excretion of a water load by 48.7%. The mean papillary sodium concentration was also greater in this group of rats. Vasopressin (10 m-units) increased the urine osmolality in control and indomethacin treated rats; however, the mean urine osmolality was greater in the indomethacin group (1521 +/- 103 compared with 1120 +/- 98 mosmol/kg; P less than 0.01), as was the papillary sodium concentration. A ten-fold increase in vasopressin depressed the papillary sodium concentration to a level similar to that in the control group and produced a marked natriuresis. Consequently, the mean urine osmolalities and urine flows were similar in control and indomethacin treated rats. These experiments suggest that a major function of renal prostaglandins is to increase the ability of the kidney to excrete a water load. Renal prostaglandins do not interfere with the vasopressin induced increase in distal nephron water permeability.
前列腺素在调节尿液浓缩和稀释过程中的确切作用尚不清楚。最近，体外实验证据对公认的理论——肾前列腺素抑制抗利尿激素的水渗透效应——提出了质疑。在给予最大浓度（10 m单位）和超最大浓度（100 m单位）抗利尿激素之前及期间，对用消炎痛处理（前列腺素缺乏）的麻醉性水利尿大鼠和对照麻醉性水利尿大鼠进行了尿清除率研究。在给予抗利尿激素之前，消炎痛处理使水负荷的排泄减少了48.7%。该组大鼠的平均乳头钠浓度也更高。抗利尿激素（10 m单位）使对照大鼠和消炎痛处理大鼠的尿渗透压升高；然而，消炎痛组的平均尿渗透压更高（分别为1521±103与1120±98 mosmol/kg；P<0.01），乳头钠浓度也是如此。抗利尿激素增加10倍会使乳头钠浓度降至与对照组相似的水平，并产生明显的利钠作用。因此，对照大鼠和消炎痛处理大鼠的平均尿渗透压和尿流量相似。这些实验表明，肾前列腺素的一个主要功能是增强肾脏排泄水负荷的能力。肾前列腺素并不干扰抗利尿激素诱导的远端肾单位水通透性增加。
