Haylor J, Lote C J, Thewles A
Clin Sci (Lond). 1986 Feb;70(2):141-5. doi: 10.1042/cs0700141.
The influence of oral water loading on the excretion rate of prostaglandin (PG) E was investigated in healthy human subjects in a control study where the urine was acidic (pH 5.7) and after oral sodium bicarbonate, which made the urine mildly alkaline (pH 7.2). PGE was immediately extracted from urine and measured by a radioimmunoassay technique. After sodium bicarbonate (5 g) the urinary PGE excretion rate was some three-fold higher (P less than 0.01) than in the control study, in the absence of any significant difference in the urine flow (approximately 80 ml/h). In the control study (urine pH 5.7) the urinary PGE excretion rate increased significantly (P less than 0.01) as the urine flow rose in response to the oral fluid load. However, after sodium bicarbonate, PGE excretion did not alter after the fluid load despite a 10-fold increase in urine flow. Since after bicarbonate administration PGE excretion is independent of urine flow, mildly alkaline urine may represent a condition under which renal PGE synthesis can be effectively assessed from measurements of urinary PGE excretion, in the presence of changes in urine flow. In addition, the results are compatible with the hypothesis that, in man, PGE may be passively reabsorbed in the distal nephron, and a reduction in this reabsorption could contribute to or be responsible for the dependency of the excretion rate of PGE on urine flow.
在一项对照研究中，对健康受试者进行了口服水负荷对前列腺素（PG）E排泄率的影响研究。该对照研究分为尿液呈酸性（pH 5.7）时以及口服碳酸氢钠使尿液呈轻度碱性（pH 7.2）后两个阶段。PGE立即从尿液中提取出来，并通过放射免疫分析技术进行测量。口服5克碳酸氢钠后，尿PGE排泄率比对照研究中高出约三倍（P<0.01），而尿流率无显著差异（约80毫升/小时）。在对照研究（尿液pH 5.7）中，随着口服液体负荷导致尿流率增加，尿PGE排泄率显著增加（P<0.01）。然而，口服碳酸氢钠后，尽管尿流率增加了10倍，但液体负荷后PGE排泄并未改变。由于给予碳酸氢钠后PGE排泄与尿流率无关，轻度碱性尿液可能代表一种情况，即在尿流率发生变化时，可通过测量尿PGE排泄有效地评估肾脏PGE的合成。此外，这些结果与以下假设相符：在人类中，PGE可能在远端肾单位被动重吸收，这种重吸收的减少可能导致或促成PGE排泄率对尿流率的依赖性。
