Drummer C, Gerzer R, Heer M, Molz B, Bie P, Schlossberger M, Stadaeger C, Röcker L, Strollo F, Heyduck B
Medizinische Klinik, Klinikum Innenstadt, Universität München, Federal Republic of Germany.
Am J Physiol. 1992 May;262(5 Pt 2):F744-54. doi: 10.1152/ajprenal.1992.262.5.F744.
Several hormonal systems participating in body fluid and electrolyte homeostasis were investigated in six healthy volunteers in a supine body position during a period of 9 days and nights. Under strictly controlled conditions, striking circadian rhythms were observed for plasma levels of vasopressin, renin, aldosterone, guanosine 3',5'-cyclic monophosphate, cortisol, and epinephrine. Nocturnal decreases and diurnal increases in urine flow rate and urinary excretion of electrolytes were observed and closely paralleled the urinary excretion of urodilatin. During 48 h after an acute isotonic saline infusion (2 liters within 25 min) and after a 48-h control experiment the urinary excretion of H2O and electrolytes, and simultaneously the alterations in endocrine systems participating in body fluid homeostasis, were determined. Urine flow and urinary electrolyte excretion rates were significantly increased during 2 days after the saline infusion. The largest increase in urinary fluid and electrolyte excretion was observed between 3 and 22 h postinfusion. These long-term changes were paralleled by altered H2O and Na balances and also by elevated body weights that returned to baseline values with an approximate half-life of 7 h. These data suggest that vasopressin, atrial natriuretic peptide, and catecholamines are unlikely to be of major importance for the renal response to this hypervolemic stimulus. The renin-aldosterone system was suppressed during 2 days postinfusion. This suppression correlated with the effects of saline load on Na excretion. However, the closest relation with Na excretion was observed for the kidney-derived member of the atrial natriuretic peptide family, urodilatin, which was considerably increased during the long-term period up to 22 h postinfusion. Thus these data show that the human body in supine position requires approximately 2 days to regulate the amount of Na and H2O provided by an acute saline infusion. The data also suggest that urodilatin and the renin-aldosterone system might participate in the long-term renal response to an acute saline infusion and also in the mediation of circadian urinary excretion rhythms.
在9个昼夜期间，对6名仰卧位的健康志愿者体内参与体液和电解质稳态的几种激素系统进行了研究。在严格控制的条件下，观察到血管加压素、肾素、醛固酮、鸟苷3',5'-环磷酸、皮质醇和肾上腺素的血浆水平呈现明显的昼夜节律。观察到夜间尿流率和电解质尿排泄量减少，白天增加，且与尿舒张素的尿排泄密切平行。在急性等渗盐水输注（25分钟内输注2升）后48小时以及48小时对照实验后，测定了水和电解质的尿排泄量，同时还测定了参与体液稳态的内分泌系统的变化。盐水输注后2天内，尿流率和尿电解质排泄率显著增加。输注后3至22小时观察到尿液体和电解质排泄量增加最大。这些长期变化与水和钠平衡的改变以及体重升高平行，体重以约7小时的半衰期恢复到基线值。这些数据表明，血管加压素、心钠素和儿茶酚胺对肾脏对这种血容量过多刺激的反应不太可能起主要作用。输注后2天内肾素-醛固酮系统受到抑制。这种抑制与盐负荷对钠排泄的影响相关。然而，与钠排泄关系最密切的是心钠素家族的肾脏来源成员尿舒张素，在输注后长达22小时的长期期间内其显著增加。因此，这些数据表明，仰卧位的人体需要大约2天来调节急性盐水输注所提供的钠和水的量。数据还表明，尿舒张素和肾素-醛固酮系统可能参与肾脏对急性盐水输注的长期反应以及昼夜尿排泄节律的调节。
