Aizman R I, Rabinowitz L, Mayer-Harnisch C
Department of Human Physiology, University of California, Davis 95616.
Am J Physiol. 1994 May;266(5 Pt 2):R1454-62. doi: 10.1152/ajpregu.1994.266.5.R1454.
The relationship between renal circadian cyclic excretion and renal compensatory adaptation after uninephrectomy for K, Na, and water was studied. Rats in a 12:12-h light-dark environment were given a liquid diet, and urine was collected for 16 days with consecutive 90-min periods. Days 1-4 were control, 5-10 followed a sham operation, and 11-16 followed uninephrectomy. The major findings were 1) the circadian cycles in excretion were virtually unchanged after sham and uninephrectomy; 2) an adaptive increase in excretion of Na, K, and water by the remaining kidney occurred within 90 min after uninephrectomy; 3) after uninephrectomy the distribution of the 24-h increment in excretion for the remaining kidney closely followed the preexisting pattern of circadian excretion for Na but was evenly distributed between light and dark phases for K; and 4) after uninephrectomy the ratio of excretion to intake was unchanged. This is the first study to document the time course of adaptation to uninephrectomy using consecutive brief collections over several days in unanesthetized and undisturbed rats. Adaptation after uninephrectomy occurred essentially immediately; was maintained unchanged; and preserved Na, K, and water homeostasis. Uninephrectomy did not alter the circadian control of excretion.
研究了单肾切除术后肾脏昼夜节律性排泄与肾脏对钾、钠和水的代偿性适应之间的关系。将大鼠置于12:12小时明暗环境中，给予流质饮食，连续90分钟收集尿液，共收集16天。第1 - 4天为对照期，第5 - 10天为假手术期，第11 - 16天为单肾切除术后期。主要发现如下：1）假手术和单肾切除术后，排泄的昼夜节律基本未变；2）单肾切除术后90分钟内，剩余肾脏对钠、钾和水的排泄出现适应性增加；3）单肾切除术后，剩余肾脏24小时排泄增量的分布紧密遵循术前钠的昼夜排泄模式，但钾在明相和暗相之间均匀分布；4）单肾切除术后，排泄与摄入的比值未变。这是第一项在未麻醉且未受干扰的大鼠中，通过连续数天的简短尿液收集来记录单肾切除术后适应时间进程的研究。单肾切除术后的适应基本立即发生；保持不变；并维持了钠、钾和水平衡。单肾切除未改变排泄的昼夜控制。
