Hansell P, Göransson A, Sjöquist M, Ulfendahl H R
Department of Physiology and Medical Biophysics, University of Uppsala, Sweden.
Acta Physiol Scand. 1990 Jan;138(1):61-6. doi: 10.1111/j.1748-1716.1990.tb08812.x.
Removal of the renal pelvis in order to expose the renal papilla has been shown to cause impairment of the renal concentrating ability by an unknown mechanism. To study this phenomenon, urine osmolality (Uosm), single-nephron glomerular filtration rate (SNGFR) in outer and inner cortical nephrons and the inner and outer medullary plasma flow were determined. Measurements were performed on groups of rats before (control) and 15, 45 and 90 min after exposure of the left renal papilla. Rats with an intact ureter were studied in parallel to see whether the variables varied within the 90-min period of the study. In all groups of animals with an exposed papilla, Uosm was lower than in non-exposed animals. Outer cortical SNGFR in rats with exposed papillae, regardless of time, was not different from that in control rats. Inner cortical SNGFR after 45 and 90 min of exposure did not differ from that in controls, but after 15 min of exposure it was lower than in control animals. Outer and inner medullary plasma flow did not differ between rats with exposed papillae and controls, irrespective of exposure time. In conclusion, papillary exposure results in a permanent decrease in urine osmolality. This impairment of the concentrating ability cannot be attributed to prolonged changes in renal haemodynamics.
为暴露肾乳头而切除肾盂已被证明会通过一种未知机制导致肾脏浓缩能力受损。为研究这一现象，测定了尿渗透压（Uosm）、外皮质和内皮质肾单位的单肾单位肾小球滤过率（SNGFR）以及内髓和外髓血浆流量。对大鼠组在暴露左肾乳头前（对照）以及暴露后15、45和90分钟进行测量。对输尿管完整的大鼠进行平行研究，以观察这些变量在90分钟的研究期间是否发生变化。在所有乳头暴露的动物组中，Uosm均低于未暴露的动物。乳头暴露的大鼠，无论时间如何，其外皮质SNGFR与对照大鼠无差异。暴露45和90分钟后的内皮质SNGFR与对照无差异，但暴露15分钟后低于对照动物。乳头暴露的大鼠与对照大鼠的外髓和内髓血浆流量，无论暴露时间如何，均无差异。总之，乳头暴露导致尿渗透压永久性降低。这种浓缩能力的损害不能归因于肾脏血流动力学的长期变化。
