Àá½Ã¸¸ ±â´Ù·Á ÁÖ¼¼¿ä. ·ÎµùÁßÀÔ´Ï´Ù.
KMID : 1128320200180010001
Electrolytes & Blood Pressure
2020 Volume.18 No. 1 p.1 ~ p.9
Urinary Concentration Defect and Renal Glycosuria in Cyclosporine-treated Rats
Lee Jun-Han

Kim Su-A
Jo Chor-Ho
Lee Chang-Hwa
Kim Gheun-Ho
Abstract
Background: Urinary concentration impairment is a major feature of cyclosporine nephrotoxicity.

Methods: We explored two possible mechanisms that may underlie cyclosporine-induced polyuria; water, and/or osmotic diuresis. Cyclosporine was subcutaneously injected to normal salt-fed Sprague-Dawley rats at a daily dose of 25mg/kg for 2 weeks (Experiment I) and 7.5mg/kg for 6 weeks (Experiment II).

Results: In Experiment I, cyclosporine treatment caused an increase in urine volume (2.7¡¾0.5 vs. 10.3¡¾1.13mL/d/100 g BW, p<0.001) and a decrease in urine osmolality (2,831¡¾554 vs. 1,379¡¾478mOsm/kg H2O, p<0.05). Aquaporin-2 (AQP2) protein expression decreased in cyclosporine-treated rat kidneys (cortex, 78¡¾8%, p<0.05; medulla, 80¡¾1%, p<0.05). Experiment II also showed that urine volume was increased by cyclosporine treatment (4.97¡¾0.66 vs. 9.65¡¾1.76mL/d/100 g BW, p<0.05). Whereas urine osmolality was not affected, urinary excretion of osmoles was increased (7.5¡¾0.4 vs. 14.9¡¾1.4mosmoles/d/100 g BW, p<0.005). Notably, urinary excretion of glucose increased in cyclosporine-treated rats (7¡¾1 vs. 10,932¡¾2,462 mg/d/100 g BW, p<0.005) without a significant elevation in plasma glucose. In both Experiment I and II, GLUT2 protein expression in the renal cortex was decreased by cyclosporine treatment (Experiment I, 55¡¾6%, p<0.005; Experiment II, 88¡¾3%, p<0.05).

Conclusion: Both water diuresis and osmotic diuresis are induced by cyclosporine nephrotoxicity. AQP2 and GLUT2 downregulation may underlie water and osmotic diuresis, respectively.
KEYWORD
Aquaporin-2, Cyclosporine, GLUT2, Osmotic diuresis, Water diuresis
FullTexts / Linksout information
 
Listed journal information
ÇмúÁøÈïÀç´Ü(KCI) KoreaMed