Abstract: SA-PO373

Heat-Induced Renal Damage (HRD) Is Dose-Dependently Worsened by Fructose (F) Concentration in Rehydration Fluid

Session Information

Category: Chronic Kidney Disease (Non-Dialysis)

  • 301 CKD: Risk Factors for Incidence and Progression

Authors

  • Sanchez-Lozada, L. Gabriela, INC Ignacio Chavez, Mexico City, Mexico
  • García-arroyo, Fernando E., INC Ignacio Chavez, Mexico City, Mexico
  • Gonzaga, Guillermo, INC Ignacio Chavez, Mexico City, Mexico
  • Blas-Marron, Monica Gabriela, INC Ignacio Chavez, Mexico City, Mexico
  • Silverio, Octaviano, INC Ignacio Chavez, Mexico City, Mexico
  • Muñoz, Itzel, Government, México City, Mexico
  • Tapia, Edilia, INC Ignacio Chavez, Mexico City, Mexico
  • Johnson, Richard J., University of Colorado Denver, Aurora, Colorado, United States
Background

Recurrent episodes of heat exposure result in HRD that is aggravated when F containing beverages are provided as rehydration fluid. The purpose of this study was to explore the effect of different concentrations of F in the rehydration fluid and correlate them with parameters of kidney damage.

Methods

Male Wistar rats were exposed to heat from Monday to Friday at 37°C, 1 h. Rats were allowed to rehydrate only at night with fluids containing the following F concentrations: 0, 2.5, 5, 7.5 and 10%. A group of the normal non-dehydrated rats was included as a reference. At 4 weeks, blood samples and urine were collected. Cr, uric acid (UA), osmolality (plasma and urine), vasopressin (plasma copeptin), and NAG were measured. Proximal and distal nephron segments were isolated, and the expression of aquaporin-2 (Aqp2) and cAMP concentrations were evaluated.

Results

Aqp2 expression and cAMP concentrations in distal segments were increased by repeated heat exposure and further by F rehydration, but there were no differences among the increasing F concentrations.

Conclusion

F rehydration aggravated the HRD in a dose-dependent fashion. F further increased UOsm and Aqp2 expression, despite there was not an additive effect caused by the increased F concentrations. These data suggest that the higher concentrations of vasopressin and hyperuricemia may contribute to exacerbating renal alterations in HDR. The fact that UOsm, Aqp2 expression and [cAMP] reached a threshold after the lower F concentration suggests that F might damage distal portions of the nephron affecting the urinary concentration capacity.

Results
[F]/GroupCrC (mg/min)PUA (mg/dL)PCopeptin (ng/mL)UNAG (uM PNP/min/d)UOsm
(mOsm/Kg)
Control1.2±.081.0±.02.01±.00101358±225
0%1.1±.131.4±.23±.0040.5±.021176±328
2.5%1.0±.101.7±.1210±.830.6±.041856±345
5%0.9±.071.7±.1022±1.11.1±.131848±367
7.5%0.76±.032.5±.2232±1.81.4±.091825±209
10%0.72±.023.4±.1449±1.61.9±.021610±150
Linear trendr2=0.72
P<.0001
r2=0.86
P<.0001
r2=0.97
P<.0001
r2=0.97
P<.0001
r2=0.17
P<.0002

Funding

  • Other U.S. Government Support