Related Experiment Videos
Renal response to a protein meal in children with single kidneys
A Tufro1, E Arrizurieta, H Repetto
1Kidney Laboratory, Instituto de Investigaciones Medicas Alfredo Lanari, Universidad de Buenos Aires, Argentina.
Insights
Children with a single kidney exhibit hyperfiltration at rest and a blunted renal response to protein loads. Protein intake influences this response in single-kidney children.
Area of Science:
- Pediatric Nephrology
- Renal Physiology
Background:
- Healthy adults show increased renal plasma flow (RPF) and glomerular filtration rate (GFR) after protein intake.
- The renal response to protein loading in children with a single kidney (SK) is not well understood.
Purpose of the Study:
- To investigate the renal response to an oral protein load in children with a single kidney (SK) compared to healthy children (C).
Main Methods:
- Studied 8 SK children and 4 healthy children.
- Measured RPF via para-amino-hippurate clearance (Cpah) and GFR via inulin clearance (Cin) before and after a protein load (1.5 g/kg).
- Results expressed as ml/min/1.73 m2 BSA.
Main Results:
- Baseline GFR was similar, but baseline Cpah was lower in SK children compared to controls.
- Healthy children showed significant increases in GFR and RPF post-protein load.
- SK children did not exhibit significant changes in GFR or RPF, indicating a blunted response. A mild vasodilating response was observed in SK children with lower protein intake.
Conclusions:
- Single-kidney children present with baseline hyperfiltration.
- The renal response to acute protein loading is diminished or absent in single-kidney children.
- Protein intake appears to modulate the renal response to protein loading in this population.
Abstract:
The renal response of healthy adults to an oral protein load results in a significant increase of renal plasma flow (RPF) and glomerular filtration rate (GFR) 100 to 150 min after the meal. The renal response to protein loading of single kidney adults is unclear and it has not been evaluated yet in children. Therefore, we studied 8 children 10.2 +/- 1.1 years old, 6.7 +/- 1.41 years after nephrectomy (SK) and 4 healthy children (C). RPF was estimated by para-amino-hippurate clearance (Cpah) and GFR by inulin clearance (Cin) before and after an oral protein load of 1.5 g protein/kg body wt and expressed in ml/min/1.73 m2 BSA. Mean baseline Cin were similar in SK and in C (90 +/- 8 vs 103 +/- 12) while baseline Cpah was lower in SK (339 +/- 19 vs 481 +/- 36, p less than 0.005). After the meal GFR and RPF increased significantly in C (155 +/- 18 and 783 +/- 68, p less than 0.005 and p less than 0.05 vs baseline values, respectively) whereas no significant GFR and RPF changes were seen in SK (81 +/- 9 and 350 +/- 42, respectively). However, the 3 SK children with lower protein intake showed a mild vasodilating response. We conclude that in single kidney children hyperfiltration occurs at baseline conditions and the renal response to acute protein loading is partially or completely blunted, being modulated by protein intake.