TY - JOUR
T1 - Compensatory renal growth due to neonatal ureteral obstruction
T2 - Implications for clinical studies
AU - Yoo, Kee Hwan
AU - Thornhill, Barbara A.
AU - Forbes, Michael S.
AU - Chevalier, Robert L.
PY - 2006/3
Y1 - 2006/3
N2 - In response to unilateral ureteral obstruction (UUO), the contralateral kidney undergoes compensatory renal growth, which is enhanced in early development. We investigated the renal growth response to UUO in the neonatal rat. Within 2 days of birth, animals were subjected to sham-operation, complete UUO, or variable partial UUO, and kidneys were harvested 3-60 days later. Contralateral kidney weight increased after only 7 days of complete UUO. Increase in contralateral kidney weight was not significant for partial UUO until 45 days, but kidney/body weight ratio increased after only 14 days of 0.3 mm partial UUO. The rate of contralateral renal growth increased with age and with increasing severity of UUO. In rats subjected to 45 days UUO, glomerular area was proportional to kidney/body weight ratio (r=0.61, p<0.01). We conclude that the rate of compensatory renal growth is dependent on the severity and duration of obstruction, and takes place at the single nephron level. The results suggest that biologic variability limits the early detection of compensatory renal growth, which is compounded by limitations in measuring renal size by clinical imaging. Factoring kidney length (or volume) by intervertebral length (or body surface area) should improve the precision of tracking renal growth.
AB - In response to unilateral ureteral obstruction (UUO), the contralateral kidney undergoes compensatory renal growth, which is enhanced in early development. We investigated the renal growth response to UUO in the neonatal rat. Within 2 days of birth, animals were subjected to sham-operation, complete UUO, or variable partial UUO, and kidneys were harvested 3-60 days later. Contralateral kidney weight increased after only 7 days of complete UUO. Increase in contralateral kidney weight was not significant for partial UUO until 45 days, but kidney/body weight ratio increased after only 14 days of 0.3 mm partial UUO. The rate of contralateral renal growth increased with age and with increasing severity of UUO. In rats subjected to 45 days UUO, glomerular area was proportional to kidney/body weight ratio (r=0.61, p<0.01). We conclude that the rate of compensatory renal growth is dependent on the severity and duration of obstruction, and takes place at the single nephron level. The results suggest that biologic variability limits the early detection of compensatory renal growth, which is compounded by limitations in measuring renal size by clinical imaging. Factoring kidney length (or volume) by intervertebral length (or body surface area) should improve the precision of tracking renal growth.
KW - Hydronephrosis
KW - Hypertrophy
KW - Neonate
KW - Rat
KW - Renal development
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U2 - 10.1007/s00467-005-2119-y
DO - 10.1007/s00467-005-2119-y
M3 - Article
C2 - 16382318
AN - SCOPUS:33244462851
VL - 21
SP - 368
EP - 375
JO - Pediatric Nephrology
JF - Pediatric Nephrology
SN - 0931-041X
IS - 3
ER -