EFFECTS OF CHRONIC PARTIAL URETERAL OBSTRUCTION (CPUO) AND UNINEPHRECTOMY (MX) ON RENAL AND SOMATIC GROWTH IN THE NEWBORN GUINEA PIG

Abstract

Although CPUO is one of the major causes of renal insufficiency in infancy, the relationship between renal impairment and growth remains poorly understood. Within the first 48 h of life, 63 guinea pigs were subjected to left (L) CPUO, 31 of which also underwent right (R) NX. 16 sham-operated and 15 NX animals were controls. At 23±2 days of age, body weight (BW), dry kidney weight (DKW), ureteral diameter (UD) and BUN were measured. Resulting UD was variable, and each group was divided into Mild (UD <3 mm) and Severe obstruction (UD≥3 mm). Control UD = 1 mm. Results were as follows (mean ± SE, *p< 0.05 vs Control):We conclude that during Mild CPUO, compensatory renal growth due to NX is impaired, but normal renal growth is not. Severe CPUO with intact R kidney results in decreased growth of the affected kidney and compensatory hypertrophy of the other, while Severe CPUO and NX results in azotemia despite compensatory hypertrophy of the obstructed kidney. Somatic growth during CPUO is limited by unidentified factors in addition to functional renal mass.