Long-Term EGF Treatment Partially Prevents Reduction of Renal Blood Flow in Response to Neonatally Induced Partial Unilateral Ureteral Obstruction

Abstract

Background/Aims: To investigate the effects of long-term epidermal growth factor (EGF) treatment on kidney growth, renal blood flow (RBF), AQP2 expression and urine output in newborn rats with partial unilateral ureteral obstruction (PUUO). Methods: PUUO (n = 29) and sham-operated control (CON) (n = 26) was created in 2-day-old rats. Fifteen PUUO and 14 CON rats were treated with EGF beginning from the second day after operation to 8 weeks of age. Total kidney volume (TKV) and RBF were measured by MRI at weeks 4 and 8, respectively. Urine volume and osmolality, plasma osmolality, and free water clearance were measured. Renal AQP2 expression was determined using semiquantitative immunoblotting. Results: PUUO induced a severe hydronephrosis and RBF reduction in the obstructed kidney which was attenuated in EGF-treated rats. Body weight, urine output and free water clearance increased, osmolality and the osmolar clearance decreased significantly in EGF-treated rats, despite unchanged AQP2 levels. Conclusions: Long-term EGF treatment attenuated the obstruction- induced RBF reduction. Body weight, urine output increased, and urine osmolality decreased in both control and PUUO rats treated with EGF. Solute-free water clearance increased in PUUO rats which seem to be independent of AQP2 expression.

Congenital ureteropelvic junction obstruction: human disease and animal models

“…Indeed, EGF administration attenuates UUO‐induced renal injury by increasing tubular proliferation and reducing apoptosis, tubular dilation, tubular atrophy and interstitial fibrosis in rat neonates (Chevalier et al. 1998; Wen et al. 2009).…”