Investigation of histopathologic changes in the ureter walls in experimental congenital obstructive uropathy

The optimal dose of Adriamycin to create a viable rat model potentially applicable to congenital obstructive uropathy

PURPOSE

The Adriamycin rat model is an established model for different organ anomalies including congenital obstructive uropathy. In the current study, we carried out a dose-response analysis to find out the optimal dose of Adriamycin to create a viable rat model of obstructive uropathy.

METHODS

Thirty time-mated Sprague-Dawley rats were divided into 5 groups including 1 control group and 4 different treatment groups. The 4 Adriamycin dosage regimens investigated in this study were 1.25, 1.5, 1.75, and 2 mg/(kg d). Experimental rats (n = 24) were injected intraperitoneally with different doses of Adriamycin on gestational days 7 to 9 (6 rats in each group). Control rats (n = 6) were injected with an equivalent volume of saline on the same days. Viable term fetuses were harvested on gestational day 21 by cesarean delivery and dissected under a dissecting microscope. Serial transverse sections from urinary tract system were obtained for histological examination.

RESULTS

One hundred thirty-three viable fetuses were recovered from Adriamycin-treated rats, and 50 were from rats in the control group. There were no resorptions in the control group; however, 52 resorptions were recorded in Adriamycin groups. The rates of hydronephrosis and resorptions were 60% and 0%, 80.5% and 5.8%, 100% and 17.3%, and 100% and 76.9% at doses of 1.25, 1.50, 1.75, and 2 mg/(kg d), respectively. Histologic examination of the kidneys in the treated groups showed a significant decrease in renal parenchyma compared with the control group.

CONCLUSIONS

The dosage of 1.5 mg/(kg d) of Adriamycin yielded the highest number of viable hydronephrotic fetuses. At this dose, urinary abnormalities are milder; but the highest number of viable fetuses is provided, which is necessary to create a reproducible and viable animal model.

Investigation of histopathologic changes in pelviureteral junction obstruction

OBJECTIVES

This study aimed to determine histopathologic changes in the pelviureteral junction in children with pelviureteral junction obstruction.

MATERIAL AND METHODS

Seventeen pelviureteral junction specimens obtained from children were divided into two groups: pelviureteral junction obstruction (n = 7) and control (n = 10). Wall thickness of the pelviureteral junction, tunica muscularis of the pelviureteral junction, uroepithelium thickness of the pelviureteral junction, and collagen thickness of the pelviureteral junction were evaluated in resected pelviureteral junctions in children with pelviureteral junction obstruction.

MAIN FINDINGS

The mean wall thickness of the pelviureteral junction, mean tunica muscularis of the pelviureteral junction, and uroepithelium thickness of the pelviureteral junction were not significantly higher than those in the control group. Collagen thickness values in the pelviureteral junction obstruction group were significantly higher than those in the control group.

CONCLUSIONS

Our data suggest that wall thickness (tunica muscularis and uroepithelium) was not significantly increased, but collagen thickness of the ureter was increased in the pelviureteral junctions of children with pelviureteral junction obstruction.

Investigation of histopathologic changes in the ureter walls in vesicoureteral reflux

PURPOSE

This study aimed to determine the histopathologic changes in ureteral walls (UWs) in children with vesicoureteral reflux (VUR).

METHODS

Twenty ureteral specimens taken from children were divided into 2 groups, refluxing (R) and control (C) groups, each containing 10 specimens. Wall thickness of the ureter, tunica muscularis of the ureter, mucosal thickness of the ureter (uroepithelium), collagen thickness of the ureter, mucosal change, and inflammation were evaluated in resected distal UWs in children with VUR.

RESULTS

The mean wall thickness of the ureter, mean tunica muscularis of the ureter, and mean uroepithelium values of the UWs in the R group were not significantly lower compared to those in the C group. Collagen thickness values in the R group were significantly lower than those in the C group.

CONCLUSIONS

Our data suggest that wall thickness (tunica muscularis and uroepithelium) was not significantly decreased, but collagen thickness of the ureter was decreased in the UWs of children with VUR.