EXPERIMENTAL URETEROHYDRONEPHROSIS IN FETAL RATS

This study tests the hypothesis that prenatal exposure to 2,4-dichloro phenyl-p-nitrophenyl ether (nitrofen), an herbicide known to induce pu lmonary hypoplasia and other malformations in fetal rats, also may ind uce ureterohydronephrosis (UHN) and oligohydramnios. Time-dated pregna nt Wistar rats were given 100 mg of the chemical on day 9 or 11 of ges tation, and the findings in their fetuses were compared with those of suitable controls. Marked bilateral UHN was found in the majority of e xposed fetuses, but without evidence of either mechanical obstruction or dysplastic parenchymal lesions. These animals had various degrees o f lung hypoplasia. The amount of fluid in their amniotic sacs was incr eased rather than decreased and it was independent of lung weight but correlated to some extent with UHN grade. Urinary tract dilatation and polyhydramnios in this model most likely are attributable to polyuria caused by nitrofen-induced impairment of renal concentrating capacity . This relatively simple animal model might facilitate research into s ome aspects of the physiology of nonobstructive, prenatally dilated ur inary tracts. Copyright (C) 1996 by W.B. Saunders Company