Expression Of Inducible Nitric Oxide Synthase In Kidneys Of Rats With Unilateral Ureteral Obstruction

ObjectiveUrinary tract obstruction is a disease process that may result from a diversity of congenital or acquired conditions,ranging from caculi to strictures and to inflammatory processes and malignances.The incidence of hydronephrosis was found in a great autopsy series to be 3.1% among 59064 patients in age from birth to 80 years,with its true incidence is considerably higher,as many of the causes resolve over time or are successfully treated.We attempted to observe the renal expression of inducible nitric oxide synthase(iNOS)in rats with unilateral ureteral obstruction(UUO).Materials and MethodsMale Sprague-Dawley rats were used throughout the study.UUO was achieved by ligation of the distal left ureter and maintained for either 4hours(group 1),12 hours(group 2),24 hours(group 3),3 days(group4),or 7 days(group 5).Control rats underwent sham operation without ligating the ureter. Expression of iNOS mRNA were examined in the obstructed kidneys by semi-quantitative RT-PCR. Expression of iNOS protein were examined by immunohistochemistry(two step Envision method). The morphological changes of the obstructed kidneys were also observed .ResultsThe gene expression and the protein level of iNOS were begun to increase at 4-hour,were up to peak at 3-day after UUO operation.A few numbers of infiltrating inflammatory cells were found at 24-hour,a large numbers ofinfiltrating inflammatory cells were found at 3-day,and the peak of the numbers of those cells was at 7-day after UUO operation.ConclusionsiNOS is involved in the pathogenesis of the injuries of UUO. iNC 3 may play a protective role in the injuries of UUO.