Effect Of Melatonin On INOS In Ureter Tissue Of Chronic Incomplete Ureteropelvic Junction Obstruction Rabbit

Objective: Explore the effect and significance of melatonin on iNOS in uretertissue of chronic incomplete UPJO rabbit.Method: Thirty two adult New Zealand rabbits without gender limitation wererandomly divided into4group with eight of each group, normal group A,sham-operation group B, operation group C, operation and drug group D. Group A gotno treatment, B, C and D group were performed a laparotomy to exposure leftureteropelvic junction, following by closing abdomen without any processing ingroup B and manufacturing the UPJO model in group C, D. After the model wassuccessfully established, all rabbits were given water and ordinary fodder, but groupD was additionally fed melatonin at pre-operation1week and post-operation untilexperiment over. Intravenous pyelogram was performed at pre-operation andpostoperative1,2,4and8week for understanding of urinary tract obstruction. Urinenitric oxide concentration of operative obstruction was detected at postoperative1,2,4and8week by laparotomy, following by taking the ureteral obstruction tissue andperforming the HE staining to observe the structure pathological changes and theimmunohistochemistry to detect the expression of iNOS.Result:1, Intravenous pyelogram: group C appeared hydronephrosis at postoperative1st week, group D appeared hydronephrosis at postoperative4th week, the degreeexacerbated with postoperative time lapse; the developing time of group C wasobviously longer than that of group A, B, D (P<0.05), increasing with thepostoperative time lapse; the development time of group D was obviously longer thanthat of group A, B (P<0.05) from the postoperative4th week, increasing with thepostoperative time lapse.2, Urine NO concentration in obstruction: urine NOconcentration of group C, D was obviously higher than that of group A, B (P<0.05),increasing along with the postoperative time lapse; urine NO concentration of groupD was obviously lower than that of group C (P<0.05).3, HE staining of ureteral obstruction tissue: group A, B had a normal structure in each ureteral layer; group Chad inflammatory and hyperplastic changes in mucosa layer, structure disorder insmooth muscle layer with a large amount of fibrous tissue hyperplasia; pathologicalchanges of group D was between group A, B and group C.4, Immunohistochemistryof ureteral obstruction tissue: iNOS mainly expresses in ureteral smooth muscle layer,its expression level in each group in the order was C>D>B>A(P<0.05); its expressionin group C enhanced along with postoperative time; its expression in group D startedenhancing along with postoperative time from the postoperative4th week(P<0.05).Conclusion:1, INOS expression and urine NO concentration of UPJOobstruction increased significantly, increasing with obstruction degree exacerbation.Maybe urine NO concentration could be an index of obstruction degree judgement,having potential value of clinical application.2, INOS and urine NO concentrationtook part in the pathology process of hydronephrosis caused by UPJO obstruction,were closely related to renal function demage.3, Melatonin may inhibit the excessiveexpression of iNOS to decrease the production of NO, reducing urine NOconcentration, slowing down oxidative damage and obstructive ureteral pathologyprocess, thus alleviate hydronephrosis and protect renal function.