Renal Tissue Damage After Experimental Pyelonephritis: Role of Anti-Oxidants and Selective Cyclooxygenase-2 Inhibitors

Abstract

Purpose Our aim was to examine the effect of anti-oxidant and selective cyclooxygenase-2 inhibitor therapy given adjunct to the conventional treatment of acute pyelonephritis on renal tissue damage. Material and Methods 48 wistar rats were divided into 4 groups according to their treatment modalities which were started one day after inoculation of all rats with 0.1 ml of E.Coli(ATCC 25922 1010 cfu/ml).First group received only antibiotic treatment with ceftriaxone(50 mg/kg, IM), second and third group received L-Carnitine(500 mg/kg, IM) and Meloxicam(.mg/kg,IM) in addition to the conventional treatment, respectively. Fourth group received combination therapy(L-Carnitine and Meloxicam)in addition to group one. 3 and 7 days after E.Coli inoculation rats were sacrificed and kidney samples were obtained for histologic determination of tubular atrophy, acute and chronic inflammation, interstitial fibrosis and biochemical determination of catalase activity(CAT), total antioxidant capacity(TAC) and malondialdehyde(MDA). Results Interstitial fibrosis(p:0.06),chronic inflammation(p:0.536) and tubular atrophy(p:0.094) decreased in group 4 compared to the other groups but there was statistically significant decrease only in acute inflammation(p:0.015). In addition,if the day of nephrectomy is considered, there was again a significant decrease in acute inflammation findings in day 7 compared to day 3 in group 2,3 and 4(p:0.002). CAT significantly increased in group 2(p:0.029),group 3(p:0.02) and group 4(p:0.014) and decreased in group 1(p:0.012) in day 7. Conclusions Acute renal inflammatory injury can be prevented much more effectively by combination therapy than conventional therapy. This process is probably due to the prevention of free oxygen radical generation by anti-oxidants and inhibition of chemotaxis by selective cyclooxygenase-2 inhibitors.