Inhibition of iNOS reduces the therapeutic effects of ozone in acute necrotizing pancreatitis: An in vivo animal study

Objective. Previously, it was shown that ozone and S-methylthiourea (SMT) treatments had ameliorative effects on experimental models of acute necrotizing pancreatitis (ANP). It is possible that the combination of ozone and SMT may be more effective than either therapy. Therefore, we investigated the efficacy of combination therapy with ozone and SMT in an experimental rat model of ANP. Material and methods. Sprague-Dawley rats were divided into five experimental groups. Groups were designed as Sham-operated, ANP, ANP + Ozone, ANP + SMT and ANP + Ozone + SMT. A model of ANP was induced by injection of sodium taurocholate into the common biliopancreatic duct. Four days after induction, blood and tissue samples were obtained for biochemical, microbiological and histopathological analysis. Results. Survival rates, serum amylase, lipase and neopterin levels, tissue oxidative stress parameters, bacterial translocation and tissue injury scores were better in the ozone and SMT groups than in the ANP group. There was no bacterial translocation in the ozone-treated groups. Tissue injury scores in the ozone group were better compared to all ANP induced groups. Ozone and SMT treatment in combination did not have better biochemical, microbiological and histological data compared to ozone or SMT treatments separately in experimental ANP. Conclusions. The combination of ozone and SMT did not provide any therapeutic advantage in ANP possibly because SMT inhibited nitric oxide synthesis which was needed for ozone action.