Changes in gut intramucosal pH and oxygen metabolism in rats with acute severe pancreatitis

Objective:To investigate the potential role of changes in gutintramucosal pH and oxygen metabolism in the development of gut mucosal barrier dysfunction associated with acute severe pancreatitis (ASP).Methods:ASP model was produced by intravenous infusion of cerulein with an intraductal administration of glycodeoxycholic acid.6,12,24 hours after the operation,blood samples were taken from the portal vein and abdominal aorta of the animals in ASP and sham operation (SO) groups,and blood gas as well as blood oxygen were analyzed.Meanwhile,the intramucosal pH and gut oxygen extraction rate were calculated,the plasma lactate levels of portal vein were also measured.Results:Gut oxygen extraction rates in ASP group increased by (45.88±6.05)% and (41.31±4.18)% at 12 and 24 hours,and they were markedly higher compared with SO group 〔（24.82±4.28）% and （23.08±3.44）%,respectively,both P<0.001〕.Intramucosal pH significantly decreased at 12 and 24 hours in ASP group after operation (12 hours:7.301±0.036 vs.7.410±0.047,P<0.001;24 hours:7.165±0.066 vs.7.390±0.044,P<0.001).Plasma lactate levels of portal vein blood in ASP group were much higher than that in SO group at 12 and 24 hours 〔(3.58±1.06)mmol/L vs.(1.16±0.97)mmol/L;(7.97±1.05)mmol/L vs.(1.24±0.29)mmol/L〕.Also,there was a negative correlation between plasma lactate levels of portal blood and intramucosal pH (r=0.868,P<0.001).Conclusions:Disorder of gut oxygen metabolism and decrease in gut intramucosal pH might be involved in the pathogenesis of gut mucosal barrier dysfunction associated with ASP.