AIM:To investigate the fluid shear stress induced changesof[Ca~(2+)]i in neutrophils in pancreatic microcirculation ofexperimental acute pancreatitis(AP).METHODS:Wistar rats(n=36)were randomized into threegroups.A model of AP was established by subcutaneousinjection of caerulein.Low-shear 30 viscometer was usedto provide steady fluid shear stress on separated neutrophils.The mean fluorescent intensity tested by flow cytometrywas used as the indication of[Ca~(2+)]i quantity.RESULTS:Under steady shear,cytosolic[Ca~(2+)]i showedbiphasic changes.The shear rate changed from low to high,[Ca~(2+)]i in different groups decreased slightly and then increasedgradually to a high level(P<0.05).A close correlation wasobserved between the cytosolic[Ca~(2+)]i level and the alterationof fluid shear stress in regional microcirculation of AP.CONCLUSION:The increase of[Ca~(2+)]i is highly related tothe activation of neutrophils,which contributes to neutrophiladhesion to endothelium in the early phase of AP.Theeffect of fluid shear stress on[Ca~(2+)]i may play a crucialrole in pancreatic microcirculatory failure of AP.Zhou ZG,Chen YQ,Liu XB,Hu WM,Tian BL,Chen HQ.Changes of cytosolic[Ca~(2+)]i in neutrophils in pancreaticmicrocirculation of rats with caerulein-induced acute pancreatitisunder fluid shear stress.World J Gastroenterol 2004;10(21):3185-3187http://www.wjgnet.com/1007-9327/10/3185.asp AIM: To investigate the fluid shear stress induced changes of [Ca ~ (2 +)] i in neutrophils in pancreatic microcirculation of experimental acute pancreatitis (AP) .METHODS: Wistar rats (n = 36) were randomized into three groups established by subcutaneous injection of caerulein. Low-shear 30 viscometer was used to provide steady fluid shear stress on separated neutrophils. The mean fluorescent intensity tested by flow cytometrywas used as the indication of [Ca ~ (2 +)] i quantity.RESULTS: Under steady The shear rate changed from low to high, [Ca ~ (2 +)] i in different groups decreased slightly and then increasedgradually to a high level (P <0.05) . A close correlation wasobserved between the cytosolic [Ca ~ (2 +)] i level and the alterationof fluid shear stress in regional microcirculation of AP.CONCLUSION: The increase of [Ca ~ (2 +)] i is highly related tothe activation of neutrophils, which contributes to neutrophiladhesion to endothelium in the early phase of A P. The Zffe, Chen YQ, Liu XB, Hu WM, Tian BL, Chen HQ. Changes in cytosolic [ Ca ~ (2 +)] i in neutrophils in pancreaticmicrocirculation of rats with caerulein-induced acute pancreatitisunder fluid shear stress. World J Gastroenterol 2004; 10 (21): 3185-3187http: //www.wjgnet.com/1007-9327/ 10 / 3185.asp