The study was undertaken for the purpose of investigating tile relationship between acute pancreatitis (AP)and nitris oxied(NO). The animals of AP were killed at the period of 24

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48 hours after induction of AP. Non-operated onrmal rats(n=12) were served as control.The degree of serum amyase levels and histopathologicalterations were investigated. At the same time the levels of nitric oxide synthase (NOS) mRNA in pancreatictissues were measured by the method of reverse transcription polymerase chain reaction(RT- PCR)

in order toreflect NOS gene expression levels. Primers were designed referring to brain NOS CDNA sequence of rats regionswhich were highly kindred to human endothelial derived NOS CDNA were seleced

actin as on innerreference. Restits:Hemorrhagic necrotizing AP was induced by the time of 24h after operation

which was similarto that found in man. As compared with control group

serum amylase level was markedly increased at24h(P<0.01)

whereas NOS mRNA level was markedly increased to 1.2 or 1.5 times the level of control group (P<0.01)

forming a peak of NOS gene expression level

then was decreased at 48h. Our preliminary results suggestthat NO may have a role in the pathogenesis of AP.