|Budget Amount *help
¥2,100,000 (Direct Cost : ¥2,100,000)
Fiscal Year 1995 : ¥400,000 (Direct Cost : ¥400,000)
Fiscal Year 1994 : ¥1,700,000 (Direct Cost : ¥1,700,000)
Many previous reports using experimental animal models of pancreatitis have suggested that oxygen free radicals plays an important role in initiation and development of pancreatitis. Infiltration of inflammatory cells, i.e., neutrophils, lymphocytes and monocytes, has been observed in damaged pancreatic glands of animal models and patients of pancreatitis. Neutrophils are known to be the highest producer of oxygen free radicals among these inflammatory cells, it seems plausible that oxygen free radicals produced by neutrophils have some pathoetiological meaning in pancreatitis. In the present study we measured the superoxide production by nutrophils obtained from patients with acute and chronic pancreatitis, and then examined the effects of pancreatic enzymes on superoxide production. Patients showed significantly higher superoxide production by 4beta-phorbol 12beta-myristate 13alpha-acetate (PMA)-stimulated neutrophils than healthy controls did. Among the three pancrestic enzymes, amylase, trypsin and elastase, elastase was the only one which increased the superoxide production by PMA-stimulated neutrophils, by an increment of 1.5-fold. It also increased the activity of NADPH oxidase prepared from PMA-stimulated neutrophils by a factor of 2.1. High affinity and low affinity binding sites fot elastase on neutrophils were identified. These results suggest that elastase plays a role in the development of pancreatitis by enhancing superoxide production of neutrophils.
本研究では,この膵エラスターゼによる好中球のO_2^-産生能増強機構について検討した.その結果,膵エラスターゼは,PMAの場合と動揺に,炎症性サイトカインであるtumor necrosis factor(TNF)や,好中球遊走因子であるIMLPで刺激した好中球のO_2^-産生も増強することを明らかにした.
また,膵エラスターゼに対するspecificbinding siteの解析を行い,以下の結果を得た.(1)膵エラスターゼに対するspecificbinding siteには,膵エラスターゼと同様にPMA刺激好中球のO_2^-産生を増強する.好中球エラスターゼも結合する.(2)specific binding siteに結合した膵エラスターゼは,経時的に細胞内に取り込まれ,分解された後,細胞外に排出される,(3)specific binding siteと膵エラスターゼとの結合の至適pHは,pH6である.