胃ホスホリパーゼの検討

DOI Web Site

書誌事項

タイトル別名
  • Study of Phospholipase in Stomach Phospholipase A<SUB>2</SUB> Activity in Rat Stomach
  • Study of Phospholipase in Stomach Phospholipase A2 Activity in Rat Stomach
  • Its Localization and Effect of Anti-ulcer and Ulcerogenic Agents on the Activity
  • ラット胃ホスホリパーゼA<SUB>2</SUB>活性の局在とその活性に及ぼす抗潰瘍剤・抗炎症剤の影響

抄録

Phospholipase A2, lysophospholipase and transacylase activities were detected in stomach of adult male rats and characterized. Of three of the activities, some properties and the localization of the phospholipase A2 activity and the effect of several clinical agents, antiulcer and ulcerogenic agents, on its activity were investigated in vitro.<BR>1) In the glandular stomach of rat, the phospholipase A2 activity was detected by 1-acy1-2-[1-14C]oleoyl-sn-glycero-3-phosphocholine as substrate, and the lysophospholipase and transacylase activities were detected by 1-[1-14C] palmitoy1-2-lyso-sn-glycero-3-phosphocholine as substrate.<BR>2) The optimal pH for phospholipase A2, lysophospholipase and transacylase activities was 8.0,7.0 and 7.0, and their specific activities (μmol/min/mg protein) were 4.9⋅10-2,4.8⋅10-2 and 2.2⋅10-2 (n = 6), respectively, in the glandular stomach homogenate.<BR>3) The glandular stomach from rat showed most abundant phosph olipase A2 activity among those stomachs from mouse, rat, rabbit and dog. In rats, the stomach had the highest activity among the organs tested (brain, heart, lung, liver, spleen, kidney, skeletal muscle, small intestine, large intestine and glandular stomach). The activity was found to vary in individual rat.<BR>4) The phospho lipase A2 activity in the stomach was calcium-dependent and relatively heat-resistant.<BR>5) More than 90% of phospholipase A2 activity was located in the corpus and less than 10% was in the antrum. In the corpus wall, the mucosal layer contained about 90% of total activity.<BR>6) The effect of some clinical agents (anti-ulcer and ulcerogenic agents) on the phospholipase A2 activity was examined. The activity in the corpus was inhibited by cimetidine (50%inhibition at 5⋅10-3 M) and stimulated by indomethacin (50% of stimulation at 5 - 10-5 M). Cetraxate hydrochloride (10-6-10-3 M),16,16-dimethylprostaglandin E2 (10-7-10-4 M) and dexamethasone (10-7-10-3 M) had no effect.<BR>In conclusion, the phospholipase A2 a ctivity in rat glandular stomach was located preferentially in the corpus mucosal layer, physiologically functional part, and was affected by several clinical anti-ulcer and ulcerogenic agents, indicating that it may have an important role for the ulceration and the protection of gastric mucosa.

収録刊行物

詳細情報 詳細情報について

問題の指摘

ページトップへ