1) ラット切歯歯髄のホモゲネートにおいてFe(++)誘導脂質過酸化反応活性が認められた.エックス線全身照射(1000R)したラットより分離した歯髄ホモゲネートのFe(++)誘導脂質過酸化反応は非照射のそれに比して促進がみられた. 2) ラット切歯歯髄脂質の構成脂質中で,過酸化反応を誘起し易い脂質はリン脂質で,中性脂質ではほとんど誘起されなかった. 3) リン脂質中,そのリン脂質構成の大部分をしめるボスファチジルコリン,ホスファチジルエタノールアミン,ホスファチジルセリンにおいて過酸化反応が誘起し得た.中でもホスファチジルエタノールアミンの脂質重量当りの比活性が最も高い値を示した. 4) リン脂質の脂肪酸組成では,アラキドン酸をはじめ,不飽和含量が多く,トリグリセリドではアラキドン酸はみられなかった.Lipid peroxidation of dental pulp homogenate isolated from rat incisors was induced by ferrous ion. Lipd peroxidation of dental pulp homogenate isolated from rat 3 days after wholebody irradiation at 1000R x-ray was also induced by ferrous ion, and the activity was higher than that of control homogenate. In the extracted lipid components of dental pulps, the peroxidation of phospholipid were marked, but those of choresterol, choresterol ester, mono-,di-, tri-glycerides, and fatty acid (non-esterified) were slightly or negligible. In the phospholipid components, the peroxidation was highly observed in lecithin, phosphatidyl ethanolamine and phosphatidyl serine, and the peroxidation of phosphatidyl ethanolamine showed the most value in them. By the analysis of the fatty acid composition, arachidonic acid was included in the phos-pholipid but not in the triglyceride, suggesting arachidonic acid is substrate of the peroxidation of dental pulps
