Studies on the lipid of rat dental pulp I. Analyses of lipid component and fatty acid composition in rat incisor pulps before and after whole-body x-ray irradiation
ラット切歯歯髄の脂質組成ならびに脂肪酸組成を解析するとともに,あわせてエックス線全身照射の各々の組成に及ぼす影響を研究し次の如き結果を得た.(1)切歯歯髄の総脂質含量は蛋白量相対比にして0.26の値を得た.エックス線全身照射群(1000R照射後3日目のもの)の歯髄も同様0.26の値を得,その差は得られなかった.(2)正常切歯歯髄の総脂質の脂肪酸組成において,パルミチン酸,オイレン酸,ステアリン酸,アラキドン酸,リノール酸の順に主成分として認められ,前三脂肪酸で78%以上を占めた.エックス線全身照射群においてはオレイン酸の減少,アラキドン酸の増加が認められた.口腔領域への部分照射(1000R)でも同様の傾向がみられた.(3)正常切歯歯髄の脂質構成としてリン脂質,コレステロール,トリグリセリド,コレステロールエステルが主成分として認められ,リン脂質は45 % ,コレステロールは30 % を占めた.エックス線全身照射群ではリン脂質,トリグリセリドの構成比に変動はみられなかったが,コレステロールの減少とコレステロールエステルの増加が認められた.(4)正常切歯歯髄リン脂質の構成を各種呈色反応で仮同定した結果,レシチン,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が主成分として90 % 以上を占めた.特にホスファチジルセリン含量が多いのが注目される.照射群ではレシチンの増加,ホスファチジルセリンの減少など若干の組成比に変動がみられたが,対照との差は有意とは言えなかった.Lipids and fatty acids extracted from rat incisor pulps before and after whole-body x-ray irradiation at 1000R were qualitatively and quantitatively analysed by means of thin-layer and gas-liquid chromatography, and the results are as follows. 1) Ratio of the total lipid weight to protein weight was obtained 0.26 in normal rat dental pulps. The ratio in the irradiated group (3 days after irradiation) did not change. 2) In fatty acid composition of lipid of normal rat incisor pulps, palmitic, oleic, stearic, arachidonic, and linoleic acids were much in this order, and palmitic, stearic and oleic acids were major component accounted for over 78% of the total fatty acids. In that of the irradiated group, the decrease of oleic acid and the increase of arachidonic acid were observed comparing those of normal pulp lipid. 3) The major lipid of normal dental pulps composed of phospholipid, choresterol, triglyceride and choresterol ester, and phospholipid and choresterol accounted for about 45% and 30% of the total lipids, respectively. In the irradiated group, the decrease of choresterol and the increase of choresterol ester were represented. 4) In results of tentative identification by various color reaction on the thin-layer chromatograph, the major phospholipids of dental pulps were lecithin, phosphatidyl ethanolamine and phosphatidyl serine, which accounted for over 90% of the total phospholipids. It is significant that phosphatidyl serine in dental pulp is greater than in any other mammalian soft tissue so far studied. In the irradiated group, it was slightly observed the increment of lecithin and the decrement of phosphatidyl serine, but they are not predominant
