Abstract
This study was undertaken to investigate the effect of indomethacin on prostaglandins in 4-Nitroquinoline-N-Oxide (4-NQO) induced palatal carcinoma of albino rats. 128 Sprague-Dawley strain albino rats-about 100g in body weight-were used in this study, divided into as belows; 1. Normal group (16-albino rats) with no treatment, 2. Control group (16-albino rats) treated with prophylene application onto palatal mucosa 3 times a week. 3. Experimental group I (48-albino rats) treated with 0.5% 4-NQO in prophylene application onto palatal mucosa 3 times a week. 4. Experimental group II (48-albino rats) treated with 0.5% 4-NQO in prophylene application with administered $20{\mu}g/ml$ of indomethacin in drinking water ad. lib. Four animals were sacrificed 7th, 13th, 19th, and 25th week respectively in normal and control group, and 7th, 9th, 11th, 13th, 15th, 17th, 19th, 21st, 23rd, 25th, 27th and 29th week respectively in experimental group I and II at each time. The palatal and lingual tissues were excised and kept frozen at $-70^{\circ}C$. Densitometer scan and Beta-counting counter were used for the thin layer chromatography of the arachidonic acid metabolites. The obtained results were as belows; 1. In normal and control group, there was little change of the arachidonic acid metabolites during experiment period, and the tissue homogenates included prostaglandin $D_2$, 6-keto-prostaglandin $F_{1{\alpha}}$, prostaglandin $E_2$, thromboxane $B_2$, prostaglandin $F_{2{\alpha}}$ in that order of relative abundances. 2. In experimental group I, prostaglandin $D_2$, and prostaglandin $E_2$ were increased, while 6-keto-prostaglandin $F_{1{\alpha}}$ and thromboxane $B_2$ were decreased in relative abundances of arachidonic acid metabolites. And there was little change in prostaglandin $F_{1{\alpha}}$ 3. In experimental group II, prostaglandin $D_2$, and prostaglandin $E_2$ were increased, while 6-keto-prostaglandin $F_{1{\alpha}}$ and thromboxane $B_2$ were decreased in relative abundances of arachidonic acid metabolites. And there was little change in prostaglandin $F_{2{\alpha}}$ also. 4. In the range of increase in prostaglandin $D_2$, and prostaglandin $E_2$, and that of decrease in 6-keto-prostaglandin $F_{1{\alpha}}$ and thromboxane $B_2$, in relative abundances, there was wider in experimental group I than in group II. 5. In the range of increase in prostaglandin $D_2$, and prostaglandin $E_2$, and that of decrease in 6-keto-prostaglandin $F_{1{\alpha}}$ and thromboxane $B_2$, in relative abundances, there was wider in palatal mucosa than in lingual mucosa in experimental group I and II.