抄録
Site of analgesic action of tolmetin sodium was investigated in the acetic acid-induced writhing test in rats. There was a rough correlation between anti-writhing activity of tolmetin sodium and tolmetin contents in the peritoneal exudatewhen given orally. Anti-writhing ED50 value of tolmetin sodium was 1.42 (0.82-2.91) and 92.0 (57.0-140) μg/kg when given i.p. and i.v., respectively, and the potency ratio of tolmetin sodium by i.v. to i.p. administration was 40.0 (18.5-80.2) . When tolmetin contents in the peritoneal exudate and the plasma were determined after i.p. or i.v. administration of tolmetin sodium with equipotent dose (5 μg/kg, i.p.; 200 μg/kg, i.v.), the content when given i.p. was nearly equal to and less than one-fortieth that when given i.v. in the exudate and the plasma, respectively. From these results, it was suggested that site of anti-writhing action of tolmetin sodium was in the peritoneum (periphery) in rats.
