ACETIC ACID-INDUCED COLITIS IN NORMAL AND ESSENTIAL FATTY-ACID DEFICIENT RATS

Eicosanoids and platelet-activating factor (PAF) production increases in experimental colitis. Both eicosanoids and PAF seem to arise from s imilar membrane phospholipids. To support both these suggestions we ha ve investigated whether a fat-free diet, which should alter production of eicosanoids and PAF, affects experimental colitis. Essential fatty acid deficient (EFAD) rats were obtained by putting 4-week-old animal s on a fat-free diet for 3 months. Experimental colitis was induced by a single intracolonic administration of 2 ml of 4% acetic acid. One t o seven days later the animals were sacrificed and the colon removed t o assess macroscopically and histologically intestinal damage. Eicosan oids and PAF levels were also measured in the mucosa scrapings by spec ific radioimmunoassay. The injury to the colon was more evident in con trol rats compared with EFAD rats. Besides colonic tissue of control r ats showed a highly significant increase of PGE(2), LTB(4) and PAF, co mpared with levels in EFAD rats. Our results indicate that fat-free di et reduces tissue damage, and at the same time PGE(2), LTB(4) and PAF colonic content.