The mode of action of ochratoxin A in acute enteritis in rats

The mode of action of ochratoxin A(OCT A) was studied in male Wistar rats in connection with the development of acute enteritis. Acute enteritis in the duodenum and jejunum identical with that induced by oral administration was also induced by parenteral application at the dose level of 15 mg/kg OCT A and was completely inhibited by ligation of the choledochus. Direct application of OCT A into the jejunal blind sac lumen constructed by two ligations induced severe inflammation in situ and also revealed remote action to the duodenum and jejunum where separated from the blind sac by ligation. This remote action was inhibited by ligation of the choledochus. These results clearly demonstrated the enterohepatic circulation of OCT A. The ileal injection also revealed remote action of OCT A, although no pathologic change was caused in the ileal mucosa. The results obtained suggest that the enteritis may be induced by direct exposure of OCT A to the intestinal mucosa without metabolic activation, although certain participation of ochratoxin alpha to accelerate the inflammation was suspected.