An assessment of salicylic acid-induced mucosal damage in vivo by measuring the metabolism of salicylamide in rabbit intestine.

An assessment of salicylic acid-induced mucosal damage in vivo by measuring the metabolism of salicylamide (SAM) was investigated in rabbit intestine. The intestinal first-pass metabolism of SAM was studied using in situ intestinal sacs with complete mesenteric venous blood collection. The appearance of both SAM and its metabolites into the mesenteric venous blood was measured directly by cannulating the mesenteric vein of exposed intestine and collecting all venous blood draining from the absorbing region. Following oral pretreatment with salicylic acid, the appearance of SAM glucuronide (SAMG) in the mesenteric venous blood was significantly increased compared with the control. The increased blood concentration of SAMG following intraduodenal administration of SAM in vivo was observed in rabbits pretreated with salicylic acid orally. The blood concentration of SAMG after the intravenous administration of SAM was not increased compared with the control. We suggest that the change in the intestinal first-pass metabolism of SAM may be due to the intestinal mucosal damage induced by oral pretreatment with salicylic acid. The measurement of SAM metabolites may be of value in the assessment of intestinal mucosal damage in vivo.