Abstract
^<131>I-labelled α-chymotrypsin was administered into the ligated intestine of adult rats, and 131I distribution was studied. Differences were found in the distribution in the kidney from the control experiment of 131I-KI administration in the same way. Furthermore, 131I-bound protein was surely observed in the serum after the intraintestinal administration of 131I-labelled α-chymotrypsin was comparatively stable in natural human intestinal and gastric juices under the addition of 0.033M Ca ion, but without Ca ion, it was rapidly degraded and lost its esterase activity with both juices. In in vitro experiment with the sac of everted intestine of rats, it was found that chymotrypsin was transferred from the mucosal to the serosal side with its esterase activity. From these experimental results, the possibility of the transfer of α-chymotrypsin across the intestine was discussed.
