In Vivo Action of Pronase-P

A biochemical study was made of in vivo action of orally administered Pronase-P. The enzymic activities of Pronase-P was determined both with casein and L-leucyl. β. naphthylamide (LN) as substrates 1) EDTA inhibited LN hydrolysing activity of Pronase-P by 83%, while it inhibited the activity serum by only about 8 % and that in intestinal fluid by 14%.Thus, EDTA was found to be a good inhibitor in differentiating Pronase-P from animal leucineaminopeptidase. 2) When Pronase-P was incubated with intestinal fluid in vitro the LN hydrolysing activity was found to be 10 to 15% less than the sum of the activity of each fraction. Pronase-P solution introduced in the tied loop of small intestine showed about 47% less activity after 1.5 hours of incubation. 3) 22 to 30% increase in LN hydrolysing activity of serum was found by oral administration or by direct introduction of Pronase-P into intestinal loop of rat. 4) No significant change was observed in LN hydrolysing activity in serum of rabbits after oral administration of Pronase-P for a week. 5) No detectable effect of Pronase-P administration on casein hydrolysing activity was found in sera of rabbits with orally administered Pronas-P and those with Pronase-P directly introduced into intestinal canal. 6) No casein hydrolysing activity was demonstrated in the urine both of human and rabbit with orally administrated Pronase-P.