Dr. Kassai Tibor - Dr. Murai Éva szerk.: Parasitologia Hungarica 10. (Budapest, 1977)
Mammalian pancreatic enzymes added to the nutrient medium were inactivated by living worm specimens kept therein. Residual enzyme activity was lower in such cases than on addition of enzymes to the enzyme-free nutrient medium. The degree of inhibitory activity was directly related to the total weight of the parasites kept in the medium. REICHENBACH-KLINKE and REICHENBACH-KLINKE (1970) postulated that intact specimens of the intestinal fish parasite Proteocephalus longicollis (Cestoda) secrete a trypsin inhibitor into the surrounding intestinal milieu. PAPPAS and READ (1972a) failed to substantiate this hypothesis in studies with Hy menolepis diminuta, because they were able to demonstrate inactivation of trypsin, as well as of CC- and (3-chymotrypsin exclusively in enzyme-containing KPT medium in which living specimens were present, and failed to detect inhibitor activity in enzyme-free medium incubated with the parasites. In the present studies evidence o f inhibitor activity could be obtained also in enzyme-free incubation systems. It follows from the present findings that tapeworms produce and release inhibitors not only in the gut, but also when localized in the body cavity of the vertebrate host. Extracts of plerocercoids contained a lower quantity of inhibitors than those of adults parasitic in the small intestine of the domestic duck. The quantitative difference may be due to metabolic alterations in the adulthood, but, more probably, it seems to represent a response to the very strong proteolytic activity present in the avian small intestine. Although in the body cavity of fishes much.lower enzyme activity can be detected, nevertheless SIEBERT and BOTTKE (1963) demonstrated the presence of amylase, katepsin-like protease (pH 4.5), neutral protease (trypsin, with pH optimum at 7.8), ribonuclease and glycolytic enzymes in the body cavity of the carp and trout. The proteolytic enzyme production of cestodes, viz. the inhibitory action on the proteolytic enzymes of the host, illustrates the complexity of the physiological interrelationship between host and parasite. Evidence of the functioning and, especially, of the secretion by the parasite of inhibitors to host's enzymes supports the formerly much disputed view that parasite-associated "anti-enzymes" play a major role in parasite ecology, in other words in the self-protection of the parasite against digestive enzymes of the host. MATSKÁSI, I. — JUHÁSZ, S.: Ligula intestinalis (L., 1758): a plerocercoidok és az aduitusok proteáz és proteáz inhibitor vizsgálata A L. intestinalis galandféreg plerocercoid lárvája és aduit példányai homogenizátumából készített kivonat kimotripszin jellegű proteolitikus enzimet, valamint az emlős hasnyálmirigy eredetű tripszint és kimotripszint inaktiváló inhibitorokat tartalmaz. Proteolitikus enzimaktivitást és proteáz inhibitorokat az "in vitro" tartott férgek tápfolyadékában is ki lehet mutatni.
