Dr. Kassai Tibor szerk.: Parasitologia Hungarica 2. (Budapest, 1969)

Preparation on antigen

: Worm metabolic antigen was obtained by keeping living, sexually mature worms in buffer solution* for 48 hours at 37°C. After centrifugation the supernatant solution was adjusted to an equivalent of 10,000 worms/ml. Assessment of enzyme inhibition

: A rapid,simple method suitable for*-investigations of small volumes was used. On a watch glass 0.06 ml of diluted intestinal fluid was mixed with 0.06 ml antigen or with 0.06 ml buffer as a control. A drop of mixture was applied to the emulsion surface of developed negative film and enzyme activity judged by the degree of gelatinolysis occurring after 15, 30 and 60 minutes at 38°C. Increased light transmission resulting from gelatinolysis was determined photometrically. The proteolytic activity of intestinal fluid was established by comparison with various dilutions of a standard trypsin solution (2 mg/lOO ml). The proteolytic activity of trypsin dilutions on rat serum proteins was confirmed by the biuret method. To determine whether the presumed enzyme inhibition of metabolic antigen extends to other hydrolytic enzymes mixtures of intestinal fluid and metabolic antigen were combined with an equal volume of polysaccharide substrate (insoluble starch) at 38°C

. The amylase activity of several samples was assessed by a starchiodine test every 5 minutes over a 30 minute period. Results The proteolytic activity of rat intestinal fluid was not uniform. In one case even a 1:50 dilution caused partial lysis (Pig. 1 A) while 1:100 dilutions of intestinal fluids of other rats produced digestions of varying degree (Pig. 1 B+C). * NaCL 127, KCl 5, CaCl

2 1, NaHPO-4 7.5, KH2PO4 2.5 mM/l; pH = 7.1