Dr. Murai Éva szerk.: Parasitologia Hungarica 13. (Budapest, 1980)

of the tegumental processes, too. We speculated that if the adsorption of amylase requires the involvement of active metabolic processes, it necessarily decrease as a result of preincubation at +5°C. The maintenance medium was stirred mechanically throughout the period of incubation. The results are shown in Table 6. Table 6 The influence of temperature on the diastase or cC-amylase adsorption by L. intestinalis larvae Temperature Per cent starch hydrolysis Temperature KRT+10 jig/ml diastase KRT+10 >ig/ml amylase Temperature 15 min preincubation after one wash 30 min preincubation after three washes 30 min preincubation after three washes +5°C 34. 22 5. 8 20. 8 38°C 56. 38 25. 0 72. 64 After preincubation in amylase containing KRT the worms were washed in three changes of KRT for 10 min. at 38°C, and transferred to 10 mg/ml starch containing KRT for 60 min. at 38°C. Amylase activity was assayed by the iodine method. Ill Determination of oC-amylase activity in somatic extracts of L. intestinalis larvae It was shown experimentally that live L. intestinalis larvae hydrolysed the starch dissolved in their maintenance medium, and adsorbed the mammalian pancreatic oC-amylase added to the latter. The results of testing larva extracts for amylolytic activity and interaction with pancreatic cC-amylase are shown in Table 7 and 8. Table 7 Effect of the length of incubation time on the amylolytic activity of L. intestinalis extracts (U/g parasite) Control Incubation for Control 5-min 15-min 30-min X 0.2610 0.2690 1. 0833 1.3000 S

2 0.0064 0.0069 0. 0025 0.0138 n 10 10 9 9 P% >5 < 0.01 < 0.01 Amylase activity was assayed by method of UJIHARA et al. (19 65). Inactivated aliquots of extract were set up as controls.