Abstract

This study investigated the enzyme histochemical localization and characteristics of lactate (LDH) and malate dehydrogenase (MDH) related with the oxidation-reduction metabolism in the sparganum and adult of S. erinacei. By enzyme histochemical assay, activity of LDH was strong in the tegument and subtegumental muscle layers of the adult and sparganum. Activity of MDH was strong in the tegument of the sparganum and subtegumental muscle layers of the adult. However it was weak in the tegument of the adult. By electrophoresis, 45 kDa band was major and common in LDH of adults and spargana. The 150 kDa molecule was the major and common band in MDH of adults and r-spargana (from experimentally infected rats). By isoelectrofocusing, isoelectric points (PI) of 4 MDH isozyme from adult worm were 6.0, 6.5, 6.7 and 7.1, respectively. PI 6.0 was the major band. The active range of pH for MDH was about pH 6 approximately 8 and the optimum pH was pH 7. The effective temperature on the MDH was about 30 degrees C approximately 50 degrees C and the optimum temperature was about 40 degrees C in spargana and adult worm. In the stability against heat, when MDH was heated at 85 degrees C for 10 seconds, the activity was denatured perfectly. Maximum activity of MDH was 19.4 unit in the s-sparganum (from snakes), 24.5 unit in the r-sparganum (from rats) and 108.0 unit in the adult worm. The maximum activity was higher in adults than in spargana. The present result showed us that the nutrients absorbed through the tegument were transferred into inner tissues and were utilized as the source of metabolism. According to the habitat of the parasite, the isozymes of LDH and MDH are activated differently, and by this different activation the sparganum and adult can adapt themselves to parasitic circumstances.