Metabolic Adaptation of Fish Intestinal Helminths: Anti-Protease Inhibitory Ability of Cestodes Triaenophorus nodulosus.

The anti-protease inhibitory ability of the cestode Triaenophorus nodulosus (Pallas, 1781) was studied in extracts of its plerocercoid larvae from the liver of a perch (Perca fluviatilis Linnaeus) and in excretory-secretory products and extracts of its mature and immature forms from the intestine of a pike (Esox lucius Linnaeus). It was found that excretory/secretory products (ESP) and extracts of both mature and immature T. nodulosus exhibited varying degrees of anti-protease inhibitory ability, including toward commercial trypsin. Tapeworm extracts had a greater inhibitory ability compared to ESP. At the same time, the extract of immature tapeworms exhibited a higher anti-protease activity compared to mature forms. Likewise, the extract of tapeworms deprived of the brush border had a higher inhibitory ability compared to the tegumental brush border fraction. [ABSTRACT FROM AUTHOR]