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Activity and properties of fructose bisphosphatase (FBPase) was studied in the free-living turbellarian Phagocata sibirica. All subcellular fractions of P. sibirica (12 000 g cytosol, 105 000 g cytosol, mitochondria, and microsomes) have the FBPase activity. There was studied dependence of the FBPase reaction rate on the substrate concentration. For realization of the enzyme activity, the high affinity to substrate and presence of bivalent cations (Mg2+ or Mn2+) are necessary. The was studied the effect of various effectors as well as of monovalent (Na+, K+, Li+, and NH4+) and bivalent (Zn2+ and Cu2+) cations.

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There have been studied the activity and properties of fructose bisphosphatase (FBPase) of Bothriocephalus scorpii parasitizing in pyloric appendages of the goby Myoxocephalus brandti. All subcellular fractions of B. scorpii (12 g-cytosol, 105 g-cytosol, mitochondria, and microsomes) have the FBPase activity. The enzyme has a high affinity to substrate and needs the presence of bivalent cations (Mg2+ or Mn2+). AMP inhibits the enzyme significantly. Action of various effectors has been studied. The monovalent (Na+, K+, Li+, NH4+) and bivalent cations (Zn2+ and Cu2+) inhibit the enzyme activity.

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There were studied activities and properties of mitochondrial and microsomal glucose-6-phosphatases (G6Pases) in free living turbellaria Phagocata sibirica and cestodes Bothriocephalus scorpii. Action of various effectors (sodium fluoride, glucose, HCO3-, citrate, Cu2+, DTT, EDTA, ATP, AFP) on the enzyme activity was studied. The obtained results and literature data demonstrate that G6Pase is present in various muscles of representatives of the animal kingdom. The conclusion can be made that invertebrate G6Pase releases glucose from glycogen and gluconeogenic precursors.

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Activities and properties of adenosine triphosphatases and glucose-6-phosphatases in microsomal fractions of cestodes Bothriocephalus scorpii were studied. The highest activity of these enzymes was observed in mitochondrial fractions. The influence of different ions and effectors is studied. The effect of 10 anthelmintic preparations on activities of the enzymes was investigated. Trichlorophen, bitionol, oxinide, G-937 and G-1028 were found to be most effective preparations for ATPases. Oxinide, bitionol, G-937, G-1028, and acemidophene were the most effective preparations for G-6-Pases.

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Activities and properties of adenosine triphosphatases (ATPases) have been studied in mitochondrial and microsomal fractions of cestodes Bothriocephalus scorpii parasitizing in pyloric appendages of the Brandt's bullhead Myoxocephalus brandti. The highest activity has been revealed in the mitochondrial fraction. The mitochondrial and microsomal fractions of B. scorpii have the ATPase activity dependent on the presence of cations Mg2+, Mn2+, and Ca2+. Effects of ions and inhibitors on the B. scorpii ATPase activity with various cations have been studied. Both subcellular fractions are able to hydrolyze, apart from ATP, also GTP, CTP, and UTP.

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Activities and properties of phosphorylases of cytosol and mitochondrial fractions are studied in free-living turbellaria Phagocata sibirica and cestodes Bothriocephalus scorpii. The phosphorylase activities in P. sibirica and B. scorpii differ significantly both in form and the total activity of this enzyme. Dependence of the phosphorylase reaction rate on substrate concentration is studied. The high activity of phosphorylase as compared with that of hexokinase suggests glycogen to be the main energy source of the studied flatworms. Effects of various effectors on activities of cytosol and mitochondrial phosphorylases are studied.

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Literary and original data on the influence of some anthelmintic preparations on the survival in vitro and activity of twenty enzymes of gluconeogenesis, carbohydrate and energy metabolism in the trematode species Eurytrema pancreaticum and Calicophoron ijimai parasitizing cattle in the Russian Far East are summarized.

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The cestodes Bothriocephalus scorpii during the incubation in vitro assimilated glucose from the incubation medium and synthesized of glycogen. End products of carbohydrate metabolism in B. scorpii were lactic, succinic and volatile fatty acids. Mitochondria isolated from B. scorpii intensively oxidized succinate, alpha-ketoglutarate, isocitrate and less intensevely oxidized citrate, oxalacetate, pyruvate, cis-aconitate and malate.

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The trematodes Eurytrema pancreaticum and Calicophoron ijimai during the incubation in vitro assimilated glucose from the incubation medium and utilized the endogenous glycogen. Final products of the carbohydrate metabolism in the calicophorones were lactic, acatic, propionic, isobutyric and alpha-methylbutyric acids; in the eurytremes they were lactic, acetic, propionic, isobutyric, alpha-methylbutyric, valerianic and capronic acids. The effect of anthelminthic preparations on the carbohydrate metabolism and its final products was investigated.

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Activities and properties of NADF-dependent isocitrate dehydrogenases in cytosol and mitochondrial fractions from trematodes Eurytrema pancreaticum and Calicophoron ijimai were examined. Cytosol and mitochondrial enzymes were activated by ions Mn2+ and Mg2+ and inhibited by ions of heavy metals and p-chloromercuribenzoate. The effect of anthelmintic preparations on activity of enzymes was investigated.

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Activities and properties of adenosine triphosphatases in mitochondrial and microsomal fractions of trematodes Eurytrema pancreaticum and Calicophoron ijimai were studied. The highest ATPase activity was observed in mitochondrial fractions. The effect of anthelmintic preparations on activity of enzyme was investigated. Trichlorophene, bitionol, oxinide, G-937 and G-1028 turned out to be the most effective preparations.

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It was shown that pyruvate kinase (PK) in the supernatant fraction from Calicophoron ijimai is able to regulate the direction of metabolic flow at glucose break down from phosphoenolpyruvate (PEP) level. The enzyme for activity required substrate, dinucleotides, cations K+ and Mn++. The activity with Mg++ as divalent cation is low. The addition of fructose-1.6-diphosphate (FDP) did not affect the enzyme activity with Mn++, however, increased the affinity for PEP. The velocity of Mg++ activated reaction increased by 8.2 times in the presence of FDP. PK in C. ijimai is sensitive to ATP inhibition, being weakly inhibited by malate. L-alanine did not influence on the enzyme activity. The effect of some anthelminthic preparations on the PK activity was shown.

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Studies have been made on the activity and properties of malate and lactate dehydrogenases from the cattle rumen trematodes Eurytrema pancreaticum, Calicophoron ijimai and the turbellarian Phagocata sibirica which has a common free-living ancestor with the trematodes. All the species studied have a highly active malate dehydrogenase, its activity in the reaction of reducing oxaloacetate being 6-14 times higher than in the reaction of malate oxidation. The affinity of malate dehydrogenase to oxaloacetate was found to be higher than that to malate. The activity of lactate dehydrogenase (reducing the pyruvate) was lower than the activity of malate dehydrogenase, the difference being 50 times for C. ijimai, 4 times for E. pancreaticum and 10 times for P. sibirica.

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Glycogen content, glucose consumption and the production of metabolic end products by Calicophoron ijimai were determined under aerobic and anaerobic conditions. The major end products of fermentation were identified as lactic, acetic, propionic, isobutyric and alpha-methylbutyric acids, propionic acid predominating. The activities and properties of some of the enzymes of carbohydrate metabolism were determined. The worms showed high phosphoenolpyruvate carboxykinase, malate dehydrogenase and malate dehydrogenase (decarboxylating) but relatively low pyruvate kinase and very low lactate dehydrogenase activities. The pH optima, coenzyme, cofactor and ionic requirements of the enzymes were similar to those of other helminths. Malate dehydrogenase had an 8-fold greater affinity for oxaloacetate than malate, and was about 14 times more active for oxaloacetate reduction than malate oxidation. Phosphoenolpyruvate carboxykinase was 2.4 times more active and had a 2-fold greater affinity for phosphoenolpyruvate and dinucleotide than pyruvate kinase. The low activities of lactate dehydrogenase and pyruvate kinase but high activities of malate dehydrogenase and phosphoenolpyruvate carboxykinase suggest that anaerobic carbohydrate catabolism follows the fumarate reductase pathway.

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The presence of active fumarate reductase system in mitochondria of the trematode Calicophoron ijimai was shown. Fumarate reductase activities in different collections of C. ijimai vary considerably. Maximum activity accounts for 47.7 +/- 1.0 nM/min/mg protein whereas minimum--for 15.1 +/- 0.1. Some properties of the enzyme were studied. The effect of thiabendazole, bitionol, oxinid and preparations of G-1026 and G-937 on the fumarate reductase activity was investigated. G-1026, G-937 preparations and bitionol have the strongest inhibitory effect on the enzyme. Thiabendazole inhibited but little the fumarate reductase reaction in C. ijimai. The enzyme activity was not affected by oxinid.

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