title: The effects of DL-tetramisole and rafoxanide on tricarboxylic acid cycle enzymes of Haemonchus contortus, in vitro.
abstract: Various enzymes of the tricarboxylic acid cycle (TCA) viz., aconitase (E.C. 4.2.1.3), isocitrate dehydrogenase (E.C. 1.1.1.42), succinate dehydrognease (E.C. 1.3.99.1), fumarate reductase (NADH: fumarate oxido-reductase), fumarase (E.C. 4.2.1.2) and maltate dehydrogenase (E.C. 1.1.1.37) were detected in adult Haemonchus contortus (Nematoda: Trichostrongylidae), in vitro. Low activities of aconitase and isocitrate dehydrogenase suggested that the TCA cycle has a minor function and the pathway of CO2 fixation is the major pathway in the energy metabolism of the parasite. In vitro incubation in Tyrode's solution had no significant effect on TCA cycle enzymes and the worm was able to maintain normal metabolism for 12 h. The effects of D L-tetramisole and rafoxanide on various enzymes of the TCA cycle were studied in adult H. contortus. At 50 micrograms ml-1 varying degrees of inhibition of succinate dehydrogenase and fumarate reductase activities were observed. At the same concentration, the activities of other enzymes remained unaltered.
mesh_terms: D000818:Animals; D002952:Citric Acid Cycle / Q000187:drug effects*; D006041:Goats; D006189:Haemonchus / Q000201:enzymology*; D011888:Rafoxanide / Q000494:pharmacology*; D012457:Salicylamides / Q000494:pharmacology*; D013773:Tetramisole / Q000494:pharmacology*; D014251:Trichostrongyloidea / Q000201:enzymology*
chemical_list: D012457:Salicylamides; D011888:Rafoxanide; D013773:Tetramisole