title: Effect of fixation on activity and cytochemistry of hydrogenosomal enzymes in Trichomonas vaginalis.
abstract: The effect of fixation on the activity of malate dehydrogenase (decarboxylating) and pyruvate synthase was investigated in Trichomonas vaginalis. Subsequently a cytochemical staining method was developed for the demonstration of malate dehydrogenase activity in hydrogenosomes. After fixation of cells in low concentrations of glutaraldehyde and incubation in the presence of malate and the tetrazolium compound 2-(2'-benzothiazolyl)-5-styryl-3-(4'-phthalhydrazidyl)tetrazolium chloride, an electron-dense deposit was produced in the hydrogenosomes. During the whole procedure strictly anaerobic conditions were required. Attempts to develop an analogous procedure for pyruvate synthase failed because even low concentrations of glutaraldehyde strongly inhibited enzyme activity. When cells were fixed in low concentrations of glycolaldehyde and acetaldehyde, a high enzyme activity was retained, but no staining could be achieved. Application of both staining methods to the sapropelic ciliates Trimyema compressum and Plagiopyla nasuta gave negative results.
authors.affiliation: Department of Microbiology, Faculty of Science, University of Nijmegen, The Netherlands.
authors.forename: N K
authors.initials: NK
authors.lastname: Goosen
authors.forename: C A
authors.initials: CA
authors.lastname: Broers
authors.forename: E J
authors.initials: EJ
authors.lastname: Hombergen
authors.forename: C K
authors.initials: CK
authors.lastname: Stumm
authors.forename: G D
authors.initials: GD
authors.lastname: Vogels
mesh_terms: D000818:Animals; D002923:Cilia / Q000648:ultrastructure; D005404:Fixatives; D005976:Glutaral; D007658:Ketone Oxidoreductases / Q000378:metabolism*; D008291:Malate Dehydrogenase / Q000378:metabolism*; D008830:Microbodies / Q000201:enzymology*; D050743:Pyruvate Synthase; D013194:Staining and Labeling; D013778:Tetrazolium Salts; D014246:Trichomonas vaginalis / Q000187:drug effects / Q000201:enzymology* / Q000648:ultrastructure
chemical_list: D005404:Fixatives; D013778:Tetrazolium Salts; D008291:Malate Dehydrogenase; D007658:Ketone Oxidoreductases; D050743:Pyruvate Synthase; D005976:Glutaral