title: 3-Nitropropionic acid toxicity in cultured murine embryonal carcinoma cells.
abstract: The morphologic and histochemical effects of 3-nitropropionic acid (NPA) were examined in cultured murine embryonal carcinoma cells. NPA caused a dose-dependent inhibition of cell proliferation of cultured murine embryonal carcinoma cells at concentrations above 1.05 mM and was lethal at 4.2 mM. Morphologic changes included gross swelling of the cells, swelling of mitochondria and accumulation of organellar debris within the cytoplasm. NPA inhibited the activity of succinate dehydrogenase but not of malate, isocitrate or glucose-6-phosphate dehydrogenases, resulting in a decrease in intracellular ATP. Although succinate dehydrogenase activity was decreased by NPA, propionic acid and its mercapto-, 2-chloro-, and 3-chloro- derivates did not affect enzyme activity. 3-Nitropropanol also inhibited succinate dehydrogenase but only at a much higher concentration than was required with NPA. The results provide evidence that cytotoxicity caused by NPA results from inhibition of succinate dehydrogenase activity leading to depression of ATP synthesis. Loss of cellular integrity is probably a direct consequence of failure of energy-dependent cell homeostatic mechanisms such as the plasma membrane Na+/K+ pump, resulting in swelling and ultimately lysis of the cell.
authors.affiliation: Department of Physiology and Pharmacology, University of Queensland, St. Lucia, Australia.
authors.forename: M A
authors.initials: MA
authors.lastname: Pass
authors.forename: C H
authors.initials: CH
authors.lastname: Carlisle
authors.forename: K R
authors.initials: KR
authors.lastname: Reuhl
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D018236:Carcinoma, Embryonal / Q000473:pathology; D002455:Cell Division / Q000187:drug effects; D003593:Cytoplasm / Q000187:drug effects / Q000473:pathology / Q000648:ultrastructure; D004305:Dose-Response Relationship, Drug; D006651:Histocytochemistry; D006706:Homeostasis; D051379:Mice; D008854:Microscopy, Electron; D008933:Mitochondrial Swelling / Q000187:drug effects; D009498:Neurotoxins / Q000633:toxicity*; D009574:Nitro Compounds; D010936:Plant Extracts / Q000633:toxicity; D011422:Propionates / Q000737:chemistry / Q000633:toxicity*; D000254:Sodium-Potassium-Exchanging ATPase / Q000187:drug effects; D013385:Succinate Dehydrogenase / Q000037:antagonists & inhibitors; D014407:Tumor Cells, Cultured
chemical_list: D009498:Neurotoxins; D009574:Nitro Compounds; D010936:Plant Extracts; D011422:Propionates; D000255:Adenosine Triphosphate; D013385:Succinate Dehydrogenase; D000254:Sodium-Potassium-Exchanging ATPase; C029658:propionic acid; C015392:3-nitropropionic acid