title: Effects of ethidium and isometamidium on adenosine triphosphate catabolism and purine nucleotide synthesis in Ehrlich ascites tumor cells in vitro.
abstract: Ethidium and isometamidium induce the breakdown of intracellular adenosine triphosphate in Ehrlich ascites tumor cells incubated in vitro. Ethidium induces appreciable adenosine triphosphate breakdown only when cells are incubated without glucose, whereas isometamidium produces this effect both in the presence and absence of glucose. In cells treated with isometamidium, purine nucleoside monophosphates accumulate, whereas these are mostly dephosphorylated when ethidium is used. Both ethidium and isometamidium inhibit purine nucleotide synthesis and incorporation of precursors into nucleic acids, although the magnitudes of these effects varied with the precursor used. Isometamidium inhibited the conversion of inosinate to adenine and guanine nucleotides, and both compounds partially inhibited the accumulation of phosphoribosyl pyrophosphate.
mesh_terms: D000225:Adenine / Q000378:metabolism; D000255:Adenosine Triphosphate / Q000378:metabolism*; D000818:Animals; D001550:Benzamidines / Q000494:pharmacology; D002286:Carcinoma, Ehrlich Tumor / Q000378:metabolism*; D004273:DNA, Neoplasm / Q000096:biosynthesis; D004996:Ethidium / Q000494:pharmacology*; D005947:Glucose / Q000378:metabolism; D005998:Glycine / Q000378:metabolism; D006019:Glycolysis; D007042:Hypoxanthines / Q000378:metabolism; D009363:Neoplasm Proteins / Q000096:biosynthesis; D009694:Nucleic Acid Precursors / Q000378:metabolism; D010085:Oxidative Phosphorylation; D010101:Oxygen Consumption; D010617:Phenanthridines / Q000494:pharmacology*; D010754:Phosphoribosyl Pyrophosphate / Q000378:metabolism; D011685:Purine Nucleotides / Q000096:biosynthesis*; D012334:RNA, Neoplasm / Q000096:biosynthesis
chemical_list: D001550:Benzamidines; D004273:DNA, Neoplasm; D007042:Hypoxanthines; D009363:Neoplasm Proteins; D009694:Nucleic Acid Precursors; D010617:Phenanthridines; D011685:Purine Nucleotides; D012334:RNA, Neoplasm; D010754:Phosphoribosyl Pyrophosphate; C000702:isometamidium chloride; D000255:Adenosine Triphosphate; D004996:Ethidium; D005947:Glucose; D000225:Adenine; D005998:Glycine