title: Ecto-ATPase activity in rat and mouse thymocytes and cytotoxic effects of various chemical substances in vitro.
abstract: Ecto-ATPase was present in thymocytes of mice and rats with higher activity in rat thymocytes. In rat but not in mouse thymocytes the ecto-ATPase was inhibited in vitro by HgCl2, tricyclohexyltin chloride, di-n-butyltin dichloride, DDT, gamma HCH and desipramine. The EC50 values ranged from 8 X 10(-7) mol/l for HgCl2 to 4 X 10(-4) mol/l for desipramine. Ecto-ATPase activity in thymocytes was not a valuable indicator of the cytotoxic effects of chemicals in vitro. Inhibition of the enzyme was not accompanied by changes of the electrophoretic mobility of thymocytes. A decrease of the spontaneous mitotic activity of thymocytes in vitro is a very sensitive parameter of cytotoxic and cytostatic drug effects.
mesh_terms: D000251:Adenosine Triphosphatases / Q000032:analysis* / Q000037:antagonists & inhibitors; D000818:Animals; D002455:Cell Division / Q000187:drug effects; D005260:Female; D008214:Lymphocytes / Q000187:drug effects / Q000201:enzymology*; D008297:Male; D008565:Membrane Proteins / Q000032:analysis* / Q000037:antagonists & inhibitors; D051379:Mice; D008815:Mice, Inbred Strains; D051381:Rats; D011919:Rats, Inbred Strains; D013045:Species Specificity; D013950:Thymus Gland / Q000166:cytology / Q000201:enzymology*
chemical_list: D008565:Membrane Proteins; D000251:Adenosine Triphosphatases