The effects of trimethyltin on the Ca+2, Mg+2 and Ca+2 + Mg+2-dependent ATPases of human neuroblastoma GM 3320.
Data presented here indicate neuroblastoma GM 3320 tissue homogenates exhibit ouabain insensitive Ca+2-dependent, Mg+2-independent, Mg+2-dependent, Ca+2-independent and Ca+2 + Mg+2-dependent ATPase activities. Inclusion of trimethyltin in homogenate preparations of these cells appears to discriminate between these various ATPase activities. At low concentrations (25 microM), trimethyltin preferentially stimulated the Ca+2-dependent, Mg+2-independent ATPase activity while inhibiting the Ca+2 + Mg+2-ATPase activity approximately 70%. At 75 microM trimethyltin, the Ca+2 + Mg+2-dependent ATPase activity is inhibited greater than 95% while the Ca+2-dependent, Mg+2-independent activity is essentially unchanged from control activity and the Mg+2-dependent, Ca+2-independent activity is inhibited approximately 50%. At concentrations greater than 75 microM, trimethyltin significantly inhibits the Ca+2-dependent, Mg+2-independent ATPase activity. Thus, at trimethyltin concentrations of 50-75 microM, preferential inhibition of the Mg+2-dependent, Ca+2-independent and Ca+2 + Mg+2-dependent ATPase activities of neuroblastoma GM 3320 is achieved.
D000251:Adenosine Triphosphatases / Q000378:metabolism*; D017301:Ca(2+) Mg(2+)-ATPase / Q000378:metabolism; D000252:Calcium-Transporting ATPases / Q000378:metabolism; D002460:Cell Line; D006801:Humans; D009447:Neuroblastoma / Q000201:enzymology*; D014220:Trialkyltin Compounds / Q000494:pharmacology*; D014298:Trimethyltin Compounds / Q000494:pharmacology*
D014220:Trialkyltin Compounds; D014298:Trimethyltin Compounds; C046488:trimethyltin; D000251:Adenosine Triphosphatases; D017301:Ca(2+) Mg(2+)-ATPase; D000252:Calcium-Transporting ATPases