title: Ca-dependent ADPase--the possible regulator of calcium channel during the deficiency of ATP.
abstract: Activation of the low affinity Ca-ATPase and Ca-ADPase by increasing concentrations of their cationic cofactor calcium (0.1-8.0 mmol.l-1) or by increasing concentration of substrates ATP or ADP (0.1-8.0 mmol.l-1) was influenced on similar mode by sodium azide. Kinetic analysis of the NaN3 induced inhibition, revealed that both enzyme activities are probably secured by the same system which is capable to hydrolyze ADP during the absence of ATP. A possible role for Ca-ADPase in controlling the calcium channel during ATP deficiency is discussed.
mesh_terms: D000244:Adenosine Diphosphate / Q000378:metabolism; D000255:Adenosine Triphosphate / Q000172:deficiency / Q000378:metabolism*; D000818:Animals; D001081:Apyrase / Q000037:antagonists & inhibitors / Q000378:metabolism*; D001386:Azides / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism*; D000252:Calcium-Transporting ATPases / Q000037:antagonists & inhibitors / Q000378:metabolism; D066298:In Vitro Techniques; D007473:Ion Channels / Q000378:metabolism*; D007700:Kinetics; D008297:Male; D009206:Myocardium / Q000378:metabolism; D010744:Phosphoric Monoester Hydrolases / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D012508:Sarcolemma / Q000378:metabolism; D019810:Sodium Azide
chemical_list: D001386:Azides; D007473:Ion Channels; D000244:Adenosine Diphosphate; D000255:Adenosine Triphosphate; D019810:Sodium Azide; D010744:Phosphoric Monoester Hydrolases; D001081:Apyrase; D000252:Calcium-Transporting ATPases; D002118:Calcium