The plasma-membrane component is the primary site of action of alloxan on ATP-driven Ca2+ transport in vascular-muscle microsomal fractions.
The direct effects of alloxan in vitro on the handling of Ca2+ by microsomal fractions from dog aortic smooth muscle were investigated. Preincubation of the vascular-muscle microsomal membranes with alloxan showed a suppression of both binding of Ca2+ (in the absence of ATP) and ATP-driven Ca2+ transport. Alloxan substantially inhibited the microsomal ATP-driven Ca2+ transport stimulated by Pi, but not that stimulated by oxalate. Studies using subfractions isolated from the microsomal membranes on a sucrose density gradient indicated that plasma membrane is the primary site of action of alloxan on the ATP-driven Ca2+ transport.
Kwan
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Department of Biomedical Sciences, McMaster University, Hamilton, Ontario, Canada.
D000255:Adenosine Triphosphate / Q000494:pharmacology*; D000496:Alloxan / Q000494:pharmacology*; D000818:Animals; D001692:Biological Transport / Q000187:drug effects; D002118:Calcium / Q000378:metabolism*; D004285:Dogs; D007425:Intracellular Membranes / Q000187:drug effects / Q000378:metabolism; D008861:Microsomes / Q000187:drug effects / Q000378:metabolism; D009131:Muscle, Smooth, Vascular / Q000187:drug effects / Q000378:metabolism*; D010070:Oxalates / Q000494:pharmacology; D019815:Oxalic Acid; D010710:Phosphates / Q000494:pharmacology
D010070:Oxalates; D010710:Phosphates; D000496:Alloxan; D000255:Adenosine Triphosphate; D019815:Oxalic Acid; D002118:Calcium