title: In vitro inhibition of calcium binding by alloxan and of calcium transport by isolated vascular smooth muscle microsomes.
abstract: The primary purpose of this study was to investigate the possible direct toxic effect of alloxan on the Ca2+ handling by microsomal membranes isolated from rat mesenteric arteries. It was found that preincubation of the vascular muscle microsomal membranes with alloxan had a suppressive effect on both binding of Ca2+ (in the absence of ATP) and ATP-supported Ca2+ transport. Such an inhibition was time, dose, pH, and temperature dependent. ATP-supported Ca2+ transport was more susceptible to the inhibitory action of alloxan than Ca2+ binding. Unlike alloxan, another commonly used diabetogenic drug, streptozotocin, was not effective in causing such an in vitro inhibition of Ca2+ handling.
authors.affiliation: Department of Neurosciences, McMaster University Health Sciences, Hamilton, Ont., Canada.
authors.forename: C Y
authors.initials: CY
authors.lastname: Kwan
authors.forename: J S
authors.initials: JS
authors.lastname: Beazley
mesh_terms: D000496:Alloxan / Q000494:pharmacology*; D000818:Animals; D002118:Calcium / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D066298:In Vitro Techniques; D008297:Male; D008861:Microsomes / Q000187:drug effects / Q000378:metabolism*; D009131:Muscle, Smooth, Vascular / Q000187:drug effects / Q000378:metabolism* / Q000648:ultrastructure; D051381:Rats; D011919:Rats, Inbred Strains
chemical_list: D000496:Alloxan; D002118:Calcium