Mg2+ modulates the binding of [3H]glibenclamide to its receptor in rat cerebral cortical membranes.
Radioligand binding studies were performed to determine the effect of various cations on the characteristics of [3H]glibenclamide binding to its high-affinity receptor in rat cerebral cortex membranes. Mg2+ was shown specifically to reduce radioligand binding to membranes pretreated with 5 mM EDTA. CaCl2 enhanced [3H]glibenclamide binding whilst MnCl2, KCl and NaCl were without significant effect. 2 mM MgCl2 induced a statistically significant rightward shift in the dissociation constant for glibenclamide obtained from both saturation and competition studies. These results suggest that Mg2+ may participate in the regulation of the sulphonylurea receptor in the rat cerebral cortex.
Lee
K
K
Department of Pharmacology, University of Cambridge, UK.
Ashford
M L
ML
D000818:Animals; D002413:Cations, Divalent / Q000494:pharmacology; D002462:Cell Membrane / Q000187:drug effects / Q000378:metabolism; D002540:Cerebral Cortex / Q000187:drug effects / Q000378:metabolism*; D005905:Glyburide / Q000493:pharmacokinetics*; D066298:In Vitro Techniques; D008274:Magnesium / Q000494:pharmacology*; D015221:Potassium Channels / Q000187:drug effects* / Q000378:metabolism; D011869:Radioligand Assay; D051381:Rats; D011955:Receptors, Drug / Q000187:drug effects* / Q000378:metabolism
D002413:Cations, Divalent; D015221:Potassium Channels; D011955:Receptors, Drug; C067662:glibenclamide receptor; D008274:Magnesium; D005905:Glyburide