title: Effects of magnesium on the action of vasodilatory agents.
abstract: Studies have shown that alterations of the magnesium (Mg2+) concentration can alter the response of certain vasoactive compounds. Responses of rabbit thoracic aorta to verapamil, diltiazem, nitroglycerin and isoproterenol were examined in zero Mg2+ (0.0 M), N Mg2+ (1.2 mM), 2 N Mg2+ (2.4 mM) and 4 N Mg2+ (4.8 mM). Preconstriction was induced with norepinephrine and cumulative dose-response curves were obtained for the vasodilators. The dose-response curve for isoproterenol was shifted to the right in zero Mg2+ while there was no effect on the other vasodilators. Elevation of the Mg2+ concentration to 4.8 mM produced a shift to the left in the dose-response curves for diltiazem, nitroglycerin and isoproterenol with no effect on verapamil. Therefore, Mg2+ deficiency does not appear to affect the vasodilatory actions of the agents tested except for the beta-receptor agonist, isoproterenol. Elevated Mg2+, however, potentiated the actions of isoproterenol, nitroglycerin and diltiazem, but not verapamil.
mesh_terms: D000818:Animals; D001013:Aorta, Thoracic / Q000187:drug effects; D004110:Diltiazem / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D004347:Drug Interactions; D007545:Isoproterenol / Q000494:pharmacology; D008274:Magnesium / Q000494:pharmacology*; D005996:Nitroglycerin / Q000494:pharmacology; D011817:Rabbits; D014664:Vasodilation / Q000187:drug effects; D014665:Vasodilator Agents / Q000494:pharmacology*; D014700:Verapamil / Q000494:pharmacology
chemical_list: D014665:Vasodilator Agents; D014700:Verapamil; D004110:Diltiazem; D005996:Nitroglycerin; D008274:Magnesium; D007545:Isoproterenol