title: Role of dietary magnesium deficiency in the pressor and arrhythmogenic response to epinephrine in the intact dog.
abstract: The effect of dietary magnesium deficiency on the pressor and arrhythmogenic responses to epinephrine was investigated in 19 dogs maintained either on a normal diet (11 dogs) or a diet deficient in magnesium (8 dogs). Magnesium-deficient dogs had significantly lower serum magnesium levels than the control dogs on a normal diet. Magnesium-deficient dogs showed an increased pressor sensitivity to epinephrine as determined by the dose of epinephrine required to cause a maximal pressor response (3.4 micrograms/kg/min compared to 13.4 micrograms/kg/min, p < 0.05). Magnesium-deficient dogs also had a significantly lower threshold dose for ventricular premature beats (0.8 microgram/kg/min compared to 2.7 micrograms/kg/min, p < 0.05). Acute administration of magnesium sulfate restored pressor sensitivity and ventricular premature beat threshold to normal levels in the magnesium-deficient dogs. Threshold dose for ventricular tachycardia beat was similar in both normal and magnesium-deficient dogs, and threshold was raised significantly in both groups by acute administration of magnesium.
authors.affiliation: Division of Cardiology, George Washington University Medical Center, Washington, DC 20037.
authors.forename: B L
authors.initials: BL
authors.lastname: Bean
authors.forename: P J
authors.initials: PJ
authors.lastname: Varghese
mesh_terms: D000818:Animals; D001794:Blood Pressure / Q000187:drug effects*; D005117:Cardiac Complexes, Premature / Q000139:chemically induced / Q000209:etiology* / Q000517:prevention & control; D004285:Dogs; D004305:Dose-Response Relationship, Drug; D004837:Epinephrine / Q000494:pharmacology*; D008275:Magnesium Deficiency / Q000150:complications* / Q000503:physiopathology; D008278:Magnesium Sulfate / Q000627:therapeutic use; D017180:Tachycardia, Ventricular / Q000139:chemically induced / Q000209:etiology* / Q000517:prevention & control
chemical_list: D008278:Magnesium Sulfate; D004837:Epinephrine