title: Intracellular free-magnesium levels in vascular smooth muscle and striated muscle cells of the spontaneously hypertensive rat.
abstract: In humans with essential hypertension and in spontaneously hypertensive rats (SHR), insulin resistance may be present even in lean individuals. As the basis for this abnormality is unknown, we have used a newly developed fluorophore to measure intracellular free-Mg2+ concentrations in cultured aortic vascular smooth muscle cells and striated muscle cells from SHR and normotensive Wistar Kyoto (WKY) rats. Intracellular free-Mg2+ levels were lower in both striated muscle cells (SHR, 0.423 +/- 0.077 mmol.L-1 v WKY, 0.559 +/- 0.068 mmol.L-1; P less than .001) and vascular smooth muscle cells (SHR, 0.406 +/- 0.067 mmol.L-1 v WKY, 0.625 +/- 0.077 mmol.L-1; P less than .001) from hypertensive animals. This widespread, intrinsic defect in the regulation of intracellular Mg2+ may explain the increased vascular resistance and reduced insulin sensitivity present in hypertension.
authors.affiliation: Department of Pharmacology, Leicester Royal Infirmary, UK.
authors.forename: L L
authors.initials: LL
authors.lastname: Ng
authors.forename: J E
authors.initials: JE
authors.lastname: Davies
authors.forename: M
authors.initials: M
authors.lastname: Ameen
mesh_terms: D000818:Animals; D002118:Calcium / Q000032:analysis; D006863:Hydrogen-Ion Concentration; D006973:Hypertension / Q000378:metabolism*; D008274:Magnesium / Q000032:analysis*; D009131:Muscle, Smooth, Vascular / Q000737:chemistry*; D009132:Muscles / Q000737:chemistry*; D051381:Rats; D011918:Rats, Inbred SHR; D011921:Rats, Inbred WKY
chemical_list: D008274:Magnesium; D002118:Calcium