Withdrawal of magnesium causes vasospasm while elevated magnesium produces relaxation of tone in cerebral arteries

Hydrogen peroxide induces contraction and raises [Ca2+]i in canine cerebral arterial smooth muscle: participation of cellular signaling pathways

“…Rings of canine basilar arteries were obtained from male mongrel dogs (18-22 kg), after pentobarbital sodium anesthesia (40 mg/kg i.v. ), and placed in normal Krebs-Ringer bicarbonate solution at pH 7.4 containing (in mM): NaCl 118, KCl 4.7, KH 2 PO 4 1.2, MgSO 4 1.2, CaCl 2 2.5, dextrose 10 and NaHCO 3 25 (Altura and Altura 1980;Zhang et al 1993). In some preparations, the endothelium was removed by gently rubbing against the teeth of a pair of forceps (Zhang et al 1992a).…”

Activation of the Na + -H + Exchanger Modulates Angiotensin II–Stimulated Na + -Dependent Mg 2+ Transport in Vascular Smooth Muscle Cells in Genetic Hypertension

“…Magnesium acts intracellularly as a Ca 2ϩ antagonist [7][8][9] or extracellularly by inhibiting transmembrane Ca 2ϩ transport and Ca 2ϩ entry, by decreasing contractile actions of vasoactive agents, and by enhancing relaxant effects of vasodilators. 5,10,11 For Mg 2ϩ to significantly modulate intracellular events, Mg 2ϩ itself must be regulated within the cell. Despite the fact that Mg 2ϩ is the most abundant cytosolic divalent cation, 12 19 A similar mechanism has been demonstrated in many cell types, including vascular smooth muscle cells (VSMCs).…”

Insights into the Possible Mechanisms By Which Platelet-Activating Factor and PAF-receptors Function in Vascular Smooth Muscle in Magnesium Deficiency and Vascular Remodeling: Possible Links to Atherogenesis, Hypertension and Cardiac Failure

“…Ceramide is now thought to play important roles in fundamental pathophysiologic processes such as cell proliferation, membrane-receptor functions, angiogenesis, atherogenesis, immune inflammatory responses, cell adhesion, programmed cell death (i.e., apoptosis), and senescence among other functions [18,[25][26][27][28][29][30][31][33][34][35][36][37][38][39]. It should be recalled, here, that MgD environments, both in vivo and in vitro, have repeatedly been shown to produce arterial and arteriolar contraction, vasospasm and vascular remodeling [18,20,22,[40][41][42][43][44][45][46][47][48][49][50][51]], which we have demonstrated to involve ceramide (and other sphingolipids), PAF, cellular entry and intracellular release of free Ca 2+ , and activation of PKC isozymes, mitogen-activated protein kinases (MAPKs), MAPK kinases, tyrosine protein kinases, P-I-3 kinases, and PAF among other cellular signaling molecules [18,24,33,[40][41][42][43][44][45][46][47][48]…”