Regulation of cation channels in cardiac and smooth muscle cells by intracellular magnesium.
Magnesium regulates various ion channels in many tissues, including those of the cardiovascular system. General mechanisms by which intracellular Mg(2+) (Mg(i)(2+)) regulates channels are presented. These involve either a direct interaction with the channel, or an indirect modification of channel function via other proteins, such as enzymes or G proteins, or via membrane surface charges and phospholipids. To provide an insight into the role of Mg(i)(2+) in the cardiovascular system, effects of Mg(i)(2+) on major channels in cardiac and smooth muscle cells and the underlying mechanisms are then reviewed. Although Mg(i)(2+) concentrations are known to be stable, conditions under which they may change exist, such as following stimulation of beta-adrenergic receptors and of insulin receptors, or during pathophysiological conditions such as ischemia, heart failure or hypertension. Modifications of cardiovascular electrical or mechanical function, possibly resulting in arrhythmias or hypertension, may result from such changes of Mg(i)(2+) and their effects on cation channels.
Mubagwa
Kanigula
K
Division of Experimental Cardiac Surgery, Department of Heart and Vessel Diseases, Katholieke Universiteit Leuven, Campus Gasthuisberg, Herestraat 49, B-3000 Leuven, Belgium. kanigula.mubagwa@med.kuleuven.be
Gwanyanya
Asfree
A
Zakharov
Sergey
S
Macianskiene
Regina
R
D000818:Animals; D002412:Cations; D007473:Ion Channels / Q000378:metabolism*; D008274:Magnesium / Q000378:metabolism*; D009130:Muscle, Smooth / Q000166:cytology / Q000378:metabolism*; D009206:Myocardium / Q000166:cytology / Q000378:metabolism*
D002412:Cations; D007473:Ion Channels; D008274:Magnesium