Significance of Magnesium

SIGNIFICANCE OF MAGNESIUM

Next to potassium, magnesium is the most abundant intracellular cation. It acts as an activator for many intracellular enzyme sys-tems and plays a role in both carbohydrate and protein metabo-lism. Magnesium balance is important in neuromuscular function. Because magnesium acts directly on the myoneural junction, variations in the serum concentration of magnesium affect neuro-muscular irritability and contractility. For example, an excess of magnesium diminishes the excitability of the muscle cells, whereas a deficit increases neuromuscular irritability and contractility.

Magnesium produces its sedative effect at the neuromuscular junction, probably by inhibiting the release of the neurotrans-mitter acetylcholine. It also increases the stimulus threshold in nerve fibers.

Magnesium exerts effects on the cardiovascular system, acting peripherally to produce vasodilation. Magnesium is thought to have a direct effect on peripheral arteries and arterioles, which re-sults in a decreased total peripheral resistance. Magnesium disor-ders include hypomagnesemia and hypermagnesemia.