Magnesium ion (Mg2 +) is one of the important ions to maintain the stress of nerve, muscle, and heart. Magnesium ions can inhibit the central nervous system, and a high concentration of magnesium ions can cause central respiratory paralysis. Magnesium ion can inhibit the release of acetylcholine from the muscular junction of the nervous system and prevent impulse conduction at the muscular junction of the nervous system, which has a sedative effect. Magnesium can inhibit the stress of the myocardium, and high blood magnesium can make the heart stop beating in diastole, which can be antagonized by Ca2 +. Magnesium ions can act on the peripheral vascular system to dilate blood vessels and reduce blood pressure. Slow absorption of magnesium ions in the intestine * can cause a large amount of water to stay in the intestinal cavity, so magnesium salt has a catharsis effect.
Magnesium ion is the activator of a variety of enzymes, such as phosphatase, phosphorylase, cholinesterase, enolase, carboxylase, kinase, DNA polymerase, RNA polymerase, ATPase, and so on. Therefore, a magnesium ion is widely involved in material and energy metabolism and various physiological activities and is the most widely involved metal ion in human life activities.
The content of magnesium in the adult body is about 20-30g, 50% – 60% of which is distributed in bones and teeth to form magnesium phosphate; 20% is distributed in muscle tissue, the rest is distributed in intracellular fluid, the concentration of magnesium ion in the extracellular fluid is very low, and serum magnesium concentration is 0.7-1.1mmol/l. There are three kinds of magnesium in plasma: free magnesium ion accounts for 50% – 60%, protein-bound magnesium accounts for 20% – 30% (non diffusion magnesium), magnesium bicarbonate, magnesium hydrogen phosphate, and magnesium organic acid account for 15%. 6 mmol / L, which is about 3 times of that in plasma. Adults need 0.15-0.18 mmol/kg of magnesium per day. Magnesium in food is mainly absorbed in the small intestine, with an absorption rate of about 30%. The factors affecting magnesium absorption are similar to those affecting calcium absorption.
Magnesium is mainly excreted through the kidney. The glomerular filtration volume is about 3.5 g per day. More than 99% of magnesium is reabsorbed by renal tubules, and the excretion amount is only 0.1-0.15 g per day. When the body is short of magnesium, the renal magnesium excretion can be reduced to 0.01-0.012 g / day. When the body magnesium increases, the high concentration of serum Mg + can inhibit the reabsorption of magnesium ions by renal tubules, and the renal excretion of magnesium can be increased to 0.5-0.6 g / day.
To sum up, magnesium is one of the indispensable elements in the human body. Key health, start with magnesium.
