Le Bouëdec G, Begon E, Monteillard C, Gioanni G, Pignide L, Bruhat M A
Polyclinique Gynécologie-Obstétrique, C.H.R.U. Clermont-Ferrand I, Université Clermont-Ferrand I.
J Gynecol Obstet Biol Reprod (Paris). 1989;18(1):53-60.
The magnesium ion, which is a bivalent cation and is necessary for life, is a co-factor in more than 300 enzyme reactions. It has an action on uterine myometrium causing it to relax by stimulating B2 adrenergic receptors and cyclical AMP. It competes with the calcium ion which brings about inhibition of myosine kinase, and therefore a drop in phosphorylated myosine. Deficiency of magnesium is one explanation for uterine overactivity; because it is difficult to estimate how important it is in certain premature labours because this is caused often by many factors, and the levels of plasma magnesium and of blood cell magnesium give poor information about the magnesium pool. The tocolytic properties of magnesium are interesting. One has to distinguish between oral magnesium-therapy, given as a preventive from the first trimester of pregnancy, and parenteral magnesium therapy which can be curative and which, like beta-mimetics, is indicated in threatened premature delivery.
镁离子是一种二价阳离子，是生命所必需的，它是300多种酶反应的辅助因子。它作用于子宫肌层，通过刺激β2肾上腺素能受体和环磷酸腺苷使其松弛。它与钙离子竞争，从而抑制肌球蛋白激酶，进而导致磷酸化肌球蛋白水平下降。镁缺乏是子宫活动过度的一个原因；由于在某些早产中难以估计其重要性，因为早产往往由多种因素引起，而且血浆镁和血细胞镁水平并不能很好地反映镁储备情况。镁的宫缩抑制特性很有意思。必须区分从妊娠早期开始作为预防措施给予的口服镁治疗，以及可作为治疗手段的胃肠外镁治疗，胃肠外镁治疗与β-拟交感神经药一样，适用于先兆早产。
