Dua K, Care A D
Institute of Biological Sciences, University College of Wales, Aberystwyth.
Br Vet J. 1995 Jul-Aug;151(4):413-26. doi: 10.1016/s0007-1935(95)80130-8.
Magnesium is absorbed mainly from the reticulo-rumen and there are a number of factors reducing its absorption. The chief of these is the increased potential difference across the rumen epithelium caused by increased intraruminal potassium concentration. A significant amount of magnesium leaves the extracellular fluid each day as saliva. As only a portion of it is reabsorbed the rest is lost through the endogenous faecal excretion of magnesium. Thus, during impaired magnesium absorption, saliva could play an important role in the aetiology of hypomagnesaemia especially during dietary sodium depletion and the resultant increase in the potassium content of the saliva.
镁主要从瘤网胃吸收，有多种因素会降低其吸收。其中主要因素是瘤胃内钾浓度升高导致瘤胃上皮细胞跨膜电位差增大。每天有大量镁随唾液离开细胞外液。由于只有一部分会被重吸收，其余部分则通过内源性粪便镁排泄而流失。因此，在镁吸收受损期间，唾液可能在低镁血症的病因中起重要作用，尤其是在饮食中钠缺乏以及由此导致唾液钾含量增加时。
