McLean A F, Buchan W, Scott D
Br J Nutr. 1984 Nov;52(3):523-7. doi: 10.1079/bjn19840120.
The effects of magnesium supplementation on Mg absorption proximal and distal to the pylorus in ewes maintained on a grass diet were investigated using a combination of balance, digesta flow and electropotential measurements. Three mature ewes each received by intrarumenal infusion a supplement of 0, 1, 2 and 3 g Mg/d in sequence over four 10-d periods. Net Mg absorption distal to the pylorus took place down its electrochemical gradient, although the quantity absorbed remained small during the control and first infusion periods. The bulk of Mg absorption occurred before the pylorus and, during the control and first infusion periods, took place against its electrochemical gradient. The net Mg absorption proximal to the pylorus rose with declining efficiency as Mg intake was increased. It is suggested that saturation of the absorption process at this site was occurring.
采用平衡法、消化物流动法和电势测量法相结合的方式，研究了在以草为食的母羊中，补充镁对幽门近端和远端镁吸收的影响。三只成年母羊在四个为期10天的时间段内，依次通过瘤胃内输注分别给予0、1、2和3克/天的镁补充剂。尽管在对照期和首次输注期吸收的镁量仍然很少，但镁在幽门远端是顺着其电化学梯度进行净吸收的。大部分镁的吸收发生在幽门之前，并且在对照期和首次输注期，镁是逆着其电化学梯度进行吸收的。随着镁摄入量的增加，幽门近端的镁净吸收量增加，但效率下降。这表明该部位的吸收过程正在发生饱和。
