Sjögren A, Edvinsson L, Ottosson A
Department of Internal Medicine, University Hospital, Lund, Sweden.
J Am Coll Nutr. 1988 Dec;7(6):461-9. doi: 10.1080/07315724.1988.10720262.
Wistar rats were fed a low magnesium diet for 8 or 12 weeks, resulting in reduced levels of magnesium in plasma, heart, and skeletal muscle, as compared with pair-fed control rats. The magnesium-deficient rats also had reduced tissue levels of potassium. Coronary arteries and thoracic aorta from magnesium-deficient rats and control rats were incubated in tissue baths and the contractile responses to potassium, 5-hydroxy-tryptamine, and prostaglandin F2 alpha were investigated using a sensitive in vitro system. The concentration-contraction curve, for all agents was shifted to the left in coronary arteries from magnesium-deficient rats. In aorta from magnesium-deficient rats, the pattern of change in reactivity to these agonists was not uniform: the concentration-contraction curve for 5-hydroxytryptamine was shifted to the left, the contractile response to prostaglandin F2 alpha was reduced, while there was no change in the response to potassium. The contractile response to the administration of calcium to calcium-depleted, potassium-depolarized vessels from magnesium-deficient rats was enhanced; the effect was more pronounced in coronary arteries as compared to the aorta. Hence, the vasomotor reactivity of coronary arteries appears to be more sensitive than is the aorta during magnesium-deficient conditions.
将Wistar大鼠喂食低镁饮食8周或12周，与配对喂养的对照大鼠相比，血浆、心脏和骨骼肌中的镁水平降低。缺镁大鼠的组织钾水平也降低。将缺镁大鼠和对照大鼠的冠状动脉和胸主动脉置于组织浴中，使用灵敏的体外系统研究对钾、5-羟色胺和前列腺素F2α的收缩反应。缺镁大鼠冠状动脉中所有药物的浓度-收缩曲线均向左移动。在缺镁大鼠的主动脉中，对这些激动剂反应性的变化模式并不一致：5-羟色胺的浓度-收缩曲线向左移动，对前列腺素F2α的收缩反应降低，而对钾的反应没有变化。向缺镁大鼠的钙耗竭、钾去极化血管中施用钙后的收缩反应增强；与主动脉相比，冠状动脉中的这种效应更明显。因此，在缺镁条件下，冠状动脉的血管运动反应性似乎比主动脉更敏感。
