DiPette D J, Simpson K, Rogers A, Holland O B
Department of Medicine, University of Texas Medical Branch, Galveston 77550.
J Hypertens. 1988 May;6(5):413-7.
Recent interest has centred on the role of divalent cations in hypertension, particularly in relation to the renin-angiotensin system. This study was undertaken to determine the hypotensive effect of magnesium administration in relation to the state of activation of the renin-angiotensin system. The mean blood pressure (MBP) and heart rate (HR) response to either the acute intravenous administration of a pharmacological dose of MgSO4 or vehicle was determined in conscious mineralocorticoid-salt (DOCA-salt, low-renin) and two-kidney, one clip renovascular, high-renin hypertensive rats. Baseline MBP was higher in the renovascular than in the DOCA-salt rats, while there was no difference in HR or serum Mg concentration between the two. Following administration of MgSO4, serum Mg increased equally in both the DOCA-salt (1.4 +/- 0.8 to 4.9 +/- 0.16 mEq/l; P less than 0.001) and in the renovascular rats (1.8 +/- 0.14 to 4.4 +/- 0.27 mEq/l; P less than 0.001). Magnesium administration significantly lowered MBP over the 1-h infusion in the DOCA-salt (167 +/- 8 to 145 +/- 5 mmHg, P less than 0.001) but not the renovascular hypertensive rats (191 +/- 5 to 183 +/- 4, NS). We conclude that the blood pressure lowering effect of Mg is related, in part, to the state of activation of the renin-angiotensin system. The mechanism of this differential effect remains to be determined.
最近，人们的兴趣集中在二价阳离子在高血压中的作用，特别是与肾素-血管紧张素系统的关系。本研究旨在确定镁给药对肾素-血管紧张素系统激活状态的降压作用。在清醒的盐皮质激素-盐（去氧皮质酮-盐，低肾素）和两肾一夹肾血管性、高肾素性高血压大鼠中，测定了对药理剂量的硫酸镁或赋形剂急性静脉给药的平均血压（MBP）和心率（HR）反应。肾血管性大鼠的基线MBP高于去氧皮质酮-盐大鼠，而两者的HR或血清镁浓度无差异。给予硫酸镁后，去氧皮质酮-盐大鼠（1.4±0.8至4.9±0.16 mEq/l；P<0.001）和肾血管性大鼠（1.8±0.14至4.4±0.27 mEq/l；P<0.001）的血清镁均同样升高。在1小时输注期间，硫酸镁给药使去氧皮质酮-盐大鼠的MBP显著降低（167±8至145±5 mmHg，P<0.001），但对肾血管性高血压大鼠无此作用（191±5至183±4，无显著性差异）。我们得出结论，镁的降压作用部分与肾素-血管紧张素系统的激活状态有关。这种差异效应的机制尚待确定。
