In vivo and in vitro magnesium effects on aortic prostacyclin generation in DOCA-salt hypertensive rats

Abstract

To investigate the blood pressure lowering effect of magnesium (Mg 2+) in the hypertensive rat, we measured the prostacyclin release (PGI 2, as immunoreactive 6-keto-PGF 1α) by isolated aortae from normotensive and deoxycorticosterone acetate (DOCA)-salt hypertensive rats fed a control or Mg 2+-enriched diet. We also studied the in vitro effect of Mg 2+ on aortic PGI 2 release. The Mg 2+-enriched diet significantly decreased by 10% blood pressure in DOCA-salt hypertensive rats but not in normotensive rats. The Mg 2+-enriched diet significantly increased by 122 % aortic PGI 2 release in DOCA-salt hypertensive rats, but not in normotensive rats. Mg 2+ supplementation in the incubation medium (4.8 mM) significantly increased aortic PGI 2 release by 94 % in DOCA-salt hypertensive rats, but not in normotensive rats. These data suggest that the Mg 2+-induced attenuation of blood pressure in DOCA-salt hypertensive rats could be linked with the enhanced vascular PGI 2 release.