BACKGROUND/
AIMS: Magnesium (Mg) is an essential
element for vascular function and
blood pressure regulation . Several studies have demonstrated that Mg concentration is inversely associated with
blood pressure , and that Mg supplementation attenuates
hypertension . The purpose of this study was to evaluate the effect of dietary Mg supplementation on the
blood pressure effects of an
angiotensin II receptor blocker (ARB) in hypomagnesemic
rats .
METHODS: Fifty
male Sprague-Dawley rats were randomly divided into Mg-deficient (n = 30), normal
diet plus Mg (n = 10), and
control groups (n = 10). Mg-free, high-Mg, and normal-Mg
diets were respectively fed to the
rats . After 14 weeks, 10 of the 30 Mg-deficient
rats were treated with Mg, 10 Mg-deficient
rats received an ARB, and 10 Mg-deficient
rats received an ARB plus Mg for 4 weeks.
RESULTS: Systolic
blood pressure was significantly higher in the Mg-deficient
rats than in the control
rats at week 14. Hypomagnesemic
rats exhibited decreased systolic
blood pressure after treatment with Mg, and systolic
blood pressure showed a greater decrease after ARB
treatment .
Treatment with the ARB/Mg combination resulted in the greatest decrease in systolic
blood pressure . Mg
deficiency did not
affect the
serum angiotensin II level, but did increase the
serum aldosterone concentration. Concomitant Mg/ARB supplementation significantly decreased the elevated
serum aldosterone level in hypomagnesemic
rats .
Kidney tissues of the hypomagnesemic
rats revealed mild to moderate inflammatory infiltrates. Mg and/or ARB
treatment did not reverse the inflammatory reaction in the
kidneys of hypomagnesemic
rats .
CONCLUSIONS: Concurrent dietary Mg supplementation can enhance ARB-induced
blood pressure reduction in
rats with hypomagnesemic
hypertension .