EFFECTS OF DIETARY MAGNESIUM ON BLOOD-PRESSURE AND VASCULAR-LESIONS IN HYPERTENSIVE RATS

The present study examines the effects of dietary magnesium on the dev elopment of hypertension and hypertensive vascular lesions in deoxycor ticosterone acetate and salt induced (DOCA-salt) and 2 kidney one clip (2K1C) hypertensive as well as normotensive control rats. Animals rec eived a regular (0.12% Mg), high (0.4% Mg) or low (0.03% Mg) magnesium diet for 6 wks. Dietary magnesium did not after the growth or blood p ressure in control, DOCA-salt and 2K1C rats even though the plasma mag nesium concentration was significantly altered by the diets (ANOVA, p< 0.05 in control, DOCA-salt and 2K1C, respectively). Dietary magnesium did not alter the urinary potassium excretion, plasma sodium, potassiu m, total calcium concentration and plasma renin activity in any group, while the high magnesium diet significantly increased the urinary sod ium excretion in DOCA-salt (p<0.05) but not in control and 2K1C rats w hen compared with the regular magnesium diet. In histological studies, dietary magnesium did not alter the percentage media area of intramyo cardial arteries, or glomerular and renal arterial and arteriolar lesi ons in DOCA-salt and 2K1C rats. This study suggests that moderate alte rations of dietary magnesium do not modify blood pressure in normotens ive control, DOCA-salt and 2K1C hypertensive rats, nor do they modify vascular disease in these 2 hypertensive models.