Friday, July 18, 2008

Tissue and blood levels of zinc, copper, and magnesium in nitric oxide synthase blockade-induced hypertension

Abstract  The aim of this study was to determine the levels of tissue and blood zinc (Zn), copper (Cu), magnesium (Mg) in nitric oxide (NO) synthase blockade-induced hypertension. A group of albino rats received a NO synthase inhibitor, N G -nitro-l-arginine-methyl ester (l-NAME, 60 mg/kg/d) in their drinking water for 21 d. l-NAME intake caused a progressive rise in this group’s resting mean arterial blood pressure compared to a control group (p<0.01). There were no differences between the groups with regard to tissue and blood levels of Zn or Cu; however, Mg concentrations were significantly lower in the hypertensive rats’ erythrocytes (20.2% reduction from control levels), cerebral cortex (17.0%), heart (9.1%), renal cortex (12%), renal medulla (16.7%), and in the tissues of the caval vein (23.7%), mesenteric artery (29.8%), renal artery (18.4%), and renal vein (22.1%). There were no significant Mg concentration changes in the hypertensive group’s plasma, cerebellum, liver, duodenum, or aortal tissue. These findings suggest that Mg depletion may play a role in the blood pressure rise that occurs in the model of chronic NO synthase inhibition-induced hypertension.

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