The Effects of Orally Administrated Magnesium on Denuded Aorta Contractility in Streptozotocin Induced Diabetic Rats

Some studies suggest that magnesium deficiency contributes to the cardiovascular complications associated with diabetes mellitus hence the present study investigated the effects of long term orally administrated magnesium on isolated denuded aorta contractility in response to KCl and Phenylephrine (Phe). Sixty male Wister rats (180–250 g) were divided into two diabetic and two control groups. One group of each received magnesium sulfate in their drinking water, while the two other groups, had only tap water. After 8 weeks, thoracic aorta was isolated, cut into 2-3 mm rings, endothelium removed and transferred to an organ bath. The tissue was then exposed to cumulative doses of KCl (10, 20, 40, 60 and 80 mM) and Phe (10-9, 10-8, 10-7, 10-6 and 10-5 M) and contractions were measured by an isometric transducer. During the study period, fasting blood samples were obtained every 2 weeks to measure Plasma Glucose level. Vasoconstrictive responses to KCl and Phe were significantly (p<0.05) higher in the control group as compared to the diabetic groups (p<0.05) and there were no significant differences between Mg-treated and non Mg-treated rats. Maximal contractions to KCl were 2.32±0.23, 2.76±0.19, 1.96±0.11 and 1.84±0.21 and the maximal responses to Phe were 2.94±0.24, 3.38±0.20, 2.24±0.27and 2.61±.27 in the control, Mg-treated control, diabetics and Mg-treated diabetic groups, respectively. No significant differences were found in plasma glucose concentrations between the Mg-treated and non Mg-treated groups. Oral administration of magnesium for 8 weeks has no effect on isolated denuded aorta contractility in diabetic rats.