Background: Some studies showed that magnesium can prevent diabetes complications. The present study was designed to determine the role of calcium channels and adenosine receptors in Mg2+-induced relaxation in streptozotocin (STZ) induced diabetic rats' vessels.
Methods: Diabetes was induced by ip injection of 60 mg/kg STZ. Eight weeks after diabetes induction, superior mesenteric arteries were isolated and perfused according to the McGregor method. Prepared vascular beds were constricted with phenylephrine to induce 70–75% of maximal constriction. Mg2+ at concentrations of 10–4 to 10–1 M was added into the medium and perfusion pressure was recorded in intact and denuded endothelium. Glutamic acide (1 mM) and theophylline (1 mM), were added into medium 20 min before phenylephrine administration with intact and denuded endothelium.
Results: Mg could decrease perfusion pressure. Mg-induced vasorelaxation was not suppressed in the presence of glutamic acid, but in the presence of theophylline vasorelaxation induced was totally suppressed.
Conclusion: From the results of this study it may be concluded that Mg2+-induced relaxation is not mediated by calcium channel, but adenosine receptors play a role in Mg2+-induced vasorelaxation.
