Magnesium protection against in vitro cerebral vasospasm after subarachnoid haemorrhage

Abstract

Mg 2+ has recently been proposed for the treatment of cerebral vasospasm and is known to dilate vessels. In this study, we examine the effects of Mg 2+ on in vitro vasospasm using CSF from vasospastic subarachnoid haemorrhage patients with vasospasm (CSF v ). Oxygen consumption and isometric force measurements in the porcine carotid artery were used to assess the contractile and metabolic status of the vessels' responses to CSF v and the effect of Mg 2+. Mg 2+ caused a dose dependant decrease in tension following contraction by CSF v. Mg 2+ (12 mM) caused a normalization of relaxation rate in tissue exposed to CSF v, caused a significant decrease in basal oxygen consumption, as well as significantly decreasing the rate of oxygen consumption of the porcine carotid artery when stimulated by CSF (0.70 - 0.12 versus. 0.46 - 0.1 w mol O 2 min -1 g -1 ). Acute Mg 2+ addition demonstrated the most effective protection using an assay based on CSF v contraction. These results suggest that Mg 2+ can protect vascular smooth muscle exposed to CSF v by benefiting contractile behaviour and metabolism of the arteries.

• Cerebral Vasospasm Magnesium Stroke Subarachnoid Haemorrhage