Effect of a calcium antagonist on experimental constriction of human brain vessels.

In search for a potent dilatator or deactivator of constriction of cerebrovascular smooth muscle, the effects of a specific antagonist of the calcium influx necessary for the excitation-contraction coupling process was studied on isolated human pial arteries. The arteries were constricted by addition of noradrenaline, 5-hydroxytryptamine, human plasma or blood. All these agents induced a strong contraction which could effectively be reduced by addition of the Ca++-antagonist, nifedipine, to the organ bath. It is suggested that calcium antagonists might be of value in the treatment of cerebrovascular spasm following a subarachnoid hemorrhage.