Intracranial vasospasm: a study with iron compounds.

The effects of topically applied hemoglobin, methemoglobin, hemin, ferrous chloride (FeCl2) and ferric chloride (FeCl3) were investigated by observation through the operating microscope to determine their effect on the normal and spastic canine basilar artery. Following transclival exposure, the artery was made spastic by puncture or topical barium chloride. No consistent changes in arterial diameter were seen with topical hemoglobin, methemoglobin, or hemin. The buffered ferrous ion (Fe++) caused marked vasodilation at concentrations of 10 microgram/ml. The buffered ferric ion (Fe++) caused mild vasoconstriction at similar concentrations. The possible role of iron (a component of hemoglobin) in vasospasm following subarachnoid hemorrhage and subsequent hemoglobin degradation is discussed.