Preliminary report: Effect of cobaltous ion on cerebral vasospasm in a rabbit subarachnoid hemorrhage model

Experimental studies have suggested what the primary role is of free radical products in the development of vasospasm. It has been suggested that the degradation products of hemolysis trigger free radical reactions leading to lipid peroxidation is subarachnoid hemorrhage (SAH). Therefore, Fe²⁺, a degradation product of hemoglobin, seems to be the most important substance in the pathogenesis of vasospasm. Cobaltous ion was shown to be a powerful inhibitor of lipid peroxidation in biological membrane. Eleven rabbits were anesthetized and received 5 ml of autologous arterial blood into the cisterna magna. Group 1 (n=6) received 0.1 mg/kg cobalt solution intratecally via the cisterna magna simultaneously with blood. Group 2 (n =5) underwent sham operation as a control group. Forty-eight hours later the rabbits were deeply anesthetized and the brainstem was quickly removed and put under the operating microscope to measure the basilar artery diameter. Afterwards, the upper part of the brainstem was used for lipid peroxidation measurement and the lower part for the histopathological examination. Significant vasospasm was observed in four and moderate vasospasm in one rabbit of group 2; mild vasospasm was seen in five rabbits and moderate vasospasm was seen in one rabbit of group 1. There was no vasospasm in the control group. A statistically significant increase in the levels of lipid peroxide was found in the brainstem of group 2. These data demonstrate that cobaltous ion represents a promising therapeutic tool in vasospasm after SAH.