Vasospasm after experimentally induced subarachnoid haemorrhage and treatment with nimodipine.

At day one and on the following day subarachnoid haemorrhage (SAH) was induced in SPF-rats by injection of a mixture of autologous blood and CSF into the cisterna magna. At day eight the animals were treated with Nimodipine. Extracellular calcium and -potassium concentrations as well as local cerebral blood flow and arterial blood pressure were measured simultaneously. The cerebral vasospasm was documented by corrosion casts. The control group underwent the same procedure without previous SAH. Cerebral vasospasm still exists after nimodipine infusion as it can be demonstrated by corrosion casts showing an intensive grooving and a vertical relief. Extracellular potassium and calcium concentration are higher in the SAH-group than in the control-group. The influence of nimodipine to blood pressure and cerebral blood flow is more impressive in rats with SAH showing a significant decrease in blood pressure and local blood flow.