CYTOTOXIC EFFECTS OF BLOODY CEREBROSPINAL-FLUID ON CEREBRAL ENDOTHELIAL-CELLS IN CULTURE

The release of intracellular products from lysed blood cells is believed to play a critical role in the etiology of vascular pathology following intracerebral hemorrhage. The present studies investigated the effects of a mixture of blood and cerebrospinal fluid (CSF) on bovine intracranial endothelial cells maintained in culture. The incorporation of H-3-leucine into endothelial cells was used as an index of cellular viability. Cerebrospinal fluid alone did not alter the incorporation of H-3-leucine into the cells. In contrast, CSF preincubated with blood for 3 days or longer prior to treatment elicited significant reductions in leucine incorporation. Treatment with CSF preincubated with blood for 5 to 7 days resulted in the rapid deterioration of the culture, with large numbers of cells detaching almost immediately. Concentrations of hemoglobin were elevated profoundly in mixtures of blood and CSF preincubated for periods longer than 3 days. The increases in hemoglobin concentration were related temporally to increases in the cytotoxic impact of the bloody CSF. These findings suggest that factors released during the breakdown of blood exert a deleterious effect on intracranial endothelial cells. The time course of this effect is closely related to the development of vasospasm in humans following subarachnoid hemorrhage. Taken together, these observations are consistent with the hypothesis that intracellular blood products, particularly hemoglobin, contribute to vasospasm by directly compromising endothelial function.