Hemolysate induces structural and functional injury to cultured cerebral endothelial cells

Damage to the vascular endothelium is considered an important feature in the development of cerebral vasospasm following subarachnoid hemorrhage. The present study examined this issue by testing the effects of hemolysate on the morphology and barrier function of cultured Bovine Middle Cerebral Artery Endothelial Cells (BMCA-ECs). Hemolysate elicited a dose-dependent loss of cells in confluent cultures of BMCA-ECs. The shape of the surviving cells changed from a typical cobblestone appearance to a spindle-like appearance with increased vacuolization. Hemolysate-induced damage was reduced by co-incubation with bovine calf serum (BCS) in a concentration-dependent manner. The early impact of hemolysate on endothelial cells was evaluated using a permeability assay in which the passage of 14C-sucrose across a BMCA-EC monolayer was analyzed. Hemolysate significantly increased the permeability of 14C-sucrose across the endothelial barrier. In contrast to its protective effects against cell loss, BCS did not block the early hemolysate-induced increase in transcellular permeability. These findings further implicate erythrocyte contents in the pathogenesis of structural and functional damage to the endothelium following subarachnoid hemorrhage.