Aims: 

Increase in cellular Ca²⁺ is a cofactor of many cellular processes including apoptosis and necrosis. This study's hypothesis was that bloody cerebrospinal fluid (CSF) from patients after intraventricular hemorrhage may cause a Ca²⁺-rise which induces apoptosis or necrosis in a in-vitro model of human cerebral astrocytes.

Method: 

Human astrocytes were incubated with CSF from patients with intraventicular hemorrhage. In control experiments native CSF was used. Single cell cytosolic Ca²⁺-concentrations were measured by fura-2. Three blockers were used: Nimodipine, APB and suramine that blocks the L-type Ca²⁺-channel, the plasmalemmal Ca²⁺ influx / endoplasmic reticulum Ca²⁺-channels; and the ATP-sensitive PY2-rezeptor, respectively. Apopotois and necrosis were evaluated by staining the cells with Hoechst-3342 and propidium iodide.

Results: 

Incubation of astrocytes with bloody-CSF provoked a bi-phasic cytosolic Ca²⁺-rise, an initial fast peak followed by a sustained slow rise lasting over the observation period of 60 minutes. The Ca²⁺-rise was significantly blocked by APB or suramin. Nimodipine had no influence on the cytosolic Ca²⁺-concentration. Incubation of the astrocytes with bloody-CSF induced necrosis but not apoptosis. The blockade of the Ca²⁺-rise by APB or Suramin significantly reduced necrosis. Nimodipine did not prevent necrosis in astrocytes.

Conclusion: 

Bloody CSF induces necrosis but not apoptosis in human astrocytes. The CSF-induced necrosis is due to increase of cytosolic Ca²⁺, which is mediated through capacitative Ca²⁺ influx involving the ATP-sensitive PY2-receptor.