Figure 4.

Adult hippocampal progenitor cells (aHPCs) were prepared from wild-type (wt), EP1−/−, and EP2−/− mice and then exposed to a metabolically stable analog of PGE₂, 16-PT-PGE₂, or cytosine arabinoside (AraC) for 24 hours before estimating cell death by LDH release (A) or proliferation by MTT assay (B). Data are presented as percentage of vehicle-exposed controls. A: AraC caused a significant increase in LDH release at 1 μmol/L (P < 0.0001) that was not further changed (P < 0.05 compared with 1 μmol/L) at 10 and 100 μmol/L. Exposure to 16-PT-PGE₂ yielded concentration-dependent increase in LDH release from 1 to 100 μmol/L that was not significantly different between wild-type and EP2−/− aHPCs. Exposure of EP1−/− aHPCs to 16-PT-PGE₂ up to 100 μmol/L did not significantly change LDH release at any concentration compared with 0.1 μmol/L (P > 0.05). B: AraC caused a concentration-dependent decrease in MTT conversion from 0.1 to 10 μmol/L that was not further significantly changed at 100 μmol/L. Exposure to 100 μmol/L 16-PT-PGE₂ (but not lower concentrations) decreased MTT conversion in wild-type and EP2−/− aHPCs (P < 0.001) but not EP1−/− aHPCs.