Role of nitric oxide in regulating secreted phospholipase A2 release from astrocytes.

Inflammatory stimuli such as lipopolysaccharide increase nitric oxide and secreted phospholipase A2 release from glial cells. However, the signaling mechanism(s) regulating secreted phospholipase A2 in glial cells is not known. Here, rat brain astrocytes treated with lipopolysaccharide generated nitrite and released secreted phospholipase A2, while microglia generated nitrite without releasing secreted phospholipase A2.

Quantification of sPLA2-induced early and late apoptosis changes in neuronal cell cultures using combined TUNEL and DAPI staining.

The terminal deoxynucleotidyl transferase (TdT) dUTP nick end labeling (TUNEL) stain is in wide use for measuring apoptosis in neurons, as well as in other cell types. TUNEL may give false positive results due to variations in labeling technique as well as staining of cells that have undergone non-apoptotic DNA strand breaks. Therefore, in isolation, TUNEL is not a certain indicator of apoptosis.