OBJECTIVETo observe the effect of nitric oxide (NO) on the differentiation of neural stem cells (NSCs) derived from subventricular zone (SVZ) of neonatal rats in vitro.

METHODSConventional method was used to isolate and culture the NSCs from SVZ. Diethylenetriamine/NO(DETA/NO) was used as NO donor and Nitro-L-arginine methylester (L-NAME) was used as inhibitor of nitric oxide synthase (NOS). The immunofluorescence was used to identify the expression of nestin (a marker of NSCs), beta-III-tubulin (Tuj-1, a marker of neurons), glial fibrillary acidic protein (GFAP, a marker of astrocytes) and nNOS. The concentration of NO in medium was measured by Greiss assay.

RESULTSCultured neurospheres were nestin-, BrdU- and nNOS-positive. After treatment with 40 micromol/L, 50 micromol/L and 60 micromol/L of DETA/NO for 5 days, the concentration of NO released was increased significantly (P < 0.01) as compared with that of the control group. The percentage of both differentiated neurons and astrocytes was increased significantly (P < 0.01 and P < 0.05) as compared with that of the control group. After treatment with 100 micromol/L, 150 micromol/L and 200 micromol/L of L-NAME for 5 days, the concentration of NO released was decreased as compared with that of the control group (P < 0.05). The percentage of both differentiated neurons and astrocytes were decreased as compared with that of the control group (P < 0.05).

CONCLUSIONNO could directly promote the differentiation of NSCs derived from rat subventricular zone in vitro.