[Expression of neuronal nitric oxide synthase in brain tissue of hypoxic-ischemic neonatal rat and the cerebral protective effect of neuronal nitric oxide synthase inhibitor 7-nitroindazole].

OBJECTIVE

To explore the effect of nNOS and its selective inhibitor 7-NI in neonatal rats with hypoxic-ischemic brain damage (HIBD).

METHODS

The model of HIBD in neonatal rat was made and the expression of nNOS mRNA was measured at different time points and compared with the control group. The levels of NOS, NO, MDA, SOD were also assayed at different time points after aderministering 7-NI, and compared with the HIBD group and the control group. In addition, we observed the degree of apoptosis after 24 h of HIBD.

RESULTS

Expression of nNOS mRNA was higher at 2 h and 6 h after hypoxia than those in the control group (P < 0.05) and reached more at 6 h (P < 0.05). Concentrations of NOS, NO, MDA increased after HIBD, but concentration of SOD decreased (P < 0.01); 7-NI reduced the levels of NOS, NO, MDA, and level of SOD was higher than those in the HIBD group (P < 0.05). There was no apoptosis in the control group, 7-NI could effectively inhibit the degree of apoptosis after HIBD (P < 0.001).

CONCLUSION

nNOS has an important role in the pathogenesis of neonatal rats with HIBD, its specific inhibitor 7-NI can protect brains from hypoxic-ischemic damage through anti-oxidation and prohibiting apoptosis.