Metabolic disturbances in hippocampal slices of fetal guinea pigs during and after oxygen-glucose deprivation: is nitric oxide involved?

The aim of this study was to investigate the role of nitric oxide in metabolic disturbances induced in brain tissue of fetal guinea pigs by oxygen-glucose deprivation. Experiments were performed on hippocampal slices so as to exclude the effects of nitric oxide on the cardiovascular system. Metabolic disturbances were assessed by measuring changes in energy metabolism and protein synthesis after different periods of oxygen-glucose deprivation (OGD). Ten min after OGD of 40 min duration, the concentration of cGMP in tissue slices rose from 1.35 +/- 0.38 to 18.6 +/- 1.04 pmol/mg protein (P < 0.05). This rise was almost completely inhibited by the addition of 100 microM N-nitro-L-arginine (NNLA), indicating that NO-synthase was strongly activated after OGD in fetal brain tissue. However, addition of NNLA improved neither protein synthesis nor energy metabolism measured 12 h after OGD. Thus, nitric oxide does not appear to contribute directly to processes leading to metabolic disturbances induced by transient ischemia in immature brain tissue.