NITRIC OXIDE AND THE BRAIN

Just as we have all been getting used to nitric oxide as a compound with desirable vaso-active properties when given by inhalation; and just as we have been considering promoting its production pharmacologically with new drugs such as sildenafil; along comes a new family of compounds that inhibit nitric oxide synthase. These may become important in neonatal care because the production of locally toxic nitric oxide appears to be a mediator of the damage caused by ischaemia and reperfusion injury in the brain, so inhibiting nitric oxide synthase may be a useful strategy following severe birth asphyxia. Nitrotyrosine is a compound formed when nitric oxide combines with oxygen, forms peroxynitrite, and reacts with tyrosine. Groenendaal et al have demonstrated that nitrotyrosine was widely distributed in the brains of babies who died following perinatal asphyxia, but not in the brain of a control infant who died with spinal muscular atrophy. Interestingly, the distribution of nitrotyrosine in the brains of the asphyxiated …