Pre-ischaemic administration of procaine suppresses ischaemic glutamate release and reduces neuronal damage in the gerbil hippocampus

The effects of intracerebroventricular administration of procaine 2 mu mol on ischaemic release of neurotransmitter amino acids in the gerbil hippocam pal CAI region were investigated using a microdialysis-high-performance liq uid chromatography procedure. Histological outcome was examined by comparin g delayed neuronal death between animals treated with procaine before ischa emia and animals treated after ischaemia. Transient forebrain ischaemia for 3 min produced increases in dialysate amino acid concentrations. Aspartate , glutamate and glycine reached 331%, 394% and 233% of pre-ischaemic values . Basal concentrations were restored immediately by reperfusion. Pre-ischae mic administration of procaine suppressed peak release and improved histolo gical outcome. However, post-ischaemic administration did not protect again st ischaemic neuronal death. Improvement in ischaemic neuronal damage by pr e-ischaemic administration of procaine may be related to suppression of exc itatory amino acid release.