Blood-brain barrier methionine transport after resuscitation from 10-min cardiac arrest in rats.

In adult rats 10-min cardiac arrest was induced by the intracarotid compression of the heart vessel bundle. The animals were sacrificed at 2 weeks and 1, 2, 3 months after resuscitation. Decapitation was performed 15 sec after intracarotid injection of mixture of L-[methyl-3H]methionine (MET) and 4-iodo[n-methyl-14C]antipyrine. By means of the dual label method the brain uptake index (BUI) of amino acid (AA) in the cerebral hemisphere was calculated. MET BUI was corrected for residual vascular radioactivity after injection of [14C]sucrose. The significant increase of MET BUI was observed 1 and 2 months after resuscitation, reaching approximately 2-fold of control values. Two weeks and 3 months after resuscitation values did not differ significantly from control. The present study revealed either periodical increase of BBB permeability for MET or increased transport of AA according to metabolic needs during the postischemic reparative processes.