Changes in the amino acid pool of cerebral hemispheres in rats with total cerebral ischemia

Abstract

Objective: assessment of changes in the pool of amino acids (AA) in rats with total cerebral ischemia (TCI). Material and Methods. Experiments were performed on 16 male outbred white rats weighing 260±20 g. TCI was modeled by decapitation of animals. Brain tissue was sampled 1 hour after decapitation. Results. In the parietal lobe (PL) and hippocampus (HC) of TCI group animals 1 hour after their decapitation, we detected an increase in the content of tyrosine (by 43%, p=0.044, and 40%, p=0.044, respectively) and tryptophan (by 24%, p=0.036, and 23%, p=0.046, respectively). Similar trend was observed for methionine that increased by 32% in PL(p=0.046) and by 27% in HC (p=0.046). Analogous increase in the content of L-arginine was noted in PL and HC (by 20%, p=0.037, and 33%, p=0.037, correspondingly). Isoleucine content increased by 12% in PL (p=0.054), while valine content decreased by 15% in HC (p=0.053). The ratio of the combined total content of branched-chain amino acids (BCAA)to the combined content of aromatic AA in TCI significantly declined from 1.4 to 1.0 in PL (p=0.053) and from 1.6 to 1.0 in GC (p=0.053). We observed an increase in methionine content by 33% (p=0.046) in PL and an increase in tryptophan content by 24% (p=0.046) in HC. Conclusion. One-hour TCI caused the following changes in the AA pool: an increase in the content of aromatic AA (tyrosine and tryptophan) and methionine; an increase in the content of L-arginine; and also, an increase in the concentration of the inhibitory neurotransmitter glycine.