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 totalcerebral ischemia (TCI). Materials 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 TCIgroup animals 1 hour aftertheir 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), whilevaline 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 TCIcaused 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.

Keywords

• total cerebral ischemia
• incomplete cerebral ischemia
• amino acid pool
• brain homogenates