CHANGES IN AMINO ACID POOL OF CEREBRAL HEMISPHERES IN RATS WITH SUBTOTAL CEREBRAL ISCHEMIA

Abstract

Amino acids and their derivatives are involved in synaptic transmission as neurotransmitters and neuromodulators. However, some amino acids are involved in the formation of neuromediators. Therefore, the study of amino acid pool in subtotal cerebral ischemia (SCI) is of great importance. The aim of the study is to evaluate the changes in amino acid pool and the role of amino acids in oxidative processes in rats with SCI. Materials and Methods. The experiments were carried out on 16 male outbred white rats (260±20 g) according to Directive 2010/63/EU on the protection of animals used for scientific purposes, September 22, 2010. Results. When modeling 1-hour partial cerebral ischemia (PCI) by unilateral ligation of the common carotid artery (CCA), no pronounced morphological changes at the microscopic and ultrastructural levels were observed. Also, there were no pronounced changes in the respiratory parameters of the mitochondrial fraction (only a slight decrease in ATP-synthase was noticed). It reflects the safety of the enzymatic complexes of the electron transport chain in the ischemic model, and changes in prooxidant-antioxidant balance of brain homogenates. There was a decrease in sulfur-containing amino acids: methionine by 12 % (p<0.05) and cysteate by 28 % (p<0.05) in the parietal lobe of rats with SCI when compared with the control. Apparently, it was the result of the activation of oxidative stress. In turn, a decrease in cysteate prevents taurine synthesis. However, taurine level did not decrease, possibly due to its long half-life in the brain. Conclusion. In rats with SСI, with 1-hour ischemia, there was a tendency to glycine increase in both studied lobes, whereas excitatory amino acids tended to decrease.