[Effect of hemorrhagic shock on catecholamine metabolism in the brain]

Content of adrenaline, noradrenaline, dopamine, DOPA and normethanephrine was estimated by means of the hydroxyindole method in brain tissue and hypothalamic region of rats subjected to hemorrhagic shock (loss of 3% of blood during 20 min) within 15 min, 2, 24 and 72 hrs. At the first day after the hemorrhage an increase in content of adrenaline and a distinct decrease in content of noradrenaline were observed in hypothalamic region, although the biosynthesis the neurotransmitters was not inhibited. Then, the noradrenaline concentration was normalized but the content of its precursors was decreased. In brain a constant posthemorrhagic increase in content of dopamine and the phase alterations in patterns of the catecholamine metabolism were observed: an initial decrease in synthesis and turnover of noradrenaline followed by its increased metabolism.