| Abstract: | Changes in the content and ratio of catecholamines, their precursors and metabolites in canine blood and tissues during the initial period of stress have been studied. A sharp increase in tissue adrenaline (A) and dopamine (DA) and a decrease in tissue noradrenaline (NA); decline in blood A and rise in blood NA; inhibition of monoamine oxidase activity and a fall in metanephrine and normetanephrine blood and tissue level have been demonstrated in the first phase of reaction developing right after exposure to stress. A sharp synchronous rise in A, NA and DA and a parallel increase in their metabolic intensity towards oxidative deamination and O-methylation have been found in the second phase of reaction that develops in 60 sec. The first phase of the reaction has been designated as dissociation phase of sympathoadrenal secretory synthetic activity, and the second phase was termed the phase of synchronous system activation. |
