[Catecholamines and their metabolic enzymes in the rat myocardium after prolonged space flight]

The concentration of catecholamines and activity of enzymes involved in their synthesis and degradation, i. e. dopamine-beta-hydroxylase, monoamine oxidase and catechol-O-methyl transferase, were measured in the myocardium of rats flown for 19.5 days aboard Cosmos-782 and used in the synchronous and vivarium experiments. The animals were decapitated either immediately or 26 days after completion of the experiments. The catecholamine concentration and heart mass of flight animals increased significantly whereas enzyme activity remained unchanged. It can be concluded that in space flight the concentration of catecholamines in the heart increases, exerting no effect on their synthesis or degradation.