[Interaction of catecholamines and corticosteroids during the process of muscle fatigue].

After prolonged (8 hrs) swimming, the level of corticosteroids was reduced and the contents of aldosterone and DOC in the blood was increased in the rats. At incubation of these rats' adrenals in the L-thyrosine substratum the synthesis of adrenaline was reduced. Addition of hydrocortisone, prednisolone and corticosterone into the medium as well as in vivo administration of these increased the adrenaline synthesis in swimming rats and did not alter it in intact rats.