[Catecholamines, their precursors and metabolites in human fatigue after exertion]. / Katekholaminy, ikh predshestvenniki i metabolity pri sostoianii utomleniia posle fizicheskoi deiatel'nosti u cheloveka.

Alterations in metabolism of catecholamines were studied in sportsmen after development of acute fatigue as a result of the test physical loading. Three types of the alterations were characterized on the basis of differences in excretion with urine of free and sulphate-bound adrenaline, noradrenaline, of their precursors DOPA and dopamine as well as acid metabolites (vanillyl mandelic acid). The first type of the alterations in catecholamines metabolism comprized the cases, when excretion of catecholamines, their precursors and metabolites did not increase; this appears to relate to the partial exhaustion of hormones and peripheric mediators of sympathoadrenal system. The second type was characterized by decreased excretion of the substances studied, by development of the "perversed" reactions due to modifications in the regulatory system, which led to the inhibition of the system instead of its stimulation. The third type was manifested as the hyperfunction of the system. The increased synthesis of catecholamines during the hyperfunction suggests that this process serves as a compensatory reaction to their preceding elevated secretion; the phenomenon appears to depend on the increased secretion of the newly formed catecholamines. Excretion of catecholamines and their precursors was decreased for a long time after development of chronic fatigue in the resting state and the increase in excretion of the substances studied was not observed after physical loading.

[Mechanisms of catecholamine synthesis disorders in the adrenals of rats subjected to physical fatigue]. / Mekhanizmy narusheniia sinteza katekholaminov v nadpochechnikakh krys pri fizicheskom utomlenii

There was a depression of transformation of noradrenaline, DOPA and thyrosine added in vitro, into catecholamines in the adrenal glands of rats after swimming for a period of 8 hours. This permitted to suppose a depression of the activity of phenylethanolamine-N-methyl-transpherase, DOPA-decarboxylase, and, possibly, of tyrosine hydroxylase under these conditions. After the end of swimming, in the presence of 1-tyrosine, there is at first an activation of noradrenaline synthesis, and then there occurs a gradual normalization (on the 7th day) of adrenaline formation. In rats trained for a period of 2 months the extent of reduction of the catecholamine synthesis in the adrenal glands in response to the 8-hour swimming was much less in comparison with the untrained aniamals.