[Results of endocrinologic studies of the 3d international crew of the scientific orbital station complex: Soyuz 29--Salyut 6--Soyuz 31 (joint space flight enterprise of the USSR--GDR). 1. Condition of the sympathico-adrenal system].

The present paper deals with the activity of the sympatho-adrenal system (SAS) in the third international crew of the scientific orbital station "Salyut-6" on the basis of catecholamines (CA) as well as of some of their primary stages and metabolites. Plasma adrenaline (A), noradrenaline (NA), and dopamine (DA) were determined on the 30th day before the flight and on the first day after landing. The parameters of A, NA, DA, DOPA, metanephrine (MN), and normetanephrine (NMN) as well as their conjugates were analysed in urine on day 30 and from days 5 to 1 before launching the spaceship and from days 0 to 5 after landing. Moreover, at the same occasions the urinary excretion of vanillilmandelic acid (VMA) and homovanillic acid (HVA) was measured. For a qualitative evaluation of the responses of SAS indices were computed providing information on the activity of the single links of CA metabolism. During the last five days before launching a gradual increase of A, NA, DA, and DOPA excretion with the urine was found in both the cosmonauts. The A/NA quotient rose to 360% in the commander and to 200% in the spacecraft engineer. The inactivation processes of A (MN/A) and NA (NMN/NA) were clearly reduced in both crew members before launching. The highest excretion of A, NA, DA and their conjugates as well as of DOPA was observed on the day of landing. The total results ascertained in the post-flight period indicate psychonerval strains experienced by the cosmonauts. However, marked stress reactions were not found. This conclusion is drawn on the basis of general criteria of the indices of CA metabolism during stress (increased secretory activity of SAS and excretion of free CA, synthesis activation, relative hypometabolism of conjugation). The rapid normalisation of the investigated parameters after the flight gave evidence of the cosmonauts' quick readaptation, which again is an expression of a high state of preparatory training.