Oxygen regimen in the human peripheral tissue during space flights.

A survey of the results of the experiment "Oxygen," carried out within the scope of the INTER-KOSMOS program in members of the permanent crews and of international visiting expeditions to the Soviet orbital station Salyut-6, is given. During the 7-day space flights of the international visiting expeditions a significant decrease in pO2ic by 3.28 kPa was observed. Local oxygen utilization reduced significantly by 0.44 kPa. During hyperventilation testing after return to earth a statistically significant decrease in the peak value by 1.39 kPa was noted. In the long-term crews of the orbital station Salyut-6 the highest decrease in pO2ic of 3.8 kPa and the absolutely lowest value of 3.4 -/+ 0.5 kPa during space flight were observed. The decrease in local oxygen utilization during the flight of 0.8 kPa/min was greater than that of the visiting crews. The results indicate the importance of investigating the dynamics of the oxygen regimen for medical control of the crew members both during the space flight and during the readaptation phase after return to earth.

[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]. / Ergebnisse endokrinologischer Untersuchungen bei der 3. internationalen Besatzung des wissenschaftlichen Orbitalkomplexes Sojuz 29--Saljut 6 - Sojuz 31 (gemeinsames Raumflugunternehmen UdSSR - DDR). 1. Mitteilung: Der Zustand des sympatho-adrenalen Systems.

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.

[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). 3. Corticosteroid excretion in urine]. / Ergebnisse endokrinologischer Untersuchungen bei der 3. internationalen Besatzung des wissenschaftlichen Orbitalkomplexes Sojuz 29 - Saljut 6 - Sojuz 31 (gemeinsames Raumflugunternehmen UdSSR - DDR) 3. Mitteilung: Die Kortikosteroidausscheidung im Urin.

In the present study the attempt was made to evaluate the functional state of the adrenal cortex after space flight by means of the urinary corticosteroid content. The urine collected over 24 hours was analysed. The following parameters were determined: Total 17-hydroxycorticosteroids (17-OHCS), their free forms, glucuronides and sulphates; cortisol (F), cortisone (E), corticosterone (B), 11-desoxycortisol (S), 11-dehydrocorticosterone (A), tetrahydrocortisol (THF), tetrahydrocortisone (THE), tetrahydrocorticosterone (THB), tetrahydro-11-desoxycortisol (THS), and aldosterone. In order to characterize the activity of the 11-hydroxylase the quotient of THS + S/THF + F + THE + E was formed. The activity of the 17-hydroxylase was determined indirectly by the quotient of THF + THE + THS + F + E + S/THB + B + A = 17-OHCS/17-DOHCS. The expected distinct increase of the 17-OHCS after the space flight failed to appear. This finding may be due to an adrenocortical dysfunction. In the space ship commander the quotients indicate a reduced 11- and 17-hydroxylation during the process of synthesis of the glucocorticoids. In the flight engineer they give evidence of an unchanged biosynthesis except on the day of landing. A hitherto not fully intensified substance ("white spot") was found in the chromatogram of the space ship commander on the first and second day after the flight. Moreover, the investigations show that the reaction of the adrenal cortex after space flights exhibits a number of individual characteristics.

[Results of endocrinolgic studies of the 3rd international crew of the scientific orbital station complex; Soyuz 29 - Salyut 6 - Soyuz 31 (joint space flight enterprise of the USSR - GDR). 2. Hormones and biologically active substances in blood]. / Ergebnisse endokrinologischer Untersuchungen bei der 3. internationalen Besatzung des wissenschaftlichen Orbitalkomplexes Sojuz 29 - Saljut 6 - Sojuz 31 (gemeinsames Raumflugunternehmen UdSSR - DDR) 2. Mitteilung: Hormone und biologisch aktive Stoffe im Blut.

Cortisol, insulin, somatotropin, thyreotropin, thyroxine, triiodothyronine, testosterone, aldosterone, c-AMP, c-GMP, prostaglandins (PGF1-x, PGF2-x, PGA + E), and renin concentrations in serum or plasma of the venous blood of the third international crew of the scientific orbital complex of "Soyuz 29 - Salyut 6 - Soyuz 31" were determined following the 7-day space flight. The increased activity of the renin-angiotensin-aldosterone system before the flight as well as variations in the pressor/depressor prostaglandin ratios indicate an increased strain during the pre-flight period. During the first stage of the post-flight period some parameters were changed due to the landing process and the returning to earth gravity. The associated physical load and the onset of reactions for enhancement of the orthostatic tolerance resulted in an increase of cyclic nucleotid and thyroxine concentrations. The relatively higher levels of the pressor PGs of group F in comparison with the prostaglandins A + E could be evaluated as a compensatory reaction for enhancement of the orthostatic tolerance. The cortisol and STH concentrations increased with growing motor activity. The variations seen after the 7-day space flight were essentially within the reference areas. It may be assumed that the readaptation was not yet totally accomplished by the 8th day after landing.