Changes of human serum proteome profile during 7-day “dry” immersion

The aim of this study was to characterize changes of serum proteome profile during 7-day “dry” immersion (DI). The experiment with DI consisted of three series: control group without countermeasures (10 men), with using mechanical stimulation (6 men) and low-frequency myostimulation (5 men) as preventive means. Serum samples were fractionated using ClinProt robot (Bruker Daltonics) on magnetic beads (weak cation exchange magnetic beads-MB WCX) prior to mass-spectral profiling. It was obtained 170 peaks after fractionation of serum samples in each group. On 7th immersion day peak areas of fibrinopeptide A (m/z=1206; 1464), angiotensin II (m/z=1051), high molecular mass kininogen fragment (m/z=2133 Da) and C3-fragment of the complement system (m/z=1350 Da) were significantly decreased comparing with pre-experimental values of all experimental series. Peak areas of apolipoprotein C III (m/z=9419) and C4a fragment of the complement system (m/z=3206 Da) were increased. On 7th day of the recovery peak areas of all changed peaks were not close to pre-experimental values. This fact provided evidence of incomplete recovery of an organism after DI. The depth of the alterations had considerable individual variability. Thereby the detected changes of serum proteome profile in the experiment. They indicated a reorganization of the hormonal, immune systems and lipid metabolism. The use of myostimulation and mechanical stimulation as countermeasures partly compensated adverse effects of 7-day dry immersion on the parameters of coagulation system (fibrinopeptide A) and lipid metabolism (apolipoprotein CIII).