Grigoriev AI, VB Noskov, VV Polyakov, DV Vorobiev, IA Nichiporuk, HG Hinghofer-Szalkay, A Rössler, R Kvetnansky, L Macho

Dynamics of the hormonal regulation during LBNP sessions in (a) long-term space mission

Aviakosm Ecol Med. 1998; 32: 18-23.

Study design. The ‚Interstititum’ experiment was performed on days 3, 170, 287, and 430 of the long-term MIR mission of the Russian cosmonaut-physician in order to evaluate hormonal reactivity during LBNP sessions.

Results. The data revealed different types of reaction of the volume control to LBNP at the onset (F-3), in the course of, and soon after recovery (R-4) from the extended mission which are signs of specific phases of adaptive shifts in cosmonauts. Increased inflight reactivity of the hormonal systems during LBNP suggests significant consequences of in microgravity for the human cardiovascular system. The most distinct hormonal reaction to LBNP was seen at the beginning of the postflight period. Plasma cGMP was much reduced inflight, remained low on R-4 but fully returned to preflight levels on R-90.

Conclusion. Judged on hormonal responses to LBNP, complete recovery took three months after landing.