[Action on water-salt metabolism as a prophylactic method in orthostatic intolerance in crew members of the 2d expedition of the Saliut-1 station].

The water-salt supplement developed in ground-based experiments in order to increase human tolerance to LBNP and orthostatic tests was recommended to be given to the crewmembers at the final stage of the second expedition of Salyut-4. On the 53rd flight day, concomitantly with an intake of 4.0 g sodium chloride and 900-1200 ml water, an LBNP test was carried out to assess the effectiveness of this supplement, to select its optimal doses and to clarify individual responses. After the intake both cosmonauts showed a better tolerance of the LBNP test. They also displayed individual variations in their responses, viz. the commander in arterial circulation, and the flightengineer in venous circulation. As suggested by the ground-based experiments and the inflight provocative test, both cosmonauts were requested to take 9.0 g sodium chloride and 1000--1200 ml water on the last flight day. The postflight examinations demonstrated that the countermeasures applied (physical exercises, LBNP) in combination with the direct action on the fluid-electrolyte metabolism gave a pronounced positive effect.