[Effect of horizontal immersion into water at 38 degrees C on the urinary elimination of catecholamines].

The urinary excretion of noradrenaline, adrenaline and creatinine has been studied in normal young individuals during a water bath at 38 degrees C for 40 minutes. The noradrenalinuria and the ratio noradrenalinuria/creatininuria are decreased, indicating an inhibition of the vasomotor activity of the orthosympathetic system. This inhibition is related to the consequence of the external hydrostatic pressure of the water filling the intrathoracic venous reservoirs and increasing the systemic blood pressure at the sino-baroreceptor level, hyperthermia playing a very limited role.

Influence of water temperature on thermal, circulatory and respiratory responses to muscular work.

Different muscular exercises have been executed on a bicycle ergometer during immersion in water, the temperature of which varied between 20 and 40 degrees C. During submaximal works, O2 consumption was not modified by the temperature of the water. On the other hand, body temperature (rectal and muscular) are clearly influenced by environment.

Telemetric control of heart adaptation during automatic and free-fall parachute jumps.

Telmetered heart rate recordings have been ovtaine from 17 parachutists (6 during automatic jumps) 9 Catecholamine (adrenaline and noradrenaline) concentrations have been measured in urine and plasma of six of these subjects. No difference appears between heart rates recorded in the two jumps at egress and at parachute deployment. On the other hand, higher heart rate values are recorded during automatic jumps during descent and at ground impace.