In an experiment with 7-d immersion of 8 male test-subjects (21-26 y.o.) we investigated excretion with urine of total protein, creatinine, urea, uric acid, glucose, K, Na, Ca, P, Mg, 12 groups of proteins and 5 enzymes. Results of the investigation bring to the conclusion that 7-d immersion does not impact the kidney functioning. Analysis of uroproteinogram failed to detect shifts in glomerular filtration or tubular reabsorption which correlates with the absence of significant changes in uroenzymogram. Even profuse diuresis was unable to provoke abnormally high protein and glucose excretion, whereas electrolyte excretion normalized fairly soon. Increased excretion of creatinine, urea, Ca, Mg and P appears to reflect activation of catabolism in skeletal muscles.