| Abstract: | Head-out water immersion (HOI) induces a profound diuresis and natriuresis, which may endanger the body fluid balance of breath-hold divers during prolonged diving work. To investigate if adaptation is acquired by professional breath-hold divers, we have evaluated renal responses to 3-h HOI in 5 Korean women divers (Amas) and 11 nondiving housewives (controls). In both control and diver groups, the average urine flow during 3-h immersion was four times greater and Na+ excretion was 70%–80% greater than the pre-immersion value urine flow: 3.7 (SD 1.0) ml·min–1 vs 0.9 (SD 0.4), P<0.001, in controls; 4.3 (SD 0.9) vs 1.1 (SD 0.4), P<0.001, in divers; Na+ excretion: 270 (SD 176)  mol· min–1 vs 161 (SD 84), P<0.025, in controls; 303 (SD 31) vs 164 (SD 62), P<0.005, in divers]. In all cases, the values for a given period were not significantly different between the two groups. The plasma concentrations of Na+ and osmolality, and renal clearance of creatinine did not change significantly. However, the osmolal clearance increased from 2.0 (SD 0.8) ml·min–1 to 2.8 (SD 0.7), P<0.05, in the controls; from 2.2 (SD 0.4) to 2.6 (SD 0.4), P<0.05, in the divers] and free water clearance changed from negative to positive values from -1.1 (SD 0.5) ml·min–1 to 1.2 (SD 0.3), P<0.005, in the controls; from -1.2 (SD 0.4) to 1.6 (SD 1.1), P<0.01, in the divers] during immersion, again the pattern of change being similar in the two groups. It was, therefore, concluded from our study that the renal response to HOI was unchanged in the Korean women professional breath-hold divers compared to the nondiving women. |
