[Changes in the parameters of the rhythms of the electrolyte-excreting function of the kidneys in women in relation to the seasons of the year].

The characteristics (period, mesor, amplitude) of the rhythms of urinary excretion of sodium, potassium, chlorine, calcium, magnesium, and phosphorus were examined in normal women during various seasons. The urine was collected for 5 days with 4-hour intervals. The rhythms were detected and their parameters established with the use of mathematical methods for the assessment of the tested curve fragments repetitions and by the least squares nonlinear method. The rhythms of renal urinary and electrolyte excretion were found very smooth, particularly so in the fall and winter. The circadian rhythms have been found the most stable during all the seasons. Examinations of individual electrolyte excretion have shown that Na and K excretion is more stable all the year round and therefore this parameter is the most informative for the detection of disorders in renal electrolyte excretion.