Excretion of urinary acids during inverted sleep-waking rhythm.

Some organic acids that occur in human urine are excreted in very different amounts during the day and the night. The day-night rhythm in the excretion rate of citric acid and propylurofuran acid changes only gradually if the normal rhythm of life is inverted, e.g., if a person sleeps during the day and works at night (shift of 12 h), paralleling the gradual adjustment of steroid metabolism under the same conditions. In contrast, the typical rhythm in the excretion rate of tetrahydrofuran acids and tartaric acid inverts immediately if the sleep-waking rhythm of a person is inverted. In contrast to propylurofuran acid, pentylurofuran acid is excreted unrhythmically. No change in the excretion rate of amino acids was observed if the daily rhythm was inverted. Quantifications were achieved by liquid-liquid extraction, derivatization and gas chromatography computerized peak area integration.