Uromucoid in normal urine.

Uromucoid was determined in urine from persons or various ages with normal kidney function by a radial immunodiffusion technique. Uromucoid concentration was inversely correlated to diuresis. Excretion rates showed a weak correlation to body surface area in young adults of both sexes. Children had a greater excretion of uromucoid per m2 than young adults, and even newborn had a considerable excretion. Elderly subjects had similar excretion rates to young adults. Excretion rates were uninfluenced by sex, salt load or diuresis, and no difference between day and night excretion rates was observed. Intraindividual fluctuations were small, and determination of uromucoid in one single night's urine therefore gives an adequate expression of the uromucoid excretion rate.