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H WU

Publications and source records attributed to H WU.

16 recordsLinked to original sources
PubMed1951

Relative concentrations of N15 in urinary ammonia N and urea N after feeding N15-labeled compounds.

Available data on the isotopic ratio See PDF for Equation of ammonia (r(a)) and that of urea (r(u)) after a single feeding of glycine, aspartic acid, and ammonium citrate are analyzed. From this analysis the following conclusions are drawn. 1. The isotopic ratio See PDF for Equation of ammonia (r(a)) is always higher than that of urea (r(u)) in the initial period after a single feeding of isotopic glycine or aspartic acid, but the relation is reversed later. A similar relation probably holds after feeding isotopic ammonia. 2. It is pointed out that the ratio of average r(a) to average r(u) depends on the time interval for which urine is collected, on the schedule of feeding, and probably also on the amount taken at each feeding. When the amount fed and the feeding schedule are unknown, theoretical interpretation of the ratio of average r(u) to average r(u) is impossible. 3. At the point of maximum isotopic ratio of urea, it is very probably equal to the isotopic ratio of ammonia. A possible explanation is suggested.

Ammonia↗
PubMed1951

Rate of excretion of N15 after feeding N15-labeled l-aspartic acid in man.

1. l-Aspartic acid labeled with N(15) was fed to one human adult and six infants, and the total N and N(15) were determined in the urine from time to time. 2. The N(15) concentration (or isotopic ratio) of urinary N reached its maximum in the adult about 2 hours and in the infants about 4 hours after feeding, then fell off logarithmically. 3. Assuming that the N of aspartic acid readily entered into equilibrium with other N compounds in the pool, the rate of turnover of the N pool was calculated from the rate of fall of the isotopic ratio of urinary N. This rate of turnover of N was about 4 per cent per hour in the adult and 6 to 12 per cent per hour in the infants. 4. The rate of protein synthesis calculated from the rate of turnover of N was 10 mg. N per kilo per hour in the adult and 18 to 27 mg. N per kilo per hour in the infants, with one exception which showed a higher rate of 52 mg. N per kilo per hour. The size of the metabolic pool of N per kilo in non-growing infants was about the same as that in the adult (0.4 to 0.5 gm.) but it was somewhat larger in growing infants (0.5 to 0.8 gm.).

Adult↗