+ Site Statistics
+ Search Articles
+ PDF Full Text Service
How our service works
Request PDF Full Text
+ Follow Us
Follow on Facebook
Follow on Twitter
Follow on LinkedIn
+ Subscribe to Site Feeds
Most Shared
PDF Full Text
+ Translate
+ Recently Requested

Estimation of urea production rate with [(15)n(2)]urea and [(13)c]urea to measure catabolic rates in diabetes mellitus



Estimation of urea production rate with [(15)n(2)]urea and [(13)c]urea to measure catabolic rates in diabetes mellitus



Isotopes in Environmental and Health Studies 33(1-2): 107-118



Abstract For verifying catabolic states in insulin-dependent patients and dogs the method estimating urea production rates with (13)C and with doubly (15)N labeled urea, respectively, has been established. For a fast steady state of urea tracer dilution, a prime of 600 times the continuous infusion rate had to be injected. Urea was isolated from plasma samples by protein precipitation and cation exchange chromatography with a consecutive derivatization of the dried urea fraction (trimethylsilyl derivatives). The masses of the fragment ions m/z 189 ((14)N(14)N), 190 ((14)N(15)N) and 191 ((15)N(15)N) urea are monitored to estimate the [(15)N(2)]urea frequency in the overall body urea pool in mol percent excess (MPE). 1 to 15 ng of derivatized urea were measured efficiently. An excellent correlation between expected standard and measured MPE (r = 0.9977) was achieved from solutions containing 1 to 7% [(15)N(2)]urea. The interassay coefficient of variation amounted to < 10% for a [(15)N(2)]urea portion of ≥ 3%. Normoglycemic diabetic patients who were treated with insulin overnight showed significantly higher urea production compared to healthy controls (9.22 ± 2.07 vs. 5.4 ± 0.32 μmol·kg(-1) · min(-1); p < 0.05). Measurements in chronic diabetic dogs proved an increased rate of amino acid catabolism (+ 20% urea production) in systemic versus portal application of insulin in paired studies. This increased nitrogen load in diabetics may accelerate progression of diabetic nephropathy. - Thus, the established stable isotope technique may serve as a sensitive and useful indicator of amino acid catabolism in clinical and experimental research.

Please choose payment method:






(PDF emailed within 0-6 h: $19.90)

Accession: 053042174

Download citation: RISBibTeXText

PMID: 22087488

DOI: 10.1080/10256019708036338


Related references

Estimation of urea production rate with [15N2]urea and [13C]urea to measure catabolic rates in diabetes mellitus. Isotopes in Environmental and Health Studies 34(1-2): 107-118, 1998

A method for estimating uptake and production rates for urea in seawater using carbon 14 urea and nitrogen 15 urea. Canadian Journal of Fisheries & Aquatic Sciences 46(2): 198-202, 1989

A Method for Estimating Uptake and Production Rates for Urea in Seawater using [ 14 C] Urea and [ 15 N] Urea. Canadian Journal of Fisheries and Aquatic Sciences 46(2): 198-202, 1989

In-vivo protein synthesis in the rumen following the administration of urea or mixtures of urea and acetamide, urea and acetamide, urea and acetyl urea, or urea and acetyl urea + ammonium hydrogen carbonate in shop. 1. experiments with 15 N labelling. 1972

In vivo turnover and synthesis of proteins from urea or mixtures of urea + acetamide, urea + acetyl urea or urea + acetyl urea + ammonium hydrogen carbonate in sheep. 4. formation of free fatty acids. 1972

In-Vivo Turnover and Synthesis of Proteins from Urea, or Mixtures of Urea + Acetamide, Urea + Acetyl Urea, or Urea + Acetyl Urea + Ammonium Hydrogen Carbonate in Sheep. II. Experiments with 35S -labelling and N -balance studies. 1972

In vivo protein synthesis in the rumen following the administration of urea or mixtures of urea and acetamide urea and acetyl urea or urea and acetyl urea and ammonium hydrogen carbonate part 1 experiments with nitrogen 15 labeling. Archiv Fuer Tierernaehrung: 297-314, 1972

In vivo turnover and synthesis of proteins from urea or mixtures of urea plus acetamide urea plus acetyl urea or urea and acetyl urea plus ammonium hydrogen carbonate in sheep part 4 formation of free fatty acids. Archiv fuer Tierernaehrung 22(8): 501-507, 1972

In vivo turnover and synthesis of proteins from urea or mixtures of urea plus acetamide urea plus acetyl urea or urea plus acetyl urea plus ammonium hydrogen carbonate in sheep part 2 experiments with sulfur 35 labeling and nitrogen balance studies. Archiv fuer Tierernaehrung 22(6): 377-388, 1972

Errors in Computing the Normalized Protein Catabolic Rate due to Use of Single-pool Urea Kinetic Modeling or to Omission of the Residual Kidney Urea Clearance. Journal of Renal Nutrition 27(4): 256-259, 2017

Metabolism by sheep in vivo and protein synthesis from urea and mixtures of urea with acetamide, urea with acetylurea and urea, acetylurea and ammonium bicarbonate. 4. Production of free fatty acids. Archiv fur Tierernahrung 22(8): 501-507, 1972

Determination of protein catabolic rate in patients on chronic intermittent hemodialysis: urea output measurements compared with dietary protein intake and with calculation of urea generation rate. American Journal of Kidney Diseases 25(6): 887-895, 1995

In-vivo turnover and synthesis of proteins from urea or mixtures of urea + acetamide, urea + acetyl urea or acetyl urea + ammonium hydrogen carbonate in sheep. III. A further trial with 35S labelling and summarizing remarks on nitrogen utilization. 1972

In vivo turnover and synthesis of proteins from urea or mixtures of urea plus acetamide urea plus acetyl urea or acetyl urea plus ammonium hydrogen carbonate in sheep part 3 a further trial with sulfur 35 labeling and summarizing remarks on nitrogen utilization. Archiv fuer Tierernaehrung 22(7): 457-466, 1972

The Effect of the Administration of Urea on the Ratio between the Rate of Urea Excretion and the Concentration of Urea in the Blood in Experimental Glomerulonephritis. Journal of Urology 2(3): 227-236, 1918