These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


PUBMED FOR HANDHELDS

Search MEDLINE/PubMed


  • Title: Ornithine loading did not prevent induced hyperammonemia in a patient with hyperornithinemia-hyperammonemia-homocitrullinuria syndrome.
    Author: Simell O, Mackenzie S, Clow CL, Scriver CR.
    Journal: Pediatr Res; 1985 Dec; 19(12):1283-7. PubMed ID: 4080446.
    Abstract:
    Impairment of urea cycle function in hyperornithinemia-hyperammonemia-homocitrullinuria syndrome is presumably caused, in some patients, by deficient transport of ornithine from cytoplasm into mitochondria. We studied the effect of L-ornithine on L-alanine-induced hyperammonemia in a French-Canadian proband with the syndrome by giving: a 90-min intravenous alanine load (6.6 mmol/kg) together with ornithine (1.1 mmol/kg); an intravenous ornithine bolus (0.3 mmol/kg) followed by ornithine infusion (1.1 mmol/kg) 90 min prior to loading with alanine and ornithine; ornithine supplementation per os (1 g, four times daily X 2 wk) prior to loading with alanine and ornithine. Blood ammonia increased from high normal values to 975, 990, and 750 mumol/liter (normal less than 70) and urinary orotic acid from trace to 539, 494, and 1296 mumol/mmol creatinine (normal 5-11) after the respective loads. Plasma alanine peaked at 1.56-4.24 mmol/liter and ornithine at 1.29-1.95 mmol/liter, but other amino acids were stable. Therefore, ornithine loading did not protect this hyperornithinemia-hyperammonemia-homocitrullinuria patient from hyperammonemia induced by amino-nitrogen loading. Renal fraction excretion of citrulline, lysine, ornithine, glycine, alanine, and tyrosine increased more than 3-fold during ornithine priming, whereas all amino acids were excreted in excess after alanine + ornithine loads; homocitrulline excretion remained unchanged; some urine collections indicated "negative reabsorption" (i.e. apparent secretion) of lysine, histidine, and citrulline. Dietary supplementation with ornithine could deplete lysine pools by impairing lysine reabsorption.
    [Abstract] [Full Text] [Related] [New Search]