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Published on: September 17, 2008
THE METABOLISM OF AMINO ACIDS AND CASEIN DIGEST IN PHLORHIZINIZED DOGS
W B Hawkins1, F W McKee, G M Hawley
1Department of Pathology, The University of Rochester School of Medicine and Dentistry, Rochester, New York.
The Journal of Experimental Medicine
|October 30, 2009
Summary
Phlorhizinized dogs given sugar-forming amino acids or casein digests excrete extra urinary sugar and nitrogen. Administration route does not affect amino acid metabolism, indicating these are readily available nutrient sources.
Area of Science:
- Biochemistry
- Animal Physiology
- Metabolic Studies
Background:
- Phlorhizinization induces renal glycosuria, creating a model to study carbohydrate metabolism.
- Amino acids are fundamental building blocks, but their direct conversion to glucose in vivo requires investigation.
Purpose of the Study:
- To investigate the metabolic fate of sugar-forming amino acids and casein digests in phlorhizinized dogs.
- To determine if the route of administration (oral vs. parenteral) impacts amino acid metabolism and glucose conversion.
Main Methods:
- Administration of sugar-forming amino acids and casein digests to phlorhizinized dogs via oral and parenteral routes.
- Measurement of urinary sugar and nitrogen excretion to quantify metabolic conversion.
- Comparison of metabolic efficiency between different administration routes.
Main Results:
- Phlorhizinized dogs receiving amino acids or casein digests showed increased urinary excretion of sugar and nitrogen.
- The route of administration (oral or parenteral) did not significantly alter the metabolic pathway or efficiency of amino acid conversion to sugar.
- Recovery rates for administered amino acids were high (89% oral, 81% parenteral), and casein digests showed efficient conversion (53% oral, 56% intravenous).
Conclusions:
- Sugar-forming amino acids and casein digests serve as readily available sources of nitrogen and carbohydrate for the body.
- The body efficiently metabolizes these substances into glucose, irrespective of whether they are administered orally or parenterally.
- These findings support the role of specific amino acids and protein digests as viable substrates for gluconeogenesis.
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