The problem of nitrogen disposal in the obese

dc.contributor.authorAlemany, Marià, 1946-
dc.date.accessioned2014-05-05T14:23:12Z
dc.date.available2014-05-05T14:23:12Z
dc.date.issued2012-06
dc.date.updated2014-05-05T14:23:12Z
dc.description.abstractAmino-N is preserved because of the scarcity and nutritional importance of protein. Excretion requires its conversion to ammonia, later incorporated into urea. Under conditions of excess dietary energy, the body cannot easily dispose of the excess amino-N against the evolutively adapted schemes that prevent its wastage; thus ammonia and glutamine formation (and urea excretion) are decreased. High lipid (and energy) availability limits the utilisation of glucose, and high glucose spares the production of ammonium from amino acids, limiting the synthesis of glutamine and its utilisation by the intestine and kidney. The amino acid composition of the diet affects the production of ammonium depending on its composition and the individual amino acid catabolic pathways. Surplus amino acids enhance protein synthesis and growth, and the synthesis of non-protein-N-containing compounds. But these outlets are not enough; consequently, less-conventional mechanisms are activated, such as increased synthesis of NO∙ followed by higher nitrite (and nitrate) excretion and changes in the microbiota. There is also a significant production of N(2) gas, through unknown mechanisms. Health consequences of amino-N surplus are difficult to fathom because of the sparse data available, but it can be speculated that the effects may be negative, largely because the fundamental N homeostasis is stretched out of normalcy, forcing the N removal through pathways unprepared for that task. The unreliable results of hyperproteic diets, and part of the dysregulation found in the metabolic syndrome may be an unwanted consequence of this N disposal conflict.
dc.format.extent11 p.
dc.format.mimetypeapplication/pdf
dc.identifier.idgrec605750
dc.identifier.issn0954-4224
dc.identifier.urihttps://hdl.handle.net/2445/53851
dc.language.isoeng
dc.publisherCambridge Universtity Press
dc.relation.isformatofReproducció del document publicat a: http://dx.doi.org/10.1017/S0954422411000163
dc.relation.ispartofNutrition Research Reviews, 2012, vol. 25, num. 1, p. 18-28
dc.relation.urihttp://dx.doi.org/10.1017/S0954422411000163
dc.rights(c) Alemany, Marià, 1946-, 2012
dc.rights.accessRightsinfo:eu-repo/semantics/openAccess
dc.sourceArticles publicats en revistes (Nutrició, Ciències de l'Alimentació i Gastronomia)
dc.subject.classificationAminoàcids
dc.subject.classificationAmoníac
dc.subject.classificationDieta
dc.subject.classificationExcreció
dc.subject.classificationNitrogen
dc.subject.classificationObesitat
dc.subject.classificationSíndrome metabòlica
dc.subject.classificationTrastorns del metabolisme
dc.subject.classificationUrea
dc.subject.classificationProteïnes dels aliments
dc.subject.meshProtein content of food
dc.subject.otherAmino acids
dc.subject.otherAmmonia
dc.subject.otherDiet
dc.subject.otherExcretion
dc.subject.otherNitrogen
dc.subject.otherObesity
dc.subject.otherMetabolic syndrome
dc.subject.otherDisorders of metabolism
dc.subject.otherUrea
dc.titleThe problem of nitrogen disposal in the obese
dc.typeinfo:eu-repo/semantics/article
dc.typeinfo:eu-repo/semantics/publishedVersion

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