Nitrogenous compounds of interest in clinical nutrition.

The term "conditionally essential" (or semi-essential), initially applied to amino acids, has been generalized to other nutrients. A conditionally essential nutrient is a compound usually produced in adequate amounts by endogenous synthesis but that is exogenously required under certain circumstances. Thus, arginine, glutamine, cysteine, glycine, carnitine, choline, and polyamines are conditionally essential compounds. In addition, dietary nucleotides are considered semi-essential since some rapidly growing tissues such as the gut, bone marrow, and lymphocytes, preferentially use preformed purine and pyrimidine bases for nucleic acid synthesis. This review discusses the study of conditionally essential nitrogenous nutrients of interest in clinical nutrition. Among them we highlight arginine, involved in endothelial, immune, gastrointestinal, and renal functions, in reproduction, neonatal development, wound healing, and tumorigenicity; glutamine, necessary for maintaining bowel integrity, and with beneficial effects on catabolic states such as sepsis, infection, trauma, and cancer; and nucleotides, implicated in cell growth and differentiation, and with various effects on lipid metabolism, intestinal microbiota, and immune system.

Compuestos nitrogenados de interés en nutrición clínica / Nitrogenous compounds of interest in clinical nutrition

El término " condicionalmente esencial " (o semiesencial), aplicado inicialmente a los aminoácidos, se utiliza de forma generalizada para otros nutrientes. Un nutriente condicionalmente esencial es un compuesto producido usualmente en cantidades adecuadas por síntesis endógena pero que se requiere de forma exógena bajo determinadas circunstancias. Así, la arginina, la glutamina, la cisteína, la glicina, la prolina y la tirosina son aminoácidos semiesenciales. Entre los derivados de aminoácidos, la carnitina, la colina, y las poliaminas tienen también el carácter de compuestos condicionalmente esenciales. Asimismo, los nucleótidos de la dieta se consideran compuestos semiesenciales debido a que algunos tejidos de rápido crecimiento como el intestino, la médula ósea y los linfocitos utilizan preferentemente bases púricas y pirimidínicas preformadas para la síntesis de ácidos nucleicos. Esta revisión se dedica al estudio de nutrientes condicionalmente esenciales de naturaleza nitrogenada y con interés en nutrición hospitalaria. Entre ellos destacan la arginina, implicada en las funciones endotelial, inmunitaria, gastrointestinal y renal, la reproducción, el desarrollo neonatal, la curación de heridas y la tumorigénesis; la glutamina, necesaria para el mantenimiento de la integridad intestinal y con efectos beneficiosos en estados catabólicos como la sepsis, la infección, el trauma y el cáncer; y los nucleótidos, involucrados en el crecimiento y la diferenciación celular, y con efectos sobre el metabolismo lipídico, la microbiota intestinal y el sistema inmunitario (AU)

The term "conditionally essential" (or semi-essential), initially applied to amino acids, has been generalized to other nutrients. A conditionally essential nutrient is a compound usually produced in adequate amounts by endogenous synthesis but that is exogenously required under certain circumstances. Thus, arginine, glutamine, cysteine, glycine, carnitine, choline, and polyamines are conditionally essential compounds. In addition, dietary nucleotides are considered semi-essential since some rapidly growing tissues such as the gut, bone marrow, and lymphocytes, preferentially use preformed purine and pyrimidine bases for nucleic acid synthesis. This review discusses the study of conditionally essential nitrogenous nutrients of interest in clinical nutrition. Among them we highlight arginine, involved in endothelial, immune, gastrointestinal, and renal functions, in reproduction, neonatal development, wound healing, and tumorigenesis; glutamine, necessary for maintaining bowel integrity, and with beneficial effects on catabolic states such as sepsis, infection, trauma, and cancer; and nucleotides, implicated in cell growth and differentiation, and with various effects on lipid metabolism, intestinal microbiota, and immune system (AU)