Perspectives of glutamine and its derivatives as feed additives for farm animals

Abstract

Glutamine and its derivatives e.g., alpha-ketoglutaric acid (AKG) or ornithine-alpha-ketoglutarate (OKG) are molecules with a central role (via the Krebs cycle) in systemic, intestinal and gut bacterial metabolism. Studies have shown that AKG is a precursor not only of glutamine and arginine, but also of some other keto acids e.g., alpha-ketoisocaproate which in turn is a precursor of hydroxy-methyl-butyrate, which itself is regarded as a protein catabolic protector. Recently it has been postulated that AKG is not only an important energy donor, but that it also functions as an ammonium ion scavenger via transformation to glutamate, ornithine and putrescine and finally to GABA or succinate. Several beneficial effects of AKG have been reported in human medicine e.g., improved patients' recovery following gastrointestinal surgery. On the other hand, is was reported that 100 per cent glutamate metabolism in the first pass in infant pigs' small intestine. In the current presentation we discuss the potential benefits of using glutamine derivatives in human clinical nutrition as well as their role as feed additives in the production of farm animals.KEY WORDS: feed additives, glutamine, alpha-keto-glutarate METABOLIC AND PHYSIOLOGICAL EFFECTS OF GLUTAMINE AND ITS DERIVATIVESIn certain physiological and pathological conditions associated with acute or chronic malnutrition and/or hormonal stress, the human body shows signs of increased protein degradation or decreased protein synthesis, or both (Ahlman et al.,

Dietary supplementation with glutamate precursor α-ketoglutarate attenuates lipopolysaccharide-induced liver injury in young pigs

“…AKG is a key intermediate in the tricarboxylic acid cycle as well as a precursor of glutamate and glutamine (Blachier et al 2009;Hou et al 2011a;Yao et al 2012). Exogenous AKG can be converted to glutamate and glutamine in many tissues (Pierzynowski and Sjodin 1998;Kristensen et al 2002) and may have a sparing effect on glutamate and aspartate in cells by serving as a fuel source (Hou et al 2011a;Junghans et al 2006;Lambert et al 2006). When AKG enters the tricarboxylic acid cycle, it is oxidized by AKG dehydrogenase (Blachier et al 2009;Junghans et al 2006).…”

Alpha-ketoglutarate inhibits glutamine degradation and enhances protein synthesis in intestinal porcine epithelial cells

“…Thus, AKG may be able to inhibit glutamine utilization by intestinal cells. Emerging evidence shows beneficial effects of AKG in clinical and experimental nutrition, particularly with respect to intestinal growth and integrity (Hou et al 2011;Pierzynowski and Sjodin 1998). For example, enteral administration of AKG reduces infectious complications after trauma and surgery in humans in the early postoperative phase (Junghans et al 2006), whereas AKG improves nitrogen balance in burn patients (De Bandt et al 1998) and the healing of the small intestine after radiation (Kalfarentzos et al 1996).…”

Anticatabolic activity of alpha-ketoglutaric acid in growing rats

“…Therefore, the improvement of the enterocytes height was probably due to the higher availability of Gln resulting from the AKG acid administration (Pierzynowski and Sjodin, 1998;Drozdowski and Thomson, 2006).…”