Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Keto Acids”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 37 records · Page 2Linked to original sources

Growth of rats fed by a continuous intragastric infusion containing amino acids and keto acids.

A nutrient mixture was designed to minimize electrolyte and nitrogen excretion in rats while permitting growth. It contained lysine, threonine, histidine, tryptophan, ornithine, N-free analogues of the other essential amino acids, sucrose, corn oil, minerals, and vitamins. Intragastric infusion of this mixture for 25 days into 150-g rats with no access to food or water produced an average weight gain (after a 4-day lag period) of 3.48 +/- 0.09 g/day with proportionate increase in tail length. Urinary excretion rates of N, urea, Na, K, and P became very low. Fecal N fell to 4 mg/day. Urine pH averaged 6.1. Plasma amino acid concentrations changed markedly. Carcass analysis showed that an average of 63% of the 144 mg/day of administered N was retained for growth. Thus, this nutrient mixture is unusually efficiently utilized and leads to minimal excretion of waste products.

Amino Acids↗

Evaluation of essential amino acids and keto acids in uremic patients on low-protein diet.

The effectiveness of a mixture of five analogues of essential amino acids and the remaining four essential amino acids as compared to a preceeding treatment period of the nine essential amino acids was evaluated in 16 chronic uremic patients fed a low-protein diet. During amino acid analogues supplementation, there was a tendency for blood urea nitrogen to fall whereas creatinine did not change. Serum phosphate decreased in most patients, whereas serum calcium rose in some subjects. Protein metabolism, as judged by serum transferrin, Clq, C3c, total complement activity, was improved. Furthermore, the concentrations of prealbumin and retinol-binding protein, which are elevated in uremia, showed a further increase that might favor a vitamin A intoxication.

Adult↗

Influence of essential amino acids and keto acids on protein metabolism and anemia of patients on intermittent hemodialysis.

Ten patients were treated with 10 g/day of essential amino acids orally; nine patients received 9.5 g/day of a mixture of essential amino acids (lysine, threonine, tryprophan, histidine, and tyrosine) and keto analogues of isoleucine, leucine, phenylalanine, valine, and methionine. A control group of 11 patients received no supplementation. All patients were on a liberal food intake amounting to 1 g of protein per kilogram of body weight and 31 kcal/kg of body weight daily. Before and 3 months after the beginning of the supplementation, the following parameters were measured: amino acids, albumin, transferrin, urea and creatinine concentrations in plasma, hemoglobin, and hematocrit in blood. None of these parameters was altered by either treatment. It is concluded that supplementation with essential amino acids or their keto analogues is ineffective in well-nourished dialysis patients.

Administration, Oral↗

2-ketoglutarate generation in pancreatic B-cell mitochondria regulates insulin secretory action of amino acids and 2-keto acids.

The various neutral amino acids and aliphatic 2-keto acids exhibit differential effects on insulin secretion. The common denominator for all these effects is the 2-ketoglutarate generation in the pancreatic B-cell mitochondria. The neutral amino acids L-leucine and L-norvaline and the aliphatic ketomonocarboxylic acids 2-ketoisocaproate, 2-ketocaproate, 2-ketovalerate, and 2-keto-3-methylvalerate all stimulate insulin secretion and increase 2-ketoglutarate generation in pancreatic B-cell mitochondria through activation of glutamate dehydrogenase and transamination with L-glutamate and L-glutamine, respectively. The neutral amino acids L-valine, L-norleucine, and L-alanine and the aliphatic 2-keto acids 2-ketoisovalerate and pyruvate do not stimulate insulin secretion and do not increase 2-ketoglutarate generation in pancreatic B-cell mitochondria. Inhibition of 2-keto acid induced insulin secretion by L-valine and L-isoleucine is accompanied by reduced 2-ketoglutarate generation in pancreatic B-cell mitochondria. Thus intramitochondrial 2-ketoglutarate generation in pancreatic B-cells may regulate the insulin secretory potency of amino acids and 2-keto acids.

Amino Acids↗

Transamination of neutral amino acids and 2-keto acids in pancreatic B-cell mitochondria.

High aminotransferase activities catalyzing the reactions between L-glutamate and L-glutamine and the aliphatic ketomonocarboxylic acids 2-ketoisocaproate, 2-ketocaproate, and 2-ketoisovalerate were observed in pancreatic B-cell mitochondria. While maximal rates of transamination with L-glutamate were observed in the presence of micromolar concentrations of keto acid, maximal rates of transamination with L-glutamine were recorded only in the presence of millimolar concentrations of keto acid. The insulin secretagogue 2-ketoisocaproate was the most effective transamination partner for L-glutamate, while the insulin secretagogue 2-ketocaproate was the most effective transamination partner for L-glutamine. Since B-cell mitochondria are well supplied with L-glutamate and L-glutamine, 2-ketoglutarate generation in the presence of these two neutral 2-keto acids may be an important prerequisite for their insulin secretory potency. High rates of transamination of 2-ketoglutarate were observed in the pancreatic B-cell mitochondria with the branched-chain amino acids L-leucine and L-valine, but not with L-norleucine. In connection with the ability of L-leucine to activate glutamate dehydrogenase, this high activity of the branched-chain amino acid aminotransferase in pancreatic B-cell mitochondria may provide an explanation for the insulin secretory potency of this amino acid.

Animals↗