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Query: UMLS:C0011849 (diabetes)
 277,896 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Competition between glucose and free fatty acids as metabolic fuels is supported by both in vitro and in vivo data, but whether amino acids can also compete with glucose as a source of energy in vivo remains to be established. To determine the effect of increased availability of an amino acid on whole-body glucose flux and glucose carbon uptake by the human forearm, five groups of overnight-fasted normal subjects were infused with either saline, leucine (at 0.5 or 1.0 mumol X kg-1 X min-1), isoleucine (0.5 mumol X kg-1 X min-1), or threonine (0.5 mumol X kg-1 X min-1). Plasma glucose concentrations and glucose flux decreased similarly in all groups. No significant changes in forearm output of leucine carbon, isoleucine carbon, or threonine were seen during saline infusion. In contrast, during leucine infusion there was a dose-dependent increase (r = .86, P less than .001) in leucine carbon uptake with increased arterial leucine and alpha-ketoisocaproate concentrations. During infusions of isoleucine and threonine, increases (P less than .05) in isoleucine carbon uptake and threonine uptake, respectively, were observed. Glucose uptake by forearm tissues did not change during the saline infusion, but it decreased (P less than .05) in all four groups receiving an amino acid infusion. Changes in leucine carbon uptake were strongly correlated (r = -.76, P less than .001) with changes in glucose uptake. Therefore, amino acids affect glucose uptake in human forearm tissue and presumably compete as oxidative fuels.
Diabetes 1987 Feb
PMID:Decreased uptake of glucose by human forearm during infusion of leucine, isoleucine, or threonine. 310 Mar 68

Previous studies showed that the diabetogenic action of streptozotocin is reduced in rats adapted to a high-protein, carbohydrate-free diet, that have markedly elevated plasma concentrations of valine, leucine and isoleucine. In order to test the role of these branched chain amino acids (BCAA) in the beneficial effects of the high-protein diets, rats adapted (15 days) either to a balanced synthetic diet, or to the same diet supplemented with BCAA were injected with streptozotocin (STZ) (40 mg/kg body weight) and maintained on the same diets after drug injection. Rats previously fed the BCAA enriched diet showed a partial but significant reduction in the severity of diabetes, as indicated by higher rates of body weight gain, lower food and water intake, lower excretion of glucose and higher serum insulin levels. Rats previously fed the control diet for 14 days, but transferred to the BCAA diet 3 days after STZ injection, also showed reduced severity of diabetes, as indicated by rates of body weight gain, water and food ingestion, glucose and insulin levels. The data suggest that the increased supply of BCAA is responsible, at least in part, for the previously reported beneficial effects of high-protein diets in rats with STZ-induced diabetes.
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PMID:Dietetic supplementation with branched chain amino acids attenuates the severity of streptozotocin-induced diabetes in rats. 322 89

Plasma amino acid concentrations were measured in six insulin-dependent diabetic women and seven non-diabetic women in early pregnancy while fasting and one hour after a standard meal. Fasting plasma levels of total amino acids and individual amino acids were similar in the two groups, excepting isoleucine, which was raised in the diabetics. One hour post-prandially total amino acid concentrations were similar in the two groups; however, mean concentrations of total branched chain amino acids and mean concentration of the individual amino acids, serine, valine, isoleucine, leucine and tyrosine were elevated in the diabetics. Amino acids are important in early islet development and in insulin secretion from fetal pancreas in vitro. The elevated post-prandial amino acid levels found in pregnant diabetics in early pregnancy may contribute to fetal islet hypertrophy and hyperinsulinaemia.
Diabetes Res Clin Pract 1986 Jun
PMID:Amino acid profiles in early diabetic and non-diabetic pregnancy. 374 58

Insulin-dependent diabetes mellitus (IDDM) induces plasma amino acid (AA) abnormalities, including low alanine and high branched-chain (BCAA). While insulin treatment restores plasma AA pattern, proline, methionine, valine, isoleucine, and total BCAA remain elevated in skeletal muscle intracellular water. This suggests that the restoration of plasma AA concentrations is not a satisfactory index of recovered AA metabolism in IDDM.
Diabetes 1985 Aug
PMID:Plasma and skeletal muscle free amino acids in type I, insulin-treated diabetic subjects. 389 23

The effect of diabetes (streptozotocin, 65 mg/kg ip), dietary protein intake (15-60%), and plasma amino acid concentrations on brain large neutral amino acid levels in rats was examined. After 20 days, the plasma concentrations of methionine and the branched chain amino acids (BCAA), valine, isoleucine, and leucine were increased in diabetic rats. In brain tissue, methionine and valine levels were increased but threonine, tyrosine, and tryptophan concentrations were depressed. Increased protein consumption promoted a diabetic-like plasma amino acid pattern in normal rats while enhancing that of diabetic animals. However, with the exception of threonine, glycine, valine, and tyrosine, there was little effect on brain amino acid levels. A good association was found between the calculated brain influx rate and the actual brain concentration of threonine, methionine, tyrosine, and tryptophan in diabetic animals. There was no correlation, however, between brain influx rate and brain BCAA levels. Thus, the brain amino acid pattern in diabetes represents the combined effects of insulin insufficiency and composition of the diet ingested on plasma amino acid levels as well as metabolic adaptation within the brain itself.
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PMID:The effect of insulin deficiency, dietary protein intake, and plasma amino acid concentrations on brain amino acid levels in rats. 404 90

1. The effect of three types of diabetes (alloxan, partial pancreatectomy and anti-insulin serum) on the concentrations of individual amino acids in the plasma and heart muscle of rats was studied. 2. Insulin deficiency produced complex alterations in the concentrations of amino acids in plasma and heart muscle; the concentrations of some (alanine, valine, leucine and isoleucine) increased, others decreased and a small number were unchanged. The complexity of the results may in part be attributed to the diverse hormonal and metabolic changes that accompany diabetes.
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PMID:Effect of diabetes on the concentration of amino acids in plasma and heart muscle of rats. 596 35

1. Concentrations of polyamines, amino acids, glycogen, nucleic acids and protein, and activities of ornithine decarboxylase and S-adenosylmethionine decarboxylase, were measured in livers from control, streptozotocin-diabetic and insulin-treated diabetic rats. 2. Total DNA per liver and protein per mg of DNA were unaffected by diabetes, whereas RNA per mg of DNA and glycogen per g of liver were decreased. Insulin treatment of diabetic rats induced both hypertrophy and hyperplasia, as indicated by an increase in all four of these constituents to or above control values. 3. Spermidine content was increased in the livers of diabetic rats, despite the decrease in RNA, but it was further increased by insulin treatment. Spermine content was decreased by diabetes, but was unchanged by insulin treatment. Thus the ratio spermidine/spermine in the adult diabetic rat was more typical of that seen in younger rats, whereas insulin treatment resulted in a ratio similar to that seen in rapidly growing tissues. 4. Ornithine decarboxylase activity was variable in the diabetic rat, showing a positive correlation with endogenous ornithine concentrations. This correlation was not seen in control or insulin-treated rats. Insulin caused a significant increase in ornithine decarboxylase activity relative to control or diabetic rats. 5. S-Adenosylmethionine decarboxylase activity was increased approx. 2-fold by diabetes and was not further affected by insulin. 6. Hepatic concentrations of the glucogenic amino acids, alanine, glutamine and glycine were decreased by diabetes. Their concentrations and that of glutamate were increased by injection of insulin. Concentrations of ornithine, proline, leucine, isoleucine and valine were increased in livers of diabetic rats and were decreased by insulin. Diabetes caused a decrease in hepatic concentration of serine, threonine, lysine and histidine. Insulin had no effect on serine, lysine and histidine, but caused a further fall in the concentration of threonine.
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PMID:Polyamine and amino acid content, and activity of polyamine-synthesizing decarboxylases, in liver of streptozotocin-induced diabetic and insulin-treated diabetic rats. 616 56

Male rats treated 3 wk earlier with streptozotocin showed abnormally high blood levels of leucine, isoleucine, and valine throughout the 24-h period. Serum phenylalanine levels were slightly increased, while those of tryptophan and tyrosine were occasionally reduced. In brain, the level of each branched-chain amino acid was significantly increased above normal at all times. The brain concentration of each aromatic amino acid was always below normal. These changes were restored almost to normal by exogenous insulin therapy. Since the ingestion of protein is normally a major factor influencing blood amino acid levels, the effect of ingesting single, protein-containing meals on the blood and brain levels of these amino acids was also studied. After an overnight fast, the ingestion of a protein-containing meal by diabetic rats increased substantially both blood and brain levels of each branched-chain amino acid. No such increases occurred in normal rats. Ingestion of this meal produced only small changes in the brain and blood levels of the aromatic amino acids in both diabetic and normal rats. The changes in the brain level of each large neutral amino acid in some cases paralleled those in its blood level. More often, they paralleled the changes in the blood ratio of each amino acid to the sum of the other aromatic and branched-chain amino acids. This ratio is often a good predictor of the competitive transport of these amino acids into brain (Fernstrom and Faller, 1978). The observed changes in the brain levels of these amino acids in diabetes may influence the rates at which they are consumed in metabolic pathways within this organ.
Diabetes 1983 Mar
PMID:Effect of experimental diabetes on the levels of aromatic and branched-chain amino acids in rat blood and brain. 633 1

Experimental diabetes was induced in the bovine in two experiments by intravenous injection of alloxan (110 mg/kg or 60 mg/kg) in order to determine the role of insulin on nitrogen and amino acid metabolism. In experiment 1, insulin was injected to control hyperglycemia in one group of steers immediately after alloxan treatment (110 mg/kg). In experiment 2, insulin was injected beginning 6 days following alloxan treatment (60 mg/kg) to control hyperglycemia. Plasma glucose increased to 800-1400 mg/100 ml within 5-6 days following alloxan administration (experiment 1). A large surge of insulin release occurred immediately after alloxan administration, which was followed by a decrease in insulin concentrations to subnormal levels in those animals not treated with insulin. Alloxan-treated steers became acidotic by day 2 as indicated by a drop in blood pH, bicarbonate and base excess. Acid-base status improved in steers treated with alloxan plus insulin but did not return to normal. Alloxan treatment caused a marked increase in serum urea-N and creatinine concentrations and insulin treatment of the alloxanized animal decreased both serum urea-N and creatinine concentrations. Treatment with alloxan caused a two- to threefold increase in the plasma concentrations of valine, isoleucine, leucine, lysine and 3-methylhistidine and a decrease in alanine, threonine, citrulline and arginine. Insulin treatment of the alloxanized bovine maintained normal plasma concentrations of valine, isoleucine and leucine. In a third experiment, the injection of insulin (6 U/kg) into normal cattle caused a transient decline in plasma concentrations of branched-chain amino acids (BCAA); however, if glucose was continuously infused (125 mmol/hour) in addition to insulin injection, a sustained decrease in plasma BCAA concentrations was observed. These data support the concept that insulin promotes decreased plasma concentrations of BCAA either by promoting tissue anabolism by stimulating tissue uptake and protein synthesis or decreasing proteolysis and BCAA release.
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PMID:Role of insulin in regulating amino acid metabolism in normal and alloxan-diabetic cattle. 634 16

Alterations in plasma branched-chain amino acids (valine, isoleucine and leucine) and alanine have been described in patients with insulin-dependent diabetes mellitus who have poor metabolic control. To assess the relevance of these abnormalities as indices of metabolic control, we sequentially evaluated plasma amino acids in 14 poorly controlled diabetics (seven Type 1 (insulin-dependent) and seven Type 2 (non-insulin-dependent) patients) until good control was achieved. The sum of branched-chain amino acids in both groups of uncontrolled diabetic patients was significantly increased compared with the values for the same subjects in good metabolic control. No statistically significant differences were present between ketotic and non-ketotic uncontrolled patients. The amelioration of the diabetic state with either insulin treatment or oral hypoglycaemic agents, reduced progressively branched-chain amino acids. The sum of valine, isoleucine and leucine strictly correlated with daily urinary glucose (r = 0.73), but less well with fasting blood glucose (r = 0.43), non-esterified fatty acids (r = 0.46) and glycosylated haemoglobin (r = 0.38). Alanine did not show any statistically significant differences at various stages of diabetic control. Branched-chain amino acids, but not alanine, may be used as indices of short-term diabetic control.
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PMID:Branched-chain amino acids and alanine as indices of the metabolic control in type 1 (insulin-dependent) and type 2 (non-insulin-dependent) diabetic patients. 680 94


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