Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P01275 (glucagon)
 26,492 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The in vivo capacity of urea nitrogen synthesis (CUNS) during alanine stimulation was measured within the blood amino acid concentration interval 7.3-11.6 mmol/l, where urea synthesis is at maximum and independent of substrate concentration. Three groups of rats were fed for 14 days, either a low protein diet (8%), a normal diet (17%), or a high protein diet (53%). Diet protein modified both CUNS and plasma glucagon concentration. CUNS was 5.86 +/- 2.93, 7.43 +/- 2.16, and 19.31 +/- 4.32 mumol/(min.100 g BW) (mean +/- SD, N = 6), respectively. The corresponding plasma glucagon concentrations after alanine stimulation were 222 +/- 400, 633 +/- 229, and 1700 +/- 627 ng/l, respectively. The in vivo kinetics of urea production is regulated by dietary protein, possibly via glucagon. This implies that the liver plays an active part in adaptation of whole body nitrogen homeostasis to dietary changes.
 ...
PMID:Effect of dietary protein on the capacity of urea synthesis in rats. 207 58

The relation of urea synthesis rate to blood alanine concentration was assessed in seven healthy controls and in 18 patients with insulin-dependent diabetes mellitus (HbAlc = 8.4 +/- 1.0% (mean +/- SD)). Following an overnight fast alanine was infused at 2 mmol h-1 kg-1 body weight. The hourly rate of urea synthesis was determined as the urinary excretion of urea corrected for accumulation of urea in total body water and intestinal hydrolysis. The functional hepatic nitrogen clearance, i.e. the relation of urea synthesis rate to blood alanine concentration, was calculated as the slope of linear regression of urea synthesis rates on blood alanine concentrations. Fasting glucagon concentrations were 85 +/- 26 ng l-1 in controls and 161 +/- 35 ng l-1 (P less than 0.01) in patients. The functional hepatic nitrogen clearances were 21.8 +/- 4.4 l h-1 in controls and 44.7 +/- 12.4 l h-1 (P less than 0.001) in patients. By multiple step-wise linear regression analysis the functional hepatic nitrogen clearance was found to correlate independently to fasting glucagon concentration, duration of diabetes, change in blood glucose and insulin following alanine infusion (r2 = 0.74). In a simple linear regression analysis the functional hepatic nitrogen clearance correlated strongly to fasting glucagon concentration (r2 = 0.54). In conclusion the kinetics of urea synthesis in insulin-dependent diabetes is changed in favour of increased conversion of alanine-N to urea-N at any blood amino acid concentration. The increased FHNC correlates strongly with hyperglucagonaemia.
 ...
PMID:Increased hepatic efficacy of urea synthesis from alanine in insulin-dependent diabetes mellitus. 210 34

We studied some metabolic and hormonal effects of a very early nutrition supplementation in burned patients. The patients were divided into two groups of 10 patients each. Supplementation in the first group, the very early nutritionally supplemented (VENS) group, was started immediately after admission, ie, after 4.4 +/- 0.5 h (mean +/- SEM) from the injury; it was started after 57.7 +/- 2.6 h from the injury in the second group (control group). Hormonal and metabolic indices were recorded every 4 d up to 28 d. In the VENS group, the nitrogen balance became positive in 8.8 +/- 4.1 d whereas it took 24.1 +/- 6.9 d in the control group (p less than 0.05). Urinary catecholamine excretion and plasma glucagon concentrations were lower during the first 2 wk of observation in the VENS group compared with the control group. Insulin concentrations were significantly higher on the fourth and eighth days in VENS patients and plasma cortisol concentrations were similar in both groups.
 ...
PMID:Very early nutrition supplementation in burned patients. 211 39

Infusion of total parenteral nutrition (TPN) with excess carbohydrate calories leads to hepatic steatosis in rats and is associated with an elevated portal insulin/glucagon molar ratio. Previously we have shown that adding glucagon to TPN prevents and reverses hepatic steatosis in rats, possibly by increasing hepatic lipid export. It has been reported that steatosis is eliminated in rats by the addition of L-glutamine to TPN. In this study, we examined the effect of glutamine on portal insulin and glucagon levels and the development of hepatic steatosis. Adult rats (n = 19) received internal jugular catheters: Group 1 (n = 6), saline (3 cc/hr) and chow ad libitum; Group 2 (n = 7), 25% dextrose base TPN; Group 3 (n = 6), 25% dextrose base TPN with 2% glutamine. The infusion rate of TPN was 1.2 cc/100 g body wt/hr. Daily nitrogen balance was determined and at 7 days, portal venous blood was drawn for insulin and glucagon radioimmunoassay, livers were removed for histology and lipid content determination, and the small intestines were removed for mucosal protein and DNA content determination. Panlobular vacuolization of the hepatocytes was noted on histology in Group 2 (TPN) while Group 1 (chow) and Group 3 (TPN + glutamine) showed normal liver morphology. Hepatic lipid content was significantly elevated in Group 2 (P less than 0.05). The portal insulin/glucagon molar ratio was increased because of excessive portal venous insulin in Group 2 (TPN). In contrast, portal glucagon was significantly elevated while the insulin/glucagon ratio and hepatic lipid content did not increase above control levels in the glutamine-supplemented Group 3 rats.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:Addition of L-glutamine to total parenteral nutrition and its effects on portal insulin and glucagon and the development of hepatic steatosis in rats. 211 67

Six severely malnourished patients with chronic obstructive pulmonary disease were maintained for 3 days with infusions of 5% dextrose in water followed by 12 days of eucaloric total parenteral nutrition. On days 8 through 11, they received 30 micrograms/d of growth hormone and twice this amount on days 11 through 15. Growth hormone had no significant effects on the plasma concentration of glucose, cortisol, or glucagon but caused a 50% increase in insulin and a 250% increase in somatomedin C concentrations. A positive nitrogen balance of 2 g/d due to growth hormone was probably mediated by insulin. Growth hormone-induced increases in energy expenditure and fat oxidation and decrease in glucose oxidation cannot be accounted for by insulin. The ability of growth hormone to improve nitrogen balance may be particularly important for malnourished patients with chronic obstructive pulmonary disease who, because of their pulmonary insufficiency, are intolerant of excess nutrients.
 ...
PMID:Growth hormone and pulmonary disease. Metabolic effects in patients receiving parenteral nutrition. 211 5

1. The effects of increasing glucose intake on nitrogen balance, energy expenditure and fuel utilization were measured in 12 malnourished adult patients receiving parenteral nutrition with constant, very high nitrogen intake (500 mg of N/kg), high (105 kJ/kg) or low (30 kJ/kg) glucose intake and constant fat intake (7 kJ/kg). Each patient received each diet for 8-day periods in random order. 2. Energy balance and nitrogen balance were determined daily. Blood samples, taken at admission, during 5% (w/v) dextrose (D-glucose) infusion and at the end of days 7 and 8 of each diet, were analysed for urea, glucose, lactate, triacylglycerols, fatty acids, glycerol, 3-hydroxybutyrate, insulin and glucagon. 3. The effect of increasing glucose intake was to increase nitrogen balance by 0.60 +/- 0.25 (SEM) mg/kJ. At zero energy balance, nitrogen balance was 48 mg day-1 kg-1. This confirms findings of previous studies: that the effects of glucose on nitrogen balance are greater at high than at low nitrogen intakes, and that, in malnourished patients, unlike in normal adults, markedly positive nitrogen balance can be achieved at zero or negative energy balances. 4. Changes in nitrogen balance were due almost entirely to changes in urea excretion. 5. The high nitrogen intake markedly increased plasma insulin and glucagon concentrations and reduced glycerol, fatty acid and 3-hydroxybutyrate concentrations, independent of any glucose effect. Glucagon concentrations were significantly decreased by added glucose intake, an effect not previously seen at low nitrogen intakes. At this high nitrogen intake, the effects of added glucose appear to be mediated by both insulin and glucagon.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:Effects of glucose on nitrogen balance during high nitrogen intake in malnourished patients. 215 47

Fasting concentrations, clearance of exogenous infused amino acids, and lean body mass were studied in a patient with glucagonoma syndrome (fasting glucagon = 380 pmol/l, normal range 15-45 pmol). The fasting concentrations of all amino acids were reduced. The clearances of alanine, arginine, glycine, isoleucine, leucine, lysine, methionine, proline, serine, threonine, and tyrosine were increased. The urea synthesis rate during amino acid infusion was 27 mumols/kg per minute (normal range 20-24 mumols/kg per minute). The lean body mass of the patients was reduced to 59% of the expected value. It is suggested that the weight loss of patients with glucagonoma syndrome is partly due to increased hepatic conversion of amino acid nitrogen to urea nitrogen, resulting in decreased blood amino acid concentration, and secondary to this, organ protein catabolism, as shown by the decreased lean body mass.
 ...
PMID:Increased amino acid clearance and urea synthesis in a patient with glucagonoma. 216 78

The effects of gender on substrate utilization during prolonged submaximal exercise were studied in six males and six equally trained females. After 3 days on a controlled diet (so that the proportions of carbohydrate, protein, and fat were identical), subjects ran on a treadmill at a velocity requiring an O2 consumption of approximately 65% of maximal. They ran a total "distance" of 15.5 km with a range in performance time of 90-101 min. Plasma glycerol, glucose, free fatty acids, and selected hormones (catecholamines, growth hormone, insulin, and glucagon) were measured throughout and after the run by sampling from an indwelling venous catheter, and glycogen utilization was calculated from pre- and postexercise needle biopsies of vastus lateralis. Exercise protein catabolism was estimated from 24-h urinary urea nitrogen excretion over the test day and a nonexercise day. The males were found to have significantly higher respiratory exchange ratios (mean 0.94 vs. 0.87), greater muscle glycogen utilization (by 25%), and greater urea nitrogen excretion (by 30%) than the females. No gender differences were evident in the hormonal response to the exercise with the exception of a lower insulin concentration and a higher epinephrine concentration in the males. We conclude that, during moderate-intensity long-duration exercise, females demonstrate greater lipid utilization and less carbohydrate and protein metabolism than equally trained and nourished males.
 ...
PMID:Gender differences in substrate for endurance exercise. 217 7

To study the consequences of hyperglycemia on glucose and nitrogen metabolism in cirrhosis, an hyperglycemic clamp was performed in 5 cirrhotic patients and 5 normal controls during two subsequent periods of 90 min, at 7.78 and then at 13.89 mmol/l. In the first period, glucose infusion and metabolic clearance rates were decreased in cirrhotics vs controls (p less than 0.05). In the second period, this difference between the two groups disappeared because of a more important enhancement in cirrhotics. Baseline plasma C peptide levels and those during hyperglycemia were the same during hyperglycemia in both groups, but plasma insulin level rose more in cirrhotics (p less than 0.05). Baseline insulin secretion following IV glucagon was reduced in cirrhotics vs controls (p less than 0.05), but became normal in the hyperglycemic state. Plasma glucagon levels were enhanced at all times in cirrhotics vs controls (p less than 0.01), but dropped more in cirrhotics vs controls (p less than 0.05). Insulin responsiveness, defined as the "glucose consumption: plasma insulin concentration" ratio was reduced in cirrhotics at 7.78 mmol/l (p less than 0.01), but was the same in both groups at 13.80 mmol/l because of a more important enhancement in cirrhotics, reflecting an improvement of insulin action probably at the post-receptor level and of non-insulin-mediated glucose transport. Hyperglycemia induced a drop in plasma concentration and muscular release of all aminoacids, excepted alanine, between the basal state and the end of the study. Aminoacid concentration rose only in cirrhotics, without any change in muscular output. In the same time, blood ammonia level rose only in cirrhotics, without reduction of muscular uptake.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:[Consequences of hyperglycemia on glucose and nitrogen metabolism in liver cirrhosis. A study using a hyperglycemic clamp]. 219 90

This study was conducted to determine whether an amino acid solution enriched with branched-chain amino acids altered protein catabolic rates and plasma ammonia in patients with cirrhosis. Nine stable subjects were given two peripheral intravenous infusions: a standard amino acid solution (solution A) and a branched-chain-enriched solution containing 97% more leucine (solution B). Each solution was given for separate 9-day (group 1, n = 6) or 3-day (group 2, n = 3) periods. Amino acid solutions delivered 0.7 gm protein.kg-1.day-1. Diets provided an additional 0.3 gm protein plus maintenance calories. Protein turnover was assessed by a primed continuous infusion of [1-14C] leucine in six patients (three patients in group 1 and three patients in group 2). Nitrogen balance and urinary 3-methyl histidine excretion were determined in group 1 patients. Compared with solution A, solution B increased leucine flux and leucine oxidation but had no significant effect on protein synthesis or catabolism based on the plasma specific activity of either leucine or alpha-ketoisocaproic acid. The additional leucine infused with solution B was quantitatively oxidized. Nitrogen balance did not differ with the two solutions and there was also no difference in the urinary excretion of 3-methyl histidine, suggesting that muscle protein catabolism was unchanged. Plasma ammonia concentration decreased significantly during the infusion of solution B and was associated with a slight fall in plasma glucagon concentration. The results indicated that a branched-chain-enriched amino acid solution did not alter protein synthesis or catabolism although it did lower the plasma ammonia when compared with a standard amino acid formula in stable cirrhotic patients.
 ...
PMID:Effects of branched-chain amino acids on nitrogen metabolism in patients with cirrhosis. 219 23


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>