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

The effect of low protein intake on alpha-aminioisobutyric acid (AIB) transport has been examined in liver slices from meal-fed rats. Treatments (force-feeding casein or gelatin hydrolysates, glycine, or potassium chloride; injecting glucagon, or preincubating liver slices with cyclic AMP) which stimulated transport in control rat fed 3-hour meals containing 18% casein were less effective in rats fed 6% casein meals for 8 days. Responses of protein-depleted rats to glucagon or cyclic AMP had become essentially normal after they had consumed 18% casein meals for 2 days, whereas between 6 to 10 days were required for complete recovery of the response to casein hydrolysate. Stimulation of AIB transport by casein hydrolysate was also normal in depleted rats after they had consumed 40% casein meals for 2 days. Basal, non-stimulated transport of AIB was not significantly depressed in rats fed the low protein diet. Casein hydrolysate-induced increases in hepatic cyclic AMP concentrations were smaller in rats fed low protein meals. The results show that, although various stimuli of hepatic AIB transport become less effective in the protein-deprived rat, relatively rapid recovery of the response can occur upon refeeding adequate or high levels of protein.
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PMID:alpha-Aminoisobutyric acid transport in liver slices from rats fed low protein meals. 18 60

This study shown an abnormality in glucagon levels that may explain the glucose intolerance, abnormal insulin reactions, and abnormal plasma amino acid levels seen in amyotrophic lateral sclerosis (ALS). We randomly administered two test meals, differing only in protein source (soy versus casein) at least 1 week apart and measured fasting and postprandial bloods for glucagon, insulin, and glucose levels in 11 ALS patients. With the soy test meal, glucagon levels were elevated in all ALS patients compared with controls: at fasting (237 +/- 111 versus 108 +/- 46 pg/ml, p less than 0.01) and 1/2 hour (389 +/- 94 versus 133 +/- 68 pg/ml, p less than 0.001), and 2 hours postprandial (379 +/- 75 versus 108 +/- 53 pg/ml, p less than 0.001). Glucagon levels after the casein test meal were also significantly elevated. Insulin was elevated by both test meals. Casein produced significant glucose intolerance.
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PMID:Elevated plasma glucagon in amyotrophic lateral sclerosis. 849 33

The amino acid composition of the diet influences the postprandial levels of plasma amino acids along with the hormones insulin and glucagon in humans fed single test meals identical in composition except for protein source. Soy protein (hypocholesterolemic), vs. casein (hypercholesterolemic), contains a higher amount of arginine and glycine and induces an increase in postprandial arginine and glycine. Soy protein induces a low postprandial insulin/glucagon ratio in both hypercholesterolemic and normocholesterolemic subjects. Casein induces a high postprandial insulin/glucagon ratio among hypercholesterolemic subjects. Amino acids such as arginine and glycine are associated with a decrease, while lysine and branched-chain amino acids are associated with increased serum cholesterol levels. Our data are consistent with the hypothesis that the control of cholesterol by insulin and glucagon is regulated by dietary and plasma amino acids. From this hypothesis the insulin/glucagon ratio is proposed as an early metabolic index of the effect of dietary proteins on serum cholesterol levels, a risk factor and a common mechanism through which dietary and lifestyle factors influence cardiovascular disease.
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PMID:Plasma amino acids and the insulin/glucagon ratio as an explanation for the dietary protein modulation of atherosclerosis. 176 11

The amino acid composition of the diet influences the postprandial levels of plasma amino acids along with the hormones insulin and glucagon in humans fed single test meals identical in composition except for protein source. Soy protein (hypocholesterolemic), versus casein (hypercholesterolemic), contains a higher amount of arginine and glycine and induces an increase in postprandial arginine and glycine. Soy protein induces a low postprandial insulin/glucagon ratio in both hypercholesterolemic and normocholesterolemic subjects. Casein induces a high postprandial insulin/glucagon ration among hypercholesterolemic subjects. Amino acids such as arginine and glycine are associated with a decrease, while lysine and branched-chain amino acids are associated with increased serum cholesterol levels. Our data are consistent with the hypothesis that the control of cholesterol by insulin and glucagon is regulated by dietary and plasma amino acids. From this hypothesis the insulin/glucagon ratio is proposed as an early metabolic index of the effect of dietary proteins on serum cholesterol levels, a risk factor and a common mechanism through which dietary and lifestyle factors influence cardiovascular disease.
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PMID:Plasma amino acids and the insulin/glucagon ratio as an explanation for the dietary protein modulation of atherosclerosis. 194 85

Four Holstein cows were utilized in a Latin square design with a factorial arrangement of treatments to examine the interaction between effects of dry matter intake (107 vs. 78% of energy requirements) and postruminal infusions (water vs. 395 g/d casein) on lactational performance, utilization of nitrogen and energy, and plasma concentrations of hormones. Yields of milk and milk protein were decreased by feed restriction and increased by casein infusion with no treatment interactions. Restricting feed intake decreased total nitrogen intake by 143 g/d and resulted in smaller quantities of fecal, absorbed, urinary, milk, and retained nitrogen compared with cows fed ad libitum. Casein infusion increased total nitrogen intake (55 g/d), absorbed nitrogen (54 g/d), urinary nitrogen excretion (28 g/d), and milk nitrogen (13 g/d). Casein by dry matter intake interactions were not significant for nitrogen utilization. Restricting feed intake increased plasma growth hormone and decreased concentrations of insulin and triiodothyronine. Glucagon, prolactin, and thyroxine were not affected by intake. Casein infusion did not affect growth hormone, insulin, prolactin, triiodothyronine, or thyroxine. Increased milk and milk protein yields obtained with casein infusion were apparently not mediated through changes in circulating concentrations of these hormones; however, plasma glucagon was increased by casein infusions.
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PMID:Effects of intake and postruminal casein infusion on performance and concentrations of hormones in plasma of lactating cows. 354 15

1. The effect of variation in arginine: lysine on the relative cholesterolaemic effects of dietary soya-bean protein and casein was studied. Male rats received semi-purified diets containing soya-bean protein isolate or casein supplemented respectively with varying amounts of lysine or arginine for 40 d and blood samples were taken after a 5 h fast. 2. Neither the addition of arginine to casein nor lysine to soya-bean protein modified the intrinsic effect of these proteins on serum cholesterol. 3. Serum triglyceride levels tended to rise with increasing amounts of lysine supplementation. The opposite trend was obtained with arginine supplementation. 4. Casein caused an increase in the concentration of serum insulin, but not glucagon. The glucagon level was increased proportionately with increasing amounts of arginine, while the addition of lysine showed no effect. The effects of added amino acids on serum insulin were inconclusive. 5. There was a parallel increase in serum apo E and glucagon in response to arginine supplementation, while lysine supplementation increased serum apo E. 6. Thus, arginine: lysine was more effective in regulating serum triglyceride than serum cholesterol. Insulin was associated with different effects of these proteins on serum lipids.
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PMID:Effects of arginine and lysine addition to casein and soya-bean protein on serum lipids, apolipoproteins, insulin and glucagon in rats. 681 Sep 16

Casein, beef protein, and soy protein were used in combination with oat bran and wheat bran in six balanced diets to verify the verify the effects of protein and fiber-source nature on glucose metabolism in rats, according to a 3 x 2 factorial arrangement. Fifteen animals were fed each diet for 26 days. On day 27, blood samples were drawn from the portal vein and abdominal aorta, and liver was excised in fasted (0830) and fed (1130 and 1430) rats from each group. Wheat-bran feeding induced lower portal glycemia at 1130 (p < 0.01) and 1430 (p < 0.02) and lower portoaortic differences in glycemia at 1130 (p < 0.01) than did oat bran feeding. Animals fed beef protein had a higher insulin-glucagon ratio at 0830 (p < 0.05) and higher arterial lactate concentrations at 1430 (p < 0.04) than those fed casein. Also, groups of rats fed animal proteins tended to have higher total hepatic glycogen stores at 1430 (p < 0.08) than those fed soy protein. Furthermore, at 1130, an interaction between dietary fiber and animal protein nature was evidenced on arterial insulin concentrations (p < 0.05), indicating that casein and beef protein seem to react differently when combined with different fiber sources. These results confirm that fiber-source nature affects the appearance in circulation of glucose in the postprandial period. In addition, this work indicates that protein and fiber-source nature interact to modulate some aspects of glucose systemic utilization.
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PMID:Role of protein and fiber-source nature on glucose metabolism in rats. 802 68

Casein hydrolysate administration to fasted rats resulted in a biphasic response of glycogen synthase. Fifteen minutes after the protein meal, synthase R (active form) was increased. This was associated with a transient increase in hepatic glucose and glucose-6-phosphate (G6P) concentrations. Both glucose and G6P are known to stimulate synthase phosphatase activity, which would result in activation of synthase. Portal plasma insulin concentration was directly related to the amount of synthase R present. By 1 hour after the meal, synthase R activity was decreased compared with the control activity. Hepatic glycogen concentration was variable during the first 30 minutes after the meal, and then decreased progressively. Portal plasma glucagon concentration and phosphorylase a activity were elevated at all time points. The data suggest that the increased portal plasma glucagon concentration is the major hormonal signal for glycogen metabolism during the second hour following a pure protein meal. However, during the first 30 minutes glycogenolysis is attenuated, perhaps due to the transient increase in insulin and an increased intracellular G6P concentration.
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PMID:The effect of oral casein on hepatic glycogen metabolism in fasted rats. 849 22

Eight Angus steers (290 +/- 8 kg), surgically prepared with pancreatic pouch-duodenal reentrant cannulas and abomasal infusion catheters were used in a replicated 4 x 4 Latin square experiment to investigate the effects of abomasal infusion of starch hydrolyzate (SH) and/or casein on pancreatic exocrine secretion and plasma concentration of hormones. Steers were fed a basal diet of alfalfa (1.2 x NEm) in 12 equal portions daily. Abomasal infusion treatments (6-L total volume infused per day) were water (control), SH [2.7 g/(kg BW x d)], casein [0.6 g/(kg BW x d)], and SH + casein. Periods were 3 d for adaptation and 8 d of full infusion. Pancreatic juice and jugular blood samples were collected over 30-min intervals for 6 h on d 11. Weight and pH of pancreatic samples were measured, and a 10% subsample was composited and frozen until analysis of total protein and pancreatic enzyme activities. The remaining sample was returned to the duodenum. Plasma was harvested and frozen until analyzed. Pancreatic juice (67 mL/h) and protein (1.8 g/h) secretion rates were not affected by nutrient infusion. There were SH x casein interactions for all pancreatic enzyme secretions (U/h; alpha-amylase, P < 0.03; trypsin, P < 0.08; and chymotrypsin, P < 0.03) and plasma insulin concentration (P < 0.10). Secretion of pancreatic enzymes was increased by SH (trypsin) and casein (alpha-amylase, trypsin, and chymotrypsin) but not when SH + casein were infused together. Glucose (P < 0.10) and cholecystokinin octapeptide concentrations (CCK-8; P < 0.05) were increased by SH, but glucagon was decreased (P < 0.10). Casein decreased (P < 0.10) plasma CCK-8 concentrations. These data indicate that positive effects of postruminal casein on enzyme secretion were inhibited by SH, emphasizing the complexity of the regulatory mechanisms involved in dietary adaptation of pancreatic exocrine secretion. Changes in hormone concentration may not relate directly to changes in enzyme secretion.
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PMID:Pancreatic exocrine secretion and plasma concentration of some gastrointestinal hormones in response to abomasal infusion of starch hydrolyzate and/or casein. 1521 6

The effects of specific nutrients on secretion and plasma concentrations of gut peptides (glucagon-like peptide-1((7-36)) amide (GLP-1), glucose-dependent insulinotropic polypeptide (GIP), and cholecystokinin-8 (CCK)) differ across species, but are not reported for cattle. Our objective was to determine acute (hours) and chronic (1 week) effects of increased abomasal supply of protein, carbohydrate, or fat to the small intestine on dry matter intake (DMI) and plasma concentrations of GLP-1, GIP, CCK, and insulin. Four mid-lactation Holstein cows were used in a 4 x 4 Latin square design experiment. Treatments were 7-day abomasal infusions of water, soybean oil (500 g/d), corn starch (1100 g/d), or casein (800 g/d). Jugular vein plasma was obtained over 7h at the end of the first and last day of infusions. Oil infusion decreased DMI on day 7, but total metabolizable energy (ME) supply (diet plus infusate) did not differ from water infusion. Casein and starch infusion had no effect on feed DMI; thus, ME supply increased. Decreased DMI on day 7 of oil infusion was accompanied by increased plasma GLP-1 concentration, but decreased plasma CCK concentration. Increased plasma GIP concentration was associated with increased ME supply on day 7 of casein and starch infusion. Casein infusion tended to increase plasma CCK concentration on both days of sampling, and increased plasma GLP-1 and insulin concentration on day 1 of infusion. The present data indicate a sustained elevation of plasma concentration of GLP-1, but not CCK, may contribute to the reduced DMI observed in dairy cows provided supplemental fat.
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PMID:Abomasal infusion of casein, starch and soybean oil differentially affect plasma concentrations of gut peptides and feed intake in lactating dairy cows. 1830 2


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