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 present experiments were undertaken to assess lactate and gluconeogenic precursor metabolism in the 30 h following consumption of a mixed meal by the overnight-fasted, conscious dog. The arterial glucose level rose by a maximum of 13 mg/dl 4 h after the meal and had returned to control levels by 12 h. Hepatic glucose production was suppressed for 12 h after feeding, but net hepatic glucose uptake did not occur. The arterial lactate level rose from 0.55 +/- 0.10 to 1.28 +/- 0.14 mM within 1 h of feeding and remained elevated for 12 h. Net hepatic lactate production, measured with an A-V difference technique, rose from 3.5 +/- 2.8 to 19.4 +/- 3.1 mumol X kg-1 X min-1 h after the meal and declined slowly over the next 22 h. The liver then began to consume lactate so that at 30 h net hepatic uptake was 5.7 +/- 0.5 mumol X kg-1 X min-1. The total hepatic uptake of the gluconeogenic amino acids (alanine, glycine, serine, threonine) increased from 5.3 +/- 0.8 to 11.5 +/- 2.5 mumol X kg-1 X min-1 at 1 h and remained elevated for 4 h. The arterial alanine level rose from 0.36 +/- 0.03 to 0.51 +/- 0.04 mM at 2 h and remained elevated for 18 h. Insulin increased from 11 +/- 2 microU/ml to a maximum of 44 +/- 5 4 h after the meal, and the glucagon level rose from 59 +/- 8 pg/ml to a maximum of 150 +/- 22 1 h after feeding.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Effect of a mixed meal on hepatic lactate and gluconeogenic precursor metabolism in dogs. 638 70

Duodenopancreatectomy induces a severe glucagon deficiency and elevated plasma concentrations of alanine, aspartate, glycine, proline, serine, arginine, citrulline, ornithine, phenylalanine and tyrosine. Restoring high physiological plasma glucagon in six such patients by infusing 0.3 mg/24 h of exogenous glucagon reduced significantly (P less than 0.01 or 0.001) the mentioned amino acids (except phenylalanine) and further asparagine, glutamine, methionine and threonine. In six normal subjects the same infusion reduced significantly (P less than 0.05 to 0.001) plasma alanine, asparagine, glutamate, glutamine, glycine, proline, serine, threonine, arginine, ornithine, lysine and tyrosine. However, the effect was significantly (P less than 0.01 or 0.001) less marked for alanine, glutamine, glycine, methionine, serine, threonine and arginine. This particular glucagon sensitivity of duodenopancreatectomized patients suggests that glucagon deficiency is the cause of their hyperaminacidaemia. By contrast, lipoprotein concentrations were virtually unaffected by either glucagon deficiency or its replacement. In the light of the marked hypoaminacidaemia in glucagonoma patients these results attribute to glucagon a major role as a regulator of protein metabolism.
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PMID:Amino acids and lipoproteins in plasma of duodenopancreatectomized patients: effects of glucagon in physiological amounts. 640 37

Threonine dehydratase, threonine aldolase and threonine dehydrogenase activities were assayed in livers of rats that had been normally-fed, starved for 72 h, fed a high-protein diet or normally-fed and injected with glucagon or cortisone. A modified continuous spectrophotometric assay for threonine aldolase overcame interference resulting from threonine dehydratase activity and revealed that threonine aldolase activity was very low in rat liver, irrespective of the metabolic state of the animal. The concentration of free threonine was determined in livers of animals subjected to the same treatments as described above. Using Michaelis-Menten kinetics to estimate enzyme activities in vivo at intracellular threonine concentrations it was calculated that in the normally-fed state, 87% of the threonine degraded was catabolized by threonine dehydrogenase. In other metabolic states (except in glucagon-treated animals) threonine dehydratase was the major enzyme catalysing threonine catabolism. It was concluded that threonine dehydrogenase activity plays a hitherto unrecognized role in the metabolic homoeostasis of threonine in the normally-fed rat and that this enzyme activity, in association with 2-amino-3-oxobutyrate CoA-ligase, accounts for the known rate of glycine formation from threonine in the rat.
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PMID:Metabolic homoeostasis of L-threonine in the normally-fed rat. Importance of liver threonine dehydrogenase activity. 641 60

Eleven patients after total pancreatectomy and 68 patients after pancreatoduodenectomy were reviewed for evaluating the importance of nutritional management after massive resection of the pancreas. Nutritional supply by IVH resulted in maintaining and improving the hepatic function under obstructive jaundice in clinical and experimental studies. Administration of elemental diet after the operation shortened the period of IVH, and had a effect to spare the requirement of exogenous insulin. One of the most important problems after pancreatectomy with extensive dissection of the lymph nodes and the nerves around superior mesenteric artery was a malnutrition which appeared frequently after long term follow-up. The malnutrition should be treated by IVH as soon as possible for preventing further aggravation of digestive and absorptive function of the alimentary tract. Oral or nasogastric tube administration of elemental diet is useful for weaning the patient from IVH, and it serves to prevent subsequent development of malnutrition. In six totally pancreatectomized patients studied, postabsorptive plasma concentration of Arg., Lys., Thr., Ala., Gly., Ser. and Pro. were greatly elevated compared to normal value, however these abnormalities were normalized by 1 to 3 mg of glucagon administration. Glucagon administration resulted in no significant change in daily nitrogen balance.
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PMID:[Nutritional management after massive resection of the pancreas]. 643 88

The authors have studied the behavior of Aminoacids (AA), GH, Prolactin (PRL), Insulin (IRI) and blood sugar (BS) after fast intravenous injection of 1 mg of Glucagon (G), in eight normal volunteers. The rise in BS levels soon after G. administration at time 10', 20', 30', 45', 60' prompted to consider the initial phase of the experimental to be under G predominance, although IRI did respond to the infusion with a sharp rise, at time 10', 20', 30', 45'. Glycine, serine, threonine, alanine, lysine, phenylalanine and arginine displayed a significant reduction already at time 10' or 20', when G metabolic effects were dominant, a selective G influence on these AA can be supposed. At time 45' and 60' tyrosine, histidine, methionine, valine, leucine, isoleucine, proline, decreased significantly and glycine, serine, threonine, lysine, alanine, phenylalanine, evidenced further reduction. GH and PRL were not affected by the administration of G.
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PMID:[Behavior of blood amino acids after acute administration of glucagon in humans]. 645 90

Investigations were made on the effects of catecholamine (Cat) infusions with and without ammonia (NH3) on plasma and brain amino acids (AA) and brain neurotransmitters in dogs. Groups of four dogs were infused for 5 h with epinephrine (E), epinephrine + norepinephrine (E + NE), epinephrine + norepinephrine with NH3 during h 4 and 5 (E + NE + NH3), epinephrine + norepinephrine + tryptophan with NH3 during h 4 and 5 (T + E + NE + NH3), or saline (C). Cat decreased (P less than 0.05) plasma Gly, Thr, Lys, Pro, Val, Ser, Arg, Leu, Trp, Phe, Asn, Tyr, Met, Ile, Cit, and Asp. The decreases at h 3 for all were to a mean of 45% of 0 h and were associated with no changes in plasma insulin or glucagon. Cat increased plasma Tau and Orn. Of the most abundant brain AA (82% of total), E + NE + NH3 had no effect (GABA, Asp, Gly, Ala, p-ethanolamine) or increased (Glu, Gln, Tau) brain levels. These AA were unchanged by Cat alone. Of the remaining brain AA, most were decreased by Cat (7 of 16, P less than 0.05) and E + NE + NH3 increased brain Trp but had no effect on brain serotonin, 5-hydroxyindoleacetic acid, or NE. Cat changed plasma AA in a way similar to changes produced by NH3 infusion and seen with hepatic insufficiency due to portacaval shunts and nitrosamine-induced pathology. Cat reduced brain AA levels, and this was partially restored by NH3.
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PMID:Effects of catecholamines and ammonia on plasma and brain amino acids in dogs. 646 11

A novel form of the polypeptide termed PHI (peptide HI with N-terminal histidine and C-terminal isoleucine amide) has been isolated from bovine upper intestine. This bovine peptide was obtained in a 40 times higher yield than the corresponding polypeptide isolated from porcine intestine. Bovine PHI is, like porcine PHI, composed of 27 amino acid residues. The complete amino acid sequence of the bovine peptide is His-Ala-Asp-Gly-Val-Phe-Thr-Ser-Asp-Tyr-Ser-Arg-Leu-Leu-Gly-Gln-Leu-Ser- Ala- Lys-Lys-Tyr-Leu-Glu-Ser-Leu-Ile-NH2. This sequence differs from porcine PHI at position 10 and from human PHI at positions 10, 12 and 27. The amino acid residue exchange between porcine and bovine PHI makes the latter more similar to the vasoactive intestinal polypeptide (VIP), gastric inhibitory polypeptide (GIP), glucagon and the growth-hormone-releasing factor (GRF).
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PMID:A novel form of the polypeptide PHI isolated in high yield from bovine upper intestine. Relationships to other peptides of the glucagon-secretin family. 654 46

Two cardioacceleratory peptides from the corpora cardiaca of Periplaneta americana have been purified by gel filtration and reversed-phase liquid chromatography, Based on analysis of the intact factors and their chymotryptic fragments, we have assigned the primary structure of these octapeptides as pGlu-Val-Asn-Phe-Ser-Pro-Asn-Trp-NH2, designated periplanetin CC-1, and pGlu-Leu-Thr-Phe-Thr-Pro-Asn-Trp-NH2, designated periplanetin CC-2. They represent new members of a family of invertebrate peptides that includes locust adipokinetic hormone and crustacean red-pigment concentrating hormone. Both peptides show adipokinetic activity in grasshoppers and hyperglycemic activity in cockroaches. One of these peptides (CC-2) has provocative sequence homology with the NH2-terminal portion of glucagon.
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PMID:Isolation and primary structure of two peptides with cardioacceleratory and hyperglycemic activity from the corpora cardiaca of Periplaneta americana. 659 Dec 5

Using solid-phase methodology and preparative medium- and high-performance reverse-phase liquid chromatography, we have synthesized glucagon and its Arg12 analogue in approximately 5% yields. The synthetic glucagon was fully active relative to natural material, and the Arg12 peptide exhibited 50% activity. Since perhaps the most critical part of the glucagon-family peptides is the N-terminal hexapeptide region, both batches of resin were split during synthesis in order to prepare two series of analogues based on glucagon and [Arg12]glucagon with changes in the His-Ser-Gln-Gly-Thr-Phe sequence. The following new analogues were tested for their effects on blood glucose levels in normal male rats relative to glucagon and gave the following activities: [Ac-His1,Arg12]glucagon, 46%; [3-Me-His1,Arg12]glucagon, 30%; [Phe1,Arg12 )glucagon, 31%; [Des-His1,Arg12]glucagon, 4%; [D-Ala2,Arg12]glucagon, 44%; [D-p-Cl-Phe1,D-Ala4,Arg12]glucagon, 9%; [D-Phe4]glucagon, 655%; [Ala2]glucagon, 9%. These data indicate that the amino or imidazole nitrogens of the histidine residue are not essential for biological activity. However, an aromatic group in position 1 may be important, since the Phe1 analogue is almost as active as glucagon in our bioassay. The superagonist activity with [D-Phe4]glucagon, which was synthesized to test the hypothesis that a beta-bend conformation occurs at this position in glucagon by analogy with luteinizing hormone-releasing hormone and other Gly-containing peptides, indicates that this is indeed the case and has important implications for the receptor-recognition requirements of the glucagon-secretin-vasoactive intestinal peptide family of peptides.
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PMID:Structure-activity studies on the N-terminal region of glucagon. 669 76

The effects of a 4-day isocaloric isoprotenic dietary replacement of carbohydrate by fats were studied in six healthy subjects, the experimental diet being preceded and followed by a 3-day period of balanced diet. During the ketogenic regimen, the concentrations of fat derived substrates (free fatty acids, glycerol and 3-hydroxybutyrate) rose significantly and glucose levels decreased by 16.5 +/- 3.2% (mean +/- SEM). The hormonal pattern switched towards a catabolic mode with a fall in insulin levels (-44.0 +/- 6.3%) and a rise in glucagon concentration (+39.0 +/- 10.4%). A significant fall in triiodothyronine and rise in reverse triiodothyronine were observed, while thyroxine levels remained unchanged. The average levels of the most important gluconeogenic amino acids (alanine, glutamine, glycine, serine and threonine) were reduced by 8-34% while those of the branched chain amino acids increased by more than 50%. Since these changes reproduce those observed after a few days of total fasting, we suggest that it is the carbohydrate restriction itself which is responsible for the metabolic and hormonal adaptations of brief fasting.
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PMID:Hormonal and metabolic changes induced by an isocaloric isoproteinic ketogenic diet in healthy subjects. 676 Nov 85


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