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 activity of hepatic lysine-2-oxoglutarate reductase was determined in white female rats maintained on one of two dietary lysine levels (0.23 and 0.54% in diets A and B, respectively). The high dietary lysine increased the enzyme activity (p less than 0.05) twofold compared with the activity obtained with the diet A (67 vs. 27 mumol saccharopine/30 min/g liver protein). Repeated intraperitoneal injection of glucagon (259 microgram/100 g body weight/day) showed a short initial drop in the enzyme activity, followed by a marked rise, which remained above the basal level after withdrawal of the drug. Repeated injections of cycloheximide increased the enzyme activity, and the findings suggested that the apparent increase was due to the inhibition of the system responsible for the degradation of the enzyme. The individual free amino acids of the livers varied as a function of treatment. The ratio of E/N amino acids was found to be a good measure of the physiological condition of the animal, with the lowest value in animals treated with cycloheximide.
 ...
PMID:Rat hepatic lysine-2-oxoglutarate reductase activity. Induction by lysine, glucagon and cycloheximide administration. 61 19

Blood substrate and hormone concentration were determined in 16 children with Reye syndrome prior to and following administration of hypertonic glucose. Baseline concentrations of lactate, pyruvate, alanine, glutamine, glutamate, proline, hydroxyproline, lysine, and aspartate were elevated (p less than 0.01), whereas citrulline and arginine were low. All substrate concentrations were below or within the normal range following 36 hours of therapy except those of lactate, pyruvate, and aspartate. Urea nitrogen excretion was reduced (p less than 0.05) on the second day of therapy. Plasma concentrations of insulin and growth hormone increased and glucagon decreased during the first day. Cortisol remained elevated throughout the study period. We conclude that the high circulating concentrations of substrates are the result of both increased mobilization and decreased clearance and that hypertonic glucose infusion suppresses substrate mobilization. A primary abnormality of the mitochondria could explain the metabolic perturbations that occurred. A possible relationship between the encephalopathy in this disorder and an insult to both brain and brain capillary mitochondria is discussed.
 ...
PMID:Metabolic response to hypertonic glucose administration in Reye syndrome. 66 61

Arterial blood concentrations of insulin, glucagon, and various substrates were determined in six anephric subjects in the postabsorptive state and immediately after hemodialysis. Plasma glucose and serum insulin concentrations were normal, and declined during dialysis. Plasma glucagon was elevated and remained unchanged. There was moderate hypertriglyceridemia before dialysis, but this decreased significantly after administration of heparin just before the start of dialysis, and at the end of dialysis was lowered further into the normal range. Comparison of postabsorptive whole blood concentrations of amino acids with those in normal, healthy adults revealed striking differences. Glutamine, proline, citrulline, glycine and both 1- and 3-methyl-histidines were increased, while serine, glutamate, tyrosine, lysine, and branched-chain amino acids were decreased. The glycine/serine ratio was elevated to 300% and tyrosine/phenylalanine ratio was lowered to 60% of normal. To investigate the potential role of blood cells in amino acid transport, the distribution of individual amino acids in plasma and blood cell compartments was studied. Despite a markedly diminished blood cell mass (mean hematocrit, 20.6 +/- 1.4%), there was no significant decrease in the fraction of most amino acids present in the cell compartment, and this was explained by increases of several amino acids in cellular water. None were decreased. Furthermore, during dialysis, whole blood and plasma amino acids declined by approximately 30% and 40%, respectively, whereas no significant change was observed in the cell compartment. Alanine was the only amino acid whose concentration declined in the cells as well as in plasma. The results indicate (a) significant alterations in the concentrations of hormones and substrates in patients on chronic, intermittent hemodialysis; (b) removal of amino acids during hemodialysis, predominantly from the plasma compartment, with no significant change in cell content; and (c) a redistribution of amino acids in plasma and blood cell compartments with increased gradients of most of the amino acids per unit cell water, by mechanism(s) as yet undetermined.
 ...
PMID:Hormone-fuel concentrations in anephric subjects. Effect of hemodialysis (with special reference to amino acids). 93 88

Seven synthetic analogues of somatostatin helped clarify structural requirements for suppression of growth hormone secretion in rats. Size of the ring is not critical; deletions of serine-13, lysine-4 or asparagine-5 result in peptides which retain an appreciable fraction of the activity. The analogue des-Ala1, Gly2, Asn5-somatostatin lowers plasma growth hormone and insulin levels without affecting plasma glucagon levels significantly.
 ...
PMID:Structure activity studies on somatostatin. 105 80

Trypsin and elastase isolated from the pancreas of the moose (Alces alces), a member of the Cervidae (deer) family, were characterized with respect to their amino acid composition and specificity towards polypeptides. Moose trypsin possessed 234 residues, based on alanine recoveries equal to 16.0 residues, with a molecular weight calculated at 24 476. Moose trypsin readily hydrolysed peptide bonds in which the carbonyl group was contributed by arginine, lysine and S-2-aminoethylcysteine as indicated by the peptides isolated following hydrolysis of the oxidized and the S-aminoethylated B-chain of insulin. Moose elastase possessed 231 residues, based on alanine recoveries equal to 17.0 residues, with a molecular weight calculated as 24 201. The high lysine (9 residues), low arginine (3 residues) content was in contrast to the opposite situation with porcine elastase and the elastase-like, alpha-lytic protease from Sorangium. The hydrolysis of the oxidized B-chain of insulin by moose elastase was similar to that produced by porcine elastase with major cleavages occurring at Val-12-Glu-13, Ala-14-Leu-15 and Val-18-Cys(O-3H)-19 and minor cleavages occurring at Ser-9-His-10 and Arg-21-Gly-22. The hydrolysis of glucagon with moose elastase produced major cleavages at Thr-7-Ser-8, Ser-11-Lys-12, Val-23-Gln-24 and Leu-26-Met-27. The facile hydrolysis of Arg-17-Arg-18 was also observed and attributed, in part, to trypsin.
 ...
PMID:Characterization of trypsin and elastase from the moose (Alces alces). I. Amino acid composition and specificity towards polypeptides. 112 77

The net hepatic metabolism of amino glycerol, lactate, and pyruvate was determined in conscious fed sheep by multiplying the venoarterial concentration differences by the hepatic blood or plasma flow. In each experiment several sets of control blood samples were taken; glucagon or insulin then was infused intraportally for 2 h during which additional samples were taken. Four types of experiments were performed: 1) glucagon infusion (150 mug/h) into normal sheep, 2) glucagon infusion (100 mug/h) into insulin-treated alloxanized sheep, 3) insulin infusion (1.17 U/h) into normal sheep, and 4) insulin plus glucose infusion (12.3 mmol/h) into normal sheep. The second group of experiments was performed to prevent reflex hyperinsulinemia, and the fourth was performed to prevent reflex hyperglucagonemia. Glucagon directly stimulated the net hepatic uptake of alanine, glycine, glutamine, arginine, asparagine, threonine, serine, and lactate. Glucagon also stimulated lipolysis in adipose tissue. Insulin, on the other hand, appeared to have a lipogenic effect on adipose tissue and to stimulate directly the uptake of valine, isoleucine, leucine, tyrosine, lysine, and alanine only at extrahepatic sites. The study showed that, in sheep, the effects of glucagon primarily are on liver, and insulin's effects primarily are on skeletal muscle and adipose tissue where it promotes protein and lipid synthesis.
 ...
PMID:Effects of glucagon and insulin on net hepatic metabolism of glucose precursors in sheep. 120 Jan 53

A reduction in the release of substrate amino acids from skeletal muscle largely explains the decrease in gluconeogenesis characterizing prolonged starvation. Brief starvation is associated with an increase in gluconeogenesis, suggesting increased release of amino acids from muscle. In the present studies, accelerated amino acid release from skeletal muscle induced by brief starvation was sought to account for the accompanying augmentation of gluconeogenesis. To do this amino acid balance across forearm muscles was quantified in 15 postabsorptive (overnight fasted) subjects and in 7 subjects fasted for 60 h. Fasting significantly reduced basal insulin (11.3-7.5 muU/ml) and increased glucagon (116-134 pg/ml). Muscle release of the principal glycogenic amino acids increased. Alanine release increased 59.4%. The increase in release for all amino acids averaged 69.4% and was statistically significant for threonine, serine, glycine, alanine, alpha-aminobutyrate, methionine, tyrosine, and lysine. Thus, with brief starvation, muscle release of glycogenic amino acids increases strikingly. This contrasts with the reduction of amino acid release characterizing prolonged starvation. The adaptation of peripheral tissue metabolism to brief starvation is best explained by the decrease in insulin.
 ...
PMID:Effects of brief starvation on muscle amino acid metabolism in nonobese man. 125 28

Two hundred and forty-one cases of isolated ACTH deficiency have been reported in Japan since 1969. Pituitary hormone responsiveness to stimulation tests before and after hydrocortisone supplementation was investigated in these cases. Plasma ACTH level showed no or little change in response to lysine vasopressin, metyrapone, CRF or insulin-induced hypoglycemia in 97.3-100% of the cases. Serum GH level changed little or not at all in response to GRF, insulin-induced hypoglycemia, glucagon, 1-dopa and arginine in 26.9, 29.3, 40.0, 50.0 and 56.1%, respectively. Serum TSH and prolactin (PRL) levels showed hyperresponse to TRH in 34.7 and 35.6%, respectively. After hydrocortisone therapy, GH secretion was more responsive than before therapy in 78.9% of the cases. After supplementation, TSH level was less responsive to TRH stimulation than before therapy in 59.3% of the cases. After hydrocortisone supplementation, TSH response to TRH decreased in 75% of ACTH-deficient patients without primary hypothyroidism but did not decrease in more than half of those with primary hypothyroidism. TSH response to TRH decreased after supplementation in 76.5% of the patients with TSH hyperresponsiveness before therapy, and increased after therapy in 66.7% of those with normal TSH responses before therapy. After supplementation, PRL response to TRH was less than that before therapy in 43.5% of ACTH--deficient patients, and greater than that before therapy in 30.4%. PRL response to TRH decreased after therapy in 66.7% of the patients with PRL hyperresponsiveness before therapy, and increased in 63.6% of those with normal PRL response before therapy. Primary hypothyroidism and Hashimoto's thyroiditis were complicated in 21.6 and 11.6%, respectively, of the 241 patients with isolated ACTH deficiency. In patients who had TSH hyperresponsiveness and/or high basal TSH levels and PRL hyperresponsiveness and/or high basal PRL levels, primary hypothyroidism was complicated in 58.4 and 42.3%, respectively. Hashimoto's thyroiditis was complicated in 29.8 and 20.5%, respectively, of these patients. Pituitary cell antibody (PCA) was detected in 36.6% of ACTH-deficient patients who were examined. Pituitary cell surface antibody (PCSA) to AtT-20 cells and GH3 cells was detected in 50.0 and 28.0% of the examined cases, respectively. The prevalence of PCA and PCSA did not differ between TSH-hyperresponsive patients and those with normal TSH basal levels and response, whereas PCA and PCSA were significantly more prevalent in PRL-hyperresponsive patients than in those with normal PRL levels and response. An empty sella was found in 30.2% of the examined case.(ABSTRACT TRUNCATED AT 400 WORDS)
 ...
PMID:[Hyperresponsiveness of TSH and prolactin and impaired responsiveness of GH in Japanese patients with isolated ACTH deficiency]. 133 97

Continuous responses of insulin and glucagon to physiological challenges are essential for the maintenance of normoglycemia and for avoiding subsequent health complications. Transplantation of microencapsulated islets of Langerhans is a promising solution to obtain such a physiological system in diabetic patients. The integrity of the islets' secretory mechanism after encapsulation was studied using rat islets. Islets were isolated by collagenase digestion after which half of the islets were encapsulated with an alginate-poly-L-lysine-alginate membrane. The islets were then challenged for 24 h with glucose (0, 2.7, 5.5, or 20 mM) alone or with 0.1 mM 3-isobutyl-1-methyl-xanthine or 0.1 microM phorbol 12-myristate 13-acetate (PMA), protein kinase A and C pathway stimulators, respectively. The bathing media and cellular contents were radioimmunoassayed for insulin and glucagon. Results obtained using a three-way analysis of variance for microencapsulated and free islets demonstrated that high glucose (P less than 0.05), 3-isobutyl-1-methyl-xanthine (P less than 0.05), and PMA (P less than 0.01) increased insulin secretion, and that glucagon secretion was decreased by high glucose (P less than 0.01) but increased by PMA (P less than 0.05). Free islets secreted more insulin than those which were microencapsulated under all conditions (P less than 0.01). This appeared to be due to the encapsulation process itself, however, as islets which had been 'freed' from the capsules also exhibited a reduced capacity for insulin secretion (P less than 0.05). Analysis of the hormone content of islets after microencapsulation demonstrated reduced insulin levels (P less than 0.01), thus, accounting for the reduction in insulin secretion. As the responses of microencapsulated islets to physiological regulation by glucose and protein kinases A and C were qualitatively identical to those of free islets, transplantation of microencapsulated islets into diabetic patients could mimic the physiological responses of the normal pancreas.
 ...
PMID:Maintenance of long-term secretory function by microencapsulated islets of Langerhans. 137 Jul 93

1. Developmental aspects of L-lysine-ketoglutarate reductase, the first enzyme in saccharopine pathway of L-lysine degradation in rat liver and brain tissues were studied. 2. Although the adult rat brain shows negligible activity, the enzyme activity was shown to be highly active during the early stages of development. 3. The enzyme activity gradually decreased through development in the brain, whereas it gradually increased in the liver, establishing the fact that the saccharopine pathway is the major pathway in liver. 4. Our results also show that glucagon stimulated the induction of this enzyme by 2-3-fold in both adult liver and brain tissues.
 ...
PMID:Developmental changes of L-lysine-ketoglutarate reductase in rat brain and liver. 145 33


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