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)

Hyperglycemia and impaired glucose tolerance are well known phenomena occurring in patients with renal failure. In contrast to true diabetic subjects, an elevated ratio of insulin to glucose during the glucose tolerance test is consistently observed indicating a peripheral insulin insensitivity. Among the possible reasons, a disturbance at the cellular level seems to be most likely. There is some evidence of reduced peripheral glucose utilization on the one hand and increased hepatic glucose output--probably by stimulation of gluconeogenesis--on the other. Agents that have been suggested to be involved in these alterations of carbohydrate metabolism in uremia are hormones, electrolytes, pH, and "toxic" metabolic intermediates or end-products. Of these, an increase in insulin antagonistic hormones; among them growth hormone, catecholamines, and glucagon, seems to be of most significance. Although for the individual hormones no equivocal correlation with glucose intolerance has been proved, the interaction of all of them may result in a preponderance of insulin antagonism thus leading to an apparent insulin resistance.
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PMID:Carbohydrate metabolism in renal failure. 2 64

Pancreatic islet cell vacuolization, hyperglycemia, and glucose intolerance develop in rats after oral administration of cyproheptadine (CPH). In order to determine whether these effects were associated with abnormal insulin secretion, pancreas segments from CPH-treated and control rats were compared for their ability to secrete insulin in response to several stimuli. Oral administration of CPH (45 mg/kg/day) to rats for 1 or 8 days inhibited glucose-mediated insulin secretion from pancreas segments obtained 3 and 24 hr after the last dose of the drug. Insulin secretion had returned to normal by 48 hr after drug administration. Intraperitoneal administration of the drug was less effective than oral administration in inhibiting in vitro insulin secretion. Other stimuli for insulin secretion (tolbutamide, glucagon, L-leucine, and dibutyryl 3',5'cyclic AMP), like glucose, were incapable of releasing normal amounts of insulin from pancreas segments of CPH-treated rats. CPH and a metabolite, desmethyl-CPH, inhibited glucose-stimulated insulin secretion when added in vitro to pancreas segments from control rats. This suggests that the inhibition of insulin secretion in pancreas segments taken from animals treated with CPH could be due, at least in part, to the presence of drug and its metabolite in the tissue. A previously observed reduction in the pancreatic content of insulin in CPH-treated rats may also contribute to the abnormal insulin release in animals given the drug.
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PMID:Cyproheptadine and beta cell function in the rat: insulin secretion from pancreas segments in vitro. 17 78

Described here is a patient who had an islet cell carcinoma containing both glucagon (glucagonoma) and insulin (insulinoma). Complete removal of the tumor was possible. Immunoreactive glucagon (IRG) could be extracted from all parts of the tumor (approximately 50 mug./gm.) and was shown to be fully bioactive. Immunoreactive insulin (IRI) could be extracted only from one section of the tumor (approximately 30 mug./gm.). The clinical and biochemical manifestations of the disease were dermatitis, diabetes, weight loss, anemia, hypoaminoacidemia, and hyperketonemia. The diabetes was characterized by low or normal fasting blood glucose concentrations and by impaired glucose tolerance (Kg = 0.4). After complete removal of the tumor, the dermatitis cleared, the catabolic state changed into an anabolic state, blood amino acid concentrations increased, and blood ketone-body concentrations decreased. Fasting blood glucose concentrations, however, rose above 200 mg./dl., and glucose tolerance declined further (Kg = 0.15). Hourly blood sampling for 24 hours, intravenous and oral glucose tolerance tests, intravenous arginine and tolbutamide tolerance tests with serial determinations of IRG, IRI, and blood glucose were performed preoperatively and again two weeks and two months postoperatively. The results of these studies demonstrated marked abnormalities in the stimulation and suppression of glucagon and insulin release. In addition, they failed to demonstrate a glycemic effect on the chronically elevated glucagon concentrations in this patient, while identifying insulin as the dominant factor determining blood glucose homeostasis.
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PMID:An islet cell carcinoma containing glucagon and insulin. Chronic glucagon excess and glucose homeostasis. 19 71

Hyperglycemia, glucose intolerance, hyperinsulinemia and resistance to exogenous insulin were found in a 10-year-old Japanese boy diagnosed as having congenital generalized lipodystrophy. Studies on insulin receptors of circulating mononuclear leucocytes indicated that insulin-resistant diabetes combined with congenital generalized lipodystrophy may be due to disturbance of insulin binding to membrane receptors. No insulin-binding antibody or antibody that impairs insulin-receptor binding was found. Plasma glucagon showed an exaggerated response to L-arginine before treatment. After treatment with a controlled diet and an oral sulfonylurea (500 mg/day) for 4 weeks, there was improvement in the plasma glucagon response to L-arginine. Improvement in the hyperglycemia, hyperinsulinemia and acanthosis nigricans was also observed. On the other hand, on completion of a 7-day high-fat diet, a marked increase in serum free fatty acids, triglycerides and beta-lipoproteins was observed. The total plasma post-heparin lipolytic activity during the high fat diet was within the normal range. However, the level of protamine-inactivated activity was 3 times that of the control.
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PMID:Congenital generalized lipodystrophy with insulin-resistant diabetes. 20 64

Ketotic, insulin-requiring diabetes mellitus and a severe peripheral neuropathy developed in a previously healthy 25-year-old man several days after he attempted suicide with rat poison containing N-3-pyridylmethyl N'-p-nitrophenyl urea. Study of islet-cell function ten months after ingestion showed a reduced disappearance rate of intravenous glucose and depressed C-peptide response to intravenous glucose when compared with a normal control but no impairment of glucagon release after intravenous arginine stimulation. Nerve conduction studies demonstrated severe sensory and mild motor neuropathy. Quadriceps capillary basement membrane thickness was in the diabetic range. Because at least 15 similar occurrences have been reported to the manufacturer, this agent appears to be diabetogenic in man, probably causing beta-cell destruction. Niacinamide, which can prevent glucose intolerance in both streptozocin- and alloxan-treated animals and prevents death in rats given this rodenticide, may be a useful antidote.
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PMID:Diabetes mellitus following rodenticide ingestion in man. 20 29

We have studied a 2-year-old girl with acanthosis nigricans, glucose intolerance, marked hyperinsulinemia, and somatic features characteristic of the leprechaunism syndrome. Circulating plasma insulin levels were increased up to 50-fold and the patient showed a blunted hypoglycemic response to an injection of exogenous insulin (0.2 units/kg), indicating the presence of severe insulin resistance. Insulin purified from the patient's plasma was normal on the basis of chromatographic, electrophoretic, and immunologic criteria. Furthermore, the purified insulin competed effectively with (125)I-labeled insulin for binding to insulin receptors on cultured IM-9 lymphocytes and rat fat cells and also exhibited normal biological potency when tested on rat fat cells. Anti-insulin receptor and anti-insulin antibodies were not detected in the patient's plasma, and plasma levels of glucagon, growth hormone, and cortisol were normal. Insulin binding to the patient's circulating monuclear leukocytes was only slightly depressed into the low normal range and could not account for the severe insulin resistance. Studies on the patient's fibroblasts revealed normal levels of insulin receptors but a total absence of insulin's ability to accelerate glucose transport. Because rates of glucose transport and metabolism were normal in the basal state in the absence of insulin, we conclude that this patient's insulin resistance is due to an inherited cellular defect in the coupling mechanism between occupied insulin receptors and the plasma membrane glucose transport system.
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PMID:Insulin resistance due to a defect distal to the insulin receptor: demonstration in a patient with leprechaunism. 27 48

To investigate the role of glucagon and insulin receptor binding in the glucagon hypersensitivity and insulin resistance which characterize the glucose intolerance of uremia, liver plasma membranes were prepared from control rats (blood urea nitrogen [BUN] 15+/-1 mg/100 ml, creatinine 0.7+/-0.2 mg/100 ml), and from 70% nephrectomized rats (BUN 30+/-2 mg/100 ml, creatinine 2.2+/-0.2 mg/100 ml), and from 90% nephrectomized rats (BUN 46+/-3 mg/100 ml, creatinine 4.20+/-0.7 mg/100 ml), 4 wk after surgery. As compared to controls, the 90% nephrectomized rats had significantly higher levels of plasma glucose (95+/-4 vs. 125+/-11 mg/100 ml), plasma insulin (28+/-9 vs. 52+/-11 muU/ml), and plasma glucagon (28+/-5 vs. 215+/-18 pg/ml). Similar, but less marked, elevations were observed in the 70% nephrectomized animals. In liver plasma membranes from nephrectomized rats, specific binding of (125)I-glucagon was increased by 80-120%. Furthermore, glucagon (2 muM)-stimulated adenylate cyclase activity in nephrectomized rats was twofold higher than in controls. In contrast, fluoridestimulated adenylate cyclase activity was similar in both groups of rats. In marked contrast to glucagon binding, specific binding of (125)I-insulin to liver membranes from nephrectomized rats was reduced by 40-50% as compared to controls. Data analysis suggested that the changes in both glucagon and insulin binding are a consequence of alterations in binding capacity rather than changes in affinity. Liver plasma membranes from nephrectomized rats degraded (125)I-glucagon and (125)I-insulin to the same extent as control rats. THESE RESULTS DEMONSTRATE THAT: (a) the 70 and 90% nephrectomized rats simulate the hyperglycemia, hyperinsulinemia, and hyperglucagonemia observed in clinical uremia; (b) in these animals specific binding of glucagon to liver membranes is increased and is accompanied by higher glucagon-stimulated adenylate cyclase activity; and (c) specific binding of insulin is markedly decreased. These findings thus provide evidence of oppositely directed, simultaneous changes in glucagon and insulin receptor binding in partially nephrectomized rats. Such changes may account for the hypersensitivity to glucagon and may contribute to resistance to insulin observed in the glucose intolerance of uremia.
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PMID:Glucagon and insulin binding to liver membranes in a partially nephrectomized uremic rat model. 700 82

The prevailing concept of etiologic heterogeneity for the diabetes mellitus syndrome is one of multiple genetic factors interacting with a variety of environmental influences. Variation in expression of the disorder, particularly the need for insulin, does not correlate with known etiologic distinctions. There is much evidence for genetic heterogeneity, as well as phenotypic variation when etiology can be presumed to be identical. The vascular manifestations of diabetes include microangiopathy unique to diabetes and larger vessel disease that differs from that of normal aging only by its prematurity. There is as much evidence for heterogeneity of the vascular expression as there is for glucose intolerance. Approximately 25% of persons with insulin-dependent diabetes may never develop the microvascular disease. The pathogenesis of vascular disease in diabetes may involve a number of abnormalities of plasma, circulating cells, and vascular tissue. Were absolute control of glycemia possible, some of the contributing factors involved in vasculopathy would possibly be alleviated. In the absence of automated physiologic insulin replacement the potential deleterious effect of our current methods of treatment might be reduced by specific inhibition of excess catecholamine, growth hormone and/or glucagon responses.
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PMID:Nature and nurture in the expression of diabetes mellitus and its vascular manifestations. 33 1

Colony-bred sand rats were fed with rat pellet chow in restricted quantities or ad libitum for 8--10 or 28--31 weeks after weaning. The changes of glucose metabolism were characterized by an intraperitoneal glucose tolerance test. The daily food intake and the average weight gain differed only in the first 5--7 weeks of pellet nutrition. In the impaired glucose tolerance tests of all sand rats the high basal plasma IRI levels were not significantly increased by the grossly enhanced blood glucose concentrations. The insulin secretion of either acutely incubated or for 8 days cultivated isolated pancreatic islets, however, was stimulated already by low (1.7 and 5 mM) glucose concentrations in all diet groups. Otherwise the glucagon secretion of isolated islets was not suppressed by high glucose concentrations. No changes of insulin or glucagon contents of islets were found in the different diet groups. The adipocytes of all animals revealed a complete ineffectiveness of insulin on the glucose utilization to CO2 and triglycerides. The basal glucose conversion to CO2 and glycogen in skeletal muscle and the stimulatory potency of insulin was low and not distinctly different in all groups. In liver glycogen and triglyceride contents as well as gluconeogenic enzyme activities were not influenced by feeding of different quantities of pellet diet at the investigated time points. The time course of the metabolic and clinical alterations demonstrates that the peripheral organs become insensitive to insulin in the first weeks after weaning.
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PMID:Insulin and glucagon secretion and the insulin sensitivity of peripheric organs of colony-bred sand rats fed with pellet diet after weaning. 34 38

The early phase of insulin secretion to an oral glucose load was blunted in spontaneous diabetic rats. The blunted insulin secretion was associated with markedly impaired glucose tolerance. A single injection of the islet activating protein (IAP), a protein derived from the culture medium of Bordetella pertussis, into the spontaneous diabetic rats normalised glucose tolerance. The increase in insulin response to glucose was an important contributing factor to the improvement of glucose tolerance. This curative effect of the IAP on the diabetic state was of long duration; glucose tolerance remained virtually normal over a period of one month in the diabetic rats. Perfusion of the isolated pancreas of the diabetic rats pretreated with IAP showed an increase in insulin response to glucose and loss of suppression of glucagon secretion by noradrenaline.
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PMID:Islet activating protein (IAP) derived from the culture supernatant fluid of Bordetella pertussis: effect on spontaneous diabetic rats. 34 42


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