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)

A genetically diabetic model, KK-CAy mice which were bred by mating female KK mice (aa, BB, cc) with male KK-CAy mice (Aya, BB, CC) was studied on the usefulness as a tool for a pharmacological assay. Body weights of KK-CAy mice increased more rapidly than those of control mice, KK-C. When the body weights of male KK-CAy mice reached about 30 g 10 weeks after birth, their blood glucose levels increased. Severe hyperglycemia (over 300 mg/100 ml) was often observed in the males, but not in the females. Glucose tolerance in the KK-CAy mice was more markedly impaired than that in the control mice. The increase in blood FFA level correlated with the increase in body weight on both KK-CAy mice and the controls. On hyperinsulinemia observed, the ratio of plasma immunoreactive insulin (IRI) level to blood glucose level in the male mice was lower than that seen in the female mice. On hyperglucagonemia observed, elevation of plasma immunoreactive glucagon (IRG) was more remarkable in the males than in the females. Morphological study showed insular degranulation only in the males. Since the dose-dependent insulin-induced falling was observed on blood glucose level in nonfasted KK-CAy mice, they could be used as a feasible tool for an assay of antidiabetic drugs.
 ...
PMID:A genetically diabetic model "KK-CAy mice" for a pharmacological assay. 38 73

To evaluate the influence of hyperglycemia on hepatic glucose output in the absence of a rise in insulin, glucose was infused for 2 hours into six juvenile-onset diabetics receiving a constant infusion of insulin at a rate of 0.05-0.15 microM kg-1min-1. Prior to the infusion of glucose, insulin administration resulted in stable levels of plasma glucose (76 +/- 8 mg/dl) and glucose output (1.9 +/- 0.1 mg kg-1min-1). The addition of glucose produced a 2-3 fold rise in plasma glucose and a prompt fall in glucose output to 0.2-0.4 mg kg-1min-1, despite the unchanged rate of insulin infusion and the absence of a reduction in plasma glucagon or catecholamines. A similar decline in glucose output was observed when exogenous glucagon (1 ng kg-1-min-1) was added to the glucose infusion. We conclude that in the presence of basal insulin levels hyperglycemia inhibits glucose output independent of a rise in insulin or a fall in anti-insulin hormones.
 ...
PMID:Hyperglycemia inhibits glucose production in man independent of changes in glucoregulatory hormones. 40 Jul 37

Intravenous hyperalimentation allows complete nutrition and anabolism in patients who cannot be fed by the oral route. However, several complications have been reported, e.g. septicaemia and hyperglycaemina. In 51 intensive-care patients receiving hyperalimentation, 18% were found to be hyperglycaemic in spite of insulin administration. Hyperglycaemia was frequently associated with stress. In 8 patients undergoing major surgery, which was chosen as a stress model, decreased insulin and increased glucagon, growth hormone and cortisone levels were observed. These findings could explain stress-induced glucose intolerance. In a further experiment, 8 intensive-care patients were given alternative intravenous feedings with either 600g of a mixture of glucose, fructose and xylitol in a ration of 1:2:1 or 600g glucose per day. During both regimens insulin administration was required in 4 patients, but the insulin dosage was lower with the mixture. Plasma glucose during glucose infusion was 205+/-25mg/100ml(M+/-SEM) and the sum of plasma glucose, fructose and xylitol during infusion of the mixture was 176+/-33mg/100ml, the difference being of borderline significance (p less than 0.05). The advantages and disadvantages of infusable substrates are summarized on the basis of the available literature and it is concluded that, in general, glucose is preferable. However, if hyperglycaemia is difficult to control, partial replacement of glucose by glucose substitutes or fat emulsions may be advantageous. A routine infusion programme for central venous feeding is suggested. Causes and prevention of side-effects are reviewed. In many patients receiving central venous nutrition less hazardous and less expensive methods could be used such as nasogastric tube feeding, elemental diet or peripheral venous nutrition.
 ...
PMID:[Parenteral hyperalimentation (author's transl)]. 40 48

The glucagon-secreting A cell is a vital component of the organ system which regulates the distribution of fuel--the islets of Langerhans. Bihormonal control of glucoregulation through a push-pull system maintains the glucose concentration of extracellular fluid within narrow limits irrespective of glucose flux rates through relative equality of glucose influx and efflux. This equality requires appropriate secretion mixtures of the biologic antagonists, insulin and glucagon, directed by a glucose sensor. In severe diabetes, there are virtually no B cells and A cells are in contact largely with other A cells and their glucose-sensing capacity is lost. The A cell hypersecretes and in most juvenile type diabetics aggressive therapy with insulin fails to restore it to normal. Glucagon is a factor in the development of endogenous hyperglycemia, and ketoacidosis. Its suppression may provide a possible approach in the future pharmacologic management of diabetic hyperglycemia.
 ...
PMID:Role of glucagon in diabetes. 40 69

We investigated the importance of glucagon in the development of diabetic ketoacidosis by withholding insulin from six patients with juvenile-type diabetes and four totally pancreatectomized subjects. Patients were fasting and had previously been maintained on intravenous insulin for 24 hours. In diabetic patients plasma glucagon concentrations rose sharply after withdrawal of insulin, and the increases were accompanied by a rise in blood ketone concentration of 4.1+/-0.7 (S.E.M.) and blood glucose concentration of 12.5+/-1.8 mmol per liter by 12 hours. In the pancreatectomized patients, despite the absence of measurable glucagon, blood ketones rose by 1.8+/-0.8 and blood glucose by 7.7+/-1.5 mmol per liter. Thus, glucagon is not essential for the development of ketoacidosis in diabetes, as has previously been suggested, but it may accelerate the onset of ketonemia and hyperglycemia in situations of insulin deficiency.
 ...
PMID:Ketoacidosis in pancreatectomized man. 40 53

In order to separate direct effects of epinephrine on fuel metabolism from those mediated by glucagon, epinephrine (0.1 microng/kg-min) was infused for 120 min in 18- and 65-h fasted, nonanesthetized baboons with and without a concomitant somatostatin infusion. At both stages of fasting, epinephrine stimulated glucagon, secretion, and this was blocked by somatostatin. At 18 h, with epinephrine alone, glucose rose early and remained elevated throughout the infusion. In the glycogen-depleted 65-h fasted animals, there was attenuation of the early glucose rise, with glucose reaching a maximum level at 100-120 min. With somatostatin blockade of glucagon release in the 18-h fasted animals, a pattern of attenuated early glucose rise similar to that of the 65-h fasted animals occurred. Somatostatin also inhibited this early glycogenolytic response when the epinephrine dose was increased fivefold. The behavior of FFA, glycerol, and beta-hydroxybutyrate was unchanged by the addition of somatostatin to epinephrine at either stage of fasting. Thus, glucagon mediates the early glycogenolytic response to epinephrine, but not the delayed hyperglycemia and probably not the lipolysis.
 ...
PMID:Role of glucagon in mediating metabolic effects of epinephrine. 40 88

Augmentation of insulin release after oral glucose by a gastrointestinal humoral mechanism is well accepted. The suggestion of a similar mechanism for suppression of glucagon release after oral glucose has not been previously tested. In this study, plasma glucagon levels have been estimated in five normal subjects after both oral and iv administration of glucose. A variable iv glucose infusion rate with frequent monitoring of blood glucose was used to match the hyperglycemia produced by the 50 g oral glucose and the iv glucose loads. Virtually complete suppression of plasma glucagon levels was seen in both cases (nadir of glucagon levels 16 +/- 6 pg/ml for oral glucose; 11.4 +/- 3 pg/ml for iv glucose). Thus, enteric humoral factors did not facilitate glucagon suppression after oral glucose ingestion in man. The vagus nerve is also involved in mediating the alpha-cell response to hypoglycemia and, thus, to examine whether hyperglycemia suppresses glucagon release through a vagal mechanism, iv atropine (15 microgram/kg) was given 20 min before administration of oral or iv glucose. Atropinization delayed the glucagon suppression after oral glucose, but this delay was probably related to delayed glucose absorption from the gut. With iv glucose, atropinization did not affect the degree of suppression of glucagon levels. It is concluded that alpha-cell suppression in response to hyperglycemia is not mediated via the vagus.
 ...
PMID:Hyperglycemia and glucagon suppression: possible importance of the vagus and enteric humoral factors. 42 94

We examined the effect of hyperglycemia per se on net splanchnic glucose balance. In 2 groups of normal postabsorptive men who had undergone hepatic vein catheterization, somatostatin was administered to block endogenous insulin and glucagon secretion. Exogenous glucose was infused in both groups to maintain euglycemia for 2 h in one group (n = 7) and to induce hyperglycemia of 220-240 mg/dl after 30 minutes of euglycemia in the second group (n = 4). In both groups the induction of insulinopenia and glucagonopenia with euglycemia maintained resulted in an initial 75% fall in net splanchnic glucose production (NSGP). In the group in which euglycemia was maintained NSGP returned to basal rates (157 +/- 31 mg/min) within 2 h. However, in the group in which hyperglycemia was induced, NSGP did not return to basal rates but remained suppressed (28 +/- 4 mg/min) for the duration of the study. These data in normal man indicate that hyperglycemia per se with insulin and glucagon acutely withdrawn can suppress splanchnic glucose production but does not induce net splanchnic glucose storage.
 ...
PMID:Hyperglycemia per se (insulin and glucagon withdrawn) can inhibit hepatic glucose production in man. 42

The administration of cyproheptadine (25 mg/kg; i.p.) resulted in an increase of plasma insulin and glucagon (measured using 30 K antibody) 30, 60 and 120 min after injection to fasted rats. This dose of cyproheptadine also induced a hyperglycemia whereas a lower dose (5 mg/kg; i.p.), which did not alter plasma hormone levels, was associated with a hypoglycemia. Fed rats showed a reduction of plasma insulin with a similar elevation of blood glucose after cyproheptadine. Administration of an exogenous load of arginine resulted in increases of plasma insulin and glucagon of a greater magnitude than induced by cyproheptadine, however, cyproheptadine pretreatment (25 mg/kg) completely suppressed the pancreatic response to the amino acid, resulting in blood hormone levels similar to values seen after cyproheptadine administered alone. Cyproheptadine pretreatment also prevented the hyperinsulinemia and hypoglucagonemia resulting from glucose loading. alpha-Adrenergic receptor blockade (with phentolamine), beta adrenergic receptor blockade (with propranolol) and adrenodemedullation did not alter pancreatic responsiveness to the drug.
 ...
PMID:Paradoxical short-term effects of cyproheptadine on insulin and glucagon release in the rat. 43 34

Somatostatin (SRIF) has been tested for its actions on the central nervous system to affect glucoregulation. In doses ineffective when given systemically , SRIF and SRIF analogs given intracisternally (ic) reduce hyperglycemia and hyperglucagonemia after ic bombesin administration. The SRIF analog, des-AA1, 2, 4, 5, 12, 13-[D-Trp8]SRIF, decreases plasma insulin and elevates plasma glucose and glucagon when given systemically. However, when given ic, this peptide prevents the rise in glucose and glucagon after ic bombesin administration and is 10 times more potent than SRIF in reducing bombesin-induced hyperglycemia. Other analogs of SRIF and various unrelated peptides were found to be ineffective in reducing bombesin-induced hyperglycemia. des-AA1, 2, 4, 5, 12, 13-[D-Trp]SRIF prevented the hyperglycemia induced by surgical stress or by ic administration of beta-endorphin or carbacol. des-AA1, 2, 4, 5, 12, 13-[D-Trp]SRIF given ic did not prevent hyperglycemia induced by systemic administration of epinephrine, arginine, or glucagon. These studies suggest that SRIF and its analogs may act within the brain to affect glucoregulation.
 ...
PMID:Somatostatin: central nervous system actions on glucoregulation. 44 91


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