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)

HCO3(-) secretion across in vitro duodenal mucosa of Rana catesbeiana was investigated under baseline conditions and during secretory stimulation. Baseline secretion was abolished by removal of CO2-HCO3(-)and reduced approximately 60% by removal of nutrient Na+, but was not sensitive to changes in Cl- or K+. Baseline secretion was not directly altered by exposure to 10(-3) M amiloride or 10(-3) M H2DIDS (dihydro-4,4'-diisothiocyanostilbene-2,2'-disulfonic acid) in the nutrient solution and only mildly reduced by acetazolamide. Following removal and restoration of Na+, recovery of secretion was impaired by exposure to acetazolamide (5 x 10(-4) M) or H2DIDS (5 x 10(-4) M) in the nutrient solution. Secretion stimulated by glucagon (10(-6) M) or 16,16-dimethyl prostaglandin E2 (10 microg.mL(-1)) was markedly attenuated by removal of Na+ or by exposure to H2DIDS, but secretion was not altered by acetazolamide (5 x 10(-4) M) or nutrient amiloride (1 mM). Thus, the HCO3(-) that is secreted under nonstimulated conditions derives partly from basolateral Na(+)-dependent uptake and partly from cellular CO2 hydration. Secretagogue-stimulated secretion by duodenal surface epithelium depends on stilbene-sensitive Na+(HCO3(-))n uptake across the basolateral membrane.
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PMID:HCO3-secretion by bullfrog duodenum: dependence on nutrient Na+ during secretory stimulation. 1006 38

Ingested fructose is rapidly utilized by the liver and is either stored as glycogen, converted to glucose, or oxidized to CO2 for energy. The glycemic response to fructose is known to be modest. However, the relative importance of these pathways in humans is unclear. In the present study, a tritiated glucose tracer dilution technique was used to determine the effect of fructose ingestion on the glucose appearance rate (Ra) in the peripheral circulation over an 8-hour period beginning at 8:00 AM. Six normal healthy males ingested 50 g fructose with 500 mL water. On a separate occasion, the same subjects received 500 mL water without fructose as a control. Serum insulin, triglycerides, plasma glucagon, glucose, lactate, alanine, urea nitrogen, and total amino acids also were determined. The plasma glucose concentration was not significantly different following ingestion of fructose or water, other than a transient increase beginning at 8:30 AM of 0.8 mmol/L in response to ingested fructose. Glucose appearing in the peripheral circulation as a result of ingestion of 50 g fructose was calculated to be 9.8 +/- 2.4 g. Following the ingestion of fructose, there was a small increase in glucagon but a 2-fold increase in insulin concentration. There was a large transient increase in lactate and alanine concentrations. The total amino acid concentration remained unchanged, as did the urea production rate. In summary, in men fasted overnight, ingestion of 50 g fructose resulted in a modest increase in the circulating glucose concentration. However, it is likely that a larger proportion of the ingested fructose was converted to glucose in the liver and stored as glycogen and that fructose substituted, at least in part, for lactate and alanine as a gluconeogenic substrate. The increase in glucose production occurred even in the presence of an increase in the insulin concentration and an unchanged glucagon concentration. The metabolic fate of the remaining fructose is yet to be determined.
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PMID:Peripheral glucose appearance rate following fructose ingestion in normal subjects. 1114 18

We investigated, by a combined in vivo and in vitro approach, the temporal changes of islet nitric oxide synthase (NOS)-derived nitric oxide (NO) and heme oxygenase (HO)-derived carbon monoxide (CO) production in relation to insulin and glucagon secretion during acute endotoxemia induced by lipopolysaccharide (LPS) in mice. Basal plasma glucagon, islet cAMP and cGMP content after in vitro incubation, the insulin response to glucose in vivo and in vitro, and the insulin and glucagon responses to the adenylate cyclase activator forskolin were greatly increased after LPS. Immunoblots demonstrated expression of inducible NOS (iNOS), inducible HO (HO-1), and an increased expression of constitutive HO (HO-2) in islet tissue. Immunocytochemistry revealed a marked expression of iNOS in many beta-cells, but only in single alpha-cells after LPS. Moreover, biochemical analysis showed a time dependent and markedly increased production of NO and CO in these islets. Addition of a NOS inhibitor to such islets evoked a marked potentiation of glucose-stimulated insulin release. Finally, after incubation in vitro, a marked suppression of NO production by both exogenous CO and glucagon was observed in control islets. This effect occurred independently of a concomitant inhibition of guanylyl cyclase. We suggest that the impairing effect of increased production of islet NO on insulin secretion during acute endotoxemia is antagonized by increased activities of the islet cAMP and HO-CO systems, constituting important compensatory mechanisms against the noxious and diabetogenic actions of NO in endocrine pancreas.
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PMID:Evaluation of islet heme oxygenase-CO and nitric oxide synthase-NO pathways during acute endotoxemia. 1128 38

Nuclear radiology is valuable in assessing pathophysiology of a variety of organ systems. Pharmacologic interventions are often employed in radionuclide imaging to monitor the physiologic changes, which in turn facilitate the diagnosis. Metoclopramide, erythromycin, and cisapride have been used for gastric emptying studies. To overcome false-negative results, cimetidine, pentagastrin, and glucagon have been used in imaging of Meckel diverticula. Pharmacologic intervention with either cholecystokinin-8 or morphine is used primarily for the assessment of diseases of the gallbladder, common bile duct, and sphincter of Oddi. Pharmacologic interventions performed during renography include diuretic administration, angiotensin-converting enzyme inhibition, and aspirin renography. Recombinant thyrotropin can be used in patients with previously treated thyroid carcinoma who require lifelong follow-up for recurrent disease. Cardiac pharmacologic stress agents fall into two categories: coronary vasodilating agents, such as dipyridamole and adenosine, and cardiac positive inotropic agents, such as dobutamine and arbutamine. Measurement of hemodynamic responses to pharmacologic flow augmentation with carbon dioxide or acetazolamide is valuable in cerebrovascular perfusion studies.
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PMID:Pharmacologic interventions in nuclear radiology: indications, imaging protocols, and clinical results. 1200 82

CT colonography is likely to play an important role in colorectal cancer screening. The ability of this new technique to detect colorectal polyps and cancer is predicated on an optimally cleansed and distended colon. Whereas the most common reported colonic cleansing regimen employed for CT colonography is polyethylene glycol lavage solution, saline cathartics such as sodium phosphate and magnesium citrate offer the advantage of a drier cleansed colon. Positive labeling of residual stool and fluid combined with electronic substraction of tagged material is under investigation. This new technique would eliminate purgative bowel cleansing and increase patient acceptance of CT colonography. Colonic distention is easily and reliably achieved with atmospheric air, although carbon dioxide is being evaluated as a more comfortable alternative. The use of antispasmodics for CT colonography is controversial. Glucagon is no longer used at centers where a clear benefit has not been found. Intravenous contrast may be useful in a specific subset of patients undergoing CT colonography, although it is doubtful that it will be used routinely for CT colonography.
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PMID:CT colonography: examination prerequisites. 1217 54

Four multiparous lactating cows (175 to 220 d in milk [DIM]) were used in a 4 x 4 Latin square design to assess the effects of four doses (0.0, 0.5, 1.0, and 1.5 microg/kg of body weight) of lipopolysaccharide (LPS; Escherichia coli 0111:B4) on performance and plasma metabolite and hormone concentrations. In addition, effects of immune activation on in vitro hepatic metabolic capacity were evaluated in 12 multiparous lactating cows (150 to 220 DIM) infused with 0 (n = 6), 1.0 (n = 4) or 2.0 (n = 2) microg of LPS/kg. Milk production and DMI decreased linearly with LPS dose for 24 h after LPS infusion. Overall mean plasma tumor necrosis factor-alpha, insulin, glucagon, and cortisol concentrations increased linearly with LPS dose, and plasma beta-hydroxybutyrate decreased linearly by dose after LPS infusion. Infusion of LPS decreased the insulin:glucagon molar ratio, but did not affect plasma concentrations of growth hormone, insulin-like growth factor-1, leptin, or L-(+)-lactate. Plasma concentrations of glucose tended to increase initially and subsequently decrease, and there was a quadratic tendency for increased plasma nonesterified fatty acid concentrations after LPS administration. In vitro hepatic capacity for conversion of [1-(14)C]L-(+)-lactate and [1-(14)C]palmitate, but not [1-(14)C]propionate or [1-(14)C]L-alanine, to CO2 increased after LPS administration. Hepatic capacity to convert [1-(14)C]propionate to glucose tended to increase, but neither esterification nor the conversion of palmitate to acid soluble products was altered by LPS. The LPS infusion resulted in significant changes of endocrine mediators responsible for regulation of energy metabolism of lactating cows and tended to alter subsequent in vitro hepatic metabolic capacity.
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PMID:Effect of lipopolysaccharide on indices of peripheral and hepatic metabolism in lactating cows. 1467 74

Glucagon-like peptide-1 (GLP-1), derived from proglucagon, is thought to act as a negative regulator of energy homeostasis in mammals, since intracerebroventricular (ICV) injection of GLP-1 inhibits feeding behavior and enhances energy expenditure. The anorexigenic effect of GLP-1 is also observed in chicks, but whether brain GLP-1 enhances energy expenditure has not been investigated. The aim of the present study was to clarify the effect of ICV injection of GLP-1 on energy expenditure as well as metabolic changes in chicks. The injection of GLP-1 did not affect energy expenditure calculated from oxygen consumption and carbon dioxide production. On the other hand, the injection of GLP-1 significantly decreased respiratory quotient, suggesting that brain GLP-1 shifted the use of energy sources from carbohydrates to lipids. In support of this, ICV injection of GLP-1 increased plasma non-esterified fatty acid concentration while plasma glucose concentration was decreased. In conclusion, GLP-1 appears to act in the brain as a metabolic modulator rather than as a regulator of total energy expenditure in chicks.
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PMID:Intracerebroventricular injection of glucagon-like peptide-1 changes lipid metabolism in chicks. 1746 52

The present work investigated the effect of Morinda lucida (M. lucida) extract on isolated uterine smooth muscle of pregnant and non-pregnant mice. Pregnant and non-pregnant mice were pretreated with oral stilboesterol (0.1 mg/kg body weight) and killed by cervical dislocation. Thin strips of the uterus were cut and mounted in a 20 ml organ bath containing De Jalon solution bubbled with 95%O2-5% CO2 gas mixture. The strips were connected to a force transducer coupled to a Grass 7D Polygraph for the recording of isometric tension. Effects of graded concentrations of oxytocin (OXY; 10-5-10-2 mol/L), acetylcholine (ACh; 10-9-10-5 mol/L) and M. lucida extract (0.015-1.5 mg/ml) were recorded. Fresh uterine strips were then incubated with M. lucida extract for 5 mins and cumulative response to OXY was repeated. Another set of fresh strips was incubated in L-NAME for 15 mins and the cumulative responses to M.lucida extract were repeated. OXY resulted in increased contractile responses in both pregnant and non-pregnant uterine muscles. M. lucida resulted in relaxation of the uterine smooth muscle in both pregnant and non-pregnant mice at all doses. However, at 1.5mg/ml, M. lucida completely blocked spontaneous uterine contractions. Following incubation with L-NAME, M. lucida extract led to a slightly greater relaxation of the uterine strips. In conclusion, M. lucida reduced contractility of uterine smooth muscle in both pregnant and non-pregnant mice as well as blocking contractile responses to OXY and Ach in uterine smooth muscle of pregnant and non-pregnant mice. There was no significant alteration of M. lucida activity by L-NAME suggesting that the action of the compound on uterine muscle is not associated with impaired nitric oxide synthase.
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PMID:Morinda lucida reduces contractility of isolated uterine smooth muscle of pregnant and non-pregnant mice. 1837 32

Glucagon-like peptide-1 (GLP-1) is a peptide released by the intestine and the brain. We previously demonstrated that brain GLP-1 increases glucose-dependent hyperinsulinemia and insulin resistance. These two features are major characteristics of the onset of type 2 diabetes. Therefore, we investigated whether blocking brain GLP-1 signaling would prevent high-fat diet (HFD)-induced diabetes in the mouse. Our data show that a 1-month chronic blockage of brain GLP-1 signaling by exendin-9 (Ex9), totally prevented hyperinsulinemia and insulin resistance in HFD mice. Furthermore, food intake was dramatically increased, but body weight gain was unchanged, showing that brain GLP-1 controlled energy expenditure. Thermogenesis, glucose utilization, oxygen consumption, carbon dioxide production, muscle glycolytic respiratory index, UCP2 expression in muscle, and basal ambulatory activity were all increased by the exendin-9 treatment. Thus, we have demonstrated that in response to a HFD, brain GLP-1 signaling induces hyperinsulinemia and insulin resistance and decreases energy expenditure by reducing metabolic thermogenesis and ambulatory activity.
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PMID:Brain glucagon-like peptide 1 signaling controls the onset of high-fat diet-induced insulin resistance and reduces energy expenditure. 1880 47

To determine the effect of an acute increase in hepatic glycogen on net hepatic glucose uptake (NHGU) and disposition in response to insulin in vivo, studies were performed on two groups of dogs fasted 18 h. During the first 4 h of the study, somatostatin was infused peripherally, while insulin and glucagon were replaced intraportally in basal amounts. Hyperglycemia was brought about by glucose infusion, and either saline (n = 7) or fructose (n = 7; to stimulate NHGU and glycogen deposition) was infused intraportally. A 2-h control period then followed, during which the portal fructose and saline infusions were stopped, allowing NHGU and glycogen deposition in the fructose-infused animals to return to rates similar to those of the animals that received the saline infusion. This was followed by a 2-h experimental period, during which hyperglycemia was continued but insulin infusion was increased fourfold in both groups. During the initial 4-h glycogen loading period, NHGU averaged 1.18 +/- 0.27 and 5.55 +/- 0.53 mg x kg(-1) x min(-1) and glycogen synthesis averaged 0.72 +/- 0.24 and 3.98 +/- 0.57 mg x kg(-1) x min(-1) in the saline and fructose groups, respectively (P < 0.05). During the 2-h hyperinsulinemic period, NHGU rose from 1.5 +/- 0.4 and 0.9 +/- 0.2 to 3.1 +/- 0.6 and 2.5 +/- 0.5 mg x kg(-1) x min(-1) in the saline and fructose groups, respectively, a change of 1.6 mg x kg(-1) x min(-1) in both groups despite a significantly greater liver glycogen level in the fructose-infused group. Likewise, the metabolic fate of the extracted glucose (glycogen, lactate, or carbon dioxide) was not different between groups. These data indicate that an acute physiological increase in the hepatic glycogen content does not alter liver glucose uptake and storage under hyperglycemic/hyperinsulinemic conditions in the dog.
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PMID:A physiological increase in the hepatic glycogen level does not affect the response of net hepatic glucose uptake to insulin. 1947 Aug 36


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