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)

To determine whether synthetic somatostatin originally isolated from sheep hypothalamus can inhibit hormone secretion in the same species, we measured plasma levels of GH, insulin, glucagon, and glucose of normal sheep under a variety of experimental conditions in the presence and absence of somatostatin infusion. An oral dose of 2.5 mg./kg. 3,5-dimethypyrazole increase plasma GH from 10.9 to 376.9 ng. per milliliter, which was suppressed by 50 per cent and 80 per cent with 0.5 and 1 mg. synthetic cyclic somatostatin, respectively. Linear somatostatin (0.5 mg.) was without effect in two animals tested. Propionate (0.5 mmole per kilogram) and arginine (10 gm.) induced a rise in plasma insulin and GH, and glucagon was effectively blocked by cyclic somatostatin (0.5 mg.). Similarly, somatostatin inhibited glucose, and glucagon provoked GH and insulin secretory responses without affecting glucose or FFA levels. Somatostatin had no effect on the disappearance of injected glucagon. Finally, addition of somatostatin to incubation media prevented PGE promoted GH release, and suppressed cyclic AMP accumulation, although to a lesser extent, in sheep anterior pituitary pieces. In view of the large amounts required to suppress stimulated hormone release and the general lack of specificity of somatostatin, it is suggested that this peptide may have a functional role only in the release of hormones of the pituitary, where it could occur in relatively high local concentrations. Its inhibition of extrapituitary hormone secretion may be purely a pharmacologic effect that, nevertheless, suggests an interference with a step common to the secretory process of hormones.
 ...
PMID:Studies on growth hormone secretion. VII. Effects of somatostatin on plasma GH, insulin, and glucagon in sheep. 16 76

Adipose tissue from streptozotocin-diabetic rats exhibits half-maximal lipolytic responses (FFA, glycerol release, increase in tissue FFA) to epinephrine at hormone concentrations 5-10 times lowere than those required for half-maximal stimulation of lipolysis in adipose tissue from normal rats. The lipolytic response to epinephrine also occurs more promptly and the antilipolytic effect of insulin in the presence of submaximal epinephrine conceptrations is much less pronounced than in normal tissue. In contrast, diabetic adipose tissue is less responsive to ACTH and glucagon than normal tissue. Half-maximal lipolytic responses are elicited by similar dibutyryl cyclic AMP concentrations in both tissues. Insulin treatment of diabetic rats during 24 hrs restores the lipolytic response of their adipose tissue to epinephrine to nearly normal. Our findings point to an abnormality of diabetic adipose tissue possibly related to the hypersensitivity of catecholamines encountered in denervated organs which are adrenergically innvervated. They are consistent with present concept of different hormone discriminators on the fat cell membrane and offer a further explanation for increased FFA mobilization in the diabetic state.
 ...
PMID:Increased sensitivity of diabetic rat adipose tissue towards the lipolytic action of epinephrine. 17 11

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

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

The relationship between thermoreception, hormonal secretion and muscular activity was studied. 6 men swam 60 min in 21, 27 and 33 degrees C water at a speed requiring 68% of VO2 max (determined in 27 degrees C water). Rectal temperature increased in 33 degrees C (1.3 +/- 0.2 degrees C, mean and S.E.) and 27 degrees C (0.7+/- 0.1 degrees C) expts. but decreased in 21 degrees C expts. (0.8 +/- 0.3 degrees C). Changes in esophageal and muscle temperatures parallelled changes in rectal temperature. Plasma noradrenaline was higher in 33 degrees C than in 27 degrees C expts. and growth hormone, cortisol and glucagon concentrations increased in 27 degrees C and 33 degrees C expts. only. Insulin concentrations were uniformly depressed during swimming at the different water temperatures. In 21 degrees C expts. noradrenaline and adrenaline concentrations were higher than in 27 degrees C expts. VO2, carbohydrate combustion and peak lactate were slightly lower in 33 degrees C expts. Plasma glucose decreased slightly and FFA and glycerol concentrations increased identically in all expts. Heart rate increased continuously during swimming in 27 degrees C and 33 degrees C expts., but not in 21 degrees C expts. In conclusion the rise in body temperatures normally observed during exercise enhances the exercise induced increases in the plasma concentrations of noradrenaline, cortisol, growth hormone and glucagon. Decreased body temperatures may elicit catecholamine secretion as a direct consequence of thermoreception. Shivering may account for previously observed decreases in insulin secretion during cold stress but not for increases in cortisol and growth hormone.
 ...
PMID:The effect of water temperature on the hormonal response to prolonged swimming. 44 63

The metabolic and hormonal changes during a standard physical exercise were studied in healthy subjects and in insulin-dependent diabetics well matched for body weight, and therefore submitted to a similar work load in a physiologic range, and in obese subjects that, owing to their weight, faced a significant heavier work in the same environmental conditions. Moderate work load did not lead to significant changes in metabolic and hormonal blood parameters (blood glucose, FFA and glycerol; insulin, glucagon, growth hormone and cortisol) in healthy subjects. A similar substrate homeostatis was seen in insulin-dependent diabetics, that however showed marked hormonal alterations. In these subjects, indeed, higher levels of plasma glucagon and GH were reached during work and in the recovery phase. Obese subjects, submitted to a heavier work load, presented a marked increase in blood glucose and glycerol which agrees with high GH and cortisol levels, and a subsequent increment of IRI which corresponds to a normalization of blood glucose and glycerol. Obese subjects, therefore, show a normal sensitivity to work load. Considerations about the work load in everyday life are discussed.
 ...
PMID:Metabolic and hormonal changes during exercise in healthy, diabetic and obese subjects. 45 17

In order to study endocrine and metabolic responses to normal food ingestion, 8 'healthy' subjects received a standard mixed meal which reflected the composition of Western diet (CHO 47%, protein 23%, fat 26%, alcohol 4%), in 20 min. Before and after the meal, in each subject glucose, lactate, FFA, insulin, C-peptide, glucagon and HGH were determined. The results showed that glycemic and insulinemic responses were not very different from those observed after the classical oral glucose tolerance test. Plasma FFA and blood lactate decreased progressively after the meal. Plasma glucagon and HGH showed opposite changes: pancreatic glucagon rose and HGH slightly declined after composite food ingestion.
 ...
PMID:Metabolic and endocrine responses to a standard mixed meal. A physiologic study. 45 19

The aim of this study was to compare the metabolic and hormonal effects of somatostatin to those of propranolol, a beta-adrenergic blocking agent known to reduce basal insulin secretion. For this purpose, 6 normal subjects received somatostatin (4 microgram/min) per 60 min and 6 subjects were infused with propranolol (0.08 mg/min). Somatostatin resulted in a significant decrease of basal insulin (p less than 0.05) and glucagon (p less than 0.01) and raised plasma FFA levels from a mean basal value of 417 +/- 24 muEq/1 (x +/- SEM) to 600 +/- 46 muEq/1 at 60 min (p less than 0.01). Propranolol significantly decreased basal insulin (p less than 0.05) and glucagon (p less than 0.05); FFA levels rose slightly at the end of propranolol administration (p less than 0.05). The levels of FFA which were significantly higher (p less than 0.025) during somatostatin as compared to those observed during propranolol, seem to suggest a role for this tetradecapeptide in lipid metabolism independent of its inhibiting action on islet hormone release.
 ...
PMID:A comparative study of metabolic and hormonal responses to somatostatin and propranolol in man. 45 22

The importance of autonomic nervous activity for the pancreatic hormonal response to exercise in man was studied. 7 men ran at 58% of V(O2)max (determined without administration of drugs) to exhaustion during alpha-adrenergic blockade with phentolamine (P), during parasympathetic blockade with atropine (A), or without drugs (C). At rest phentolamine increased the plasma concentrations of both insulin and norepinephrine. During exercise norepinephrine concentrations increased and were in P experiments 3 times the concentrations in C experiments. Insulin always declined during exercise but in P experiments never decreased below basal levels. At identical times neither glucagon nor glucose differed significantly in the different expts. Thus during exercise alpha-adrenergic blockade increased insulin concentrations but did not diminish the glucagon response. Nor was this response increased when beta-receptor stimulation in P experiments was intensified by the particularly high catecholamine concentrations. The concentrations of FFA, glycerol and lactate were highest in P experiments and identical in A and C experiments. These findings indicate that during prolonged moderate exercise in man insulin secretion is depressed by stimulation of alpha-adrenergic receptors whereas glucagon secretion is not influenced by adrenergic receptors. Stimulation of beta-adrenergic receptors enhances lipolysis but neither lipolysis nor pancreatic hormonal secretion is influenced by cholinergic activity during exercise.
 ...
PMID:Catecholamines and pancreatic hormones during autonomic blockade in exercising man. 59 18

At birth there is a statistically significant correlation between the maternal blood sugar and the umbilical venous and arterial blood glucose. The glucose concentration in the mother is higher than in the umbilical vein, and in the latter higher than in the umbilical artery. The free fatty acids also show a falling gradient from the mother to the umbilical vein and artery. This supports the assumption that glucose and FFA pass the placenta from the mother to the foetus. Insulin concentration is significantly higher in the mother than in the cord blood. There is however no difference between umbilical venous and arterial plasma insulin. A statistically significant correlation between glucose and insulin is only demonstrable in the maternal blood. Glucagon levels are about the same in maternal and umbilical arterial blood, but are significantly higher in umbilical venous blood. These results are consistent with the supposition that insulin and glucagon do not cross the placenta to a significant extent and can be synthesised by the foetus. In the first few hours after birth, a fall of glucose and a rise in FFA occur at the same time. Insulin tends to be lower than at birth and glucagon rises.
 ...
PMID:Interrelation of maternal and foetal glucose and free fatty acids. The role of insulin and glucagon. 66 26


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