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  • Insulin  (4)
  • Euglycaemic clamp  (2)
  • Secretin  (2)
  • 1
    ISSN: 1432-1440
    Keywords: Semisynthetic human insulin ; Biological potency ; Insulin hypoglycaemia ; Euglycaemic clamp
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The biological potency of semisynthetic human insulin (Actrapid HM, Novo) and purified pork insulin (Actrapid MC, Novo) was assessed in normal and diabetic subjects. The blood glucose lowering effect and the related counter-regulatory response were initially tested in six healthy subjects who received an i.v. injection of 0.15 U/kg body weight of either insulin preparation. The attained insulin levels were very similar (peak at 15 min: HM 139±7, MC 129±7 µU/ml), as well as the resulting blood glucose curves. A prolonged suppression of C-peptide values was observed after injecting both preparations. The evoked counter-regulatory response [glucagon, growth hormone (GH), cortisol and catecholamines] showed minimal differences. Prolactin secretion was almost identical after HM and MC injection. A glucose clamp study was subsequently performed in six insulin-dependent diabetic (IDD) patients. Blood glucose levels were maintained at 80 mg/dl by the artificial pancreas during a 180 min infusion of MC or HM insulin (30 mU/kg/h). The amounts of dextrose infused during the last 60 min of the study were not significantly different (121±14 vs 137±11 mg/kg/h for MC and HM, respectively). It is clear from our results that at the dose levels used in this study, the biological potency of i.v. injected HM is very similar to that of MC.
    Type of Medium: Electronic Resource
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  • 2
    ISSN: 1432-0428
    Keywords: Secretin ; pancreozymin ; exocrine pancreatic insufficiency ; insulin ; free fatty acids ; glucose
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Résumé L'effet des hormones intestinales sécrétine et pancréozymine sur la sécrétion d'insuline, sur la glycémie, les acides gras et le glycérol a été étudié chez onze malades sans diabète mais ayant une insuffisance pancréatique exocrine d'après des résultats cliniques et chimiques. Un groupe de 30 sujets normaux a été utilisé comme témoins. Les hormones intestinales n'ont causé aucune augmentation d'insuline dans le sérum des malades ayant une insuffisance pancréatique exocrine. La sécrétion d'insuline après l'injection intraveineuse de glucose était normale. Il semble que la présence du tissu exocrine du pancréas soit nécessaire pour obtenir une stimulation de la sécrétion d'insuline par la sécrétine et la pancréozymine. Comme il était prévu, il n'y a pas eu chez ces malades — contrairement à ce qui se passe chez les personnes normales — de sécrétion d'insuline différente après l'application de glucose oral et intraveineux. Ces résultats montrent que la similitude des modifications de l'insuline plasmatique après administration de glucose par voie orale et parentérale peut signifier un mauvais fonctionnement du pancréas exocrine. On peut en déduire qu'un récepteur du glucose de la cellule bêta ou de la membrane superficielle peut opérer indépendamment du tissu pancréatique exocrine et des hormones intestinales. D'autre part, il est proposé comme conclusion qu'un «entérorécepteur» de la cellule bêta est sensible à l'action des hormones intestinales et qu'il est dépendant, plus ou moins, d'un tissu pancréatique exocrine.
    Abstract: Zusammenfassung Bei 11 nicht-diabetischen Patienten mit klinisch und laborchemisch nachgewiesener chronischer exkretorischen Pankreasinsuffizienz wurde die Wirkung der intestinalen Hormone Sekretin und Pankreozymin auf die Insulinsekretion, den Blutzucker, die freien Fettsäuren und das Glycerin untersucht und verglichen mit den an 30 normalen Versuchspersonen gewonnenen Befunden. — Bei den Patienten mit exkretorischer Pankreasinsuffizienz bewirkten die oben genannten intestinalen Hormone keine Erhöhung des Seruminsulins, obwohl die Insulinsekretion nach der i.v. Verabreichung von Glucose nicht beeinträchtigt war. Offensichtlich ist für eine Insulinausschüttung nach Sekretin und Pankreozymin beim Menschen ein intaktes exkretorisches Pankreas erforderlich. Erwartungsgemäß konnte bei diesen Patienten, im Gegensatz zu Normalpersonen, kein Unterschied in der Insulinausschüttung nach oraler und intravenöser Verabreichung von Glucose festgestellt werden. Aus diesen Ergebnissen ist zu schließen, daß die Ähnlichkeit der Plasmainsulin-Veränderungen nach oraler und parenteraler Gabe von Glucose bereits auf einen frühen Schaden der exokrinen Pankreasfunktion hinweisen könnte. Man kann daraus die Folgerung ziehen, daß ein (hypothetischer) „Glucose receptor“ derβ-Zelle oder ihrer Oberflächenmembran mehr oder weniger unabhängig von exokrinem Pankreasgewebe und intestinalen Hormonen funktioniert. Andererseits scheint der „Entero-Rezeptor“ derβ-Zelle, der auf die insulinstimulierende Wirkung der intestinalen Hormone reagiert, mehr oder weniger abhängig zu sein von ausreichendem Vorhandensein intakten exokrinen Pankreasgewebes.
    Notes: Summary In 11 non-diabetic patients with clinical and laboratory evidence of chronic exocrine pancreatic insufficiency, the effect of intestinal hormones secretin and pancreozymin upon insulin secretion, blood sugar, free fatty acids and glycerol was studied and compared with the findings obtained in 30 normal volunteers. — In the patients suffering from exocrine pancreatic insufficiency the above mentioned enterohormones did not elicit any increase in serum insulin although insulin secretion after i.v. glucose loads was perfectly undisturbed. Obviously, the mediator inducing insulin release following secretin and pancreozymin in man depends on intact exocrine pancreatic tissue. As had been expected, no differences in the serum-insulin responses to oral and intravenous glucose, as found in normals, were established in these patients. From theses results it is inferred that similarity of plasma insulin changes after oral and parenteral glucose loads might hint at an early impairment of exocrine pancreatic tissue function. That implies, that a (hypothetical) “Glucose receptor” of theβ-cell or its surface works more or less independently of both the exocrine pancreatic tissue and the intestinal hormones. On the other hand, the “Entero-receptor” of theβ-cell responding to the insulin-stimulating action of intestinal hormones, such as secretin and pancreozymin, is likely to be more or less dependent upon sufficient amounts of intact exocrine pancreatic tissue.
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  • 3
    ISSN: 1432-1440
    Keywords: Somatostatin ; Insulin ; C-peptide ; Diabetes ; Pituitary function ; Gastric acid secretion
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A case of somatostatinoma syndrome in a 30-year-old woman is presented. Basal levels of growth hormone and of pancreatic and gastric hormones were reduced and the response of growth hormone, insulin and C-peptide to stimuli such as arginine, glucose, glibenclamide and calcium was virtually abolished. Similarly, gastric acid secretion, pancreatic exocrine function and intestinal absorption were significantly reduced. On the other hand, basal and stimulated levels of adrenocorticotropic hormone (ACTH), luteinizing hormone (LH), follicle-stimulating hormone (FSH) and thyroid-stimulating hormone (TSH) were within the normal range. Plasma somatostatin-like immunoreactivity was increased to 600 2,000 pg/ml (normal: 88–140 pg/ml). Immunocytochemical studies demonstrated the presence of somatostatin immunoreactive material in the primary tumour in the head of the pancreas and in the liver metastases. In spite of two courses of chemotherapy with streptozotocin and 5-fluorouracil the patient died due to liver failure 5 months after the first admission to hospital.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Journal of molecular medicine 63 (1985), S. 545-553 
    ISSN: 1432-1440
    Keywords: Type I diabetes ; Insulin resistance ; Euglycaemic clamp ; Insulin receptor binding ; Insulin antibodies
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Insulin sensitivity was assessed using the euglycaemic clamp technique in eight type I diabetic patients (after overnight blood glucose normalization with an artificial pancreas) and in six healthy subjects. Basal insulin concentrations were higher in diabetic patients (25±4 µU/ml) than in control subjects (17±1 µU/ml;P〈0.05). Insulin infusion of 0.5, 1.0, 2.0 and 5.0 mU/kg per min during subsequent 2-h periods resulted in similar mean steady-state insulin concentrations in both groups. The mean dextrose requirements during the last 40 min of each period were nevertheless decreased in diabetic patients (1.6±0.5, 3.5±0.8, 6.5±0.7, 10.2±0.7 mg/kg per min) as compared with control subjects (4.7±0.3, 8.2±0.9, 10.2±0.9, 12.4±0.9 mg/kg per min). At low insulin concentrations dextrose requirements were diminished in all diabetic subjects. At the highest insulin levels, individual dose-response curves from only four patients were within the normal range. Under basal conditions, the monocyte receptor number was significantly reduced in diabetic patients (17,500±2,800 sites/cell) as compared with control subjects (26,700±2,500 sites/cell;P〈0.05), whereas there were no differences regarding empty site affinities. Receptor data did not differ in patients with normal and decreased maximal dextrose requirements. Insulin resistance is apparently a common feature of type I diabetes at serum insulin concentrations of approximately 100 µU/ml. Normalization of the insulin effect by higher insulin concentrations is not possible in all patients. Insulin antibodies at concentrations observed in this study (〈0.16 mU/ml) do not contribute significantly to insulin resistance; receptor and postreceptor defects are possibly more important.
    Type of Medium: Electronic Resource
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  • 5
    ISSN: 1433-8580
    Keywords: Insulin ; Intestinal hormones ; Atropine ; Vagus ; Insulin ; Intestinale Hormone ; Atropin ; Vagus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung und Schluβfolgerung Bei 35 stoffwechselgesunden freiwilligen Probanden wurde vor sowie nach Atropingabe die Wirkung der intestinalen Hormone Sekretin und Cholecystokinin-Pankreozymin (CCK-PZ) auf die endokrine und exokrine Pankreasfunktion untersucht. Außerdem wurde die Wirkung von intravenös und oral bzw. intraduodenal verabreichter Glucose und Aminosäuren auf die Insulinsekretion, den Blutzucker und die freien Fettsäuren ebenfalls vor und nach Atropinmedikation geprüft. Intravenös verabreichtes Sekretin konnte weder in seiner exokrinen noch endokrinen Pankreasfunktion durch Atropin beeinflußt werden. Intravenös injiziertes CCK-PZ konnte mittels Atropin sowohl in seiner ekbolischen wie auch endokrinen Pankreasfunktion gehemmt werden. Die Wirkung von CCK-PZ ist somit an ein cholinerges System gebunden, so daß es erlaubt erscheint, bezüglich der Pankreozyminwirkung von einem synergistisch bzw. additiv wirksam werdenden „neurohormonalen“ Mechanismus zu sprechen. Die durch parenteral verabreichte Glucose oder Aminosäuren induzierte Insulinsekretion wurde durch Atropin nicht beeinflußt; hingegen hemmte Atropin dieβ-cytotrope Wirkung von oral bzw. intraduodenal verabreichter Glucose oder Aminosäuren. Dies läßt auf eine Abhängigkeit von einem cholinergen oder parasympathischen System in der Freisetzung dieser intestinalen Hormone schließen.
    Notes: Summary and Conclusions In 35 metabolically normal subjects the effect of i.v. secretin and cholecystokinin-pancreozymin (CCK/PZ) on the endocrine and exocrine pancreatic function was investigated, before and after atropine. In addition, the effect of oral, intravenous and intraduodenal administration of glucose and amino acids on blood sugar and free fatty acids before and after the injection of atropine was studied. The secretin stimulated endocrine and exocrine pancreas was not affected by atropine. However, atropine inhibited the ecbolic and endocrine pancreatic function after stimulation with CCK/PZ. Therefore, the effect of i.v. CCK/PZ seems to be mediated by the cholinergic system, or even a “neuro-hormonal” system which acts synergically or additively. No influence of atropine on the insulin secretion induced by i.v. glucose or amino acids was observed. On the other hand, atropine inhibited the beta-cytotropic effect of glucose and amino acids after oral or intraduodenal administration. These findings indicate that the release of these intestinal hormones is dependent on the cholinergic or parasympathetic system.
    Type of Medium: Electronic Resource
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  • 6
    ISSN: 1433-8580
    Keywords: Secretin ; Cholecystokinin-Pancreozymin ; Intestinal hormones ; Intestinal absorption
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The effects of natural secretin (90%) and synthetic secretin as well as impure (10%) and pure (99%) cholecystokinin-pancreozymin (CCK) on net absorption of water, electrolytes, and glucose in human jejunum were studied in 31 normal subjects. An intestinal perfusion technique with a triple-lumen tube was used. Net absorption of water and solute was significantly inhibited by both hormones only with larger doses, pure CCK being less active than impure CCK. A dose-dependent response of water and electrolyte absorption to graded doses of pure CCK was observed, without concomitant inhibition of glucose absorption with lower doses. The findings suggest that secretin and CCK may not be of physiologic importance regarding intestinal absorption in man. The definite changes in intestinal motility and transit rate caused by these hormones seem more likely to result in a reduction of intestinal absorption and an increase in the secretion of water and electrolytes along the proximal small bowel.
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  • 7
    ISSN: 1433-8580
    Keywords: Oscillations ; Insulin ; Glucose
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The present study was designed to determine the effect of low dose continuous and oscillatory intraportal insulin infusions upon subsequent glucose-induced insulin release. In overnight-fasted and anesthetized rats with indwelling catheters in the jugular vein, carotic artery, and mesenteric vein insulin was infused intraportally for 3 h via the mesenteric vein catheter at a continuous rate of 45 µU/kg·min, or the same amount of insulin was administered at alternating high (72 µU/kg·min) and low infusion rates (18 µU/kg·min), respectively, in 2-, 4-, 8-, and 16-min cycles (oscillatory infusions). Another group received a continuous infusion of saline. Glucose (0.4 g/kg) was given i.v. 30 min after the end of the insulin or saline infusion. During the 3-h infusion of insulin or saline the peripheral glucose level remained unchanged in all groups. In response to the i.v. glucose load peripheral arterial plasma insulin levels were significantly elevated after preceding oscillatory infusions compared to the continuous insulin infusion. As compared to the group receiving saline the glucose-induced insulin response after continuous insulin infusion was significantly reduced. The plasma glucose responses were not different except for inexplicably elevated glucose levels in the 4-min cycle group. No difference was observed for plasma glucagon levels in all groups. The present data demonstrate an augmented responsiveness of theβ-cell to glucose after a preceding oscillatory infusion of insulin and an impaired responsiveness to glucose after continuous insulin infusion. This indicates that an oscillatory insulin release might be of importance for an adequate regulation ofβ-cell function.
    Type of Medium: Electronic Resource
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  • 8
    ISSN: 1433-8580
    Keywords: H2-Receptor ; Somatostatin ; Pancreatic polypeptide ; Gastrin ; Insulin
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The effect of histamine H2-receptor stimulation via the infusion of impromidine was assessed with regard to postprandial plasma insulin, pancreatic polypeptide (PP), somatostatin, and gastrin levels. The effect of impromidine was assessed in the postprandial state during a liver extract/sucrose test meal which had a buffer capacity to maintain the intragastric pH at a constant level for the time impromidine was infused. Postprandial plasma insulin and gastrin levels were not changed by impromidine (10µg/kg·h−1). Plasma somatostatin levels rose significantly, whereas the postprandial increase of plasma PP levels was attenuated. The effects on somatostatin and PP were antagonized by the infusion of cimetidine, a specific histamine H2-receptor blocker. In conclusion the present data demonstrate that in the postprandial state activation of H2-receptors stimulates somatostatin and inhibits PP release while insulin and gastrin release are not affected.
    Type of Medium: Electronic Resource
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