Library

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    ISSN: 1432-0428
    Keywords: Hypothermia ; temperature ; insulin release ; glucagon release ; isolated perfused rat pancreas ; glucose ; acetylcholine ; tolbutamide ; arginine
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Two series of experiments with the isolated perfused rat pancreas were performed in parallel. The conditions differed only with respect to temperature, which was 37.5 °C in one series and 28 °C in the other. The lowering of the temperature decreased insulin secretion induced by glucose as well as the insulin response to tolbutamide and acetylcholine. Unlike insulin, glucagon secretion was not significantly modified by hypothermia. Our results suggest that the mechanisms involved in glucagon and insulin secretion are different.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    ISSN: 1432-0428
    Keywords: Acyl-amino-alcyl benzoic acid derivative ; hypoglycaemic agent ; insulin release ; pancreatic polypeptide ; glucagon ; somatostatin ; tolbutamide ; unanaesthetized dogs
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The effects of HB 699, a non-sulphonyl urea acyl-amino-alcyl benzoic acid derivative, were studied in unanaesthetized dogs. Changes in blood glucose and plasma insulin, glucagon, pancreatic polypeptide and somatostatin were measured after a single intravenous injection. HB 699 caused hypoglycaemia and stimulated insulin secretion in a dosedependent manner. The effects of HB 699 (40 mg/ kg) on pancreatic hormone secretion were compared to those of tolbutamide given at a dose (12 mg/kg) which induced a similar maximal hypoglycaemia. Both drugs caused a similar increase in insulin release (180±32% for tolbutamide and 240±41% for HB 699) lasting for approximately 1 hour. Despite hypoglycaemia, plasma glucagon concentrations were unaltered by either substance. HB 699 caused a marked increase in the secretion of pancreatic polypeptide (220±60% at 30 min) for up to 2 hours, whereas tolbutamide caused no significant change in plasma pancreatic polypeptide levels. In contrast, while tolbutamide caused a significant (45±12%) but short-lived increase in plasma somatostatin concentrations, HB 699 had no significant effect.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 3
    ISSN: 1432-0428
    Keywords: Insulin-secretion ; tolbutamide ; sulfonyl-urea hypoglycemic sulfonamide ; mannoheptulose ; diazoxide ; isolated perfused rat pancreas
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The stimulating action of tolbutamide on insulin secretion presents two components; the first is independent of the presence of glucose in the medium which perfuses the beta cells; the second is, on the contrary, dependent upon glucose. D-mannoheptulose and diazoxide permit the dissociation of these two components; the antagonistic effect of the first exerts itself uniquely on that part of the stimulating action of tolbutamide which is gluco-dependent; on the contrary, the antagonistic effect of the second exerts itself on both phases of the stimulating action of the sulfonamide.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 4
    ISSN: 1432-0428
    Keywords: Beta cell ; isolated pancreas ; insulin secretion ; acetylcholine ; eserine ; cholinergic receptors ; muscarinic receptors ; atropine ; muscarine
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Studies of the role and nature of the cholinergic receptors acting on the secretion of isolated perfused rat pancreas have shown the following: The infusion of acetylcholine at a dose of 2.5 μM in the presence of a concentration of glucose of 1.5 g/1, provoked a first phase of immediate and important stimulation of the secretion of insulin; this initial peak of insulin secretion was followed by a second phase during which a new less intense stimulation occurred; the latter was followed by an inhibition appearing at a time that depended on the pancreas used. At a dose of 0.5 μM of acetylcholine, the first phase of stimulation always appeared; during the second phase some pancreases were inhibited, others remained stimulated. — The peak of insulin secretion obtained by stimulation with acetylcholine during the first phase was dose related. — Eserine intensified the effects of acetylcholine. — The presence of glucose was essential for the insulinsecretory action of acetylcholine. The muscarinic nature of the cholinergic receptors implicated in the secretion of insulin was demonstrated by the use of: — Atropine which completely blocked the effects of acetylcholine, — Muscarine which produced the same effects as acetylcholine on our pancreas preparation, effects which were equally inhibited by atropine. The cholinergic receptors of the endocrine beta cell of the islet of Langerhans of the pancreas are therefore of the muscarinic type.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 5
    ISSN: 1432-0428
    Keywords: Insulin secretion ; adrenaline ; noradrenaline ; catecholamines ; dog ; blood glucose ; propranolol
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The effects of adrenaline and noradrenaline infusions on pancreaticoduodenal venous insulin output were studied in anaesthetized normal dogs. Two experimental protocols were used. In the first, the dogs had a normal blood glucose level at the start of the catecholamine infusion (normoglycaemic dogs). In the second, the animals were made hyperglycaemic by a continuous glucose infusion (hyperglycaemic dogs). In the normoglycaemic dogs, adrenaline (0.5 μg · kg-1 · min-1) provoked hyperglycaemia accompanied by an increase in insulin output. Noradrenaline (0.5 μg · kg-1 · min-1) also caused an increase in insulin output but without any significant change in blood glucose. In hyperglycaemic dogs, adrenaline (2 μg · kg-1 · min-1) reduced the insulin response and enhanced the hyperglycaemia; noradrenaline (2 μg · kg-1 · min-1) markedly increased the insulin response (+ 2250%) without any significant change in blood glucose. Propranolol (0.3 mg/kg, IV) prevented the increase of insulin induced by noradrenaline. These findings show that, in the normal dog, adrenaline and noradrenaline infusions can produce opposite effects on insulin response depending on the experimental conditions.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 6
    ISSN: 1432-1041
    Keywords: somatostatin analogue ; oral formulation ; gastrointestinal absorption ; SMS 201-995 ; healthy volunteers
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary To determine the local gastrointestinal absorption of a new synthetic somatostatin analogue (SMS 201-995 = Sandostatin), an intestinal tube was passed in eight healthy volunteers and on different days an aqueous solution was administered at four different locations: stomach, proximal duodenum, ligament of Treitz and jejunum. In a follow-up study, an oro-ileal tube was passed in six of the original volunteers and the drug solution was administered in to the terminal ileum. The aqueous solution of SMS was rapidly absorbed from the gastrointestinal tract after local application, and it was well tolerated. Absorption of the drug from the different sites was comparable, although there was a tendency to decreased peptide absorption after ileal administration. Absorption of the drug was quite variable between the subjects and the different locations. The dose-corrected systemic availability relative to subcutaneous administration in another study was 0.28%. However, significant plasma SMS concentrations were achieved, suggesting that oral delivery of the polypeptide may eventually be possible for long-term treatment of a variety of disorders.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 7
    ISSN: 1432-0428
    Keywords: Benzothiadiazine analogue ; LN 5330 ; diazoxide ; glucagon ; insulin ; somatostatin secretion ; dog ; isolated perfused rat pancreas
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary LN 5330 is a new benzothiadiazine which is a structural analogue of diazoxide. Its effects in vivo were studied on blood glucose levels and insulin, glucagon and somatostatin secretion in normal dogs, and in vitro on glucagon and insulin secretion from the isolated perfused rat pancreas. The results were compared with those obtained with diazoxide at equimolar dose or concentration. In the normal anaesthetized dog having a T-shaped catheter inserted in the pancreaticoduodenal vein, the infusion of LN 5330 (87.8 μmol/kg for 20 min) induced (1) a progressive increase in blood glucose levels, (2) a rapid decrease in insulin and somatostatin output rate, (3) an immediate increase in pancreatic glucagon secretion, and (4) a delayed decrease of arterial blood pressure. The equimolar dose of diazoxide provoked the same effects on blood glucose levels, insulin and somatostatin output, but a marked decrease in glucagon output and in arterial blood pressure. In the isolated rat pancreas perfused with 8.3 mmol/l glucose, the infusion of LN 5330 (440 μmol/l for 30 min) induced a drastic fall in insulin and a rapid and persistent increase in glucagon output. This stimulatory effect on glucagon secretion was not found with diazoxide at equimolar concentration. These findings show that LN 5330 is a substance which is distinct from diazoxide and interesting because of its double action: inhibition of insulin secretion and stimulation of glucagon secretion.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...