Investigations on isolated islets of langerhans in vitro. 16.Modification of the glucose-dependent inhibition of glucagon secretion.
Biochim Biophys Acta
; 499(3): 362-72, 1977 Oct 25.
Article
em En
| MEDLINE
| ID: mdl-334269
ABSTRACT
Investigation of glucagon secretion in isolated Wistar rat islets was carried out to elucidate further the regulatory function of glucose and arginine on pancreatic A-cells. The suppressive effect of D-glucose could also be demonstrated with L-glucose, D-mannose, D-fructose, D-galactose, D-glyceraldehyde and DL-dihydroxyacetone, but not in the presence of 3-O-methylglucose or mannitol. Sugars other than D-glucose inhibited glucagon secretion only at much higher concentrations than those at which D-glucose was effective. Furthermore, although 7.5 mM D-glucose up to 80% inhibition, the effects of other sugars appeared to level off at only 50--60% inhibition. The inhibitory action of D-glucose or D-glyceraldedyde on glucagon secretion could not be overcome by L-arginine, but 3-O-methylglucose, mannoheptulose, 2-deoxy-D-glucose, iodoacetamide, theophylline, epinephrine and acetylcholine were effective. The insulin secretion in response to glucose was inhibited by the metabolic inhibitors used, whereas the B-cell response in the presence of glyceraldehyde was diminished by iodoacetamide only. Like D-glucose, a variety of other sugars markedly reduced the stimulatory effect of L-arginine in glucagon release. The results show that the suppression of glucagon secretion is not specific for D-glucose and not strongly connected on a stimulated insulin secretion.
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Base de dados:
MEDLINE
Assunto principal:
Arginina
/
Glucagon
/
Ilhotas Pancreáticas
/
Glucose
Limite:
Animals
Idioma:
En
Ano de publicação:
1977
Tipo de documento:
Article