ISSN:
1432-0428
Keywords:
Perifused islets
;
glucagon and insulin secretion
;
glucose
;
arginine
;
epinephrine
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
Notes:
Summary Glucagon secretion and its control have been studied in perifused isolated islets of Langerhans of the rat. It was shown that a low concentration of glucose per se does not cause increased glucagon secretion, but that at low glucose concentrations the amino acid arginine stimulates a biphasic secretory response. Such amino acid stimulated glucagon secretion can be suppressed by increasing the glucose content of the perifused media from 1.67 to 5.5 or 16.7 mM; insulin secretion is also then increased. Since high concentrations of added porcine insulin (10 mU/ml) did not affect amino acid stimulated glucagon secretion at low glucose concentration, it was concluded that high concentrations of glucose and not insulin secreted in response to that glucose are probably responsible for suppression of glucagon secretion. At low concentrations of glucose, epinephrine (2.5 × 10−7 M) also stimulated glucagon secretion. It is concluded that isolated rat islets of Langerhans can be used for the study of glucagon secretion in vitro, and that substances appearing in the blood in vivo at low glucose concentrations are probably responsible for increased glucagon secretion under conditions associated with hypoglycemia.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00420972
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