Effect of a phospho-oligosaccharidic putative insulin messenger on insulin release in rats.
The phospho-oligosaccharide extracted from rat liver and supposed to act as the insulin second messenger inhibits glucose-stimulated insulin release. In the present study, this phospho-oligosaccharide was found not to affect D-[U-14C]glucose oxidation and 45Ca net uptake, but to inhibit insulin release evoked by either D-glucose or 2-ketoisocaproate in isolated rat islets. The relative extent of the latter inhibition was unaffected by either the concentration of D-glucose or the presence of dibutyryl-cyclic AMP, forskolin or glucagon in the incubation medium. At variance with the inhibitory effect of clonidine, that of the phospho-oligosaccharide was resistant to both blockade of alpha 2-adrenergic receptors or pre-treatment with the toxin of Bordetella pertussis. It is speculated, therefore, that such a phospho-oligosaccharide might interfere with a distal event in the insulin secretory sequence.
Malaisse
W J
WJ
Laboratory of Experimental Medicine, Brussels Free University, Belgium.
Albor
A
A
Blachier
F
F
Valverde
I
I
Sener
A
A
Mato
J M
JM
D000818:Animals; D002118:Calcium / Q000378:metabolism; D005947:Glucose / Q000378:metabolism; D006019:Glycolysis; D066298:In Vitro Techniques; D007295:Inositol Phosphates; D007328:Insulin / Q000378:metabolism*; D000078790:Insulin Secretion; D007515:Islets of Langerhans / Q000378:metabolism*; D007700:Kinetics; D008099:Liver / Q000502:physiology*; D009844:Oligosaccharides / Q000302:isolation & purification / Q000502:physiology*; D011134:Polysaccharides; D051381:Rats; D015290:Second Messenger Systems
D007295:Inositol Phosphates; D007328:Insulin; D009844:Oligosaccharides; D011134:Polysaccharides; C028039:inositol phosphate glycan; D005947:Glucose; D002118:Calcium