The effects of glucose, N-acetylglucosamine, glyceraldehyde and other sugars on insulin release in vivo.
The specificity for carbohydrates of insulin secretory responses in vivo was studies. Test sugars were injected via a left femoral vein cannula into conscious rats. Blood samples collected over the ensuing 60 min via a left femoral arterial cannula were assayed for plasma insulin and glucose, and, in some experiments, for N-acetyl glucosamine. Whereas L-glucose or saline produced no significant changes in plasma insulin or glucose concentrations, D-glucose, N-acetylglucosamine, D-glucosamine, fructose, D-glyceraldehyde and DL-glyceraldehyde were potent secretagogues. Simultaneous injection of mannoheptulose abolished the insulinortopic action of glucose and N-acetylglucosamine, but not of DL-glyceraldehyde. Fructose, glucosamine, and DL-glyceraldehyde induced hyperglycaemia, but peak insulin concentraions occurred before any change in plasma glucose concentration. No evidence was obtained for a stimulatory effect of galactose on insulin release. Infusion for 60 min of N-acetyglucosamine produced a sustained elevated plasma insulin concentration and significant hypoglycaemia. The present in vivo results agree with previous in vitro observations and could indicate a role for sugars other than glucose in the regulation of insulin release.
D000117:Acetylglucosamine / Q000097:blood / Q000494:pharmacology*; D000818:Animals; D001786:Blood Glucose / Q000378:metabolism; D005632:Fructose / Q000494:pharmacology; D005690:Galactose / Q000494:pharmacology; D005944:Glucosamine / Q000031:analogs & derivatives* / Q000494:pharmacology; D005947:Glucose / Q000494:pharmacology*; D005985:Glyceraldehyde / Q000494:pharmacology*; D007328:Insulin / Q000097:blood / Q000378:metabolism*; D000078790:Insulin Secretion; D008297:Male; D008356:Mannoheptulose / Q000494:pharmacology; D051381:Rats; D013237:Stereoisomerism
D001786:Blood Glucose; D007328:Insulin; D005632:Fructose; D005985:Glyceraldehyde; D008356:Mannoheptulose; D005947:Glucose; D005944:Glucosamine; D000117:Acetylglucosamine; D005690:Galactose