ISSN:
1432-0428
Keywords:
Standard oral glucose tolerance test
;
splanchnic glucose output
;
splanchnic glucose retention
;
insulin production rate
;
non-esterified fatty acids
;
glucagon
;
pancreatic polypeptide
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
Notes:
Summary To determine the effect of the 75 g oral glucose tolerance test on carbohydrate and lipid metabolism, the splanchnic exchange of glucose, lactate, pyruvate, non-esterified fatty acids, β- hydroxybutyrate and acetoacetate as well as the release of insulin, C-peptide, glucagon and pancreatic polypeptide were evaluated in eight healthy male volunteers in the basal state and for 150 min following glucose ingestion. Oral glucose loading was followed by a rapid rise in splanchnic output of glucose (mean±SEM; 154±12 mmol/150 min), pyruvate (1.2±1.2 mmol/150 min) and lactate (8.6±2.0 mmol/150 min), whereas there were reductions in the splanchnic uptake of non-esterified fatty acids (-10.7±4.4 mmol/150 min) and the splanchnic output of β-hydroxybutyrate (-4.8±3.3 mmol/150 min) and acetoacetate (-3.0±1.2 mmol/150 min). In parallel, splanchnic output of insulin (12.3±2.7 nmol/150 min), C-peptide (36.1±5.0 nmol/ 150 min) and transiently of pancreatic polypeptide rose, whereas that of glucagon fell (-0.58±0.21 nmol/150 min). Even at 150 min after glucose ingestion, splanchnic ouptut and arterial concentrations of glucose, lactate, insulin and C-peptide were still above their respective basal values while those of non-esterified fatty acids and glucagon were reduced. Taking into account the partial suppression of endogenous glucose production by ingested glucose it is concluded that, in normal postabsortive man, only 49–63% of a 75 g oral glucose load is retained by the splanchnic bed during the first 150 min, the rest being available for non-hepatic tissues. Since typical metabolic responses to oral glucose loading were maintained up to 150 min after glucose ingestion, it appears that glucose absorption from the gut was not yet complete within this time. This finding partially jeopardizes the interpretation of calculated post-prandial hepatic glucose uptake for short observation periods.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00284457
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