[Intravenous administration of insulin and tolbutamide. A mathematical simulation on the different glycolytic activity in the organism (author's transl)].
A system theoretical model is developed for the different effects on the glucose metabolism after i.v. insulin injection and after the release of endogenous insulin release induced by sulfonylurea derivates. The model is based on our clinical results on the change of blood glucose and blood lactate levels after application of insulin or tolbutamide, resp.: Concerning the blood glucose depressing effects equivalent concentrations of insulin and tolbutamide cause an increase of lactate and pyruvate to different extents in healthy subjects. Possible reasons for this behaviour could be additional insulin-independent effects of tolbutamide on the glucose metabolism. The mathematical simulation of glycolysis stimulation as dynamical system with 6 variables and 14 parameters can demonstrate that a different insulin distribution in the blood circulation is sufficient to explain the different glycolytic activities. Simply the different paths of insulin entrance--either evenly distributed in the blood or directly at liver entry--may cause the different increases of lactate levels. The calculations of the time courses between 0 and 60 min after injection are in close agreement with experimental findings.
D001786:Blood Glucose / Q000378:metabolism; D006019:Glycolysis / Q000187:drug effects*; D006801:Humans; D007275:Injections, Intravenous; D007328:Insulin / Q000008:administration & dosage / Q000097:blood / Q000494:pharmacology*; D007773:Lactates / Q000097:blood; D008954:Models, Biological; D014044:Tolbutamide / Q000494:pharmacology*
D001786:Blood Glucose; D007328:Insulin; D007773:Lactates; D014044:Tolbutamide
Intravenöse Insulin- und Tolbutamid-Belastung. Eine Modellbetrachtung zur unterschiedlichen Glykolyse-Aktivierung.