Showing papers by "Rüdiger Göke published in 1988"
TL;DR: Binding of the peptide resulted in a dose-dependent increase in cyclic AMP concentrations and binding sites for GLP-1 (7-36)amide were not present on dispersed enterocytes from porcine small intestine.
Abstract: Specific binding of 125I-labelled glucagon-like peptide-1(7-36)amide (GLP-1(7-36)amide) to rat insulinoma-derived RINm5F cells was dependent upon time and temperature and was proportional to cell concentration. Binding of radioactivity was inhibited in a concentration-dependent manner by GLP-1(7-36) amide consistent with the presence of a single class of binding site with a dissociation constant (Kd) of 204 +/- 8 pmol/l (mean +/- S.E.M.). Binding of the peptide resulted in a dose-dependent increase in cyclic AMP concentrations (half maximal response at 250 +/- 20 pmol/l). GLP-1(1-36)amide was approximately 200 times less potent than GLP-1(7-36)amide in inhibiting the binding of 125I-labelled GLP-1(7-36)amide to the cells (Kd of 45 +/- 6 nmol/l). Binding sites for GLP-1 (7-36)amide were not present on dispersed enterocytes from porcine small intestine.
156 citations
Journal Article•
TL;DR: In this model system for B-cell studies the peptide has potent stimulatory effects on cAMP formation, insulin-mRNA transcript synthesis, and insulin release, and further studies in the insulinotropic action of GLP-1(7-36) amide in health and disease will be of great importance.
Abstract: The functional connection between the gut and pancreatic islets is described by the term "enteroinsular axis". A humoral factor of the gut that might enhance the glucose-induced secretion of insulin is named "incretin". For many years glucose-dependent insulin-releasing polypeptide (GIP) was the strongest incretin candidate. However, recent evidence suggests that glucagon-like peptide-1(7-36)amide represents a more potent physiological incretin. The sequence of GLP-1 is identical in various mammals including man. The 7-36 sequence of the original peptide is a potent insulin-releasing peptide in vitro and in vivo. GLP-1(7-36)amide was found in the human bowel; its circulating level rises in answer to oral glucose and after meals. Recently, specific high-affinity binding sites for GLP-1(7-36)amide were demonstrated on rat insulinoma-derived RINm5F cells. In this model system for B-cell studies the peptide has potent stimulatory effects on cAMP formation, insulin-mRNA transcript synthesis, and insulin release. Further studies in the insulinotropic action of GLP-1(7-36) amide in health and disease will be of great importance.
7 citations
TL;DR: Both PHI and VIP produced dose-dependent increases in cAMP production in the cells that were significantly above unstimulated rates for ligand concentrations between 10(-8) and 10(-6) M.
7 citations
TL;DR: The effects of the low molecular weight serine proteinase inhibitor FOY (gabexate mesilate) upon insulin action was studied in three different experimental systems, finding that high concentrations of FOY decreased the effect of insulin on the hexose transport.
Abstract: The effects of the low molecular weight serine proteinase inhibitor FOY (gabexate mesilate) upon insulin action was studied in three different experimental systems. Placenta membranes containing insulin receptors preincubated with FOY (10 μM) showed a reduction of insulin-stimulated tyrosine kinase activity (p<0.01). However, FOY (0.1–100 μM) did not affect the insulin-stimulated tyrosine kinase activity in a preparation of solubilized and partially purified insulin receptors from placental membranes. Isolated adipocytes were used to study the effect of FOY on intact cells. FOY neither altered the insulin induced inhibition of the catecholamine-stimulated lipolysis nor (at the low concentration of 0.1 mM) the stimulation of glucose transport by the hormone. High concentrations (0.5 mM) of FOY decreased the effect of insulin on the hexose transport.