Insulin-dependent inhibition of hepatic glycogenolysis by gastric inhibitory polypeptide (GIP) in perfused rat liver.

The effect of porcine gastric inhibitory polypeptide on hepatic glycogen metabolism was investigated in the isolated in situ perfused rat liver. Glycogenolysis was stimulated by infusion of glucagon into the portal vein (half maximal effective portal vein concentration approximately 30 pmol/l). When glucagon was infused at a final portal vein concentration of 0.

Purification and characterization of two isoforms of Acanthamoeba profilin.

Acanthamoeba profilin purified according to E. Reichstein and E.D.

Comparison of gastric inhibitory polypeptide and intraduodenal or intravenous fat on gastric acid secretion from vagally innervated and denervated canine stomach.

Gastric inhibitory polypeptide (GIP), given to dogs in graded doses (range 0.25-2 micrograms/kg/hr) against a constant background stimulation with pentagastrin (4 micrograms/kg/hr), failed to affect the acid secretion at all doses used except the largest one (2 micrograms/kg/hr) which significantly reduced the acid secretion only from the vagally denervated portion of the stomach (Heidenhain pouch, HP) while raising plasma GIP two to three times above the levels reached with duodenal fat. GIP infused in a constant dose (1 microgram/kg/hr) significantly reduced the HP responses to lower (0.

Reduced incretin effect in type 2 (non-insulin-dependent) diabetes.

Integrated incremental immunoreactive insulin and connecting peptide responses to an oral glucose load of 50 g and an "isoglycaemic" intravenous glucose infusion, respectively, were measured in 14 Type 2 (non-insulin-dependent) diabetic patients and 8 age- and weight-matched metabolically healthy control subjects. Differences between responses to oral and intravenous glucose administration are attributed to factors other than glucose itself (incretin effect). Despite higher glucose increases, immunoreactive insulin and connecting peptide responses after oral glucose were delayed in diabetic patients.

Localization of a fibrinogen calcium binding site between gamma-subunit positions 311 and 336 by terbium fluorescence.

Calcium is required for effective fibrin polymerization. The high affinity Ca2+ binding capacity of fibrinogen was directly localized to the gamma-chain by autoradiography of nitrocellulose membrane blots of fibrinogen subunits incubated with 45Ca2+. Terbium (Tb3+) competitively inhibited 45Ca2+ binding to fibrinogen during equilibrium dialysis, accelerated fibrin polymerization, and limited fibrinogen fragment D digestion by plasmin.

New developments in the incretin concept.

Experimental and clinical work over the last 6 years has confirmed and broadened, but also challenged, the incretin concept. The nervous component of the entero-insular axis is still poorly defined, especially the peptidergic nerves, of which several contain insulinotropic regulatory peptides. The incretin effect is preserved after complete denervation of the porcine pancreas.

Assay of human fibrinopeptides by high-performance liquid chromatography.

Fibrinopeptides A, AP, and B, desarginine fibrinopeptide B, and a previously unknown peptide corresponding to B beta 3-14 were resolved within 10 min by an HPLC technique using an isocratic solvent system (22% acetonitrile in 0.1% trifluoroacetic acid) and a 0.46 X 10-cm Spherisorb ODS-2 (3-micron) octadecylsilane column.

Protective effect of divalent cations in the plasmin degradation of fibrinogen.

Calcium limits the plasmic proteolysis of fibrinogen fragment D by binding to a specific site on the carboxy-terminal segment of the D gamma chain. Employing sodium dodecyl sulfate-polyacrylamide gel electrophoresis to visualize plasmic fragments, Sr2+, Ba2+, and Mn2+ were found to have an equivalent capacity to limit the degradation of fibrinogen fragment D (Mr 94,000). Mg2+, Fe2+, Co2+, and Zn2+ did not comparably limit the digestion of fragment D.

Fibrinogen Baltimore IV: congenital dysfibrinogenemia with delayed fibrin monomer polymerization.

A congenital dysfibrinogenemia, fibrinogen Baltimore IV, has been found in a 56-year-old Caucasian man. Clinical laboratory studies disclosed a slightly prolonged prothrombin time, but were otherwise unremarkable. Release of fibrinopeptides by thrombin occurs normally, as does ligation of the fibrin polymer by Factor XIII.

Preserved incretin effect after complete surgical denervation of the pancreas in young pigs.

Plasma insulin responses to intragastric (i.g.) (1.

Effect of dialysate glucose load on plasma glucose and glucoregulatory hormones in CAPD patients.

The effect of a dialysate exchange with both 1.5 and 4.25% glucose solutions on plasma levels of glucose, insulin, gastric inhibitory polypeptide (GIP), and glucagon has been investigated in 5 continuous ambulatory peritoneal dialysis (CAPD) patients.

Role of gastrointestinal transit in the delay of absorption by viscous fibre (guar).

The influence of guar gum on gastric emptying of liquids in healthy volunteers and on mouth-to-caecum transit time in controls and partially gastrectomized patients has been studied. Together with a flattening effect on blood glucose profiles after a liquid glucose load, guar significantly delays mouth-to-caecum transit time both in healthy controls and partially gastrectomized patients. The retardation of transit is not explicable by a delay in gastric emptying, as can be shown by means of an isotope technique.

Hyperinsulinaemia in non-cirrhotic haemochromatosis: impaired hepatic insulin degradation?

This study investigated early alterations of glucose metabolism in idiopathic haemochromatosis. Circulating concentrations of glucose, insulin, C-peptide, glucagon, and gastric inhibitory polypeptide (GIP) were measured after a 100-g oral glucose load in 10 men with idiopathic haemochromatosis in the non-cirrhotic stage of the disease. All had normal glucose tolerance and normal body weight.

Preceding hyperinsulinemia prevents demonstration of insulin effect on fat-induced gastric inhibitory polypeptide (GIP).

The effect of insulin on fat-induced gastric inhibitory polypeptide (GIP) release has been studied in seven healthy volunteers during euglycemic blood glucose clamping. In the first protocol, insulin (0.1 U/kg/h) was infused 2 h before ingestion of 100 g fat and continued for 2 h thereafter.

Effect of nicotine chewing gum on plasma nicotine levels of cigarette smokers.

This study was designed to determine whether the use of nicotine chewing gum modifies the inhalation and absorption of nicotine by cigarette smokers. Our subjects, 12 subjects who smoked cigarettes regularly, were studied for 4 days. On the first day, they smoked as usual, and on the second, third, and fourth days they also chewed a placebo gum, 2-mg nicotine gum, or 4-mg nicotine gum.

Recovery from effects of brief monocular deprivation in the kitten.

The potential for recovery from the cortical effects of monocular deprivation (MD) was studied in kittens that were briefly deprived and then exposed to various periods of normal binocular vision. In eight kittens, recordings from the hemisphere ipsilateral to the deprived eye revealed that at 4 wk of age, exposure to 12 h of MD (six 2-h sessions spread over 2 days) was sufficient to cause a massive shift in the ocular dominance of striate cortex neurons in favor of the nondeprived eye. Six of these MD kittens were allowed 3 wk of normal binocular vision and then recorded from a second time to assess the extent to which their cortex could recover from the effects of this brief period of deprivation.

Different response of gastric inhibitory polypeptide to glucose and fat from duodenum and jejunum.

Gastric inhibitory polypeptide (GIP), insulin, and blood glucose after ingestion of glucose or fat were examined in patients after gastrectomy with esophagojejunostomy or esophagoduodenostomy. After a glucose load patients without duodenal passage had significantly higher glucose and significantly smaller insulin levels than patients with duodenal passage. The fasting levels of serum immunoreactive GIP were moderately elevated and reached significantly higher levels after oral glucose ingestion in both gastrectomized groups as compared with normal subjects.

Elevated plasma cholecystokinin concentrations in exocrine pancreatic atrophy in the rat.

Rats were fed with a copper-deficient diet combined with penicillamine to produce an atrophy of the exocrine pancreas by selective destruction of the acinar cells, which are replaced by fat cells. Plasma cholecystokinin (CCK) concentrations in animals with exocrine pancreatic atrophy were 250% higher compared to control animals (21.7 +/- 7.

Fibrinogen Baltimore II: congenital hypodysfibrinogenemia with delayed release of fibrinopeptide B and decreased rate of fibrinogen synthesis.

A congenital hypodysfibrinogenemia, fibrinogen Baltimore II, was found in a young asymptomatic Caucasian female. Prothrombin, partial thromboplastin, and euglobulin lysis times were normal, as were platelet function and coagulation factor assays. Subnormal plasma fibrinogen levels were found using chronometric, rate-independent, and immunologic assay methods.