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Biomedical subjects

S Gustavsson

Publications and source records attributed to S Gustavsson.

At least 109 records · Page 6Linked to original sources
PubMed1982

Effects of neurotensin on small bowel propulsion in intact and vagotomized rats.

The effects of intravenous infusion of neurotensin on small bowel motility was studied in conscious rats. During 1 h a standardized test meal of glucose, polyethyleneglycol (PEG) 3000, phenol red and 125I-labelled polyvinylpyrrolidone was administered via a permanent gastric catheter and simultaneously the bile-excreted radio-pharmaceutic 99Tcm-Solco-HIDA was infused intravenously. Immediately after the infusions the gastrointestinal specimen was excised and examined for distribution of radioactivity. Both doses of neurotensin (0.1 and 0.3 microgram . kg-1 . h-1) resulted in an increase in the neurotensin-like immunoreactivity (NTLI) of plasma to levels similar to that found after a fatty meal. Concurrently the small bowel transport pattern was changed from an interdigestive state to one similar to that found after a meal. In animals not receiving the gastric test meal, neurotensin (0.1-0.5 microgram . kg-1 . h-) had no effect on motility. Infusion of the gastric test meal alone did not change the interdigestive motility or the NTLI value. This indicates that the presence of gastric infusates potentiates the effect of neurotensin on small bowel motility. The motility response to neurotensin did not differ between intact and vagotomized animals. This contrasts to earlier findings that the small bowel motility response to a fatty meal is dependent on intact vagal function. Thus, a difference in the mechanism responsible for the motility responses between a fatty meal and neurotensin exists. In view of this finding it seems reasonable to assume that neurotensin cannot be the only factor responsible for the shift in motility found after a fatty meal.

Animals↗
PubMed1982

Glycoproteins of axonal transport: affinity chromatography on fucose-specific lectins.

Rapidly transported fucose-labeled glycoproteins from axons of rabbit retinal ganglion cells were solubilized with nonionic detergents. The solubilized components were subjected to affinity chromatography on three different fucose-specific lectins. A recently characterized fucose-specific lectin from Aleuria aurantia bound reversibly approximately 60% of the applied protein-bound radioactivity. The lectins from Lotus tetragonolobus and Ulex europaeus bound are very small proportions of the labeled rapidly transported glycoproteins.

Animals↗
PubMed1982

Fasting blood levels of gastrin, somatostatin, and pancreatic polypeptide in peptic ulcer disease.

Fasting plasma levels of immunoreactive gastrin, somatostatin, and pancreatic polypeptide (PP) were determined in 67 patients with an endoscopically proven duodenal, pyloric, or prepyloric ulcer. Pretreatment gastrin (45.6 +/- 53.6 pmol/l, mean +/- S.D.) and somatostatin (54.5 +/- 27.5 pg/ml) did not differ significantly from those in 22 healthy controls (21.8 +/- 20.2 pmol/l and 64.8 +/- 24.7 pg/ml, respectively). The gastrin and somatostatin levels were not changed by 3 weeks of treatment either with propantheline and antacids or with cimetidine and antacids. The mean PP value before treatment was significantly (p less than 0.01) higher in duodenal ulcer patients (0.76 +/- 0.55 ng/ml) than in healthy subjects of similar age (0.36 +/- 0.26 ng/ml). The increased PP level was not lowered significantly by medical treatment even when this resulted in healing of the ulcer.

Adult↗
PubMed1982

Release of insulin and pancreatic somatostatin in response to increased circulating growth hormone (GH) levels.

In an experimental study of 5 anaesthetized pigs the effects of increased circulating levels of growth hormone (GH) on the release of insulin and somatostatin from the pancreas was investigated. Blood was sampled simultaneously from the pancreatic venous effluent and from mixed venous blood. As measured by radioimmunoassay infusion of GH (20 micrograms x kg-1 x h-1) resulted in a significant (p less than 0.01) increase both in insulin and somatostatin concentration in pancreatic venous blood. In mixed venous blood no significant changes in hormone levels were found. The results illustrate one possible mechanism for the close relation between circulating GH and endocrine pancreas.

Animals↗
PubMed1982

Studies on oesophagitis--no evidence for pyloric incompetence as a primary etiological factor. a scintigraphic study with 99Tcm-Solco-HIDA.

Duodeno-gastric bile reflux was studied by means of a non-invasive scintigraphic technique in 15 patients with symptomatic oesophagitis. The fate of an intravenously administered, bile-excreted radiopharmaceutic, 99Tcm-Solco-HIDA, was followed with a gamma camera. In 12 patients with an intact pylorus and in one patient operated upon by truncal vagotomy and pyloroplasty no evidence of bile reflux to the stomach was found. One of two patients earlier operated upon by a Billroth I gastrectomy had scintigraphic evidence of a severe bile reflux. We conclude that duodeno-gastric bile reflux is uncommon in patients with hiatal hernia and oesophagitis, and hence that normally pyloric incompetence is of minor importance for the development of this disorder.

Adult↗
PubMed1981

Effect of parathyroid hormone on gastrin and somatostatin release from the gastric antrum.

The release of immunoreactive gastrin and somatostatin form the gastric antrum was studied in anesthetized pigs after parathyroid hormone (PTH) infusion into the antral circulation. PTH (40 units/20 min) was infused into the right gastro-epiploic artery. Blood was sampled from the right gastro-epiploic vein (antral venous blood) and from the superior vena cava (mixed venous blood). The basal gastrin concentration in antral venous blood was 17 times higher than that in mixed venous blood (1220 + 367 versus 71 +25 pmol/1, mean +SE). The somatostatin concentrations in antral and mixed venous blood were 127 +20 and 82 +23 pg/ml (mean +SE), respectively. After PTH infusion the gastrin level both in antral and mixed venous blood increased significantly without inducing systemic hypercalcemia. PTH infusion did not significantly influence the somatostatin level either in antral venous blood or in mixed venous blood. The findings demonstrate that PTH can induce gastrin release from the gastric antrum without concomitant systemic hypercalcemia and that this release of gastrin is not accompanied by a change in the somatostatin level in antral venous blood.

Animals↗
PubMed1980

A radioimmunoabsorbent assay for plasma somatostatin.

A solid phase radioimmunoassay for determination of immunoreactive somatostatin (IRS) in plasma is described. Plasma samples obtained from 30 apparently healthy persons and from 5 anaesthetized pigs were extracted with acetone-petroleum ether. The antibodies (R 141 and R 101) were conjugated to cyanogenbromide activated microcrystalline cellulose. Tyr1-somatostatin was iodinated according to the lactoperoxidase method. After extraction the recovery of somatostatin varied between 80 and 118%. The sensitivity of the assay was 5--10 pg/ml and the intra- and interassay variation ranged between 8 and 20%. The mean (+/- S.D.) value of IRS in systemic blood in man was 77 (+/- 19) pg/ml. Intravenous administration of 10 micrograms/kg synthetic somatostatin to anaesthetized pigs was followed by a 20-fold increase in plasma IRS. The hypersomatostatinemia rapidly vanished with a half-life of 3.5 min. The level of IRS in cerebrospinal fluid was unchanged by intravenous somatostatin at this dose.

Animals↗
PubMed1980

Study of small bowel transport pattern in fasted, conscious rats with an intact gastrointestinal tract. A methodological study with bile-excreted 99Tcm-Solco-HIDA.

A method is presented for studies of small bowel propulsion in conscious rats with an intact gastrointestinal tract. A bile-excreted test substance, 99Tcm-Solco-HIDA, was infused intravenously for time periods varying between 0.25 and 5 h. Immediately after the infusion, radioactivity was recorded from the excised bowel specimen. The activity distribution along the small bowel was always found to be 'peaky', i.e. the intestinal contents were transported in portions separated by fairly long completely empty regions. In a control experiment with simultaneous intravenous infusion of 99Tc-Solco-HIDA and infusion of a nonabsorbable test substance (125I-PVP) through a permanent duodenal catheter a similar activity distribution was observed. This indicates that the peaky appearance of the activity distribution is not due to a periodicity in the discharge of bile but reflects small bowel propulsive activity.

Animals↗
PubMed1980

Scintigraphic assessment of biliary reflux into the residual stomach after subtotal gastrectomy and gastrojejunostomy.

A method is described for evaluating biliary reflux into the gastric remnant after subtotal gastrectomy, avoiding naso- or orogastric intubation. Gamma camera detection and continuous recording of the distribution and possible gastric reflux of 99Tcm-HIDA after intravenous injection was employed, before and after stimulation of bile flow by a fatty meal. The technique is simple and specific, but further clinical evaluation is needed.

Bile Reflux↗
PubMed1980

Pancreatic hormonal release after glucose and arginine administration in anaesthetized pigs.

Somatostatin, pancreatic polypeptide (PP), insulin and glucagon were measured in pancreatic venous effluent and in mixed venous blood of anaesthetized pigs. After stimulation of insulin release with glucose and arginine, respectively, a prompt decrease in PP levels was found in pancreatic venous blood. Somatostatin declined after glucose administration but was unaffected by arginine. The changes in PP and somatostatin levels were not evident in systemic blood. The present results emphasize the advantage of selective sampling of pancreatic venous blood in studies on the possible interactions between pancreatic hormones. The marked decrease in PP seen after stimulation of insulin release in the present study, indicates that PP should be included together with somatostatin in further studies on pancreatic hormonal interplay.

Animals↗
PubMed1979

Determination of prekallikrein in plasma by means of a chromogenic tripeptide substrate for plasma kallikrein.

A method for plasma prekallikrein determination utilizing a chromogenic tripeptic substrate is presented. The method has a good reproducibility and can easily be automized. Several parameters have been optimized. By using mixtures of deficient plasmas and pooled normal plasma or purified factors it was proved that prekallikrein was the factor determined and that more than 10% (of normal plasma concentration) of FXII and HMW kininogen were essential for the activation of prekallikrein in our method. Further experiments showed that the method was fairly selective and was not influenced by inhibitors present in normal plasma. The later finding was attributed to the high dilution of plasma made possible by using a potent activator and a sensitive substrate.

Dextrans↗
PubMed1979

Plasma levels of somatostatin-like immunoreactivity-independence of kidney function.

Plasma levels of somatostatin-like immunoreactivity (SLI) and gastrin were determined by radioimmunoassay in patients with varying degrees of renal dysfunction. The plasma SLI was not increased in patients with end-stage renal failure as compared to healthy controls. In patients with varying degrees of renal insufficiency no significant correlation was found between the plasma SLI and kidney function as estimated by the 51Cr-EDTA-clearance rate. In uraemic patients a significant inverse correlation was found between plasma SLI and plasma gastrin.

Adolescent↗
PubMed1979

Transport of small bowel contents after interposition of an antiperistaltic jejunal segment in the rat.

The effect of antiperistaltic jejunal segments on small bowel transport was studied with an experimental technique permitting quantitative studies of propulsive as well as non-propulsive intestinal motility. 79 rats were provided with a permanent duodenal catheter and at the same laparotomy an anti- or isoperistaltic bowel segment based on 1, 2 or 3 mesenteric end-arcades was inserted at the midpoint of the jejunum. The evaluation of intestinal motility 1 week later indicated that an antiperistaltic segment of the rat jejunum has to be made at least 6 cm long, i.e. based on 3 mesenteric end-arcades in order to retard the propulsion of luminal contents. Not even this relatively long antiperistaltic segment was found to influence propulsion through bowel segments proximal to it, and distally the propagation velocity was accelerated. This implied that the total small bowel transit was unaffected. The non-propulsive intestinal motility, i.e. the mixing of small bowel contents was increased by the long reversed loop. The possible beneficial effect of antiperistaltic jejunal segments in short bowel syndrome and post-vagotomy diarrhoea in man may thus be attributed not to a retardation of the propulsive intestinal motility but to an increase in the non-propulsive intestinal motility.

Animals↗
PubMed1979

Gastrointestinal motility and absorption of calcium during infusion of somatostatin in the rat.

The effect of somatostatin on gastric evacuation, small bowel propulsion and gastrointestinal (GI) absorption of calcium was studied in conscious rats. Nonabsorbable 125I-PVP was deposited in the stomach or in the duodenum and the distribution of the radioactivity along the excised GI specimen was recorded after 15 min. 47Ca in chloride from was administered simultaneously and the amont of radioactivity remaining in the GI speciment at sacrifice could easily be measured. Intravenous infusion of synthetic somatostatin (50 micrograms.kg-1.h-1), which resulted in a manifest although not extreme hypersomatostatinemia had no effect either on gastric evacuation, small bowel propulsion or GI absorption of calcium. The findings do not indicate that somatostatin has a direct effect on GI motility or absorption of calcium.

Animals↗